Appendix M to Subpart B of Part 430 - Uniform Test Method for Measuring the Energy Consumption of Central Air Conditioners and Heat Pumps
10:3.0.1.4.18.2.13.6.22 : Appendix M
Appendix M to Subpart B of Part 430 - Uniform Test Method for
Measuring the Energy Consumption of Central Air Conditioners and
Heat Pumps Note:
Prior to July 5, 2017, any representations, including compliance
certifications, made with respect to the energy use, power, or
efficiency of central air conditioners and central air conditioning
heat pumps must be based on the results of testing pursuant to
either this appendix or the procedures in Appendix M as it appeared
at 10 CFR part 430, subpart B, Appendix M, in the 10 CFR parts 200
to 499 edition revised as of January 1, 2017. Any representations
made with respect to the energy use or efficiency of such central
air conditioners and central air conditioning heat pumps must be in
accordance with whichever version is selected.
On or after July 5, 2017 and prior to January 1, 2023, any
representations, including compliance certifications, made with
respect to the energy use, power, or efficiency of central air
conditioners and central air conditioning heat pumps must be based
on the results of testing pursuant to this appendix.
On or after January 1, 2023, any representations, including
compliance certifications, made with respect to the energy use,
power, or efficiency of central air conditioners and central air
conditioning heat pumps must be based on the results of testing
pursuant to appendix M1 of this subpart.
1. Scope and Definitions 1.1 Scope
This test procedure provides a method of determining SEER, EER,
HSPF and PW,OFF for central air conditioners and central air
conditioning heat pumps including the following categories:
(a) Split-system air conditioners, including single-split,
multi-head mini-split, multi-split (including VRF), and
multi-circuit systems (b) Split-system heat pumps, including
single-split, multi-head mini-split, multi-split (including VRF),
and multi-circuit systems (c) Single-package air conditioners (d)
Single-package heat pumps (e) Small-duct, high-velocity systems
(including VRF) (f) Space-constrained products - air conditioners
(g) Space-constrained products - heat pumps
For purposes of this appendix, the Department of Energy
incorporates by reference specific sections of several industry
standards, as listed in § 430.3. In cases where there is a
conflict, the language of the test procedure in this appendix takes
precedence over the incorporated standards.
All section references refer to sections within this appendix
unless otherwise stated.
1.2 Definitions
Airflow-control settings are programmed or wired control
system configurations that control a fan to achieve discrete,
differing ranges of airflow - often designated for performing a
specific function (e.g., cooling, heating, or constant
circulation) - without manual adjustment other than interaction
with a user-operable control (i.e., a thermostat) that meets
the manufacturer specifications for installed-use. For the purposes
of this appendix, manufacturer specifications for installed-use are
those found in the product literature shipped with the unit.
Air sampling device is an assembly consisting of a
manifold with several branch tubes with multiple sampling holes
that draws an air sample from a critical location from the unit
under test (e.g. indoor air inlet, indoor air outlet,
outdoor air inlet, etc.).
Airflow prevention device denotes a device that prevents
airflow via natural convection by mechanical means, such as an air
damper box, or by means of changes in duct height, such as an
upturned duct.
Aspirating psychrometer is a piece of equipment with a
monitored airflow section that draws uniform airflow through the
measurement section and has probes for measurement of air
temperature and humidity.
Blower coil indoor unit means an indoor unit either with
an indoor blower housed with the coil or with a separate designated
air mover such as a furnace or a modular blower (as defined in
appendix AA to the subpart).
Blower coil system refers to a split system that includes
one or more blower coil indoor units.
Cased coil means a coil-only indoor unit with external
cabinetry.
Coefficient of Performance (COP) means the ratio of the
average rate of space heating delivered to the average rate of
electrical energy consumed by the heat pump. These rate quantities
must be determined from a single test or, if derived via
interpolation, must be determined at a single set of operating
conditions. COP is a dimensionless quantity. When determined for a
ducted coil-only system, COP must include the sections 3.7 and
3.9.1 of this appendix: Default values for the heat output and
power input of a fan motor.
Coil-only indoor unit means an indoor unit that is
distributed in commerce without an indoor blower or separate
designated air mover. A coil-only indoor unit installed in the
field relies on a separately-installed furnace or a modular blower
for indoor air movement. Coil-only system refers to a system
that includes only (one or more) coil-only indoor units.
Condensing unit removes the heat absorbed by the
refrigerant to transfer it to the outside environment and consists
of an outdoor coil, compressor(s), and air moving device.
Constant-air-volume-rate indoor blower means a fan that
varies its operating speed to provide a fixed air-volume-rate from
a ducted system.
Continuously recorded, when referring to a dry bulb
measurement, dry bulb temperature used for test room control, wet
bulb temperature, dew point temperature, or relative humidity
measurements, means that the specified value must be sampled at
regular intervals that are equal to or less than 15 seconds.
Cooling load factor (CLF) means the ratio having as its
numerator the total cooling delivered during a cyclic operating
interval consisting of one ON period and one OFF period, and as its
denominator the total cooling that would be delivered, given the
same ambient conditions, had the unit operated continuously at its
steady-state, space-cooling capacity for the same total time (ON +
OFF) interval.
Crankcase heater means any electrically powered device or
mechanism for intentionally generating heat within and/or around
the compressor sump volume. Crankcase heater control may be
achieved using a timer or may be based on a change in temperature
or some other measurable parameter, such that the crankcase heater
is not required to operate continuously. A crankcase heater without
controls operates continuously when the compressor is not
operating.
Cyclic Test means a test where the unit's compressor is
cycled on and off for specific time intervals. A cyclic test
provides half the information needed to calculate a degradation
coefficient.
Damper box means a short section of duct having an air
damper that meets the performance requirements of section 2.5.7 of
this appendix.
Degradation coefficient (CD) means a parameter
used in calculating the part load factor. The degradation
coefficient for cooling is denoted by CD c. The degradation
coefficient for heating is denoted by CD h.
Demand-defrost control system means a system that
defrosts the heat pump outdoor coil-only when measuring a
predetermined degradation of performance. The heat pump's controls
either:
(1) Monitor one or more parameters that always vary with the
amount of frost accumulated on the outdoor coil (e.g., coil
to air differential temperature, coil differential air pressure,
outdoor fan power or current, optical sensors) at least once for
every ten minutes of compressor ON-time when space heating or
(2) operate as a feedback system that measures the length of the
defrost period and adjusts defrost frequency accordingly. In all
cases, when the frost parameter(s) reaches a predetermined value,
the system initiates a defrost. In a demand-defrost control system,
defrosts are terminated based on monitoring a parameter(s) that
indicates that frost has been eliminated from the coil. (Note:
Systems that vary defrost intervals according to outdoor dry-bulb
temperature are not demand-defrost systems.) A demand-defrost
control system, which otherwise meets the above requirements, may
allow time-initiated defrosts if, and only if, such defrosts occur
after 6 hours of compressor operating time.
Design heating requirement (DHR) predicts the space
heating load of a residence when subjected to outdoor design
conditions. Estimates for the minimum and maximum DHR are provided
for six generalized U.S. climatic regions in section 4.2 of this
appendix.
Dry-coil tests are cooling mode tests where the wet-bulb
temperature of the air supplied to the indoor unit is maintained
low enough that no condensate forms on the evaporator coil.
Ducted system means an air conditioner or heat pump that
is designed to be permanently installed equipment and delivers
conditioned air to the indoor space through a duct(s). The air
conditioner or heat pump may be either a split-system or a
single-package unit.
Energy efficiency ratio (EER) means the ratio of the
average rate of space cooling delivered to the average rate of
electrical energy consumed by the air conditioner or heat pump.
Determine these rate quantities from a single test or, if derived
via interpolation, determine at a single set of operating
conditions. EER is expressed in units of
When
determined for a ducted coil-only system, EER must include, from
this appendix, the section 3.3 and 3.5.1 default values for the
heat output and power input of a fan motor.
Evaporator coil means an assembly that absorbs heat from
an enclosed space and transfers the heat to a refrigerant.
Heat pump means a kind of central air conditioner that
utilizes an indoor conditioning coil, compressor, and
refrigerant-to-outdoor air heat exchanger to provide air heating,
and may also provide air cooling, air dehumidifying, air
humidifying, air circulating, and air cleaning.
Heat pump having a heat comfort controller means a heat
pump with controls that can regulate the operation of the electric
resistance elements to assure that the air temperature leaving the
indoor section does not fall below a specified temperature. Heat
pumps that actively regulate the rate of electric resistance
heating when operating below the balance point (as the result of a
second stage call from the thermostat) but do not operate to
maintain a minimum delivery temperature are not considered as
having a heat comfort controller.
Heating load factor (HLF) means the ratio having as its
numerator the total heating delivered during a cyclic operating
interval consisting of one ON period and one OFF period, and its
denominator the heating capacity measured at the same test
conditions used for the cyclic test, multiplied by the total time
interval (ON plus OFF) of the cyclic-test.
Heating season means the months of the year that require
heating, e.g., typically, and roughly, October through
April.
Heating seasonal performance factor (HSPF) means the
total space heating required during the heating season, expressed
in Btu, divided by the total electrical energy consumed by the heat
pump system during the same season, expressed in watt-hours. The
HSPF used to evaluate compliance with 10 CFR 430.32(c) is based on
Region IV and the sampling plan stated in 10 CFR 429.16(a). HSPF is
determined in accordance with appendix M.
Independent coil manufacturer (ICM) means a manufacturer
that manufactures indoor units but does not manufacture
single-package units or outdoor units.
Indoor unit means a separate assembly of a split system
that includes -
(1) An arrangement of refrigerant-to-air heat transfer coil(s)
for transfer of heat between the refrigerant and the indoor
air,
(2) A condensate drain pan, and may or may not include
(3) Sheet metal or plastic parts not part of external cabinetry
to direct/route airflow over the coil(s),
(4) A cooling mode expansion device,
(5) External cabinetry, and
(6) An integrated indoor blower (i.e. a device to move
air including its associated motor). A separate designated air
mover that may be a furnace or a modular blower (as defined in
appendix AA to the subpart) may be considered to be part of the
indoor unit. A service coil is not an indoor unit.
Multi-head mini-split system means a split system that
has one outdoor unit and that has two or more indoor units
connected with a single refrigeration circuit. The indoor units
operate in unison in response to a single indoor thermostat.
Multiple-circuit (or multi-circuit) system means a split
system that has one outdoor unit and that has two or more indoor
units installed on two or more refrigeration circuits such that
each refrigeration circuit serves a compressor and one and only one
indoor unit, and refrigerant is not shared from circuit to
circuit.
Multiple-split (or multi-split) system means a split
system that has one outdoor unit and two or more coil-only indoor
units and/or blower coil indoor units connected with a single
refrigerant circuit. The indoor units operate independently and can
condition multiple zones in response to at least two indoor
thermostats or temperature sensors. The outdoor unit operates in
response to independent operation of the indoor units based on
control input of multiple indoor thermostats or temperature
sensors, and/or based on refrigeration circuit sensor input
(e.g., suction pressure).
Nominal capacity means the capacity that is claimed by
the manufacturer on the product name plate. Nominal cooling
capacity is approximate to the air conditioner cooling capacity
tested at A or A2 condition. Nominal heating capacity is
approximate to the heat pump heating capacity tested in H12 test
(or the optional H1N test).
Non-ducted indoor unit means an indoor unit that is
designed to be permanently installed, mounted on room walls and/or
ceilings, and that directly heats or cools air within the
conditioned space.
Normalized Gross Indoor Fin Surface (NGIFS) means the
gross fin surface area of the indoor unit coil divided by the
cooling capacity measured for the A or A2 Test, whichever
applies.
Off-mode power consumption means the power consumption
when the unit is connected to its main power source but is neither
providing cooling nor heating to the building it serves.
Off-mode season means, for central air conditioners other
than heat pumps, the shoulder season and the entire heating season;
and for heat pumps, the shoulder season only.
Outdoor unit means a separate assembly of a split system
that transfers heat between the refrigerant and the outdoor air,
and consists of an outdoor coil, compressor(s), an air moving
device, and in addition for heat pumps, may include a heating mode
expansion device, reversing valve, and/or defrost controls.
Outdoor unit manufacturer (OUM) means a manufacturer of
single-package units, outdoor units, and/or both indoor units and
outdoor units.
Part-load factor (PLF) means the ratio of the cyclic EER
(or COP for heating) to the steady-state EER (or COP), where both
EERs (or COPs) are determined based on operation at the same
ambient conditions.
Seasonal energy efficiency ratio (SEER) means the total
heat removed from the conditioned space during the annual cooling
season, expressed in Btu's, divided by the total electrical energy
consumed by the central air conditioner or heat pump during the
same season, expressed in watt-hours. SEER is determined in
accordance with appendix M.
Service coil means an arrangement of refrigerant-to-air
heat transfer coil(s), condensate drain pan, sheet metal or plastic
parts to direct/route airflow over the coil(s), which may or may
not include external cabinetry and/or a cooling mode expansion
device, distributed in commerce solely for replacing an uncased
coil or cased coil that has already been placed into service, and
that has been labeled “for indoor coil replacement only” on the
nameplate and in manufacturer technical and product literature. The
model number for any service coil must include some mechanism
(e.g., an additional letter or number) for differentiating a
service coil from a coil intended for an indoor unit.
Shoulder season means the months of the year in between
those months that require cooling and those months that require
heating, e.g., typically, and roughly, April through May,
and September through October.
Single-package unit means any central air conditioner or
heat pump that has all major assemblies enclosed in one
cabinet.
Single-split system means a split system that has one
outdoor unit and one indoor unit connected with a single
refrigeration circuit. Small-duct, high-velocity system
means a split system for which all indoor units are blower coil
indoor units that produce at least 1.2 inches (of water column) of
external static pressure when operated at the full-load air volume
rate certified by the manufacturer of at least 220 scfm per rated
ton of cooling.
Split system means any air conditioner or heat pump that
has at least two separate assemblies that are connected with
refrigerant piping when installed. One of these assemblies includes
an indoor coil that exchanges heat with the indoor air to provide
heating or cooling, while one of the others includes an outdoor
coil that exchanges heat with the outdoor air. Split systems may be
either blower coil systems or coil-only systems.
Standard Air means dry air having a mass density of 0.075
lb/ft 3.
Steady-state test means a test where the test conditions
are regulated to remain as constant as possible while the unit
operates continuously in the same mode.
Temperature bin means the 5 °F increments that are used
to partition the outdoor dry-bulb temperature ranges of the cooling
(≥65 °F) and heating (<65 °F) seasons.
Test condition tolerance means the maximum permissible
difference between the average value of the measured test parameter
and the specified test condition.
Test operating tolerance means the maximum permissible
range that a measurement may vary over the specified test interval.
The difference between the maximum and minimum sampled values must
be less than or equal to the specified test operating
tolerance.
Tested combination means a multi-head mini-split,
multi-split, or multi-circuit system having the following
features:
(1) The system consists of one outdoor unit with one or more
compressors matched with between two and five indoor units;
(2) The indoor units must:
(i) Collectively, have a nominal cooling capacity greater than
or equal to 95 percent and less than or equal to 105 percent of the
nominal cooling capacity of the outdoor unit;
(ii) Each represent the highest sales volume model family, if
this is possible while meeting all the requirements of this
section. If this is not possible, one or more of the indoor units
may represent another indoor model family in order that all the
other requirements of this section are met.
(iii) Individually not have a nominal cooling capacity greater
than 50 percent of the nominal cooling capacity of the outdoor
unit, unless the nominal cooling capacity of the outdoor unit is
24,000 Btu/h or less;
(iv) Operate at fan speeds consistent with manufacturer's
specifications; and
(v) All be subject to the same minimum external static pressure
requirement while able to produce the same external static pressure
at the exit of each outlet plenum when connected in a manifold
configuration as required by the test procedure.
(3) Where referenced, “nominal cooling capacity” means, for
indoor units, the highest cooling capacity listed in published
product literature for 95 °F outdoor dry bulb temperature and 80 °F
dry bulb, 67 °F wet bulb indoor conditions, and for outdoor units,
the lowest cooling capacity listed in published product literature
for these conditions. If incomplete or no operating conditions are
published, the highest (for indoor units) or lowest (for outdoor
units) such cooling capacity available for sale must be used.
Time-adaptive defrost control system is a demand-defrost
control system that measures the length of the prior defrost
period(s) and uses that information to automatically determine when
to initiate the next defrost cycle.
Time-temperature defrost control systems initiate or
evaluate initiating a defrost cycle only when a predetermined
cumulative compressor ON-time is obtained. This predetermined
ON-time is generally a fixed value (e.g., 30, 45, 90
minutes) although it may vary based on the measured outdoor
dry-bulb temperature. The ON-time counter accumulates if controller
measurements (e.g., outdoor temperature, evaporator
temperature) indicate that frost formation conditions are present,
and it is reset/remains at zero at all other times. In one
application of the control scheme, a defrost is initiated whenever
the counter time equals the predetermined ON-time. The counter is
reset when the defrost cycle is completed.
In a second application of the control scheme, one or more
parameters are measured (e.g., air and/or refrigerant
temperatures) at the predetermined, cumulative, compressor ON-time.
A defrost is initiated only if the measured parameter(s) falls
within a predetermined range. The ON-time counter is reset
regardless of whether or not a defrost is initiated. If systems of
this second type use cumulative ON-time intervals of 10 minutes or
less, then the heat pump may qualify as having a demand defrost
control system (see definition).
Triple-capacity, northern heat pump means a heat pump
that provides two stages of cooling and three stages of heating.
The two common stages for both the cooling and heating modes are
the low capacity stage and the high capacity stage. The additional
heating mode stage is the booster capacity stage, which offers the
highest heating capacity output for a given set of ambient
operating conditions.
Triple-split system means a split system that is composed
of three separate assemblies: An outdoor fan coil section, a blower
coil indoor unit, and an indoor compressor section.
Two-capacity (or two-stage) compressor system means a
central air conditioner or heat pump that has a compressor or a
group of compressors operating with only two stages of capacity.
For such systems, low capacity means the compressor(s) operating at
low stage, or at low load test conditions. The low compressor stage
that operates for heating mode tests may be the same or different
from the low compressor stage that operates for cooling mode tests.
For such systems, high capacity means the compressor(s) operating
at high stage, or at full load test conditions.
Two-capacity, northern heat pump means a heat pump that
has a factory or field-selectable lock-out feature to prevent space
cooling at high-capacity. Two-capacity heat pumps having this
feature will typically have two sets of ratings, one with the
feature disabled and one with the feature enabled. The heat pump is
a two-capacity northern heat pump only when this feature is enabled
at all times. The certified indoor coil model number must reflect
whether the ratings pertain to the lockout enabled option via the
inclusion of an extra identifier, such as “+LO”. When testing as a
two-capacity, northern heat pump, the lockout feature must remain
enabled for all tests.
Uncased coil means a coil-only indoor unit without
external cabinetry.
Variable refrigerant flow (VRF) system means a
multi-split system with at least three compressor capacity stages,
distributing refrigerant through a piping network to multiple
indoor blower coil units each capable of individual zone
temperature control, through proprietary zone temperature control
devices and a common communications network. Note: Single-phase VRF
systems less than 65,000 Btu/h are central air conditioners and
central air conditioning heat pumps.
Variable-speed compressor system means a central air
conditioner or heat pump that has a compressor that uses a
variable-speed drive to vary the compressor speed to achieve
variable capacities.
Wet-coil test means a test conducted at test conditions
that typically cause water vapor to condense on the test unit
evaporator coil.
2. Testing Overview and Conditions
(A) Test VRF systems using AHRI 1230-2010 (incorporated by
reference, see § 430.3) and appendix M. Where AHRI 1230-2010 refers
to the appendix C therein substitute the provisions of this
appendix. In cases where there is a conflict, the language of the
test procedure in this appendix takes precedence over AHRI
1230-2010.
For definitions use section 1 of appendix M and section 3 of
AHRI 1230-2010 (incorporated by reference, see § 430.3). For
rounding requirements, refer to § 430.23(m). For determination of
certified ratings, refer to § 429.16 of this chapter.
For test room requirements, refer to section 2.1 of this
appendix. For test unit installation requirements refer to sections
2.2.a, 2.2.b, 2.2.c, 2.2.1, 2.2.2, 2.2.3(a), 2.2.3(c), 2.2.4,
2.2.5, and 2.4 to 2.12 of this appendix, and sections 5.1.3 and
5.1.4 of AHRI 1230-2010. The “manufacturer's published
instructions,” as stated in section 8.2 of ANSI/ASHRAE 37-2009
(incorporated by reference, see § 430.3) and “manufacturer's
installation instructions” discussed in this appendix mean the
manufacturer's installation instructions that come packaged with or
appear in the labels applied to the unit. This does not include
online manuals. Installation instructions that appear in the labels
applied to the unit take precedence over installation instructions
that are shipped with the unit.
For general requirements for the test procedure, refer to
section 3.1 of this appendix, except for sections 3.1.3 and 3.1.4,
which are requirements for indoor air volume and outdoor air
volume. For indoor air volume and outdoor air volume requirements,
refer instead to section 6.1.5 (except where section 6.1.5 refers
to Table 8, refer instead to Table 4 of this appendix) and 6.1.6 of
AHRI 1230-2010.
For the test method, refer to sections 3.3 to 3.5 and 3.7 to
3.13 of this appendix. For cooling mode and heating mode test
conditions, refer to section 6.2 of AHRI 1230-2010. For
calculations of seasonal performance descriptors, refer to section
4 of this appendix.
(B) For systems other than VRF, only a subset of the sections
listed in this test procedure apply when testing and determining
represented values for a particular unit. Table 1 shows the
sections of the test procedure that apply to each system. This
table is meant to assist manufacturers in finding the appropriate
sections of the test procedure; the appendix sections rather than
the table provide the specific requirements for testing, and given
the varied nature of available units, manufacturers are responsible
for determining which sections apply to each unit tested based on
the unit's characteristics. To use this table, first refer to the
sections listed under “all units”. Then refer to additional
requirements based on:
(1) System configuration(s),
(2) The compressor staging or modulation capability, and
(3) Any special features.
Testing requirements for space-constrained products do not
differ from similar equipment that is not space-constrained and
thus are not listed separately in this table. Air conditioners and
heat pumps are not listed separately in this table, but heating
procedures and calculations apply only to heat pumps.
2.1 Test Room
Requirements
a. Test using two side-by-side rooms: An indoor test room and an
outdoor test room. For multiple-split, single-zone-multi-coil or
multi-circuit air conditioners and heat pumps, however, use as many
indoor test rooms as needed to accommodate the total number of
indoor units. These rooms must comply with the requirements
specified in sections 8.1.2 and 8.1.3 of ANSI/ASHRAE 37-2009
(incorporated by reference, see § 430.3).
b. Inside these test rooms, use artificial loads during cyclic
tests and frost accumulation tests, if needed, to produce
stabilized room air temperatures. For one room, select an electric
resistance heater(s) having a heating capacity that is
approximately equal to the heating capacity of the test unit's
condenser. For the second room, select a heater(s) having a
capacity that is close to the sensible cooling capacity of the test
unit's evaporator. Cycle the heater located in the same room as the
test unit evaporator coil ON and OFF when the test unit cycles ON
and OFF. Cycle the heater located in the same room as the test unit
condensing coil ON and OFF when the test unit cycles OFF and
ON.
2.2 Test Unit Installation Requirements
a. Install the unit according to section 8.2 of ANSI/ASHRAE
37-2009 (incorporated by reference, see § 430.3), subject to the
following additional requirements:
(1) When testing split systems, follow the requirements given in
section 6.1.3.5 of AHRI 210/240-2008 (incorporated by reference,
see § 430.3). For the vapor refrigerant line(s), use the insulation
included with the unit; if no insulation is provided, use
insulation meeting the specifications for the insulation in the
installation instructions included with the unit by the
manufacturer; if no insulation is included with the unit and the
installation instructions do not contain provisions for insulating
the line(s), fully insulate the vapor refrigerant line(s) with
vapor proof insulation having an inside diameter that matches the
refrigerant tubing and a nominal thickness of at least 0.5 inches.
For the liquid refrigerant line(s), use the insulation included
with the unit; if no insulation is provided, use insulation meeting
the specifications for the insulation in the installation
instructions included with the unit by the manufacturer; if no
insulation is included with the unit and the installation
instructions do not contain provisions for insulating the line(s),
leave the liquid refrigerant line(s) exposed to the air for air
conditioners and heat pumps that heat and cool; or, for
heating-only heat pumps, insulate the liquid refrigerant line(s)
with insulation having an inside diameter that matches the
refrigerant tubing and a nominal thickness of at least 0.5 inches.
However, these requirements do not take priority over instructions
for application of insulation for the purpose of improving
refrigerant temperature measurement accuracy as required by
sections 2.10.2 and 2.10.3 of this appendix. Insulation must be the
same for the cooling and heating tests.
(2) When testing split systems, if the indoor unit does not ship
with a cooling mode expansion device, test the system using the
device as specified in the installation instructions provided with
the indoor unit. If none is specified, test the system using a
fixed orifice or piston type expansion device that is sized
appropriately for the system.
(3) When testing triple-split systems (see section 1.2 of this
appendix, Definitions), use the tubing length specified in section
6.1.3.5 of AHRI 210/240-2008 (incorporated by reference, see §
430.3) to connect the outdoor coil, indoor compressor section, and
indoor coil while still meeting the requirement of exposing 10 feet
of the tubing to outside conditions;
(4) When testing split systems having multiple indoor coils,
connect each indoor blower coil unit to the outdoor unit using:
(a) 25 feet of tubing, or
(b) tubing furnished by the manufacturer, whichever is
longer.
At least 10 feet of the system interconnection tubing shall be
exposed to the outside conditions. If they are needed to make a
secondary measurement of capacity or for verification of
refrigerant charge, install refrigerant pressure measuring
instruments as described in section 8.2.5 of ANSI/ASHRAE 37-2009
(incorporated by reference, see § 430.3). Section 2.10 of this
appendix specifies which secondary methods require refrigerant
pressure measurements and section 2.2.5.5 of this appendix
discusses use of pressure measurements to verify charge. At a
minimum, insulate the low-pressure line(s) of a split system with
insulation having an inside diameter that matches the refrigerant
tubing and a nominal thickness of 0.5 inch.
b. For units designed for both horizontal and vertical
installation or for both up-flow and down-flow vertical
installations, use the orientation for testing specified by the
manufacturer in the certification report. Conduct testing with the
following installed:
(1) The most restrictive filter(s);
(2) Supplementary heating coils; and
(3) Other equipment specified as part of the unit, including all
hardware used by a heat comfort controller if so equipped (see
section 1 of this appendix, Definitions). For small-duct,
high-velocity systems, configure all balance dampers or restrictor
devices on or inside the unit to fully open or lowest
restriction.
c. Testing a ducted unit without having an indoor air filter
installed is permissible as long as the minimum external static
pressure requirement is adjusted as stated in Table 4, note 3 (see
section 3.1.4 of this appendix). Except as noted in section 3.1.10
of this appendix, prevent the indoor air supplementary heating
coils from operating during all tests. For uncased coils, create an
enclosure using 1 inch fiberglass foil-faced ductboard having a
nominal density of 6 pounds per cubic foot. Or alternatively,
construct an enclosure using sheet metal or a similar material and
insulating material having a thermal resistance (“R” value) between
4 and 6 hr·ft 2· °F/Btu. Size the enclosure and seal between the
coil and/or drainage pan and the interior of the enclosure as
specified in installation instructions shipped with the unit. Also
seal between the plenum and inlet and outlet ducts.
d. When testing a coil-only system, install a toroidal-type
transformer to power the system's low-voltage components, complying
with any additional requirements for the transformer mentioned in
the installation manuals included with the unit by the system
manufacturer. If the installation manuals do not provide
specifications for the transformer, use a transformer having the
following features:
(1) A nominal volt-amp rating such that the transformer is
loaded between 25 and 90 percent of this rating for the highest
level of power measured during the off mode test (section 3.13 of
this appendix);
(2) Designed to operate with a primary input of 230 V, single
phase, 60 Hz; and
(3) That provides an output voltage that is within the specified
range for each low-voltage component. Include the power consumption
of the components connected to the transformer as part of the total
system power consumption during the off mode tests; do not include
the power consumed by the transformer when no load is connected to
it.
e. Test an outdoor unit with no match (i.e., that is not
distributed in commerce with any indoor units) using a coil-only
indoor unit with a single cooling air volume rate whose coil
has:
(1) Round tubes of outer diameter no less than 0.375 inches,
and
(2) a normalized gross indoor fin surface (NGIFS) no greater
than 1.0 square inches per British thermal unit per hour (sq.
in./Btu/hr). NGIFS is calculated as follows:
NGIFS = 2 × Lf × Wf × Nf ÷ Q
c(95)
where: Lf = Indoor coil fin length in inches, also height of the
coil transverse to the tubes. Wf = Indoor coil fin width in inches,
also depth of the coil. Nf = Number of fins. Q c(95) = the
measured space cooling capacity of the tested outdoor unit/indoor
unit combination as determined from the A2 or A Test whichever
applies, Btu/h.
ƒ. If the outdoor unit or the outdoor portion of a
single-package unit has a drain pan heater to prevent freezing of
defrost water, the heater shall be energized, subject to control to
de-energize it when not needed by the heater's thermostat or the
unit's control system, for all tests.
g. If pressure measurement devices are connected to a
cooling/heating heat pump refrigerant circuit, the refrigerant
charge Mt that could potentially transfer out of the connected
pressure measurement systems (transducers, gauges, connections, and
lines) between operating modes must be less than 2 percent of the
factory refrigerant charge listed on the nameplate of the outdoor
unit. If the outdoor unit nameplate has no listed refrigerant
charge, or the heat pump is shipped without a refrigerant charge,
use a factory refrigerant charge equal to 30 ounces per ton of
certified cooling capacity. Use Equation 2.2-1 to calculate Mt for
heat pumps that have a single expansion device located in the
outdoor unit to serve each indoor unit, and use Equation 2.2-2 to
calculate Mt for heat pumps that have two expansion devices per
indoor unit.
where: Vi
(i=2,3,4. . .) = the internal volume of the pressure measurement
system (pressure lines, fittings, and gauge and/or transducer) at
the location i (as indicated in Table 2), (cubic inches) fi (i=5,6)
= 0 if the pressure measurement system is pitched upwards from the
pressure tap location to the gauge or transducer, 1 if it is not. r
= the density associated with liquid refrigerant at 100 °F bubble
point conditions (ounces per cubic inch)
Table 2 - Pressure Measurement
Locations
Location
Compressor
Discharge
1
Between Outdoor
Coil and Outdoor Expansion Valve(s)
2
Liquid Service
Valve
3
Indoor Coil
Inlet
4
Indoor Coil
Outlet
5
Common Suction
Port (i.e. vapor service valve)
6
Compressor
Suction
7
Calculate the internal volume of each pressure measurement
system using internal volume reported for pressure transducers and
gauges in product literature, if available. If such information is
not available, use the value of 0.1 cubic inches internal volume
for each pressure transducer, and 0.2 cubic inches for each
pressure gauge.
In addition, for heat pumps that have a single expansion device
located in the outdoor unit to serve each indoor unit, the internal
volume of the pressure system at location 2 (as indicated in Table
2) must be no more than 1 cubic inch. Once the pressure measurement
lines are set up, no change should be made until all tests are
finished.
2.2.1 Defrost Control Settings
Set heat pump defrost controls at the normal settings which most
typify those encountered in generalized climatic region IV. (Refer
to Figure 1 and Table 20 of section 4.2 of this appendix for
information on region IV.) For heat pumps that use a time-adaptive
defrost control system (see section 1.2 of this appendix,
Definitions), the manufacturer must specify in the certification
report the frosting interval to be used during frost accumulation
tests and provide the procedure for manually initiating the defrost
at the specified time.
2.2.2 Special Requirements for Units Having a Multiple-Speed
Outdoor Fan
Configure the multiple-speed outdoor fan according to the
installation manual included with the unit by the manufacturer, and
thereafter, leave it unchanged for all tests. The controls of the
unit must regulate the operation of the outdoor fan during all lab
tests except dry coil cooling mode tests. For dry coil cooling mode
tests, the outdoor fan must operate at the same speed used during
the required wet coil test conducted at the same outdoor test
conditions.
2.2.3 Special Requirements for Multi-Split Air Conditioners and
Heat Pumps and Ducted Systems Using a Single Indoor Section
Containing Multiple Indoor Blowers That Would Normally Operate
Using Two or More Indoor Thermostats
Because these systems will have more than one indoor blower and
possibly multiple outdoor fans and compressor systems, references
in this test procedure to a singular indoor blower, outdoor fan,
and/or compressor means all indoor blowers, all outdoor fans, and
all compressor systems that are energized during the test.
a. Additional requirements for multi-split air conditioners and
heat pumps. For any test where the system is operated at part load
(i.e., one or more compressors “off”, operating at the
intermediate or minimum compressor speed, or at low compressor
capacity), record the indoor coil(s) that are not providing heating
or cooling during the test. For variable-speed systems, the
manufacturer must designate in the certification report at least
one indoor unit that is not providing heating or cooling for all
tests conducted at minimum compressor speed.
b. Additional requirements for ducted split systems with a
single indoor unit containing multiple indoor blowers (or for
single-package units with an indoor section containing multiple
indoor blowers) where the indoor blowers are designed to cycle on
and off independently of one another and are not controlled such
that all indoor blowers are modulated to always operate at the same
air volume rate or speed. For any test where the system is operated
at its lowest capacity - i.e., the lowest total air volume
rate allowed when operating the single-speed compressor or when
operating at low compressor capacity - indoor blowers accounting
for at least one-third of the full-load air volume rate must be
turned off unless prevented by the controls of the unit. In such
cases, turn off as many indoor blowers as permitted by the unit's
controls. Where more than one option exists for meeting this “off”
requirement, the manufacturer shall indicate in its certification
report which indoor blower(s) are turned off. The chosen
configuration shall remain unchanged for all tests conducted at the
same lowest capacity configuration. For any indoor coil turned off
during a test, cease forced airflow through any outlet duct
connected to a switched-off indoor blower.
c. For test setups where the laboratory's physical limitations
requires use of more than the required line length of 25 feet as
listed in section 2.2.a(4) of this appendix, then the actual
refrigerant line length used by the laboratory may exceed the
required length and the refrigerant line length correction factors
in Table 4 of AHRI 1230-2010 are applied to the cooling capacity
measured for each cooling mode test.
2.2.4 Wet-Bulb Temperature Requirements for the Air Entering the
Indoor and Outdoor Coils 2.2.4.1 Cooling Mode Tests
For wet-coil cooling mode tests, regulate the water vapor
content of the air entering the indoor unit so that the wet-bulb
temperature is as listed in Tables 5 to 8. As noted in these same
tables, achieve a wet-bulb temperature during dry-coil cooling mode
tests that results in no condensate forming on the indoor coil.
Controlling the water vapor content of the air entering the outdoor
side of the unit is not required for cooling mode tests except when
testing:
(1) Units that reject condensate to the outdoor coil during wet
coil tests. Tables 5-8 list the applicable wet-bulb
temperatures.
(2) Single-package units where all or part of the indoor section
is located in the outdoor test room. The average dew point
temperature of the air entering the outdoor coil during wet coil
tests must be within ±3.0 °F of the average dew point temperature
of the air entering the indoor coil over the 30-minute data
collection interval described in section 3.3 of this appendix. For
dry coil tests on such units, it may be necessary to limit the
moisture content of the air entering the outdoor coil of the unit
to meet the requirements of section 3.4 of this appendix.
2.2.4.2 Heating Mode Tests
For heating mode tests, regulate the water vapor content of the
air entering the outdoor unit to the applicable wet-bulb
temperature listed in Tables 12 to 15. The wet-bulb temperature
entering the indoor side of the heat pump must not exceed 60 °F.
Additionally, if the Outdoor Air Enthalpy test method (section
2.10.1 of this appendix) is used while testing a single-package
heat pump where all or part of the outdoor section is located in
the indoor test room, adjust the wet-bulb temperature for the air
entering the indoor side to yield an indoor-side dew point
temperature that is as close as reasonably possible to the dew
point temperature of the outdoor-side entering air.
2.2.5 Additional Refrigerant Charging Requirements 2.2.5.1
Instructions To Use for Charging
a. Where the manufacturer's installation instructions contain
two sets of refrigerant charging criteria, one for field
installations and one for lab testing, use the field installation
criteria.
b. For systems consisting of an outdoor unit manufacturer's
outdoor section and indoor section with differing charging
procedures, adjust the refrigerant charge per the outdoor
installation instructions.
c. For systems consisting of an outdoor unit manufacturer's
outdoor unit and an independent coil manufacturer's indoor unit
with differing charging procedures, adjust the refrigerant charge
per the indoor unit's installation instructions. If instructions
are provided only with the outdoor unit or are provided only with
an independent coil manufacturer's indoor unit, then use the
provided instructions.
2.2.5.2 Test(s) To Use for Charging
a. Use the tests or operating conditions specified in the
manufacturer's installation instructions for charging. The
manufacturer's installation instructions may specify use of tests
other than the A or A2 test for charging, but, unless the unit is a
heating-only heat pump, the air volume rate must be determined by
the A or A2 test as specified in section 3.1 of this appendix.
b. If the manufacturer's installation instructions do not
specify a test or operating conditions for charging or there are no
manufacturer's instructions, use the following test(s):
(1) For air conditioners or cooling and heating heat pumps, use
the A or A2 test.
(2) For cooling and heating heat pumps that do not operate in
the H1 or H12 test (e.g. due to shut down by the unit
limiting devices) when tested using the charge determined at the A
or A2 test, and for heating-only heat pumps, use the H1 or H12
test.
2.2.5.3 Parameters To Set and Their Target Values
a. Consult the manufacturer's installation instructions
regarding which parameters (e.g., superheat) to set and
their target values. If the instructions provide ranges of values,
select target values equal to the midpoints of the provided
ranges.
b. In the event of conflicting information between charging
instructions (i.e., multiple conditions given for charge
adjustment where all conditions specified cannot be met), follow
the following hierarchy.
(1) For fixed orifice systems:
(i) Superheat
(ii) High side pressure or corresponding saturation or dew-point
temperature
(iii) Low side pressure or corresponding saturation or dew-point
temperature
(iv) Low side temperature
(v) High side temperature
(vi) Charge weight
(2) For expansion valve systems:
(i) Subcooling
(ii) High side pressure or corresponding saturation or dew-point
temperature
(iii) Low side pressure or corresponding saturation or dew-point
temperature
(iv) Approach temperature (difference between temperature of
liquid leaving condenser and condenser average inlet air
temperature)
(v) Charge weight
c. If there are no installation instructions and/or they do not
provide parameters and target values, set superheat to a target
value of 12 °F for fixed orifice systems or set subcooling to a
target value of 10 °F for expansion valve systems.
2.2.5.4 Charging Tolerances
a. If the manufacturer's installation instructions specify
tolerances on target values for the charging parameters, set the
values within these tolerances.
b. Otherwise, set parameter values within the following test
condition tolerances for the different charging parameters:
1. Superheat: ± 2.0 °F 2. Subcooling: ± 2.0 °F 3. High side
pressure or corresponding saturation or dew point temperature: ±
4.0 psi or ± 1.0 °F 4. Low side pressure or corresponding
saturation or dew point temperature: ± 2.0 psi or ± 0.8 °F 5. High
side temperature: ±2.0 °F 6. Low side temperature: ±2.0 °F 7.
Approach temperature: ± 1.0 °F 8. Charge weight: ± 2.0 ounce
2.2.5.5 Special Charging Instructions a. Cooling and Heating Heat
Pumps
If, using the initial charge set in the A or A2 test, the
conditions are not within the range specified in manufacturer's
installation instructions for the H1 or H12 test, make as small as
possible an adjustment to obtain conditions for this test in the
specified range. After this adjustment, recheck conditions in the A
or A2 test to confirm that they are still within the specified
range for the A or A2 test.
b. Single-Package Systems
Unless otherwise directed by the manufacturer's installation
instructions, install one or more refrigerant line pressure gauges
during the setup of the unit, located depending on the parameters
used to verify or set charge, as described:
(1) Install a pressure gauge at the location of the service
valve on the liquid line if charging is on the basis of subcooling,
or high side pressure or corresponding saturation or dew point
temperature;
(2) Install a pressure gauge at the location of the service
valve on the suction line if charging is on the basis of superheat,
or low side pressure or corresponding saturation or dew point
temperature.
Use methods for installing pressure gauge(s) at the required
location(s) as indicated in manufacturer's instructions if
specified.
2.2.5.6 Near-Azeotropic and Zeotropic Refrigerants.
Perform charging of near-azeotropic and zeotropic refrigerants
only with refrigerant in the liquid state.
2.2.5.7 Adjustment of Charge Between Tests.
After charging the system as described in this test procedure,
use the set refrigerant charge for all tests used to determine
performance. Do not adjust the refrigerant charge at any point
during testing. If measurements indicate that refrigerant charge
has leaked during the test, repair the refrigerant leak, repeat any
necessary set-up steps, and repeat all tests.
2.3 Indoor Air Volume Rates.
If a unit's controls allow for overspeeding the indoor blower
(usually on a temporary basis), take the necessary steps to prevent
overspeeding during all tests.
2.3.1 Cooling Tests
a. Set indoor blower airflow-control settings (e.g., fan
motor pin settings, fan motor speed) according to the requirements
that are specified in section 3.1.4 of this appendix.
b. Express the Cooling full-load air volume rate, the Cooling
Minimum Air Volume Rate, and the Cooling Intermediate Air Volume
Rate in terms of standard air.
2.3.2 Heating Tests
a. Set indoor blower airflow-control settings (e.g., fan
motor pin settings, fan motor speed) according to the requirements
that are specified in section 3.1.4 of this appendix.
b. Express the heating full-load air volume rate, the heating
minimum air volume rate, the heating intermediate air volume rate,
and the heating nominal air volume rate in terms of standard
air.
2.4 Indoor Coil Inlet and Outlet Duct Connections
Insulate and/or construct the outlet plenum as described in
section 2.4.1 of this appendix and, if installed, the inlet plenum
described in section 2.4.2 of this appendix with thermal insulation
having a nominal overall resistance (R-value) of at least 19 hr·ft
2· °F/Btu.
2.4.1 Outlet Plenum for the Indoor Unit
a. Attach a plenum to the outlet of the indoor coil. (Note: For
some packaged systems, the indoor coil may be located in the
outdoor test room.)
b. For systems having multiple indoor coils, or multiple indoor
blowers within a single indoor section, attach a plenum to each
indoor coil or indoor blower outlet. In order to reduce the number
of required airflow measurement apparati (section 2.6 of this
appendix), each such apparatus may serve multiple outlet plenums
connected to a single common duct leading to the apparatus. More
than one indoor test room may be used, which may use one or more
common ducts leading to one or more airflow measurement apparati
within each test room that contains multiple indoor coils. At the
plane where each plenum enters a common duct, install an adjustable
airflow damper and use it to equalize the static pressure in each
plenum. Each outlet air temperature grid (section 2.5.4 of this
appendix) and airflow measuring apparatus are located downstream of
the inlet(s) to the common duct. For multiple-circuit (or
multi-circuit) systems for which each indoor coil outlet is
measured separately and its outlet plenum is not connected to a
common duct connecting multiple outlet plenums, the outlet air
temperature grid and airflow measuring apparatus must be installed
at each outlet plenum.
c. For small-duct, high-velocity systems, install an outlet
plenum that has a diameter that is equal to or less than the value
listed in Table 3. The limit depends only on the Cooling full-load
air volume rate (see section 3.1.4.1.1 of this appendix) and is
effective regardless of the flange dimensions on the outlet of the
unit (or an air supply plenum adapter accessory, if installed in
accordance with the manufacturer's installation instructions).
d. Add a static pressure tap to each face of the (each) outlet
plenum, if rectangular, or at four evenly distributed locations
along the circumference of an oval or round plenum. Create a
manifold that connects the four static pressure taps. Figure 9 of
ANSI/ASHRAE 37-2009 (incorporated by reference, see § 430.3) shows
allowed options for the manifold configuration. The cross-sectional
dimensions of plenum shall be equal to the dimensions of the indoor
unit outlet. See Figures 7a, 7b, and 7c of ANSI/ASHRAE 37-2009 for
the minimum length of the (each) outlet plenum and the locations
for adding the static pressure taps for ducted blower coil indoor
units and single-package systems. See Figure 8 of ANSI/ASHRAE
37-2009 for coil-only indoor units.
Table 3 - Size of Outlet Plenum for
Small-Duct High-Velocity Indoor Units
Cooling full-load
air volume rate
(scfm)
Maximum
diameter *
of outlet
plenum
(inches)
≤500
6
501 to 700
7
701 to 900
8
901 to 1100
9
1101 to 1400
10
1401 to 1750
11
* If the outlet plenum is rectangular,
calculate its equivalent diameter using (4A/P,) where A is the
cross-sectional area and P is the perimeter of the rectangular
plenum, and compare it to the listed maximum diameter.
2.4.2 Inlet Plenum for the Indoor Unit
Install an inlet plenum when testing a coil-only indoor unit, a
ducted blower coil indoor unit, or a single-package system. See
Figures 7b and 7c of ANSI/ASHRAE 37-2009 for cross-sectional
dimensions, the minimum length of the inlet plenum, and the
locations of the static-pressure taps for ducted blower coil indoor
units and single-package systems. See Figure 8 of ANSI/ASHRAE
37-2009 for coil-only indoor units. The inlet plenum duct size
shall equal the size of the inlet opening of the air-handling
(blower coil) unit or furnace. For a ducted blower coil indoor unit
the set up may omit the inlet plenum if an inlet airflow prevention
device is installed with a straight internally unobstructed duct on
its outlet end with a minimum length equal to 1.5 times the square
root of the cross-sectional area of the indoor unit inlet. See
section 2.5.1.2 of this appendix for requirements for the locations
of static pressure taps built into the inlet airflow prevention
device. For all of these arrangements, make a manifold that
connects the four static-pressure taps using one of the three
configurations specified in section 2.4.1.d of this appendix. Never
use an inlet plenum when testing non-ducted indoor units.
2.5 Indoor Coil Air Property Measurements and Airflow Prevention
Devices
Follow instructions for indoor coil air property measurements as
described in section 2.14 of this appendix, unless otherwise
instructed in this section.
a. Measure the dry-bulb temperature and water vapor content of
the air entering and leaving the indoor coil. If needed, use an air
sampling device to divert air to a sensor(s) that measures the
water vapor content of the air. See section 5.3 of ANSI/ASHRAE
41.1-2013 (incorporated by reference, see § 430.3) for guidance on
constructing an air sampling device. No part of the air sampling
device or the tubing transferring the sampled air to the sensor
shall be within two inches of the test chamber floor, and the
transfer tubing shall be insulated. The sampling device may also be
used for measurement of dry bulb temperature by transferring the
sampled air to a remotely located sensor(s). The air sampling
device and the remotely located temperature sensor(s) may be used
to determine the entering air dry bulb temperature during any test.
The air sampling device and the remotely located sensor(s) may be
used to determine the leaving air dry bulb temperature for all
tests except:
(1) Cyclic tests; and
(2) Frost accumulation tests.
b. Install grids of temperature sensors to measure dry bulb
temperatures of both the entering and leaving airstreams of the
indoor unit. These grids of dry bulb temperature sensors may be
used to measure average dry bulb temperature entering and leaving
the indoor unit in all cases (as an alternative to the dry bulb
sensor measuring the sampled air). The leaving airstream grid is
required for measurement of average dry bulb temperature leaving
the indoor unit for the two special cases noted above. The grids
are also required to measure the air temperature distribution of
the entering and leaving airstreams as described in sections 3.1.8
and 3.1.9 of this appendix. Two such grids may applied as a
thermopile, to directly obtain the average temperature difference
rather than directly measuring both entering and leaving average
temperatures.
c. Use of airflow prevention devices. Use an inlet and outlet
air damper box, or use an inlet upturned duct and an outlet air
damper box when conducting one or both of the cyclic tests listed
in sections 3.2 and 3.6 of this appendix on ducted systems. If not
conducting any cyclic tests, an outlet air damper box is required
when testing ducted and non-ducted heat pumps that cycle off the
indoor blower during defrost cycles and there is no other means for
preventing natural or forced convection through the indoor unit
when the indoor blower is off. Never use an inlet damper box or an
inlet upturned duct when testing non-ducted indoor units. An inlet
upturned duct is a length of ductwork installed upstream from the
inlet such that the indoor duct inlet opening, facing upwards, is
sufficiently high to prevent natural convection transfer out of the
duct. If an inlet upturned duct is used, install a dry bulb
temperature sensor near the inlet opening of the indoor duct at a
centerline location not higher than the lowest elevation of the
duct edges at the inlet, and ensure that any pair of 5-minute
averages of the dry bulb temperature at this location, measured at
least every minute during the compressor OFF period of the cyclic
test, do not differ by more than 1.0 °F.
2.5.1 Test Set-Up on the Inlet Side of the Indoor Coil: For Cases
Where the Inlet Airflow Prevention Device Is Installed
a. Install an airflow prevention device as specified in section
2.5.1.1 or 2.5.1.2 of this appendix, whichever applies.
b. For an inlet damper box, locate the grid of entering air
dry-bulb temperature sensors, if used, and the air sampling device,
or the sensor used to measure the water vapor content of the inlet
air, at a location immediately upstream of the damper box inlet.
For an inlet upturned duct, locate the grid of entering air
dry-bulb temperature sensors, if used, and the air sampling device,
or the sensor used to measure the water vapor content of the inlet
air, at a location at least one foot downstream from the beginning
of the insulated portion of the duct but before the static pressure
measurement.
2.5.1.1 If the Section 2.4.2 Inlet Plenum Is Installed
Construct the airflow prevention device having a cross-sectional
flow area equal to or greater than the flow area of the inlet
plenum. Install the airflow prevention device upstream of the inlet
plenum and construct ductwork connecting it to the inlet plenum. If
needed, use an adaptor plate or a transition duct section to
connect the airflow prevention device with the inlet plenum.
Insulate the ductwork and inlet plenum with thermal insulation that
has a nominal overall resistance (R-value) of at least 19 hr · ft 2
· °F/Btu.
2.5.1.2 If the Section 2.4.2 Inlet Plenum Is Not Installed
Construct the airflow prevention device having a cross-sectional
flow area equal to or greater than the flow area of the air inlet
of the indoor unit. Install the airflow prevention device
immediately upstream of the inlet of the indoor unit. If needed,
use an adaptor plate or a short transition duct section to connect
the airflow prevention device with the unit's air inlet. Add static
pressure taps at the center of each face of a rectangular airflow
prevention device, or at four evenly distributed locations along
the circumference of an oval or round airflow prevention device.
Locate the pressure taps at a distance from the indoor unit inlet
equal to 0.5 times the square root of the cross sectional area of
the indoor unit inlet. This location must be between the damper and
the inlet of the indoor unit, if a damper is used. Make a manifold
that connects the four static pressure taps using one of the
configurations shown in Figure 9 of ANSI/ASHRAE 37-2009
(incorporated by reference, see § 430.3). Insulate the ductwork
with thermal insulation that has a nominal overall resistance
(R-value) of at least 19 hr · ft 2 · °F/Btu.
2.5.2 Test Set-Up on the Inlet Side of the Indoor Unit: for Cases
Where No Airflow Prevention Device is Installed
If using the section 2.4.2 inlet plenum and a grid of dry bulb
temperature sensors, mount the grid at a location upstream of the
static pressure taps described in section 2.4.2 of this appendix,
preferably at the entrance plane of the inlet plenum. If the
section 2.4.2 inlet plenum is not used (i.e. for non-ducted
units) locate a grid approximately 6 inches upstream of the indoor
unit inlet. In the case of a system having multiple non-ducted
indoor units, do this for each indoor unit. Position an air
sampling device, or the sensor used to measure the water vapor
content of the inlet air, immediately upstream of the (each)
entering air dry-bulb temperature sensor grid. If a grid of sensors
is not used, position the entering air sampling device (or the
sensor used to measure the water vapor content of the inlet air) as
if the grid were present.
Fabricate pressure taps meeting all requirements described in
section 6.5.2 of ANSI/ASHRAE 37-2009 (incorporated by reference,
see § 430.3) and illustrated in Figure 2A of AMCA 210-2007
(incorporated by reference, see § 430.3), however, if adhering
strictly to the description in section 6.5.2 of ANSI/ASHRAE
37-2009, the minimum pressure tap length of 2.5 times the inner
diameter of Figure 2A of AMCA 210-2007 is waived. Use a
differential pressure measuring instrument that is accurate to
within ±0.01 inches of water and has a resolution of at least 0.01
inches of water to measure the static pressure difference between
the indoor coil air inlet and outlet. Connect one side of the
differential pressure instrument to the manifolded pressure taps
installed in the outlet plenum. Connect the other side of the
instrument to the manifolded pressure taps located in either the
inlet plenum or incorporated within the airflow prevention device.
For non-ducted indoor units that are tested with multiple outlet
plenums, measure the static pressure within each outlet plenum
relative to the surrounding atmosphere.
2.5.4 Test Set-Up on the Outlet Side of the Indoor Coil
a. Install an interconnecting duct between the outlet plenum
described in section 2.4.1 of this appendix and the airflow
measuring apparatus described below in section 2.6 of this
appendix. The cross-sectional flow area of the interconnecting duct
must be equal to or greater than the flow area of the outlet plenum
or the common duct used when testing non-ducted units having
multiple indoor coils. If needed, use adaptor plates or transition
duct sections to allow the connections. To minimize leakage, tape
joints within the interconnecting duct (and the outlet plenum).
Construct or insulate the entire flow section with thermal
insulation having a nominal overall resistance (R-value) of at
least 19 hr·ft 2· °F/Btu.
b. Install a grid(s) of dry-bulb temperature sensors inside the
interconnecting duct. Also, install an air sampling device, or the
sensor(s) used to measure the water vapor content of the outlet
air, inside the interconnecting duct. Locate the dry-bulb
temperature grid(s) upstream of the air sampling device (or the
in-duct sensor(s) used to measure the water vapor content of the
outlet air). Turn off the sampler fan motor during the cyclic
tests. Air leaving an indoor unit that is sampled by an air
sampling device for remote water-vapor-content measurement must be
returned to the interconnecting duct at a location:
(1) Downstream of the air sampling device;
(2) On the same side of the outlet air damper as the air
sampling device; and
(3) Upstream of the section 2.6 airflow measuring apparatus.
2.5.4.1 Outlet Air Damper Box Placement and Requirements
If using an outlet air damper box (see section 2.5 of this
appendix), the leakage rate from the combination of the outlet
plenum, the closed damper, and the duct section that connects these
two components must not exceed 20 cubic feet per minute when a
negative pressure of 1 inch of water column is maintained at the
plenum's inlet.
2.5.4.2 Procedures To Minimize Temperature Maldistribution
Use these procedures if necessary to correct temperature
maldistributions. Install a mixing device(s) upstream of the outlet
air, dry-bulb temperature grid (but downstream of the outlet plenum
static pressure taps). Use a perforated screen located between the
mixing device and the dry-bulb temperature grid, with a maximum
open area of 40 percent. One or both items should help to meet the
maximum outlet air temperature distribution specified in section
3.1.8 of this appendix. Mixing devices are described in sections
5.3.2 and 5.3.3 of ANSI/ASHRAE 41.1-2013 and section 5.2.2 of
ASHRAE 41.2-1987 (RA 1992) (incorporated by reference, see §
430.3).
2.5.4.3 Minimizing Air Leakage
For small-duct, high-velocity systems, install an air damper
near the end of the interconnecting duct, just prior to the
transition to the airflow measuring apparatus of section 2.6 of
this appendix. To minimize air leakage, adjust this damper such
that the pressure in the receiving chamber of the airflow measuring
apparatus is no more than 0.5 inch of water higher than the
surrounding test room ambient. If applicable, in lieu of installing
a separate damper, use the outlet air damper box of sections 2.5
and 2.5.4.1 of this appendix if it allows variable positioning.
Also apply these steps to any conventional indoor blower unit that
creates a static pressure within the receiving chamber of the
airflow measuring apparatus that exceeds the test room ambient
pressure by more than 0.5 inches of water column.
2.5.5 Dry Bulb Temperature Measurement
a. Measure dry bulb temperatures as specified in sections 4,
5.3, 6, and 7 of ANSI/ASHRAE 41.1-2013 (incorporated by reference,
see § 430.3).
b. Distribute the sensors of a dry-bulb temperature grid over
the entire flow area. The required minimum is 9 sensors per
grid.
2.5.6 Water Vapor Content Measurement
Determine water vapor content by measuring dry-bulb temperature
combined with the air wet-bulb temperature, dew point temperature,
or relative humidity. If used, construct and apply wet-bulb
temperature sensors as specified in sections 4, 5, 6, 7.2, 7.3, and
7.4 of ASHRAE 41.6-2014 (incorporated by reference, see § 430.3).
The temperature sensor (wick removed) must be accurate to within
±0.2 °F. If used, apply dew point hygrometers as specified in
sections 4, 5, 6, 7.1, and 7.4 of ASHRAE 41.6-2014 (incorporated by
reference, see § 430.3). The dew point hygrometers must be accurate
to within ±0.4 °F when operated at conditions that result in the
evaluation of dew points above 35 °F. If used, a relative humidity
(RH) meter must be accurate to within ±0.7% RH. Other means to
determine the psychrometric state of air may be used as long as the
measurement accuracy is equivalent to or better than the accuracy
achieved from using a wet-bulb temperature sensor that meets the
above specifications.
2.5.7 Air Damper Box Performance Requirements
If used (see section 2.5 of this appendix), the air damper
box(es) must be capable of being completely opened or completely
closed within 10 seconds for each action.
2.6 Airflow Measuring Apparatus
a. Fabricate and operate an airflow measuring apparatus as
specified in section 6.2 and 6.3 of ANSI/ASHRAE 37-2009
(incorporated by reference, see § 430.3). Place the static pressure
taps and position the diffusion baffle (settling means) relative to
the chamber inlet as indicated in Figure 12 of AMCA 210-2007 and/or
Figure 14 of ASHRAE 41.2-1987 (RA 1992) (incorporated by reference,
see § 430.3). When measuring the static pressure difference across
nozzles and/or velocity pressure at nozzle throats using electronic
pressure transducers and a data acquisition system, if high
frequency fluctuations cause measurement variations to exceed the
test tolerance limits specified in section 9.2 and Table 2 of
ANSI/ASHRAE 37-2009, dampen the measurement system such that the
time constant associated with response to a step change in
measurement (time for the response to change 63% of the way from
the initial output to the final output) is no longer than five
seconds.
b. Connect the airflow measuring apparatus to the
interconnecting duct section described in section 2.5.4 of this
appendix. See sections 6.1.1, 6.1.2, and 6.1.4, and Figures 1, 2,
and 4 of ANSI/ASHRAE 37-2009; and Figures D1, D2, and D4 of AHRI
210/240-2008 (incorporated by reference, see § 430.3) for
illustrative examples of how the test apparatus may be applied
within a complete laboratory set-up. Instead of following one of
these examples, an alternative set-up may be used to handle the air
leaving the airflow measuring apparatus and to supply properly
conditioned air to the test unit's inlet. The alternative set-up,
however, must not interfere with the prescribed means for measuring
airflow rate, inlet and outlet air temperatures, inlet and outlet
water vapor contents, and external static pressures, nor create
abnormal conditions surrounding the test unit. (Note: Do not use an
enclosure as described in section 6.1.3 of ANSI/ASHRAE 37-2009 when
testing triple-split units.)
2.7 Electrical Voltage Supply
Perform all tests at the voltage specified in section 6.1.3.2 of
AHRI 210/240-2008 (incorporated by reference, see § 430.3) for
“Standard Rating Tests.” If either the indoor or the outdoor unit
has a 208V or 200V nameplate voltage and the other unit has a 230V
nameplate rating, select the voltage supply on the outdoor unit for
testing. Otherwise, supply each unit with its own nameplate
voltage. Measure the supply voltage at the terminals on the test
unit using a volt meter that provides a reading that is accurate to
within ±1.0 percent of the measured quantity.
2.8 Electrical Power and Energy Measurements
a. Use an integrating power (watt-hour) measuring system to
determine the electrical energy or average electrical power
supplied to all components of the air conditioner or heat pump
(including auxiliary components such as controls, transformers,
crankcase heater, integral condensate pump on non-ducted indoor
units, etc.). The watt-hour measuring system must give readings
that are accurate to within ±0.5 percent. For cyclic tests, this
accuracy is required during both the ON and OFF cycles. Use either
two different scales on the same watt-hour meter or two separate
watt-hour meters. Activate the scale or meter having the lower
power rating within 15 seconds after beginning an OFF cycle.
Activate the scale or meter having the higher power rating within
15 seconds prior to beginning an ON cycle. For ducted blower coil
systems, the ON cycle lasts from compressor ON to indoor blower
OFF. For ducted coil-only systems, the ON cycle lasts from
compressor ON to compressor OFF. For non-ducted units, the ON cycle
lasts from indoor blower ON to indoor blower OFF. When testing air
conditioners and heat pumps having a variable-speed compressor,
avoid using an induction watt/watt-hour meter.
b. When performing section 3.5 and/or 3.8 cyclic tests on
non-ducted units, provide instrumentation to determine the average
electrical power consumption of the indoor blower motor to within
±1.0 percent. If required according to sections 3.3, 3.4, 3.7,
3.9.1 of this appendix, and/or 3.10 of this appendix, this same
instrumentation requirement (to determine the average electrical
power consumption of the indoor blower motor to within ±1.0
percent) applies when testing air conditioners and heat pumps
having a variable-speed constant-air-volume-rate indoor blower or a
variable-speed, variable-air-volume-rate indoor blower.
2.9 Time Measurements
Make elapsed time measurements using an instrument that yields
readings accurate to within ±0.2 percent.
2.10 Test Apparatus for the Secondary Space Conditioning Capacity
Measurement
For all tests, use the indoor air enthalpy method to measure the
unit's capacity. This method uses the test set-up specified in
sections 2.4 to 2.6 of this appendix. In addition, for all
steady-state tests, conduct a second, independent measurement of
capacity as described in section 3.1.1 of this appendix. For split
systems, use one of the following secondary measurement methods:
Outdoor air enthalpy method, compressor calibration method, or
refrigerant enthalpy method. For single-package units, use either
the outdoor air enthalpy method or the compressor calibration
method as the secondary measurement.
2.10.1 Outdoor Air Enthalpy Method
a. To make a secondary measurement of indoor space conditioning
capacity using the outdoor air enthalpy method, do the
following:
(1) Measure the electrical power consumption of the test
unit;
(2) Measure the air-side capacity at the outdoor coil; and
(3) Apply a heat balance on the refrigerant cycle.
b. The test apparatus required for the outdoor air enthalpy
method is a subset of the apparatus used for the indoor air
enthalpy method. Required apparatus includes the following:
(1) On the outlet side, an outlet plenum containing static
pressure taps (sections 2.4, 2.4.1, and 2.5.3 of this
appendix),
(2) An airflow measuring apparatus (section 2.6 of this
appendix),
(3) A duct section that connects these two components and itself
contains the instrumentation for measuring the dry-bulb temperature
and water vapor content of the air leaving the outdoor coil
(sections 2.5.4, 2.5.5, and 2.5.6 of this appendix), and
(4) On the inlet side, a sampling device and temperature grid
(section 2.11.b of this appendix).
c. During the free outdoor air tests described in sections
3.11.1 and 3.11.1.1 of this appendix, measure the evaporator and
condenser temperatures or pressures. On both the outdoor coil and
the indoor coil, solder a thermocouple onto a return bend located
at or near the midpoint of each coil or at points not affected by
vapor superheat or liquid subcooling. Alternatively, if the test
unit is not sensitive to the refrigerant charge, install pressure
gages to the access valves or to ports created from tapping into
the suction and discharge lines according to sections 7.4.2 and
8.2.5 of ANSI/ASHRAE 37-2009. Use this alternative approach when
testing a unit charged with a zeotropic refrigerant having a
temperature glide in excess of 1 °F at the specified test
conditions.
2.10.2 Compressor Calibration Method
Measure refrigerant pressures and temperatures to determine the
evaporator superheat and the enthalpy of the refrigerant that
enters and exits the indoor coil. Determine refrigerant flow rate
or, when the superheat of the refrigerant leaving the evaporator is
less than 5 °F, total capacity from separate calibration tests
conducted under identical operating conditions. When using this
method, install instrumentation and measure refrigerant properties
according to section 7.4.2 and 8.2.5 of ANSI/ASHRAE 37-2009
(incorporated by reference, see § 430.3). If removing the
refrigerant before applying refrigerant lines and subsequently
recharging, use the steps in 7.4.2 of ANSI/ASHRAE 37-2009 in
addition to the methods of section 2.2.5 of this appendix to
confirm the refrigerant charge. Use refrigerant temperature and
pressure measuring instruments that meet the specifications given
in sections 5.1.1 and 5.2 of ANSI/ASHRAE 37-2009.
2.10.3 Refrigerant Enthalpy Method
For this method, calculate space conditioning capacity by
determining the refrigerant enthalpy change for the indoor coil and
directly measuring the refrigerant flow rate. Use section 7.5.2 of
ANSI/ASHRAE 37-2009 (incorporated by reference, see § 430.3) for
the requirements for this method, including the additional
instrumentation requirements, and information on placing the flow
meter and a sight glass. Use refrigerant temperature, pressure, and
flow measuring instruments that meet the specifications given in
sections 5.1.1, 5.2, and 5.5.1 of ANSI/ASHRAE 37-2009. Refrigerant
flow measurement device(s), if used, must be either elevated at
least two feet from the test chamber floor or placed upon
insulating material having a total thermal resistance of at least
R-12 and extending at least one foot laterally beyond each side of
the device(s)' exposed surfaces.
2.11 Measurement of Test Room Ambient Conditions
Follow instructions for setting up air sampling device and
aspirating psychrometer as described in section 2.14 of this
appendix, unless otherwise instructed in this section.
a. If using a test set-up where air is ducted directly from the
conditioning apparatus to the indoor coil inlet (see Figure 2, Loop
Air-Enthalpy Test Method Arrangement, of ANSI/ASHRAE 37-2009
(incorporated by reference, see § 430.3)), add instrumentation to
permit measurement of the indoor test room dry-bulb
temperature.
b. On the outdoor side, use one of the following two approaches,
except that approach (1) is required for all evaporatively-cooled
units and units that transfer condensate to the outdoor unit for
evaporation using condenser heat.
(1) Use sampling tree air collection on all air-inlet surfaces
of the outdoor unit.
(2) Use sampling tree air collection on one or more faces of the
outdoor unit and demonstrate air temperature uniformity as follows.
Install a grid of evenly-distributed thermocouples on each
air-permitting face on the inlet of the outdoor unit. Install the
thermocouples on the air sampling device, locate them individually
or attach them to a wire structure. If not installed on the air
sampling device, install the thermocouple grid 6 to 24 inches from
the unit. The thermocouples shall be evenly spaced across the coil
inlet surface and be installed to avoid sampling of discharge air
or blockage of air recirculation. The grid of thermocouples must
provide at least 16 measuring points per face or one measurement
per square foot of inlet face area, whichever is less. This grid
must be constructed and used as per section 5.3 of ANSI/ASHRAE
41.1-2013 (incorporated by reference, see § 430.3). The maximum
difference between the average temperatures measured during the
test period of any two pairs of these individual thermocouples
located at any of the faces of the inlet of the outdoor unit, must
not exceed 2.0 °F, otherwise approach (1) must be used.
The air sampling devices shall be located at the geometric
center of each side; the branches may be oriented either parallel
or perpendicular to the longer edges of the air inlet area. The air
sampling devices in the outdoor air inlet location shall be sized
such that they cover at least 75% of the face area of the side of
the coil that they are measuring.
Air distribution at the test facility point of supply to the
unit shall be reviewed and may require remediation prior to the
beginning of testing. Mixing fans can be used to ensure adequate
air distribution in the test room. If used, mixing fans shall be
oriented such that they are pointed away from the air intake so
that the mixing fan exhaust does not affect the outdoor coil air
volume rate. Particular attention should be given to prevent the
mixing fans from affecting (enhancing or limiting) recirculation of
condenser fan exhaust air back through the unit. Any fan used to
enhance test room air mixing shall not cause air velocities in the
vicinity of the test unit to exceed 500 feet per minute.
The air sampling device may be larger than the face area of the
side being measured, however care shall be taken to prevent
discharge air from being sampled. If an air sampling device
dimension extends beyond the inlet area of the unit, holes shall be
blocked in the air sampling device to prevent sampling of discharge
air. Holes can be blocked to reduce the region of coverage of the
intake holes both in the direction of the trunk axis or
perpendicular to the trunk axis. For intake hole region reduction
in the direction of the trunk axis, block holes of one or more
adjacent pairs of branches (the branches of a pair connect opposite
each other at the same trunk location) at either the outlet end or
the closed end of the trunk. For intake hole region reduction
perpendicular to the trunk axis, block off the same number of holes
on each branch on both sides of the trunk.
A maximum of four (4) air sampling devices shall be connected to
each aspirating psychrometer. In order to proportionately divide
the flow stream for multiple air sampling devices for a given
aspirating psychrometer, the tubing or conduit conveying sampled
air to the psychrometer shall be of equivalent lengths for each air
sampling device. Preferentially, the air sampling device should be
hard connected to the aspirating psychrometer, but if space
constraints do not allow this, the assembly shall have a means of
allowing a flexible tube to connect the air sampling device to the
aspirating psychrometer. The tubing or conduit shall be insulated
and routed to prevent heat transfer to the air stream. Any surface
of the air conveying tubing in contact with surrounding air at a
different temperature than the sampled air shall be insulated with
thermal insulation with a nominal thermal resistance (R-value) of
at least 19 hr · ft 2 · °F/Btu. Alternatively the conduit may have
lower thermal resistance if additional sensor(s) are used to
measure dry bulb temperature at the outlet of each air sampling
device. No part of the air sampling device or the tubing conducting
the sampled air to the sensors shall be within two inches of the
test chamber floor.
Pairs of measurements (e.g., dry bulb temperature and wet
bulb temperature) used to determine water vapor content of sampled
air shall be measured in the same location.
2.12 Measurement of Indoor Blower Speed
When required, measure fan speed using a revolution counter,
tachometer, or stroboscope that gives readings accurate to within
±1.0 percent.
2.13 Measurement of Barometric Pressure
Determine the average barometric pressure during each test. Use
an instrument that meets the requirements specified in section 5.2
of ANSI/ASHRAE 37-2009 (incorporated by reference, see §
430.3).
2.14 Air Sampling Device and Aspirating Psycrhometer Requirements
Air temperature measurements shall be made in accordance with
ANSI/ASHRAE 41.1-2013, unless otherwise instructed in this
section.
2.14.1 Air Sampling Device Requirements
The air sampling device is intended to draw in a sample of the
air at the critical locations of a unit under test. It shall be
constructed of stainless steel, plastic or other suitable, durable
materials. It shall have a main flow trunk tube with a series of
branch tubes connected to the trunk tube. Holes shall be on the
side of the sampler facing the upstream direction of the air
source. Other sizes and rectangular shapes can be used, and shall
be scaled accordingly with the following guidelines:
(1) Minimum hole density of 6 holes per square foot of area to
be sampled
(2) Sampler branch tube pitch (spacing) of 6 ± 3 in
(3) Manifold trunk to branch diameter ratio having a minimum of
3:1 ratio
(4) Hole pitch (spacing) shall be equally distributed over the
branch ( 1/2 pitch from the closed end to the nearest hole)
(5) Maximum individual hole to branch diameter ratio of 1:2 (1:3
preferred)
The minimum average velocity through the air sampling device
holes shall be 2.5 ft/s as determined by evaluating the sum of the
open area of the holes as compared to the flow area in the
aspirating psychrometer.
2.14.2 Aspirating Psychrometer
The psychrometer consists of a flow section and a fan to draw
air through the flow section and measures an average value of the
sampled air stream. At a minimum, the flow section shall have a
means for measuring the dry bulb temperature (typically, a
resistance temperature device (RTD) and a means for measuring the
humidity (RTD with wetted sock, chilled mirror hygrometer, or
relative humidity sensor). The aspirating psychrometer shall
include a fan that either can be adjusted manually or automatically
to maintain required velocity across the sensors.
The psychrometer shall be made from suitable material which may
be plastic (such as polycarbonate), aluminum or other metallic
materials. All psychrometers for a given system being tested, shall
be constructed of the same material. Psychrometers shall be
designed such that radiant heat from the motor (for driving the fan
that draws sampled air through the psychrometer) does not affect
sensor measurements. For aspirating psychrometers, velocity across
the wet bulb sensor shall be 1000 ± 200 ft/min. For all other
psychrometers, velocity shall be as specified by the sensor
manufacturer.
3. Testing Procedures 3.1 General Requirements
If, during the testing process, an equipment set-up adjustment
is made that would have altered the performance of the unit during
any already completed test, then repeat all tests affected by the
adjustment. For cyclic tests, instead of maintaining an air volume
rate, for each airflow nozzle, maintain the static pressure
difference or velocity pressure during an ON period at the same
pressure difference or velocity pressure as measured during the
steady-state test conducted at the same test conditions.
Use the testing procedures in this section to collect the data
used for calculating
(1) Performance metrics for central air conditioners and heat
pumps during the cooling season;
(2) Performance metrics for heat pumps during the heating
season; and
(3) Power consumption metric(s) for central air conditioners and
heat pumps during the off mode season(s).
3.1.1 Primary and Secondary Test Methods
For all tests, use the indoor air enthalpy method test apparatus
to determine the unit's space conditioning capacity. The procedure
and data collected, however, differ slightly depending upon whether
the test is a steady-state test, a cyclic test, or a frost
accumulation test. The following sections described these
differences. For the full-capacity cooling-mode test and (for a
heat pump) the full-capacity heating-mode test, use one of the
acceptable secondary methods specified in section 2.10 of this
appendix to determine indoor space conditioning capacity. Calculate
this secondary check of capacity according to section 3.11 of this
appendix. The two capacity measurements must agree to within 6
percent to constitute a valid test. For this capacity comparison,
use the Indoor Air Enthalpy Method capacity that is calculated in
section 7.3 of ANSI/ASHRAE 37-2009 (incorporated by reference, see
§ 430.3) (and, if testing a coil-only system, compare capacities
before making the after-test fan heat adjustments described in
section 3.3, 3.4, 3.7, and 3.10 of this appendix). However, include
the appropriate section 3.3 to 3.5 and 3.7 to 3.10 fan heat
adjustments within the indoor air enthalpy method capacities used
for the section 4 seasonal calculations of this appendix.
3.1.2 Manufacturer-Provided Equipment Overrides
Where needed, the manufacturer must provide a means for
overriding the controls of the test unit so that the compressor(s)
operates at the specified speed or capacity and the indoor blower
operates at the specified speed or delivers the specified air
volume rate.
3.1.3 Airflow Through the Outdoor Coil
For all tests, meet the requirements given in section 6.1.3.4 of
AHRI 210/240-2008 (incorporated by reference, see § 430.3) when
obtaining the airflow through the outdoor coil.
3.1.3.1 Double-Ducted
For products intended to be installed with the outdoor airflow
ducted, the unit shall be installed with outdoor coil ductwork
installed per manufacturer installation instructions and shall
operate between 0.10 and 0.15 in H2O external static pressure.
External static pressure measurements shall be made in accordance
with ANSI/ASHRAE 37-2009 section 6.4 and 6.5.
3.1.4 Airflow Through the Indoor Coil
Airflow setting(s) shall be determined before testing begins.
Unless otherwise specified within this or its subsections, no
changes shall be made to the airflow setting(s) after initiation of
testing.
3.1.4.1 Cooling Full-Load Air Volume Rate 3.1.4.1.1. Cooling
Full-Load Air Volume Rate for Ducted Units
Identify the certified cooling full-load air volume rate and
certified instructions for setting fan speed or controls. If there
is no certified Cooling full-load air volume rate, use a value
equal to the certified cooling capacity of the unit times 400 scfm
per 12,000 Btu/h. If there are no instructions for setting fan
speed or controls, use the as-shipped settings. Use the following
procedure to confirm and, if necessary, adjust the Cooling
full-load air volume rate and the fan speed or control settings to
meet each test procedure requirement:
a. For all ducted blower coil systems, except those having a
constant-air-volume-rate indoor blower:
Step (1) Operate the unit under conditions specified for the A
(for single-stage units) or A2 test using the certified fan speed
or controls settings, and adjust the exhaust fan of the airflow
measuring apparatus to achieve the certified Cooling full-load air
volume rate;
Step (2) Measure the external static pressure;
Step (3) If this external static pressure is equal to or greater
than the applicable minimum external static pressure cited in Table
4, the pressure requirement is satisfied; proceed to step 7 of this
section. If this external static pressure is not equal to or
greater than the applicable minimum external static pressure cited
in Table 4, proceed to step 4 of this section;
Step (4) Increase the external static pressure by adjusting the
exhaust fan of the airflow measuring apparatus until either
(i) The applicable Table 4 minimum is equaled or
(ii) The measured air volume rate equals 90 percent or less of
the Cooling full-load air volume rate, whichever occurs first;
Step (5) If the conditions of step 4 (i) of this section occur
first, the pressure requirement is satisfied; proceed to step 7 of
this section. If the conditions of step 4 (ii) of this section
occur first, proceed to step 6 of this section;
Step (6) Make an incremental change to the setup of the indoor
blower (e.g., next highest fan motor pin setting, next
highest fan motor speed) and repeat the evaluation process
beginning above, at step 1 of this section. If the indoor blower
setup cannot be further changed, increase the external static
pressure by adjusting the exhaust fan of the airflow measuring
apparatus until the applicable Table 4 minimum is equaled; proceed
to step 7 of this section;
Step (7) The airflow constraints have been satisfied. Use the
measured air volume rate as the Cooling full-load air volume rate.
Use the final fan speed or control settings for all tests that use
the Cooling full-load air volume rate.
b. For ducted blower coil systems with a
constant-air-volume-rate indoor blower. For all tests that specify
the Cooling full-load air volume rate, obtain an external static
pressure as close to (but not less than) the applicable Table 4
value that does not cause automatic shutdown of the indoor blower
or air volume rate variation QVar, defined as follows, greater than
10 percent.
where:
Qmax = maximum measured airflow value Qmin = minimum measured
airflow value QVar = airflow variance, percent
Additional test steps as described in section 3.3.(e) of this
appendix are required if the measured external static pressure
exceeds the target value by more than 0.03 inches of water.
c. For coil-only indoor units. For the A or A2 Test,
(exclusively), the pressure drop across the indoor coil assembly
must not exceed 0.30 inches of water. If this pressure drop is
exceeded, reduce the air volume rate until the measured pressure
drop equals the specified maximum. Use this reduced air volume rate
for all tests that require the Cooling full-load air volume
rate.
Table 4 - Minimum External Static Pressure
for Ducted Blower Coil Systems
Rated Cooling
1 or Heating 2 Capacity
(Btu/h)
Minimum external
resistance 3 (Inches of water)
Small-duct,
high-velocity
systems 45
All other
systems
Up Thru
28,800
1.10
0.10
29,000 to
42,500
1.15
0.15
43,000 and
Above
1.20
0.20
1 For air conditioners and
air-conditioning heat pumps, the value certified by the
manufacturer for the unit's cooling capacity when operated at the A
or A2 Test conditions.
2 For heating-only heat pumps,
the value certified by the manufacturer for the unit's heating
capacity when operated at the H1 or H12 Test conditions.
3 For ducted units tested without
an air filter installed, increase the applicable tabular value by
0.08 inches of water.
4 See section 1.2 of this
appendix, Definitions, to determine if the equipment qualifies as a
small-duct, high-velocity system.
5 If a closed-loop, air-enthalpy
test apparatus is used on the indoor side, limit the resistance to
airflow on the inlet side of the blower coil indoor unit to a
maximum value of 0.1 inch of water. Impose the balance of the
airflow resistance on the outlet side of the indoor blower.
d. For ducted systems having multiple indoor blowers within a
single indoor section, obtain the full-load air volume rate with
all indoor blowers operating unless prevented by the controls of
the unit. In such cases, turn on the maximum number of indoor
blowers permitted by the unit's controls. Where more than one
option exists for meeting this “on” indoor blower requirement,
which indoor blower(s) are turned on must match that specified in
the certification report. Conduct section 3.1.4.1.1 setup steps for
each indoor blower separately. If two or more indoor blowers are
connected to a common duct as per section 2.4.1 of this appendix,
temporarily divert their air volume to the test room when
confirming or adjusting the setup configuration of individual
indoor blowers. The allocation of the system's full-load air volume
rate assigned to each “on” indoor blower must match that specified
by the manufacturer in the certification report.
3.1.4.1.2. Cooling Full-Load Air Volume Rate for Non-Ducted Units
For non-ducted units, the Cooling full-load air volume rate is
the air volume rate that results during each test when the unit is
operated at an external static pressure of zero inches of
water.
3.1.4.2 Cooling Minimum Air Volume Rate
Identify the certified cooling minimum air volume rate and
certified instructions for setting fan speed or controls. If there
is no certified cooling minimum air volume rate, use the final
indoor blower control settings as determined when setting the
cooling full-load air volume rate, and readjust the exhaust fan of
the airflow measuring apparatus if necessary to reset to the
cooling full load air volume obtained in section 3.1.4.1 of this
appendix. Otherwise, calculate the target external static pressure
and follow instructions a, b, c, d, or e below. The target external
static pressure, ΔPst_i, for any test “i” with a specified air
volume rate not equal to the Cooling full-load air volume rate is
determined as follows:
where:
ΔPst_i = target minimum external static pressure for test i;
ΔPst_full = minimum external static pressure for test A or A2
(Table 4); Qi = air volume rate for test i; and Qfull = Cooling
full-load air volume rate as measured after setting and/or
adjustment as described in section 3.1.4.1.1 of this appendix.
a. For a ducted blower coil system without a constant-air-volume
indoor blower, adjust for external static pressure as follows:
Step (1) Operate the unit under conditions specified for the B1
test using the certified fan speed or controls settings, and adjust
the exhaust fan of the airflow measuring apparatus to achieve the
certified cooling minimum air volume rate;
Step (2) Measure the external static pressure;
Step (3) If this pressure is equal to or greater than the
minimum external static pressure computed above, the pressure
requirement is satisfied; proceed to step 7 of this section. If
this pressure is not equal to or greater than the minimum external
static pressure computed above, proceed to step 4 of this
section;
Step (4) Increase the external static pressure by adjusting the
exhaust fan of the airflow measuring apparatus until either
(i) The pressure is equal to the minimum external static
pressure computed above or
(ii) The measured air volume rate equals 90 percent or less of
the cooling minimum air volume rate, whichever occurs first;
Step (5) If the conditions of step 4 (i) of this section occur
first, the pressure requirement is satisfied; proceed to step 7 of
this section. If the conditions of step 4 (ii) of this section
occur first, proceed to step 6 of this section;
Step (6) Make an incremental change to the setup of the indoor
blower (e.g., next highest fan motor pin setting, next
highest fan motor speed) and repeat the evaluation process
beginning above, at step 1 of this section. If the indoor blower
setup cannot be further changed, increase the external static
pressure by adjusting the exhaust fan of the airflow measuring
apparatus until it equals the minimum external static pressure
computed above; proceed to step 7 of this section;
Step (7) The airflow constraints have been satisfied. Use the
measured air volume rate as the cooling minimum air volume rate.
Use the final fan speed or control settings for all tests that use
the cooling minimum air volume rate.
b. For ducted units with constant-air-volume indoor blowers,
conduct all tests that specify the cooling minimum air volume rate
- (i.e., the A1, B1, C1, F1, and G1 Tests) - at an external
static pressure that does not cause an automatic shutdown of the
indoor blower or air volume rate variation QVar, defined in section
3.1.4.1.1.b of this appendix, greater than 10 percent, while being
as close to, but not less than the target minimum external static
pressure. Additional test steps as described in section 3.3(e) of
this appendix are required if the measured external static pressure
exceeds the target value by more than 0.03 inches of water.
c. For ducted two-capacity coil-only systems, the cooling
minimum air volume rate is the higher of (1) the rate specified by
the installation instructions included with the unit by the
manufacturer or (2) 75 percent of the cooling full-load air volume
rate. During the laboratory tests on a coil-only (fanless) system,
obtain this cooling minimum air volume rate regardless of the
pressure drop across the indoor coil assembly.
d. For non-ducted units, the cooling minimum air volume rate is
the air volume rate that results during each test when the unit
operates at an external static pressure of zero inches of water and
at the indoor blower setting used at low compressor capacity
(two-capacity system) or minimum compressor speed (variable-speed
system). For units having a single-speed compressor and a
variable-speed variable-air-volume-rate indoor blower, use the
lowest fan setting allowed for cooling.
e. For ducted systems having multiple indoor blowers within a
single indoor section, operate the indoor blowers such that the
lowest air volume rate allowed by the unit's controls is obtained
when operating the lone single-speed compressor or when operating
at low compressor capacity while meeting the requirements of
section 2.2.3.b of this appendix for the minimum number of blowers
that must be turned off. Using the target external static pressure
and the certified air volume rates, follow the procedures described
in section 3.1.4.2.a of this appendix if the indoor blowers are not
constant-air-volume indoor blowers or as described in section
3.1.4.2.b of this appendix if the indoor blowers are
constant-air-volume indoor blowers. The sum of the individual “on”
indoor blowers' air volume rates is the cooling minimum air volume
rate for the system.
3.1.4.3 Cooling Intermediate Air Volume Rate
Identify the certified cooling intermediate air volume rate and
certified instructions for setting fan speed or controls. If there
is no certified cooling intermediate air volume rate, use the final
indoor blower control settings as determined when setting the
cooling full load air volume rate, and readjust the exhaust fan of
the airflow measuring apparatus if necessary to reset to the
cooling full load air volume obtained in section 3.1.4.1 of this
appendix. Otherwise, calculate target minimum external static
pressure as described in section 3.1.4.2 of this appendix, and set
the air volume rate as follows.
a. For a ducted blower coil system without a constant-air-volume
indoor blower, adjust for external static pressure as described in
section 3.1.4.2.a of this appendix for cooling minimum air volume
rate.
b. For a ducted blower coil system with a constant-air-volume
indoor blower, conduct the EV Test at an external static pressure
that does not cause an automatic shutdown of the indoor blower or
air volume rate variation QVar, defined in section 3.1.4.1.1.b of
this appendix, greater than 10 percent, while being as close to,
but not less than the target minimum external static pressure.
Additional test steps as described in section 3.3(e) of this
appendix are required if the measured external static pressure
exceeds the target value by more than 0.03 inches of water.
c. For non-ducted units, the cooling intermediate air volume
rate is the air volume rate that results when the unit operates at
an external static pressure of zero inches of water and at the fan
speed selected by the controls of the unit for the EV Test
conditions.
3.1.4.4 Heating Full-Load Air Volume Rate 3.1.4.4.1. Ducted Heat
Pumps Where the Heating and Cooling Full-Load Air Volume Rates Are
the Same
a. Use the Cooling full-load air volume rate as the heating
full-load air volume rate for:
(1) Ducted blower coil system heat pumps that do not have a
constant-air-volume indoor blower, and that operate at the same
airflow-control setting during both the A (or A2) and the H1 (or
H12) Tests;
(2) Ducted blower coil system heat pumps with constant-air-flow
indoor blowers that provide the same air flow for the A (or A2) and
the H1 (or H12) Tests; and
(3) Ducted heat pumps that are tested with a coil-only indoor
unit (except two-capacity northern heat pumps that are tested only
at low capacity cooling - see section 3.1.4.4.2 of this
appendix).
b. For heat pumps that meet the above criteria “1” and “3,” no
minimum requirements apply to the measured external or internal,
respectively, static pressure. Use the final indoor blower control
settings as determined when setting the Cooling full-load air
volume rate, and readjust the exhaust fan of the airflow measuring
apparatus if necessary to reset to the cooling full-load air volume
obtained in section 3.1.4.1 of this appendix. For heat pumps that
meet the above criterion “2,” test at an external static pressure
that does not cause an automatic shutdown of the indoor blower or
air volume rate variation QVar, defined in section 3.1.4.1.1.b of
this appendix, greater than 10 percent, while being as close to,
but not less than, the same Table 4 minimum external static
pressure as was specified for the A (or A2) cooling mode test.
Additional test steps as described in section 3.9.1(c) of this
appendix are required if the measured external static pressure
exceeds the target value by more than 0.03 inches of water.
3.1.4.4.2. Ducted Heat Pumps Where the Heating and Cooling
Full-Load Air Volume Rates Are Different Due to Changes in Indoor
Blower Operation, i.e. Speed Adjustment by the System
Controls
Identify the certified heating full-load air volume rate and
certified instructions for setting fan speed or controls. If there
is no certified heating full-load air volume rate, use the final
indoor blower control settings as determined when setting the
cooling full-load air volume rate, and readjust the exhaust fan of
the airflow measuring apparatus if necessary to reset to the
cooling full load air volume obtained in section 3.1.4.1 of this
appendix. Otherwise, calculate target minimum external static
pressure as described in section 3.1.4.2 of this appendix and set
the air volume rate as follows.
a. For ducted blower coil system heat pumps that do not have a
constant-air-volume indoor blower, adjust for external static
pressure as described in section 3.1.4.2.a of this appendix for
cooling minimum air volume rate.
b. For ducted heat pumps tested with constant-air-volume indoor
blowers installed, conduct all tests that specify the heating
full-load air volume rate at an external static pressure that does
not cause an automatic shutdown of the indoor blower or air volume
rate variation QVar, defined in section 3.1.4.1.1.b of this
appendix, greater than 10 percent, while being as close to, but not
less than the target minimum external static pressure. Additional
test steps as described in section 3.9.1(c) of this appendix are
required if the measured external static pressure exceeds the
target value by more than 0.03 inches of water.
c. When testing ducted, two-capacity blower coil system northern
heat pumps (see section 1.2 of this appendix, Definitions), use the
appropriate approach of the above two cases. For coil-only system
northern heat pumps, the heating full-load air volume rate is the
lesser of the rate specified by the manufacturer in the
installation instructions included with the unit or 133 percent of
the cooling full-load air volume rate. For this latter case, obtain
the heating full-load air volume rate regardless of the pressure
drop across the indoor coil assembly.
d. For ducted systems having multiple indoor blowers within a
single indoor section, obtain the heating full-load air volume rate
using the same “on” indoor blowers as used for the Cooling
full-load air volume rate. Using the target external static
pressure and the certified air volume rates, follow the procedures
as described in section 3.1.4.4.2.a of this appendix if the indoor
blowers are not constant-air-volume indoor blowers or as described
in section 3.1.4.4.2.b of this appendix if the indoor blowers are
constant-air-volume indoor blowers. The sum of the individual “on”
indoor blowers' air volume rates is the heating full load air
volume rate for the system.
3.1.4.4.3. Ducted Heating-Only Heat Pumps
Identify the certified heating full-load air volume rate and
certified instructions for setting fan speed or controls. If there
is no certified heating full-load air volume rate, use a value
equal to the certified heating capacity of the unit times 400 scfm
per 12,000 Btu/h. If there are no instructions for setting fan
speed or controls, use the as-shipped settings.
a. For all ducted heating-only blower coil system heat pumps,
except those having a constant-air-volume-rate indoor blower.
Conduct the following steps only during the first test, the H1 or
H12 Test:
Step (1) Adjust the exhaust fan of the airflow measuring
apparatus to achieve the certified heating full-load air volume
rate.
Step (2) Measure the external static pressure.
Step (3) If this pressure is equal to or greater than the Table
4 minimum external static pressure that applies given the
heating-only heat pump's rated heating capacity, the pressure
requirement is satisfied; proceed to step 7 of this section. If
this pressure is not equal to or greater than the applicable Table
4 minimum external static pressure, proceed to step 4 of this
section;
Step (4) Increase the external static pressure by adjusting the
exhaust fan of the airflow measuring apparatus until either (i) the
pressure is equal to the applicable Table 4 minimum external static
pressure or (ii) the measured air volume rate equals 90 percent or
less of the heating full-load air volume rate, whichever occurs
first;
Step (5) If the conditions of step 4(i) of this section occur
first, the pressure requirement is satisfied; proceed to step 7 of
this section. If the conditions of step 4(ii) of this section occur
first, proceed to step 6 of this section;
Step (6) Make an incremental change to the setup of the indoor
blower (e.g., next highest fan motor pin setting, next
highest fan motor speed) and repeat the evaluation process
beginning above, at step 1 of this section. If the indoor blower
setup cannot be further changed, increase the external static
pressure by adjusting the exhaust fan of the airflow measuring
apparatus until it equals the applicable Table 4 minimum external
static pressure; proceed to step 7 of this section;
Step (7) The airflow constraints have been satisfied. Use the
measured air volume rate as the heating full-load air volume rate.
Use the final fan speed or control settings for all tests that use
the heating full-load air volume rate.
b. For ducted heating-only blower coil system heat pumps having
a constant-air-volume-rate indoor blower. For all tests that
specify the heating full-load air volume rate, obtain an external
static pressure that does not cause an automatic shutdown of the
indoor blower or air volume rate variation QVar, defined in section
3.1.4.1.1.b of this appendix, greater than 10 percent, while being
as close to, but not less than, the applicable Table 4 minimum.
Additional test steps as described in section 3.9.1(c) of this
appendix are required if the measured external static pressure
exceeds the target value by more than 0.03 inches of water.
c. For ducted heating-only coil-only system heat pumps in the H1
or H12 Test, (exclusively), the pressure drop across the indoor
coil assembly must not exceed 0.30 inches of water. If this
pressure drop is exceeded, reduce the air volume rate until the
measured pressure drop equals the specified maximum. Use this
reduced air volume rate for all tests that require the heating
full-load air volume rate.
3.1.4.4.4. Non-Ducted Heat Pumps, Including Non-Ducted Heating-Only
Heat Pumps
For non-ducted heat pumps, the heating full-load air volume rate
is the air volume rate that results during each test when the unit
operates at an external static pressure of zero inches of
water.
3.1.4.5 Heating Minimum Air Volume Rate 3.1.4.5.1. Ducted Heat
Pumps Where the Heating and Cooling Minimum Air Volume Rates Are
the Same
a. Use the cooling minimum air volume rate as the heating
minimum air volume rate for:
(1) Ducted blower coil system heat pumps that do not have a
constant-air-volume indoor blower, and that operate at the same
airflow-control setting during both the A1 and the H11 tests;
(2) Ducted blower coil system heat pumps with constant-air-flow
indoor blowers installed that provide the same air flow for the A1
and the H11 Tests; and
(3) Ducted coil-only system heat pumps.
b. For heat pumps that meet the above criteria “1” and “3,” no
minimum requirements apply to the measured external or internal,
respectively, static pressure. Use the final indoor blower control
settings as determined when setting the cooling minimum air volume
rate, and readjust the exhaust fan of the airflow measuring
apparatus if necessary to reset to the cooling minimum air volume
rate obtained in section 3.1.4.2 of this appendix. For heat pumps
that meet the above criterion “2,” test at an external static
pressure that does not cause an automatic shutdown of the indoor
blower or air volume rate variation QVar, defined in section
3.1.4.1.1.b of this appendix, greater than 10 percent, while being
as close to, but not less than, the same target minimum external
static pressure as was specified for the A1 cooling mode test.
Additional test steps as described in section 3.9.1(c) of this
appendix are required if the measured external static pressure
exceeds the target value by more than 0.03 inches of water.
3.1.4.5.2. Ducted Heat Pumps Where the Heating and Cooling Minimum
Air Volume Rates Are Different Due to Changes in Indoor Blower
Operation, i.e. Speed Adjustment by the System Controls
Identify the certified heating minimum air volume rate and
certified instructions for setting fan speed or controls. If there
is no certified heating minimum air volume rate, use the final
indoor blower control settings as determined when setting the
cooling minimum air volume rate, and readjust the exhaust fan of
the airflow measuring apparatus if necessary to reset to the
cooling minimum air volume obtained in section 3.1.4.2 of this
appendix. Otherwise, calculate the target minimum external static
pressure as described in section 3.1.4.2 of this appendix.
a. For ducted blower coil system heat pumps that do not have a
constant-air-volume indoor blower, adjust for external static
pressure as described in section 3.1.4.2.a of this appendix for
cooling minimum air volume rate.
b. For ducted heat pumps tested with constant-air-volume indoor
blowers installed, conduct all tests that specify the heating
minimum air volume rate - (i.e., the H01, H11, H21, and H31
Tests) - at an external static pressure that does not cause an
automatic shutdown of the indoor blower while being as close to,
but not less than the air volume rate variation QVar, defined in
section 3.1.4.1.1.b of this appendix, greater than 10 percent,
while being as close to, but not less than the target minimum
external static pressure. Additional test steps as described in
section 3.9.1.c of this appendix are required if the measured
external static pressure exceeds the target value by more than 0.03
inches of water.
c. For ducted two-capacity blower coil system northern heat
pumps, use the appropriate approach of the above two cases.
d. For ducted two-capacity coil-only system heat pumps, use the
cooling minimum air volume rate as the heating minimum air volume
rate. For ducted two-capacity coil-only system northern heat pumps,
use the cooling full-load air volume rate as the heating minimum
air volume rate. For ducted two-capacity heating-only coil-only
system heat pumps, the heating minimum air volume rate is the
higher of the rate specified by the manufacturer in the test setup
instructions included with the unit or 75 percent of the heating
full-load air volume rate. During the laboratory tests on a
coil-only system, obtain the heating minimum air volume rate
without regard to the pressure drop across the indoor coil
assembly.
e. For non-ducted heat pumps, the heating minimum air volume
rate is the air volume rate that results during each test when the
unit operates at an external static pressure of zero inches of
water and at the indoor blower setting used at low compressor
capacity (two-capacity system) or minimum compressor speed
(variable-speed system). For units having a single-speed compressor
and a variable-speed, variable-air-volume-rate indoor blower, use
the lowest fan setting allowed for heating.
f. For ducted systems with multiple indoor blowers within a
single indoor section, obtain the heating minimum air volume rate
using the same “on” indoor blowers as used for the cooling minimum
air volume rate. Using the target external static pressure and the
certified air volume rates, follow the procedures as described in
section 3.1.4.5.2.a of this appendix if the indoor blowers are not
constant-air-volume indoor blowers or as described in section
3.1.4.5.2.b of this appendix if the indoor blowers are
constant-air-volume indoor blowers. The sum of the individual “on”
indoor blowers' air volume rates is the heating full-load air
volume rate for the system.
3.1.4.6 Heating Intermediate Air Volume Rate
Identify the certified heating intermediate air volume rate and
certified instructions for setting fan speed or controls. If there
is no certified heating intermediate air volume rate, use the final
indoor blower control settings as determined when setting the
heating full-load air volume rate, and readjust the exhaust fan of
the airflow measuring apparatus if necessary to reset to the
cooling full load air volume obtained in section 3.1.4.2 of this
appendix. Calculate the target minimum external static pressure as
described in section 3.1.4.2 of this appendix.
a. For ducted blower coil system heat pumps that do not have a
constant-air-volume indoor blower, adjust for external static
pressure as described in section 3.1.4.2.a of this appendix for
cooling minimum air volume rate.
b. For ducted heat pumps tested with constant-air-volume indoor
blowers installed, conduct the H2V Test at an external static
pressure that does not cause an automatic shutdown of the indoor
blower or air volume rate variation QVar, defined in section
3.1.4.1.1.b of this appendix, greater than 10 percent, while being
as close to, but not less than the target minimum external static
pressure. Additional test steps as described in section 3.9.1(c) of
this appendix are required if the measured external static pressure
exceeds the target value by more than 0.03 inches of water.
c. For non-ducted heat pumps, the heating intermediate air
volume rate is the air volume rate that results when the heat pump
operates at an external static pressure of zero inches of water and
at the fan speed selected by the controls of the unit for the H2V
Test conditions.
3.1.4.7 Heating Nominal Air Volume Rate
The manufacturer must specify the heating nominal air volume
rate and the instructions for setting fan speed or controls.
Calculate target minimum external static pressure as described in
section 3.1.4.2 of this appendix. Make adjustments as described in
section 3.1.4.6 of this appendix for heating intermediate air
volume rate so that the target minimum external static pressure is
met or exceeded.
3.1.5 Indoor Test Room Requirement When the Air Surrounding the
Indoor Unit Is Not Supplied From the Same Source as the Air
Entering the Indoor Unit
If using a test set-up where air is ducted directly from the air
reconditioning apparatus to the indoor coil inlet (see Figure 2,
Loop Air-Enthalpy Test Method Arrangement, of ANSI/ASHRAE 37-2009
(incorporated by reference, see § 430.3)), maintain the dry bulb
temperature within the test room within ±5.0 °F of the applicable
sections 3.2 and 3.6 dry bulb temperature test condition for the
air entering the indoor unit. Dew point shall be within 2 °F of the
required inlet conditions.
3.1.6 Air Volume Rate Calculations
For all steady-state tests and for frost accumulation (H2, H21,
H22, H2V) tests, calculate the air volume rate through the indoor
coil as specified in sections 7.7.2.1 and 7.7.2.2 of ANSI/ASHRAE
37-2009. When using the outdoor air enthalpy method, follow
sections 7.7.2.1 and 7.7.2.2 of ANSI/ASHRAE 37-2009 to calculate
the air volume rate through the outdoor coil. To express air volume
rates in terms of standard air, use:
Where: V
s = air volume rate of standard (dry) air, (ft 3/min)da V mx = air
volume rate of the air-water vapor mixture, (ft 3/min)mx vn′ =
specific volume of air-water vapor mixture at the nozzle, ft 3 per
lbm of the air-water vapor mixture Wn = humidity ratio at the
nozzle, lbm of water vapor per lbm of dry air 0.075 = the density
associated with standard (dry) air, (lbm/ft 3) vn = specific volume
of the dry air portion of the mixture evaluated at the dry-bulb
temperature, vapor content, and barometric pressure existing at the
nozzle, ft 3 per lbm of dry air. Note:
In the first printing of ANSI/ASHRAE 37-2009, the second IP
equation for Qmi should read
3.1.7
Test Sequence
Before making test measurements used to calculate performance,
operate the equipment for the “break-in” period specified in the
certification report, which may not exceed 20 hours. Each
compressor of the unit must undergo this “break-in” period. When
testing a ducted unit (except if a heating-only heat pump), conduct
the A or A2 Test first to establish the cooling full-load air
volume rate. For ducted heat pumps where the heating and cooling
full-load air volume rates are different, make the first heating
mode test one that requires the heating full-load air volume rate.
For ducted heating-only heat pumps, conduct the H1 or H12 Test
first to establish the heating full-load air volume rate. When
conducting a cyclic test, always conduct it immediately after the
steady-state test that requires the same test conditions. For
variable-speed systems, the first test using the cooling minimum
air volume rate should precede the EV Test, and the first test
using the heating minimum air volume rate must precede the H2V
Test. The test laboratory makes all other decisions on the test
sequence.
3.1.8 Requirement for the Air Temperature Distribution Leaving the
Indoor Coil
For at least the first cooling mode test and the first heating
mode test, monitor the temperature distribution of the air leaving
the indoor coil using the grid of individual sensors described in
sections 2.5 and 2.5.4 of this appendix. For the 30-minute data
collection interval used to determine capacity, the maximum spread
among the outlet dry bulb temperatures from any data sampling must
not exceed 1.5 °F. Install the mixing devices described in section
2.5.4.2 of this appendix to minimize the temperature spread.
3.1.9 Requirement for the Air Temperature Distribution Entering the
Outdoor Coil
Monitor the temperatures of the air entering the outdoor coil
using air sampling devices and/or temperature sensor grids,
maintaining the required tolerances, if applicable, as described in
section 2.11 of this appendix.
3.1.10 Control of Auxiliary Resistive Heating Elements
Except as noted, disable heat pump resistance elements used for
heating indoor air at all times, including during defrost cycles
and if they are normally regulated by a heat comfort controller.
For heat pumps equipped with a heat comfort controller, enable the
heat pump resistance elements only during the below-described,
short test. For single-speed heat pumps covered under section 3.6.1
of this appendix, the short test follows the H1 or, if conducted,
the H1C Test. For two-capacity heat pumps and heat pumps covered
under section 3.6.2 of this appendix, the short test follows the
H12 Test. Set the heat comfort controller to provide the maximum
supply air temperature. With the heat pump operating and while
maintaining the heating full-load air volume rate, measure the
temperature of the air leaving the indoor-side beginning 5 minutes
after activating the heat comfort controller. Sample the outlet
dry-bulb temperature at regular intervals that span 5 minutes or
less. Collect data for 10 minutes, obtaining at least 3 samples.
Calculate the average outlet temperature over the 10-minute
interval, TCC.
3.2 Cooling Mode Tests for Different Types of Air Conditioners and
Heat Pumps 3.2.1 Tests for a System Having a Single-Speed
Compressor and Fixed Cooling Air Volume Rate
This set of tests is for single-speed-compressor units that do
not have a cooling minimum air volume rate or a cooling
intermediate air volume rate that is different than the cooling
full load air volume rate. Conduct two steady-state wet coil tests,
the A and B Tests. Use the two optional dry-coil tests, the
steady-state C Test and the cyclic D Test, to determine the cooling
mode cyclic degradation coefficient, CD c. If the two optional
tests are conducted but yield a tested CD c that exceeds the
default CD c or if the two optional tests are not conducted, assign
CD c the default value of 0.25 (for outdoor units with no match) or
0.20 (for all other systems). Table 5 specifies test conditions for
these four tests.
Table 5 - Cooling Mode Test Conditions for
Units Having a Single-Speed Compressor and a Fixed Cooling Air
Volume Rate
Test
description
Air entering
indoor unit
temperature ( °F)
Air entering
outdoor unit
temperature ( °F)
Cooling air
volume rate
Dry bulb
Wet bulb
Dry bulb
Wet bulb
A Test - required
(steady, wet coil)
80
67
95
1 75
Cooling full-load.
2
B Test - required
(steady, wet coil)
80
67
82
1 65
Cooling full-load.
2
C Test - optional
(steady, dry coil)
80
( 3)
82
Cooling full-load.
2
D Test - optional
(cyclic, dry coil)
80
( 3)
82
( 4).
1 The specified test condition
only applies if the unit rejects condensate to the outdoor
coil.
2 Defined in section 3.1.4.1 of
this appendix.
3 The entering air must have a
low enough moisture content so no condensate forms on the indoor
coil. (It is recommended that an indoor wet-bulb temperature of 57
°F or less be used.)
4 Maintain the airflow nozzles
static pressure difference or velocity pressure during the ON
period at the same pressure difference or velocity pressure as
measured during the C Test.
3.2.2 Tests for a Unit Having a Single-Speed Compressor Where the
Indoor Section Uses a Single Variable-Speed Variable-Air-Volume
Rate Indoor Blower or Multiple Indoor Blowers 3.2.2.1 Indoor Blower
Capacity Modulation That Correlates With the Outdoor Dry Bulb
Temperature or Systems With a Single Indoor Coil but Multiple
Indoor Blowers
Conduct four steady-state wet coil tests: The A2, A1, B2, and B1
tests. Use the two optional dry-coil tests, the steady-state C1
test and the cyclic D1 test, to determine the cooling mode cyclic
degradation coefficient, CD c. If the two optional tests are
conducted but yield a tested CDc that exceeds the default CDc or if
the two optional tests are not conducted, assign CDc the default
value of 0.20.
3.2.2.2 Indoor Blower Capacity Modulation Based on Adjusting the
Sensible to Total (S/T) Cooling Capacity Ratio
The testing requirements are the same as specified in section
3.2.1 of this appendix and Table 5. Use a cooling full-load air
volume rate that represents a normal installation. If performed,
conduct the steady-state C Test and the cyclic D Test with the unit
operating in the same S/T capacity control mode as used for the B
Test.
Table 6 - Cooling Mode Test Conditions for
Units With a Single-Speed Compressor That Meet the Section 3.2.2.1
Indoor Unit Requirements
Test
description
Air entering
indoor unit
temperature ( °F)
Air entering
outdoor unit
temperature ( °F)
Cooling air
volume rate
Dry bulb
Wet bulb
Dry bulb
Wet bulb
A2 Test - required
(steady, wet coil)
80
67
95
1 75
Cooling full-load.
2
A1 Test - required
(steady, wet coil)
80
67
95
1 75
Cooling minimum.
3
B2 Test - required
(steady, wet coil)
80
67
82
1 65
Cooling full-load.
2
B1 Test - required
(steady, wet coil)
80
67
82
1 65
Cooling minimum.
3
C1 Test
4 - optional (steady, dry coil)
80
( 4)
82
Cooling minimum.
3
D1 Test
4 - optional (cyclic, dry coil)
80
( 4)
82
( 5).
1 The specified test condition
only applies if the unit rejects condensate to the outdoor
coil.
2 Defined in section 3.1.4.1 of
this appendix.
3 Defined in section 3.1.4.2 of
this appendix.
4 The entering air must have a
low enough moisture content so no condensate forms on the indoor
coil. (It is recommended that an indoor wet-bulb temperature of 5
°F or less be used.)
5 Maintain the airflow nozzles
static pressure difference or velocity pressure during the ON
period at the same pressure difference or velocity pressure as
measured during the C1 Test.
3.2.3 Tests for a Unit Having a Two-Capacity Compressor (See
Section 1.2 of This Appendix, Definitions)
a. Conduct four steady-state wet coil tests: the A2, B2, B1, and
F1 Tests. Use the two optional dry-coil tests, the steady-state C1
Test and the cyclic D1 Test, to determine the cooling-mode
cyclic-degradation coefficient, CD c. If the two optional tests are
conducted but yield a tested CDc that exceeds the default CDc or if
the two optional tests are not conducted, assign CDc the default
value of 0.20. Table 6 specifies test conditions for these six
tests.
b. For units having a variable speed indoor blower that is
modulated to adjust the sensible to total (S/T) cooling capacity
ratio, use cooling full-load and cooling minimum air volume rates
that represent a normal installation. Additionally, if conducting
the dry-coil tests, operate the unit in the same S/T capacity
control mode as used for the B1 Test.
c. Test two-capacity, northern heat pumps (see section 1.2 of
this appendix, Definitions) in the same way as a single speed heat
pump with the unit operating exclusively at low compressor capacity
(see section 3.2.1 of this appendix and Table 5).
d. If a two-capacity air conditioner or heat pump locks out
low-capacity operation at higher outdoor temperatures, then use the
two dry-coil tests, the steady-state C2 Test and the cyclic D2
Test, to determine the cooling-mode cyclic-degradation coefficient
that only applies to on/off cycling from high capacity, CD c(k=2).
If the two optional tests are conducted but yield a tested CD c (k
= 2) that exceeds the default CD c (k = 2) or if the two optional
tests are not conducted, assign CD c (k = 2) the default value. The
default CD c(k=2) is the same value as determined or assigned for
the low-capacity cyclic-degradation coefficient, CD c [or
equivalently, CD c(k=1)].
Table 7 - Cooling Mode Test Conditions for
Units Having a Two-Capacity Compressor
Test
description
Air entering
indoor unit temperature ( °F)
Air entering
outdoor unit temperature ( °F)
Compressor
capacity
Cooling air
volume rate
Dry bulb
Wet bulb
Dry bulb
Wet bulb
A2 Test - required
(steady, wet coil)
80
67
95
1 75
High
Cooling Full-Load.
2
B2 Test - required
(steady, wet coil)
80
67
82
1 65
High
Cooling Full-Load.
2
B1 Test - required
(steady, wet coil)
80
67
82
1 65
Low
Cooling Minimum.
3
C2 Test - optional
(steady, dry-coil)
80
( 4)
82
High
Cooling Full-Load.
2
D2 Test - optional
(cyclic, dry-coil)
80
( 4)
82
High
( 5).
C1 Test - optional
(steady, dry-coil)
80
( 4)
82
Low
Cooling Minimum.
3
D1 Test - optional
(cyclic, dry-coil)
80
( 4)
82
Low
( 6).
F1 Test - required
(steady, wet coil)
80
67
67
1 53.5
Low
Cooling Minimum.
3
1 The specified test condition
only applies if the unit rejects condensate to the outdoor
coil.
2 Defined in section 3.1.4.1 of
this appendix.
3 Defined in section 3.1.4.2 of
this appendix.
4 The entering air must have a
low enough moisture content so no condensate forms on the indoor
coil. DOE recommends using an indoor air wet-bulb temperature of 57
°F or less.
5 Maintain the airflow nozzle(s)
static pressure difference or velocity pressure during the ON
period at the same pressure or velocity as measured during the C2
Test.
6 Maintain the airflow nozzle(s)
static pressure difference or velocity pressure during the ON
period at the same pressure or velocity as measured during the C1
Test.
3.2.4 Tests for a Unit Having a Variable-Speed Compressor
a. Conduct five steady-state wet coil tests: The A2, EV, B2, B1,
and F1 Tests. Use the two optional dry-coil tests, the steady-state
G1 Test and the cyclic I1 Test, to determine the cooling mode
cyclic degradation coefficient, CD c. If the two optional tests are
conducted but yield a tested CDc that exceeds the default CDc or if
the two optional tests are not conducted, assign CDc the default
value of 0.25. Table 8 specifies test conditions for these seven
tests. The compressor shall operate at the same cooling full speed,
measured by RPM or power input frequency (Hz), for both the A2 and
B2 tests. The compressor shall operate at the same cooling minimum
speed, measured by RPM or power input frequency (Hz), for the B1,
F1, G1, and I1 tests. Determine the cooling intermediate compressor
speed cited in Table 8 using:
where a
tolerance of plus 5 percent or the next higher inverter frequency
step from that calculated is allowed.
b. For units that modulate the indoor blower speed to adjust the
sensible to total (S/T) cooling capacity ratio, use cooling
full-load, cooling intermediate, and cooling minimum air volume
rates that represent a normal installation. Additionally, if
conducting the dry-coil tests, operate the unit in the same S/T
capacity control mode as used for the F1 Test.
c. For multiple-split air conditioners and heat pumps (except
where noted), the following procedures supersede the above
requirements: For all Table 8 tests specified for a minimum
compressor speed, at least one indoor unit must be turned off. The
manufacturer shall designate the particular indoor unit(s) that is
turned off. The manufacturer must also specify the compressor speed
used for the Table 8 EV Test, a cooling-mode intermediate
compressor speed that falls within 1/4 and 3/4 of the difference
between the full and minimum cooling-mode speeds. The manufacturer
should prescribe an intermediate speed that is expected to yield
the highest EER for the given EV Test conditions and bracketed
compressor speed range. The manufacturer can designate that one or
more indoor units are turned off for the EV Test.
Table 8 - Cooling Mode Test Condition for
Units Having a Variable-Speed Compressor
Test
description
Air entering
indoor unit
temperature ( °F)
Air entering
outdoor unit
temperature ( °F)
Compressor
speed
Cooling air
volume rate
Dry bulb
Wet bulb
Dry bulb
Wet bulb
A2 Test - required
(steady, wet coil)
80
67
95
1 75
Cooling Full
Cooling Full-Load.
2
B2 Test - required
(steady, wet coil)
80
67
82
1 65
Cooling Full
Cooling Full-Load.
2
EV Test - required
(steady, wet coil)
80
67
87
1 69
Cooling Intermediate
Cooling Intermediate.
3
B1 Test - required
(steady, wet coil)
80
67
82
1 65
Cooling Minimum
Cooling Minimum.
4
F1 Test - required
(steady, wet coil)
80
67
67
1 53.5
Cooling Minimum
Cooling Minimum.
4
G1 Test
5 - optional (steady, dry-coil)
80
( 6)
67
Cooling Minimum
Cooling Minimum.
4
I1 Test
5 - optional (cyclic, dry-coil)
80
( 6)
67
Cooling Minimum
( 6).
1 The specified test condition
only applies if the unit rejects condensate to the outdoor
coil.
2 Defined in section 3.1.4.1 of
this appendix.
3 Defined in section 3.1.4.3 of
this appendix.
4 Defined in section 3.1.4.2 of
this appendix.
5 The entering air must have a
low enough moisture content so no condensate forms on the indoor
coil. DOE recommends using an indoor air wet bulb temperature of 57
°F or less.
6 Maintain the airflow nozzle(s)
static pressure difference or velocity pressure during the ON
period at the same pressure difference or velocity pressure as
measured during the G1 Test.
3.2.5 Cooling Mode Tests for Northern Heat Pumps With
Triple-Capacity Compressors
Test triple-capacity, northern heat pumps for the cooling mode
in the same way as specified in section 3.2.3 of this appendix for
units having a two-capacity compressor.
3.2.6 Tests for an Air Conditioner or Heat Pump Having a Single
Indoor Unit Having Multiple Indoor Blowers and Offering Two Stages
of Compressor Modulation
Conduct the cooling mode tests specified in section 3.2.3 of
this appendix.
3.3 Test Procedures for Steady-State Wet Coil Cooling Mode Tests
(the A, A2, A1, B, B2, B1, EV, and F1 Tests)
a. For the pretest interval, operate the test room
reconditioning apparatus and the unit to be tested until
maintaining equilibrium conditions for at least 30 minutes at the
specified section 3.2 test conditions. Use the exhaust fan of the
airflow measuring apparatus and, if installed, the indoor blower of
the test unit to obtain and then maintain the indoor air volume
rate and/or external static pressure specified for the particular
test. Continuously record (see section 1.2 of this appendix,
Definitions):
(1) The dry-bulb temperature of the air entering the indoor
coil,
(2) The water vapor content of the air entering the indoor
coil,
(3) The dry-bulb temperature of the air entering the outdoor
coil, and
(4) For the section 2.2.4 of this appendix cases where its
control is required, the water vapor content of the air entering
the outdoor coil.
Refer to section 3.11 of this appendix for additional
requirements that depend on the selected secondary test method.
b. After satisfying the pretest equilibrium requirements, make
the measurements specified in Table 3 of ANSI/ASHRAE 37-2009 for
the indoor air enthalpy method and the user-selected secondary
method. Make said Table 3 measurements at equal intervals that span
5 minutes or less. Continue data sampling until reaching a
30-minute period (e.g., seven consecutive 5-minute samples)
where the test tolerances specified in Table 9 are satisfied. For
those continuously recorded parameters, use the entire data set
from the 30-minute interval to evaluate Table 9 compliance.
Determine the average electrical power consumption of the air
conditioner or heat pump over the same 30-minute interval.
c. Calculate indoor-side total cooling capacity and sensible
cooling capacity as specified in sections 7.3.3.1 and 7.3.3.3 of
ANSI/ASHRAE 37-2009 (incorporated by reference, see § 430.3). To
calculate capacity, use the averages of the measurements
(e.g. inlet and outlet dry bulb and wet bulb temperatures
measured at the psychrometers) that are continuously recorded for
the same 30-minute interval used as described above to evaluate
compliance with test tolerances. Do not adjust the parameters used
in calculating capacity for the permitted variations in test
conditions. Evaluate air enthalpies based on the measured
barometric pressure. Use the values of the specific heat of air
given in section 7.3.3.1 of ANSI/ASHRAE 37-2009 (incorporated by
reference, see § 430.3) for calculation of the sensible cooling
capacities. Assign the average total space cooling capacity,
average sensible cooling capacity, and electrical power consumption
over the 30-minute data collection interval to the variables Q c
k(T), Q sc k(T) and E c k(T), respectively. For these three
variables, replace the “T” with the nominal outdoor temperature at
which the test was conducted. The superscript k is used only when
testing multi-capacity units.
Use the superscript k=2 to denote a test with the unit operating
at high capacity or full speed, k=1 to denote low capacity or
minimum speed, and k=v to denote the intermediate speed.
d. For coil-only system tests, decrease Q c k(T) by
and increase E c k(T) by,
where V s
is the average measured indoor air volume rate expressed in units
of cubic feet per minute of standard air (scfm).
Table 9 - Test Operating and Test Condition
Tolerances for Section 3.3 Steady-State Wet Coil Cooling Mode Tests
and Section 3.4 Dry Coil Cooling Mode Tests
Test operating
tolerance 1
Test condition
tolerance 1
Indoor dry-bulb,
°F
Entering
temperature
2.0
0.5
Leaving
temperature
2.0
Indoor wet-bulb,
°F
Entering
temperature
1.0
2 0.3
Leaving
temperature
2 1.0
Outdoor dry-bulb,
°F
Entering
temperature
2.0
0.5
Leaving
temperature
3 2.0
Outdoor wet-bulb,
°F
Entering
temperature
1.0
4 0.3
Leaving
temperature
3 1.0
External
resistance to airflow, inches of water
0.05
5 0.02
Electrical
voltage, % of rdg.
2.0
1.5
Nozzle pressure
drop, % of rdg.
2.0
1 See section 1.2 of this
appendix, Definitions.
2 Only applies during wet coil
tests; does not apply during steady-state, dry coil cooling mode
tests.
3 Only applies when using the
outdoor air enthalpy method.
4 Only applies during wet coil
cooling mode tests where the unit rejects condensate to the outdoor
coil.
5 Only applies when testing
non-ducted units.
e. For air conditioners and heat pumps having a
constant-air-volume-rate indoor blower, the five additional steps
listed below are required if the average of the measured external
static pressures exceeds the applicable sections 3.1.4 minimum (or
target) external static pressure (ΔPmin) by 0.03 inches of water or
more.
(1) Measure the average power consumption of the indoor blower
motor (E fan,1) and record the corresponding external static
pressure (ΔP1) during or immediately following the 30-minute
interval used for determining capacity.
(2) After completing the 30-minute interval and while
maintaining the same test conditions, adjust the exhaust fan of the
airflow measuring apparatus until the external static pressure
increases to approximately ΔP1 + (ΔP1−ΔPmin).
(3) After re-establishing steady readings of the fan motor power
and external static pressure, determine average values for the
indoor blower power (E fan,2) and the external static pressure
(ΔP2) by making measurements over a 5-minute interval.
(4) Approximate the average power consumption of the indoor
blower motor at ΔPmin using linear extrapolation:
(5) Increase the total space cooling capacity, Q c k(T), by the
quantity (E fan,1−E fan,min), when expressed on a Btu/h basis.
Decrease the total electrical power, E c k(T), by the same fan
power difference, now expressed in watts.
3.4 Test Procedures for the Steady-State Dry-Coil Cooling-Mode
Tests (the C, C1, C2, and G1 Tests)
a. Except for the modifications noted in this section, conduct
the steady-state dry coil cooling mode tests as specified in
section 3.3 of this appendix for wet coil tests. Prior to recording
data during the steady-state dry coil test, operate the unit at
least one hour after achieving dry coil conditions. Drain the drain
pan and plug the drain opening. Thereafter, the drain pan should
remain completely dry.
b. Denote the resulting total space cooling capacity and
electrical power derived from the test as Q ss,dry and E ss,dry.
With regard to a section 3.3 deviation, do not adjust Q ss,dry for
duct losses (i.e., do not apply section 7.3.3.3 of
ANSI/ASHRAE 37-2009). In preparing for the section 3.5 cyclic tests
of this appendix, record the average indoor-side air volume rate, V
, specific heat of the air, Cp,a (expressed on dry air basis),
specific volume of the air at the nozzles, v′n, humidity ratio at
the nozzles, Wn, and either pressure difference or velocity
pressure for the flow nozzles. For units having a variable-speed
indoor blower (that provides either a constant or variable air
volume rate) that will or may be tested during the cyclic dry coil
cooling mode test with the indoor blower turned off (see section
3.5 of this appendix), include the electrical power used by the
indoor blower motor among the recorded parameters from the
30-minute test.
c. If the temperature sensors used to provide the primary
measurement of the indoor-side dry bulb temperature difference
during the steady-state dry-coil test and the subsequent cyclic
dry-coil test are different, include measurements of the latter
sensors among the regularly sampled data. Beginning at the start of
the 30-minute data collection period, measure and compute the
indoor-side air dry-bulb temperature difference using both sets of
instrumentation, ΔT (Set SS) and ΔT (Set CYC), for each equally
spaced data sample. If using a consistent data sampling rate that
is less than 1 minute, calculate and record minutely averages for
the two temperature differences. If using a consistent sampling
rate of one minute or more, calculate and record the two
temperature differences from each data sample. After having
recorded the seventh (i=7) set of temperature differences,
calculate the following ratio using the first seven sets of
values:
Each time a subsequent set of temperature differences is
recorded (if sampling more frequently than every 5 minutes),
calculate FCD using the most recent seven sets of values. Continue
these calculations until the 30-minute period is completed or until
a value for FCD is calculated that falls outside the allowable
range of 0.94-1.06. If the latter occurs, immediately suspend the
test and identify the cause for the disparity in the two
temperature difference measurements. Recalibration of one or both
sets of instrumentation may be required. If all the values for FCD
are within the allowable range, save the final value of the ratio
from the 30-minute test as FCD*. If the temperature sensors used to
provide the primary measurement of the indoor-side dry bulb
temperature difference during the steady-state dry-coil test and
the subsequent cyclic dry-coil test are the same, set FCD*= 1.
3.5 Test Procedures for the Cyclic Dry-Coil Cooling-Mode Tests (the
D, D1, D2, and I1 Tests)
After completing the steady-state dry-coil test, remove the
outdoor air enthalpy method test apparatus, if connected, and begin
manual OFF/ON cycling of the unit's compressor. The test set-up
should otherwise be identical to the set-up used during the
steady-state dry coil test. When testing heat pumps, leave the
reversing valve during the compressor OFF cycles in the same
position as used for the compressor ON cycles, unless automatically
changed by the controls of the unit. For units having a
variable-speed indoor blower, the manufacturer has the option of
electing at the outset whether to conduct the cyclic test with the
indoor blower enabled or disabled. Always revert to testing with
the indoor blower disabled if cyclic testing with the fan enabled
is unsuccessful.
a. For all cyclic tests, the measured capacity must be adjusted
for the thermal mass stored in devices and connections located
between measured points. Follow the procedure outlined in section
7.4.3.4.5 of ASHRAE 116-2010 (incorporated by reference, see §
430.3) to ensure any required measurements are taken.
b. For units having a single-speed or two-capacity compressor,
cycle the compressor OFF for 24 minutes and then ON for 6 minutes
(Δτcyc,dry = 0.5 hours). For units having a variable-speed
compressor, cycle the compressor OFF for 48 minutes and then ON for
12 minutes (Δτcyc,dry = 1.0 hours). Repeat the OFF/ON compressor
cycling pattern until the test is completed. Allow the controls of
the unit to regulate cycling of the outdoor fan. If an upturned
duct is used, measure the dry-bulb temperature at the inlet of the
device at least once every minute and ensure that its test
operating tolerance is within 1.0 °F for each compressor OFF
period.
c. Sections 3.5.1 and 3.5.2 of this appendix specify airflow
requirements through the indoor coil of ducted and non-ducted
indoor units, respectively. In all cases, use the exhaust fan of
the airflow measuring apparatus (covered under section 2.6 of this
appendix) along with the indoor blower of the unit, if installed
and operating, to approximate a step response in the indoor coil
airflow. Regulate the exhaust fan to quickly obtain and then
maintain the flow nozzle static pressure difference or velocity
pressure at the same value as was measured during the steady-state
dry coil test. The pressure difference or velocity pressure should
be within 2 percent of the value from the steady-state dry coil
test within 15 seconds after airflow initiation. For units having a
variable-speed indoor blower that ramps when cycling on and/or off,
use the exhaust fan of the airflow measuring apparatus to impose a
step response that begins at the initiation of ramp up and ends at
the termination of ramp down.
d. For units having a variable-speed indoor blower, conduct the
cyclic dry coil test using the pull-thru approach described below
if any of the following occur when testing with the fan
operating:
(1) The test unit automatically cycles off;
(2) Its blower motor reverses; or
(3) The unit operates for more than 30 seconds at an external
static pressure that is 0.1 inches of water or more higher than the
value measured during the prior steady-state test.
For the pull-thru approach, disable the indoor blower and use
the exhaust fan of the airflow measuring apparatus to generate the
specified flow nozzles static pressure difference or velocity
pressure. If the exhaust fan cannot deliver the required pressure
difference because of resistance created by the unpowered indoor
blower, temporarily remove the indoor blower.
e. Conduct three complete compressor OFF/ON cycles with the test
tolerances given in Table 10 satisfied. Calculate the degradation
coefficient CD for each complete cycle. If all three CD values are
within 0.02 of the average CD then stability has been achieved, and
the highest CD value of these three shall be used. If stability has
not been achieved, conduct additional cycles, up to a maximum of
eight cycles total, until stability has been achieved between three
consecutive cycles. Once stability has been achieved, use the
highest CD value of the three consecutive cycles that establish
stability. If stability has not been achieved after eight cycles,
use the highest CD from cycle one through cycle eight, or the
default CD, whichever is lower.
f. With regard to the Table 10 parameters, continuously record
the dry-bulb temperature of the air entering the indoor and outdoor
coils during periods when air flows through the respective coils.
Sample the water vapor content of the indoor coil inlet air at
least every 2 minutes during periods when air flows through the
coil. Record external static pressure and the air volume rate
indicator (either nozzle pressure difference or velocity pressure)
at least every minute during the interval that air flows through
the indoor coil. (These regular measurements of the airflow rate
indicator are in addition to the required measurement at 15 seconds
after flow initiation.) Sample the electrical voltage at least
every 2 minutes beginning 30 seconds after compressor start-up.
Continue until the compressor, the outdoor fan, and the indoor
blower (if it is installed and operating) cycle off.
g. For ducted units, continuously record the dry-bulb
temperature of the air entering (as noted above) and leaving the
indoor coil. Or if using a thermopile, continuously record the
difference between these two temperatures during the interval that
air flows through the indoor coil. For non-ducted units, make the
same dry-bulb temperature measurements beginning when the
compressor cycles on and ending when indoor coil airflow
ceases.
h. Integrate the electrical power over complete cycles of length
Δτcyc,dry. For ducted blower coil systems tested with the unit's
indoor blower operating for the cycling test, integrate electrical
power from indoor blower OFF to indoor blower OFF. For all other
ducted units and for non-ducted units, integrate electrical power
from compressor OFF to compressor OFF. (Some cyclic tests will use
the same data collection intervals to determine the electrical
energy and the total space cooling. For other units, terminate data
collection used to determine the electrical energy before
terminating data collection used to determine total space
cooling.)
Table 10 - Test Operating and Test
Condition Tolerances for Cyclic Dry Coil Cooling Mode Tests
Test operating tolerance
1
Test condition tolerance
1
Indoor entering
dry-bulb temperature, 2 °F
2.0
0.5
Indoor entering
wet-bulb temperature, °F
( 3)
Outdoor entering
dry-bulb temperature, 2 °F
2.0
0.5
External
resistance to airflow, 2 inches of water
0.05
Airflow nozzle
pressure difference or velocity pressure, 2 % of
reading
2.0
4 2.0
Electrical
voltage, 5 % of rdg
2.0
1.5
1 See section 1.2 of this
appendix, Definitions.
2 Applies during the interval
that air flows through the indoor (outdoor) coil except for the
first 30 seconds after flow initiation. For units having a
variable-speed indoor blower that ramps, the tolerances listed for
the external resistance to airflow apply from 30 seconds after
achieving full speed until ramp down begins.
3 Shall at no time exceed a
wet-bulb temperature that results in condensate forming on the
indoor coil.
4 The test condition shall be the
average nozzle pressure difference or velocity pressure measured
during the steady-state dry coil test.
5 Applies during the interval
when at least one of the following - the compressor, the outdoor
fan, or, if applicable, the indoor blower - are operating except
for the first 30 seconds after compressor start-up.
If the Table 10 tolerances are satisfied over the complete
cycle, record the measured electrical energy consumption as
ecyc,dry and express it in units of watt-hours. Calculate the total
space cooling delivered, qcyc,dry, in units of Btu using,
Where, V
, Cp,a, vn′ (or vn), Wn, and FCD* are the values recorded during
the section 3.4 dry coil steady-state test and Tal(τ) = dry bulb
temperature of the air entering the indoor coil at time τ, °F.
Ta2(τ) = dry bulb temperature of the air leaving the indoor coil at
time τ, °F. τ1 = for ducted units, the elapsed time when airflow is
initiated through the indoor coil; for non-ducted units, the
elapsed time when the compressor is cycled on, hr. τ2 = the elapsed
time when indoor coil airflow ceases, hr.
Adjust the total space cooling delivered, qcyc,dry, according to
calculation method outlined in section 7.4.3.4.5 of ASHRAE 116-2010
(incorporated by reference, see § 430.3).
3.5.1 Procedures When Testing Ducted Systems
The automatic controls that are installed in the test unit must
govern the OFF/ON cycling of the air moving equipment on the indoor
side (exhaust fan of the airflow measuring apparatus and the indoor
blower of the test unit). For ducted coil-only systems rated based
on using a fan time-delay relay, control the indoor coil airflow
according to the OFF delay listed by the manufacturer in the
certification report. For ducted units having a variable-speed
indoor blower that has been disabled (and possibly removed), start
and stop the indoor airflow at the same instances as if the fan
were enabled. For all other ducted coil-only systems, cycle the
indoor coil airflow in unison with the cycling of the compressor.
If air damper boxes are used, close them on the inlet and outlet
side during the OFF period. Airflow through the indoor coil should
stop within 3 seconds after the automatic controls of the test unit
(act to) de-energize the indoor blower. For ducted coil-only
systems (excluding the special case where a variable-speed fan is
temporarily removed), increase ecyc,dry by the quantity,
and decrease qcyc,dry by,
where V s
is the average indoor air volume rate from the section 3.4 dry coil
steady-state test and is expressed in units of cubic feet per
minute of standard air (scfm). For units having a variable-speed
indoor blower that is disabled during the cyclic test, increase
ecyc,dry and decrease qcyc,dry based on: a. The product of [τ2 -
τ1] and the indoor blower power measured during or following the
dry coil steady-state test; or, b. The following algorithm if the
indoor blower ramps its speed when cycling.
(1) Measure the electrical power consumed by the variable-speed
indoor blower at a minimum of three operating conditions: At the
speed/air volume rate/external static pressure that was measured
during the steady-state test, at operating conditions associated
with the midpoint of the ramp-up interval, and at conditions
associated with the midpoint of the ramp-down interval. For these
measurements, the tolerances on the airflow volume or the external
static pressure are the same as required for the section 3.4
steady-state test.
(2) For each case, determine the fan power from measurements
made over a minimum of 5 minutes.
(3) Approximate the electrical energy consumption of the indoor
blower if it had operated during the cyclic test using all three
power measurements. Assume a linear profile during the ramp
intervals. The manufacturer must provide the durations of the
ramp-up and ramp-down intervals. If the test setup instructions
included with the unit by the manufacturer specifies a ramp
interval that exceeds 45 seconds, use a 45-second ramp interval
nonetheless when estimating the fan energy.
3.5.2 Procedures When Testing Non-Ducted Indoor Units
Do not use airflow prevention devices when conducting cyclic
tests on non-ducted indoor units. Until the last OFF/ON compressor
cycle, airflow through the indoor coil must cycle off and on in
unison with the compressor. For the last OFF/ON compressor cycle -
the one used to determine ecyc,dry and qcyc,dry - use the exhaust
fan of the airflow measuring apparatus and the indoor blower of the
test unit to have indoor airflow start 3 minutes prior to
compressor cut-on and end three minutes after compressor cutoff.
Subtract the electrical energy used by the indoor blower during the
3 minutes prior to compressor cut-on from the integrated electrical
energy, ecyc,dry. Add the electrical energy used by the indoor
blower during the 3 minutes after compressor cutoff to the
integrated cooling capacity, qcyc,dry. For the case where the
non-ducted indoor unit uses a variable-speed indoor blower which is
disabled during the cyclic test, correct ecyc,dry and qcyc,dry
using the same approach as prescribed in section 3.5.1 of this
appendix for ducted units having a disabled variable-speed indoor
blower.
Use the two dry-coil tests to determine the cooling-mode
cyclic-degradation coefficient, CD c. Append “(k=2)” to the
coefficient if it corresponds to a two-capacity unit cycling at
high capacity. If the two optional tests are conducted but yield a
tested CD c that exceeds the default CD c or if the two optional
tests are not conducted, assign CD c the default value of 0.25 for
variable-speed compressor systems and outdoor units with no match,
and 0.20 for all other systems. The default value for two-capacity
units cycling at high capacity, however, is the low-capacity
coefficient, i.e., CD c(k=2) = CD c. Evaluate CD c using the
above results and those from the section 3.4 dry-coil steady-state
test.
where:
the
average energy efficiency ratio during the cyclic dry coil cooling
mode test, Btu/W·h the average energy
efficiency ratio during the steady-state dry coil cooling mode
test, Btu/W·h the cooling load
factor dimensionless Round the calculated value for CD c to the
nearest 0.01. If CD c is negative, then set it equal to zero. 3.6
Heating Mode Tests for Different Types of Heat Pumps, Including
Heating-Only Heat Pumps 3.6.1 Tests for a Heat Pump Having a
Single-Speed Compressor and Fixed Heating Air Volume Rate
This set of tests is for single-speed-compressor heat pumps that
do not have a heating minimum air volume rate or a heating
intermediate air volume rate that is different than the heating
full load air volume rate. Conduct the optional high temperature
cyclic (H1C) test to determine the heating mode cyclic-degradation
coefficient, CD h. If this optional test is conducted but yields a
tested CD h that exceeds the default CD h or if the optional test
is not conducted, assign CD h the default value of 0.25. Test
conditions for the four tests are specified in Table 10.
Table 11 - Heating Mode Test Conditions for
Units Having a Single-Speed Compressor and a Fixed-Speed Indoor
Blower, a Constant Air Volume Rate Indoor Blower, or No Indoor
Blower
Test
description
Air entering
indoor unit
temperature
( °F)
Air entering
outdoor unit
temperature
( °F)
Heating air
volume rate
Dry bulb
Wet bulb
Dry bulb
Wet bulb
H1 Test (required,
steady)
70
60 (max)
47
43
Heating Full-load.
1
H1C Test
(optional, cyclic)
70
60 (max)
47
43
( 2)
H2 Test
(required)
70
60 (max)
35
33
Heating Full-load.
1
H3 Test (required,
steady)
70
60 (max)
17
15
Heating Full-load.
1
1 Defined in section 3.1.4.4 of
this appendix. f 2 Maintain the airflow nozzles static
pressure difference or velocity pressure during the ON period at
the same pressure difference or velocity pressure as measured
during the H1 Test.
3.6.2 Tests for a Heat Pump Having a Single-Speed Compressor and a
Single Indoor Unit Having Either (1) a Variable Speed,
Variable-Air-Rate Indoor Blower Whose Capacity Modulation
Correlates With Outdoor Dry Bulb Temperature or (2) Multiple Indoor
Blowers
Conduct five tests: Two high temperature tests (H12 and H11),
one frost accumulation test (H22), and two low temperature tests
(H32 and H31). Conducting an additional frost accumulation test
(H21) is optional. Conduct the optional high temperature cyclic
(H1C1) test to determine the heating mode cyclic-degradation
coefficient, CD h. If this optional test is conducted but yields a
tested CD h that exceeds the default CD h or if the optional test
is not conducted, assign CD h the default value of 0.25. Test
conditions for the seven tests are specified in Table 12. If the
optional H21 test is not performed, use the following equations to
approximate the capacity and electrical power of the heat pump at
the H21 test conditions:
The quantities Q hk=2(47), E hk=2(47), Q hk=1(47), and E
hk=1(47) are determined from the H12 and H11 tests and evaluated as
specified in section 3.7 of this appendix; the quantities Q
hk=2(35) and E hk=2(35) are determined from the H22 test and
evaluated as specified in section 3.9 of this appendix; and the
quantities Q hk=2(17), E hk=2(17), Q hk=1(17), and E hk=1(17), are
determined from the H32 and H31 tests and evaluated as specified in
section 3.10 of this appendix.
Table 12 - Table Heating Mode Test
Conditions for Units With a Single-Speed Compressor That Meet the
Section 3.6.2 Indoor Unit Requirements
Test
description
Air entering
indoor unit
temperature
( °F)
Air entering
outdoor unit
temperature
( °F)
Heating air
volume rate
Dry bulb
Wet bulb
Dry bulb
Wet bulb
H12 Test
(required, steady)
70
60 (max)
47
43
Heating Full-load.
1
H11 Test
(required, steady)
70
60 (max)
47
43
Heating Minimum.
2
H1C1 Test
(optional, cyclic)
70
60 (max)
47
43
( 3)
H22 Test
(required)
70
60 (max)
35
33
Heating Full-load.
1
H21 Test
(optional)
70
60 (max)
35
33
Heating Minimum.
2
H32 Test
(required, steady)
70
60 (max)
17
15
Heating Full-load.
1
H31 Test
(required, steady)
70
60 (max)
17
15
Heating Minimum.
2
1 Defined in section 3.1.4.4 of
this appendix.
2 Defined in section 3.1.4.5 of
this appendix.
3 Maintain the airflow nozzles
static pressure difference or velocity pressure during the ON
period at the same pressure difference or velocity pressure as
measured during the H11 test.
3.6.3 Tests for a Heat Pump Having a Two-Capacity Compressor (see
section 1.2 of this appendix, Definitions), Including Two-Capacity,
Northern Heat Pumps (see section 1.2 of this appendix, Definitions)
a. Conduct one maximum temperature test (H01), two high
temperature tests (H12and H11), one frost accumulation test (H22),
and one low temperature test (H32). Conduct an additional frost
accumulation test (H21) and low temperature test (H31) if both of
the following conditions exist:
(1) Knowledge of the heat pump's capacity and electrical power
at low compressor capacity for outdoor temperatures of 37 °F and
less is needed to complete the section 4.2.3 of this appendix
seasonal performance calculations; and
(2) The heat pump's controls allow low-capacity operation at
outdoor temperatures of 37 °F and less.
If the above two conditions are met, an alternative to
conducting the H21 frost accumulation is to use the following
equations to approximate the capacity and electrical power:
Determine the quantities Q hk=1 (47) and E hk=1 (47) from the
H11 test and evaluate them according to section 3.7 of this
appendix. Determine the quantities Q hk=1 (17) and E hk=1 (17) from
the H31 test and evaluate them according to section 3.10 of this
appendix.
b. Conduct the optional high temperature cyclic test (H1C1) to
determine the heating mode cyclic-degradation coefficient, CD h. If
this optional test is conducted but yields a tested CD h that
exceeds the default CD h or if the optional test is not conducted,
assign CD h the default value of 0.25. If a two-capacity heat pump
locks out low capacity operation at lower outdoor temperatures,
conduct the high temperature cyclic test (H1C 2) to determine the
high-capacity heating mode cyclic-degradation coefficient, CD h
(k=2). If this optional test at high capacity is conducted but
yields a tested CD h (k = 2) that exceeds the default CD h (k = 2)
or if the optional test is not conducted, assign CD h the default
value. The default CD h (k=2) is the same value as determined or
assigned for the low-capacity cyclic-degradation coefficient, CD h
[or equivalently, CD h (k=1)]. Table 13 specifies test conditions
for these nine tests.
Table 13 - Heating Mode Test Conditions for
Units Having a Two-Capacity Compressor
Test
description
Air entering
indoor unit
temperature
( °F)
Air entering
outdoor unit
temperature
( °F)
Compressor
capacity
Heating air
volume rate
Dry bulb
Wet bulb
Dry bulb
Wet bulb
H01 Test
(required, steady)
70
60 (max)
62
56.5
Low
Heating Minimum.
1
H12 Test
(required, steady)
70
60 (max)
47
43
High
Heating Full-Load.
2
H1C2 Test
(optional 7, cyclic)
70
60 (max)
47
43
High
( 3)
H11 Test
(required)
70
60 (max)
47
43
Low
Heating Minimum.
1
H1C1 Test
(optional, cyclic)
70
60 (max)
47
43
Low
( 4)
H22 Test
(required)
70
60 (max)
35
33
High
Heating Full-Load.
2
H21 Test 5
6 (required)
70
60 (max)
35
33
Low
Heating Minimum.
1
H32 Test
(required, steady)
70
60 (max)
17
15
High
Heating Full-Load.
2
H31 Test
5 (required, steady)
70
60 (max)
17
15
Low
Heating Minimum.
1
1 Defined in section 3.1.4.5 of
this appendix.
2 Defined in section 3.1.4.4 of
this appendix.
3 Maintain the airflow nozzle(s)
static pressure difference or velocity pressure during the ON
period at the same pressure or velocity as measured during the H12
test.
4 Maintain the airflow nozzle(s)
static pressure difference or velocity pressure during the ON
period at the same pressure or velocity as measured during the H11
test.
5 Required only if the heat
pump's performance when operating at low compressor capacity and
outdoor temperatures less than 37 °F is needed to complete the
section 4.2.3 HSPF calculations.
6 If table note #5 applies, the
section 3.6.3 equations for Q hk=1 (35) and E hk=1 (17) may be used
in lieu of conducting the H21 test.
7 Required only if the heat pump
locks out low capacity operation at lower outdoor temperatures.
3.6.4 Tests for a Heat Pump Having a Variable-Speed Compressor
a. Conduct one maximum temperature test (H01), two high
temperature tests (H1N and H11), one frost accumulation test (H2V),
and one low temperature test (H32). Conducting one or both of the
following tests is optional: An additional high temperature test
(H12) and an additional frost accumulation test (H22). If desired,
conduct the optional maximum temperature cyclic (H0C1) test to
determine the heating mode cyclic-degradation coefficient, CD h. If
this optional test is conducted but yields a tested CD h that
exceeds the default CD h or if the optional test is not conducted,
assign CD h the default value of 0.25. Test conditions for the
eight tests are specified in Table 14. The compressor shall operate
at the same heating full speed, measured by RPM or power input
frequency (Hz), for the H12, H22 and H32 tests. For a
cooling/heating heat pump, the compressor shall operate for the H1N
test at a speed, measured by RPM or power input frequency (Hz), no
lower than the speed used in the A2 test if the tested H12 heating
capacity is less than the tested cooling capacity in A2 test. The
compressor shall operate at the same heating minimum speed,
measured by RPM or power input frequency (Hz), for the H01, H1C1,
and H11 tests. Determine the heating intermediate compressor speed
cited in Table 14 using the heating mode full and minimum
compressors speeds and:
Where a
tolerance on speed of plus 5 percent or the next higher inverter
frequency step from the calculated value is allowed.
b. If the H12 test is conducted, set the 47 °F capacity and
power input values used for calculation of HSPF equal to the
measured values for that test:
Where:
Q hcalck=2(47) and E hcalck=2(47) are the capacity and power
input representing full-speed operation at 47 °F for the HSPF
calculations,
Q hk=2(47) is the capacity measured in the H12 test, and
E hk=2(47) is the power input measured in the H12 test.
Evaluate the quantities Q hk=2(47) and from E hk=2(47) according
to section 3.7.
Otherwise, if the H1N test is conducted using the same
compressor speed (RPM or power input frequency) as the H32 test,
set the 47 °F capacity and power input values used for calculation
of HSPF equal to the measured values for that test:
Where:
Q hcalck=2(47) and E hcalck=2(47) are the capacity
and power input representing full-speed operation at 47 °F for the
HSPF calculations, Q hk=N(47) is the capacity measured in
the H1N test, and E hk=N(47) is the power input measured in
the H1N test.
Evaluate the quantities Q hk=N(47) and from E hk=N(47) according
to section 3.7.
Otherwise (if no high temperature test is conducted using the
same speed (RPM or power input frequency) as the H32 test),
calculate the 47 °F capacity and power input values used for
calculation of HSPF as follows:
Where:
Q hcalck=2(47) and E hcalck=2(47) are the capacity
and power input representing full-speed operation at 47 °F for the
HSPF calculations, Q hk=2(17) is the capacity measured in
the H32 test, E hk=2(17) is the power input measured in the
H32 test, CSF is the capacity slope factor, equal to 0.0204/ °F for
split systems and 0.0262/ °F for single-package systems, and PSF is
the Power Slope Factor, equal to 0.00455/ °F.
c. If the H22 test is not done, use the following equations to
approximate the capacity and electrical power at the H22 test
conditions:
Where:
Q hcalck=2(47) and E hcalck=2(47) are the capacity
and power input representing full-speed operation at 47 °F for the
HSPF calculations,calculated as described in section b above.
Q hk=2(17) and E hk=2(17) are the capacity and power
input measured in the H32 test.
d. Determine the quantities Q hk=2(17) and E hk=2(17) from the
H32 test, determine the quantities Q hk=2(5) and E hk=2(5) from the
H42 test, and evaluate all four according to section 3.10.
Table 14 - Heating Mode Test Conditions for
Units Having a Variable-Speed Compressor
Test
description
Air entering
indoor unit
temperature ( °F)
Air entering
outdoor unit
temperature ( °F)
Compressor
speed
Heating air
volume rate
Dry bulb
Wet bulb
Dry bulb
Wet bulb
H01 test
(required, steady)
70
60 (max)
62
56.5
Heating minimum
Heating minimum.
1
H12 test
(optional, steady)
70
60 (max)
47
43
Heating full 4
Heating full-load.
3
H11 test
(required, steady)
70
60 (max)
47
43
Heating minimum
Heating minimum.
1
H1N test
(required, steady)
70
60 (max)
47
43
Heating full
Heating full-load.
3
H1C1 test
(optional, cyclic)
70
60 (max)
47
43
Heating minimum
( 2)
H22 test
(optional)
70
60 (max)
35
33
Heating full 4
Heating full-load.
3
H2V test
(required)
70
60 (max)
35
33
Heating intermediate
Heating intermediate.
5
H32 test
(required, steady)
70
60 (max)
17
15
Heating full
Heating full-load.
3
1 Defined in section 3.1.4.5 of
this appendix.
2 Maintain the airflow nozzle(s)
static pressure difference or velocity pressure during an ON period
at the same pressure or velocity as measured during the H11
test.
3 Defined in section 3.1.4.4 of
this appendix.
4 The same compressor speed used
in the H32 test. The H12 test is not needed if the H1N test uses
this same compressor speed.
5 Defined in section 3.1.4.6 of
this appendix.
3.6.5 Additional Test for a Heat Pump Having a Heat Comfort
Controller
Test any heat pump that has a heat comfort controller (see
section 1.2 of this appendix, Definitions) according to section
3.6.1, 3.6.2, or 3.6.3, whichever applies, with the heat comfort
controller disabled. Additionally, conduct the abbreviated test
described in section 3.1.10 of this appendix with the heat comfort
controller active to determine the system's maximum supply air
temperature. (Note: Heat pumps having a variable speed compressor
and a heat comfort controller are not covered in the test procedure
at this time.)
3.6.6 Heating Mode Tests for Northern Heat Pumps With
Triple-Capacity Compressors.
Test triple-capacity, northern heat pumps for the heating mode
as follows:
a. Conduct one maximum-temperature test (H01), two
high-temperature tests (H12 and H11), one frost accumulation test
(H22), two low-temperature tests (H32, H33), and one
minimum-temperature test (H43). Conduct an additional frost
accumulation test (H21) and low-temperature test (H31) if both of
the following conditions exist: (1) Knowledge of the heat pump's
capacity and electrical power at low compressor capacity for
outdoor temperatures of 37 °F and less is needed to complete the
section 4.2.6 seasonal performance calculations; and (2) the heat
pump's controls allow low-capacity operation at outdoor
temperatures of 37 °F and less. If the above two conditions are
met, an alternative to conducting the H21 frost accumulation test
to determine Q hk=1(35) and E hk=1(35) is to use the following
equations to approximate this capacity and electrical power:
In evaluating the above equations, determine the quantities Q
hk=1(47) from the H11 test and evaluate them according to section
3.7 of this appendix. Determine the quantities Q hk=1(17) and E
hk=1(17) from the H31 test and evaluate them according to section
3.10 of this appendix. Use the paired values of Q hk=1(35) and E
hk=1(35) derived from conducting the H21 frost accumulation test
and evaluated as specified in section 3.9.1 of this appendix or use
the paired values calculated using the above default equations,
whichever contribute to a higher Region IV HSPF based on the
DHRmin.
b. Conducting a frost accumulation test (H23) with the heat pump
operating at its booster capacity is optional. If this optional
test is not conducted, determine Q h k=3(35) and E hk=3(35) using
the following equations to approximate this capacity and electrical
power:
Where:
Determine the quantities Q hk=2(47) and E hk=2(47) from the H12
test and evaluate them according to section 3.7 of this appendix.
Determine the quantities Q hk=2(35) and E hk=2(35) from the H22
test and evaluate them according to section 3.9.1 of this appendix.
Determine the quantities Q hk=2(17) and E hk=2(17) from the H32
test, determine the quantities Q h k=3(17) and E hk=3(17) from the
H33 test, and determine the quantities Q hk=3(5) and E hk=3(5) from
the H43 test. Evaluate all six quantities according to section 3.10
of this appendix. Use the paired values of Q hk=3(35) and E
hk=3(35) derived from conducting the H23 frost accumulation test
and calculated as specified in section 3.9.1 of this appendix or
use the paired values calculated using the above default equations,
whichever contribute to a higher Region IV HSPF2 based on the
DHRmin.
c. Conduct the optional high-temperature cyclic test (H1C1) to
determine the heating mode cyclic-degradation coefficient, CD h. A
default value for CD h may be used in lieu of conducting the
cyclic. The default value of CD h is 0.25. If a triple-capacity
heat pump locks out low capacity operation at lower outdoor
temperatures, conduct the high-temperature cyclic test (H1C2) to
determine the high-capacity heating mode cyclic-degradation
coefficient, CD h (k=2). The default CD h (k=2) is the same value
as determined or assigned for the low-capacity cyclic-degradation
coefficient, CD h [or equivalently, CD h (k=1)]. Finally, if a
triple-capacity heat pump locks out both low and high capacity
operation at the lowest outdoor temperatures, conduct the
low-temperature cyclic test (H3C3) to determine the
booster-capacity heating mode cyclic-degradation coefficient, CD h
(k=3). The default CD h (k=3) is the same value as determined or
assigned for the high-capacity cyclic-degradation coefficient, CD h
[or equivalently, CD h (k=2)]. Table 15 specifies test conditions
for all 13 tests.
Table 15 - Heating Mode Test Conditions for
Units With a Triple-Capacity Compressor
Test
description
Air entering
indoor unit
temperature
°F
Air entering
outdoor unit
temperature
°F
Compressor
capacity
Heating air
volume rate
Dry bulb
Wet bulb
Dry bulb
Wet bulb
H01 Test
(required, steady)
70
60 (max)
62
56.5
Low
Heating Minimum.
1
H12 Test
(required, steady)
70
60 (max)
47
43
High
Heating Full-Load.
2
H1C2 Test
(optional, 8 cyclic)
70
60 (max)
47
43
High
( 3).
H11 Test
(required)
70
60 (max)
47
43
Low
Heating Minimum.
1
H1C1 Test
(optional, cyclic)
70
60 (max)
47
43
Low
( 4).
H23 Test
(optional, steady)
70
60 (max)
35
33
Booster
Heating Full-Load.
2
H22 Test
(required)
70
60 (max)
35
33
High
Heating Full-Load.
2
H21 Test
(required)
70
60 (max)
35
33
Low
Heating Minimum.
1
H33 Test
(required, steady)
70
60 (max)
17
15
Booster
Heating Full-Load.
2
H3C3 Test 5
6 (optional, cyclic)
70
60 (max)
17
15
Booster
( 7).
H32 Test
(required, steady)
70
60 (max)
17
15
High
Heating Full-Load.
2
H31 Test
5 (required, steady)
70
60 (max)
17
15
Low
Heating Minimum.
1
H43 Test
(required, steady)
70
60 (max)
5
3 (max)
Booster
Heating Full-Load.
2
1 Defined in section 3.1.4.5 of
this appendix.
2 Defined in section 3.1.4.4 of
this appendix.
3 Maintain the airflow nozzle(s)
static pressure difference or velocity pressure during the ON
period at the same pressure or velocity as measured during the H12
test.
4 Maintain the airflow nozzle(s)
static pressure difference or velocity pressure during the ON
period at the same pressure or velocity as measured during the H11
test.
5 Required only if the heat
pump's performance when operating at low compressor capacity and
outdoor temperatures less than 37 °F is needed to complete the
section 4.2.6 HSPF2 calculations.
6 If table note 5
applies, the section 3.6.6 equations for Q hk=1(35) and E hk=1(17)
may be used in lieu of conducting the H21 test.
7 Maintain the airflow nozzle(s)
static pressure difference or velocity pressure during the ON
period at the same pressure or velocity as measured during the H33
test.
8 Required only if the heat pump
locks out low capacity operation at lower outdoor temperatures.
3.6.7 Tests for a Heat Pump Having a Single Indoor Unit Having
Multiple Indoor Blowers and Offering Two Stages of Compressor
Modulation
Conduct the heating mode tests specified in section 3.6.3 of
this appendix.
3.7 Test Procedures for Steady-State Maximum Temperature and High
Temperature Heating Mode Tests (the H01, H1, H12, H11, and H1N
Tests)
a. For the pretest interval, operate the test room
reconditioning apparatus and the heat pump until equilibrium
conditions are maintained for at least 30 minutes at the specified
section 3.6 test conditions. Use the exhaust fan of the airflow
measuring apparatus and, if installed, the indoor blower of the
heat pump to obtain and then maintain the indoor air volume rate
and/or the external static pressure specified for the particular
test. Continuously record the dry-bulb temperature of the air
entering the indoor coil, and the dry-bulb temperature and water
vapor content of the air entering the outdoor coil. Refer to
section 3.11 of this appendix for additional requirements that
depend on the selected secondary test method. After satisfying the
pretest equilibrium requirements, make the measurements specified
in Table 3 of ANSI/ASHRAE 37-2009 (incorporated by reference, see §
430.3) for the indoor air enthalpy method and the user-selected
secondary method. Make said Table 3 measurements at equal intervals
that span 5 minutes or less. Continue data sampling until a
30-minute period (e.g., seven consecutive 5-minute samples)
is reached where the test tolerances specified in Table 16 are
satisfied. For those continuously recorded parameters, use the
entire data set for the 30-minute interval when evaluating Table 16
compliance. Determine the average electrical power consumption of
the heat pump over the same 30-minute interval.
Table 16 - Test Operating and Test
Condition Tolerances for Section 3.7 and Section 3.10 Steady-State
Heating Mode Tests
Test operating
tolerance 1
Test condition
tolerance 1
Indoor dry-bulb,
°F:
Entering
temperature
2.0
0.5
Leaving
temperature
2.0
Indoor wet-bulb,
°F:
Entering
temperature
1.0
Leaving
temperature
1.0
Outdoor dry-bulb,
°F:
Entering
temperature
2.0
0.5
Leaving
temperature
2 2.0
Outdoor wet-bulb,
°F:
Entering
temperature
1.0
0.3
Leaving
temperature
2 1.0
External
resistance to airflow, inches of water
0.05
3 0.02
Electrical
voltage, % of rdg
2.0
1.5
Nozzle pressure
drop, % of rdg
2.0
1 See section 1.2 of this
appendix, Definitions.
2 Only applies when the Outdoor
Air Enthalpy Method is used.
3 Only applies when testing
non-ducted units.
b. Calculate indoor-side total heating capacity as specified in
sections 7.3.4.1 and 7.3.4.3 of ANSI/ASHRAE 37-2009 (incorporated
by reference, see § 430.3). To calculate capacity, use the averages
of the measurements (e.g. inlet and outlet dry bulb
temperatures measured at the psychrometers) that are continuously
recorded for the same 30-minute interval used as described above to
evaluate compliance with test tolerances. Do not adjust the
parameters used in calculating capacity for the permitted
variations in test conditions. Assign the average space heating
capacity and electrical power over the 30-minute data collection
interval to the variables Q h k and E h k(T) respectively. The “T”
and superscripted “k” are the same as described in section 3.3 of
this appendix. Additionally, for the heating mode, use the
superscript to denote results from the optional H1N test, if
conducted.
c. For coil-only system heat pumps, increase Q h k(T) by
where V s
is the average measured indoor air volume rate expressed in units
of cubic feet per minute of standard air (scfm). During the
30-minute data collection interval of a high temperature test, pay
attention to preventing a defrost cycle. Prior to this time, allow
the heat pump to perform a defrost cycle if automatically initiated
by its own controls. As in all cases, wait for the heat pump's
defrost controls to automatically terminate the defrost cycle. Heat
pumps that undergo a defrost should operate in the heating mode for
at least 10 minutes after defrost termination prior to beginning
the 30-minute data collection interval. For some heat pumps, frost
may accumulate on the outdoor coil during a high temperature test.
If the indoor coil leaving air temperature or the difference
between the leaving and entering air temperatures decreases by more
than 1.5 °F over the 30-minute data collection interval, then do
not use the collected data to determine capacity. Instead, initiate
a defrost cycle. Begin collecting data no sooner than 10 minutes
after defrost termination. Collect 30 minutes of new data during
which the Table 16 test tolerances are satisfied. In this case, use
only the results from the second 30-minute data collection interval
to evaluate Q h k(47) and E h k(47).
d. If conducting the cyclic heating mode test, which is
described in section 3.8 of this appendix, record the average
indoor-side air volume rate, V , specific heat of the air, Cp,a
(expressed on dry air basis), specific volume of the air at the
nozzles, vn′ (or vn), humidity ratio at the nozzles, Wn, and either
pressure difference or velocity pressure for the flow nozzles. If
either or both of the below criteria apply, determine the average,
steady-state, electrical power consumption of the indoor blower
motor (E fan,1):
(1) The section 3.8 cyclic test will be conducted and the heat
pump has a variable-speed indoor blower that is expected to be
disabled during the cyclic test; or
(2) The heat pump has a (variable-speed) constant-air
volume-rate indoor blower and during the steady-state test the
average external static pressure (ΔP1) exceeds the applicable
section 3.1.4.4 minimum (or targeted) external static pressure
(ΔPmin) by 0.03 inches of water or more.
Determine E fan,1 by making measurements during the 30-minute
data collection interval, or immediately following the test and
prior to changing the test conditions. When the above “2” criteria
applies, conduct the following four steps after determining E fan,1
(which corresponds to ΔP1):
(i) While maintaining the same test conditions, adjust the
exhaust fan of the airflow measuring apparatus until the external
static pressure increases to approximately ΔP1 + (ΔP1 − ΔPmin).
(ii) After re-establishing steady readings for fan motor power
and external static pressure, determine average values for the
indoor blower power (E fan,2) and the external static pressure
(ΔP2) by making measurements over a 5-minute interval.
(iii) Approximate the average power consumption of the indoor
blower motor if the 30-minute test had been conducted at ΔPmin
using linear extrapolation:
(iv) Decrease the total space heating capacity, Q hk(T), by the
quantity (E fan,1 − E fan,min), when expressed on a Btu/h basis.
Decrease the total electrical power, E hk(T) by the same fan power
difference, now expressed in watts.
e. If the temperature sensors used to provide the primary
measurement of the indoor-side dry bulb temperature difference
during the steady-state dry-coil test and the subsequent cyclic
dry-coil test are different, include measurements of the latter
sensors among the regularly sampled data. Beginning at the start of
the 30-minute data collection period, measure and compute the
indoor-side air dry-bulb temperature difference using both sets of
instrumentation, ΔT (Set SS) and ΔT (Set CYC), for each equally
spaced data sample. If using a consistent data sampling rate that
is less than 1 minute, calculate and record minutely averages for
the two temperature differences. If using a consistent sampling
rate of one minute or more, calculate and record the two
temperature differences from each data sample. After having
recorded the seventh (i=7) set of temperature differences,
calculate the following ratio using the first seven sets of
values:
Each time
a subsequent set of temperature differences is recorded (if
sampling more frequently than every 5 minutes), calculate
FCD using the most recent seven sets of values. Continue
these calculations until the 30-minute period is completed or until
a value for FCD is calculated that falls outside the
allowable range of 0.94-1.06. If the latter occurs, immediately
suspend the test and identify the cause for the disparity in the
two temperature difference measurements. Recalibration of one or
both sets of instrumentation may be required. If all the values for
FCD are within the allowable range, save the final value of
the ratio from the 30-minute test as FCD*. If the
temperature sensors used to provide the primary measurement of the
indoor-side dry bulb temperature difference during the steady-state
dry-coil test and the subsequent cyclic dry-coil test are the same,
set FCD*= 1. 3.8 Test Procedures for the Cyclic Heating Mode
Tests (the H0C1, H1C, H1C1 and H1C2 Tests)
a. Except as noted below, conduct the cyclic heating mode test
as specified in section 3.5 of this appendix. As adapted to the
heating mode, replace section 3.5 references to “the steady-state
dry coil test” with “the heating mode steady-state test conducted
at the same test conditions as the cyclic heating mode test.” Use
the test tolerances in Table 17 rather than Table 10. Record the
outdoor coil entering wet-bulb temperature according to the
requirements given in section 3.5 of this appendix for the outdoor
coil entering dry-bulb temperature. Drop the subscript “dry” used
in variables cited in section 3.5 of this appendix when referring
to quantities from the cyclic heating mode test. Determine the
total space heating delivered during the cyclic heating test, qcyc,
as specified in section 3.5 of this appendix except for making the
following changes:
(1) When evaluating Equation 3.5-1, use the values of V ,
Cp,a,vn′, (or vn), and Wn that were recorded during the section 3.7
steady-state test conducted at the same test conditions.
(2) Calculate Γ using
where
FCD* is the value recorded during the section 3.7
steady-state test conducted at the same test condition.
b. For ducted coil-only system heat pumps (excluding the special
case where a variable-speed fan is temporarily removed), increase
qcyc by the amount calculated using Equation 3.5-3. Additionally,
increase ecyc by the amount calculated using Equation 3.5-2. In
making these calculations, use the average indoor air volume rate
(V s) determined from the section 3.7 steady-state heating mode
test conducted at the same test conditions.
c. For non-ducted heat pumps, subtract the electrical energy
used by the indoor blower during the 3 minutes after compressor
cutoff from the non-ducted heat pump's integrated heating capacity,
qcyc.
d. If a heat pump defrost cycle is manually or automatically
initiated immediately prior to or during the OFF/ON cycling,
operate the heat pump continuously until 10 minutes after defrost
termination. After that, begin cycling the heat pump immediately or
delay until the specified test conditions have been re-established.
Pay attention to preventing defrosts after beginning the cycling
process. For heat pumps that cycle off the indoor blower during a
defrost cycle, make no effort here to restrict the air movement
through the indoor coil while the fan is off. Resume the OFF/ON
cycling while conducting a minimum of two complete compressor
OFF/ON cycles before determining qcyc and ecyc.
Use the results from the required cyclic test and the required
steady-state test that were conducted at the same test conditions
to determine the heating mode cyclic-degradation coefficient CD h.
Add “(k=2)” to the coefficient if it corresponds to a two-capacity
unit cycling at high capacity. For the below calculation of the
heating mode cyclic degradation coefficient, do not include the
duct loss correction from section 7.3.3.3 of ANSI/ASHRAE 37-2009
(incorporated by reference, see § 430.3) in determining Q h k(Tcyc)
(or qcyc). If the optional cyclic test is conducted but yields a
tested CD h that exceeds the default CD h or if the optional test
is not conducted, assign CD h the default value of 0.25. The
default value for two-capacity units cycling at high capacity,
however, is the low-capacity coefficient, i.e., CD h (k=2) =
CD h. The tested CD h is calculated as follows:
where:
the
average coefficient of performance during the cyclic heating mode
test, dimensionless. the average
coefficient of performance during the steady-state heating mode
test conducted at the same test conditions - i.e., same
outdoor dry bulb temperature, Tcyc, and speed/capacity, k, if
applicable - as specified for the cyclic heating mode test,
dimensionless. the heating load
factor, dimensionless. Tcyc = the nominal outdoor temperature at
which the cyclic heating mode test is conducted, 62 or 47 °F. Δτcyc
= the duration of the OFF/ON intervals; 0.5 hours when testing a
heat pump having a single-speed or two-capacity compressor and 1.0
hour when testing a heat pump having a variable-speed compressor.
Round the calculated value for CD h to the nearest 0.01. If CD h
is negative, then set it equal to zero.
Table 17 - Test Operating and Test
Condition Tolerances for Cyclic Heating Mode Tests
Test operating
tolerance 1
Test condition
tolerance 1
Indoor entering
dry-bulb temperature, 2 °F
2.0
0.5
Indoor entering
wet-bulb temperature, 2 °F
1.0
Outdoor entering
dry-bulb temperature, 2 °F
2.0
0.5
Outdoor entering
wet-bulb temperature, 2 °F
2.0
1.0
External
resistance to air-flow, 2 inches of water
0.05
Airflow nozzle
pressure difference or velocity pressure, 2% of
reading
2.0
3 2.0
Electrical
voltage, 4 % of rdg
2.0
1.5
1 See section 1.2 of this
appendix, Definitions.
2 Applies during the interval
that air flows through the indoor (outdoor) coil except for the
first 30 seconds after flow initiation. For units having a
variable-speed indoor blower that ramps, the tolerances listed for
the external resistance to airflow shall apply from 30 seconds
after achieving full speed until ramp down begins.
3 The test condition shall be the
average nozzle pressure difference or velocity pressure measured
during the steady-state test conducted at the same test
conditions.
4 Applies during the interval
that at least one of the following - the compressor, the outdoor
fan, or, if applicable, the indoor blower - are operating, except
for the first 30 seconds after compressor start-up.
3.9 Test Procedures for Frost Accumulation Heating Mode Tests (the
H2, H22, H2V, and H21 tests)
a. Confirm that the defrost controls of the heat pump are set as
specified in section 2.2.1 of this appendix. Operate the test room
reconditioning apparatus and the heat pump for at least 30 minutes
at the specified section 3.6 test conditions before starting the
“preliminary” test period. The preliminary test period must
immediately precede the “official” test period, which is the
heating and defrost interval over which data are collected for
evaluating average space heating capacity and average electrical
power consumption.
b. For heat pumps containing defrost controls which are likely
to cause defrosts at intervals less than one hour, the preliminary
test period starts at the termination of an automatic defrost cycle
and ends at the termination of the next occurring automatic defrost
cycle. For heat pumps containing defrost controls which are likely
to cause defrosts at intervals exceeding one hour, the preliminary
test period must consist of a heating interval lasting at least one
hour followed by a defrost cycle that is either manually or
automatically initiated. In all cases, the heat pump's own controls
must govern when a defrost cycle terminates.
c. The official test period begins when the preliminary test
period ends, at defrost termination. The official test period ends
at the termination of the next occurring automatic defrost cycle.
When testing a heat pump that uses a time-adaptive defrost control
system (see section 1.2 of this appendix, Definitions), however,
manually initiate the defrost cycle that ends the official test
period at the instant indicated by instructions provided by the
manufacturer. If the heat pump has not undergone a defrost after 6
hours, immediately conclude the test and use the results from the
full 6-hour period to calculate the average space heating capacity
and average electrical power consumption.
For heat pumps that turn the indoor blower off during the
defrost cycle, take steps to cease forced airflow through the
indoor coil and block the outlet duct whenever the heat pump's
controls cycle off the indoor blower. If it is installed, use the
outlet damper box described in section 2.5.4.1 of this appendix to
affect the blocked outlet duct.
d. Defrost termination occurs when the controls of the heat pump
actuate the first change in converting from defrost operation to
normal heating operation. Defrost initiation occurs when the
controls of the heat pump first alter its normal heating operation
in order to eliminate possible accumulations of frost on the
outdoor coil.
e. To constitute a valid frost accumulation test, satisfy the
test tolerances specified in Table 18 during both the preliminary
and official test periods. As noted in Table 18, test operating
tolerances are specified for two sub-intervals:
(1) When heating, except for the first 10 minutes after the
termination of a defrost cycle (sub-interval H, as described in
Table 18) and
(2) When defrosting, plus these same first 10 minutes after
defrost termination (sub-interval D, as described in Table 18).
Evaluate compliance with Table 18 test condition tolerances and the
majority of the test operating tolerances using the averages from
measurements recorded only during sub-interval H. Continuously
record the dry bulb temperature of the air entering the indoor
coil, and the dry bulb temperature and water vapor content of the
air entering the outdoor coil. Sample the remaining parameters
listed in Table 18 at equal intervals that span 5 minutes or
less.
f. For the official test period, collect and use the following
data to calculate average space heating capacity and electrical
power. During heating and defrosting intervals when the controls of
the heat pump have the indoor blower on, continuously record the
dry-bulb temperature of the air entering (as noted above) and
leaving the indoor coil. If using a thermopile, continuously record
the difference between the leaving and entering dry-bulb
temperatures during the interval(s) that air flows through the
indoor coil. For coil-only system heat pumps, determine the
corresponding cumulative time (in hours) of indoor coil airflow,
Δτa. Sample measurements used in calculating the air volume rate
(refer to sections 7.7.2.1 and 7.7.2.2 of ANSI/ASHRAE 37-2009) at
equal intervals that span 10 minutes or less. (Note: In the first
printing of ANSI/ASHRAE 37-2009, the second IP equation for Qmi
should read:) Record the electrical energy consumed, expressed in
watt-hours, from defrost termination to defrost termination, eDEF
k(35), as well as the corresponding elapsed time in hours,
ΔτFR.
Table 18 - Test Operating and Test
Condition Tolerances for Frost Accumulation Heating Mode Tests
Test operating
tolerance 1
Test
condition
tolerance 1
Sub-interval H 2
Sub-interval H
2
Sub-interval D
3
Indoor entering
dry-bulb temperature, °F
2.0
4 4.0
0.5
Indoor entering
wet-bulb temperature, °F
1.0
Outdoor entering
dry-bulb temperature, °F
2.0
10.0
1.0
Outdoor entering
wet-bulb temperature, °F
1.5
0.5
External
resistance to airflow, inches of water
0.05
5 0.02
Electrical
voltage, % of rdg
2.0
1.5
1 See section 1.2 of this
appendix, Definitions.
2 Applies when the heat pump is
in the heating mode, except for the first 10 minutes after
termination of a defrost cycle.
3 Applies during a defrost cycle
and during the first 10 minutes after the termination of a defrost
cycle when the heat pump is operating in the heating mode.
4 For heat pumps that turn off
the indoor blower during the defrost cycle, the noted tolerance
only applies during the 10 minute interval that follows defrost
termination.
5 Only applies when testing
non-ducted heat pumps.
3.9.1 Average Space Heating Capacity and Electrical Power
Calculations
a. Evaluate average space heating capacity, Q h k(35), when
expressed in units of Btu per hour, using:
Where, V
= the average indoor air volume rate measured during sub-interval
H, cfm. Cp,a = 0.24 + 0.444 · Wn, the constant pressure specific
heat of the air-water vapor mixture that flows through the indoor
coil and is expressed on a dry air basis, Btu/lbmda · °F. vn′ =
specific volume of the air-water vapor mixture at the nozzle, ft
3/lbmmx. Wn = humidity ratio of the air-water vapor mixture at the
nozzle, lbm of water vapor per lbm of dry air. ΔτFR = τ2 − τ1, the
elapsed time from defrost termination to defrost termination, hr.
Tal(τ) =
dry bulb temperature of the air entering the indoor coil at elapsed
time τ, °F; only recorded when indoor coil airflow occurs; assigned
the value of zero during periods (if any) where the indoor blower
cycles off. Ta2(τ) = dry bulb temperature of the air leaving the
indoor coil at elapsed time τ, °F; only recorded when indoor coil
airflow occurs; assigned the value of zero during periods (if any)
where the indoor blower cycles off. τ1 = the elapsed time when the
defrost termination occurs that begins the official test period,
hr. τ2 = the elapsed time when the next automatically occurring
defrost termination occurs, thus ending the official test period,
hr. vn = specific volume of the dry air portion of the mixture
evaluated at the dry-bulb temperature, vapor content, and
barometric pressure existing at the nozzle, ft 3 per lbm of dry
air.
To account for the effect of duct losses between the outlet of
the indoor unit and the section 2.5.4 dry-bulb temperature grid,
adjust Q h k(35) in accordance with section 7.3.4.3 of ANSI/ASHRAE
37-2009 (incorporated by reference, see § 430.3).
b. Evaluate average electrical power, E h k(35), when expressed
in units of watts, using:
For coil-only system heat pumps, increase Q h k(35) by,
and
increase E h k(35) by, where V s is the
average indoor air volume rate measured during the frost
accumulation heating mode test and is expressed in units of cubic
feet per minute of standard air (scfm).
c. For heat pumps having a constant-air-volume-rate indoor
blower, the five additional steps listed below are required if the
average of the external static pressures measured during
sub-interval H exceeds the applicable section 3.1.4.4, 3.1.4.5, or
3.1.4.6 minimum (or targeted) external static pressure (ΔPmin) by
0.03 inches of water or more:
(1) Measure the average power consumption of the indoor blower
motor (E fan,1) and record the corresponding external static
pressure (ΔP1) during or immediately following the frost
accumulation heating mode test. Make the measurement at a time when
the heat pump is heating, except for the first 10 minutes after the
termination of a defrost cycle.
(2) After the frost accumulation heating mode test is completed
and while maintaining the same test conditions, adjust the exhaust
fan of the airflow measuring apparatus until the external static
pressure increases to approximately ΔP1 + (ΔP1 − ΔPmin).
(3) After re-establishing steady readings for the fan motor
power and external static pressure, determine average values for
the indoor blower power (E fan,2) and the external static pressure
(ΔP2) by making measurements over a 5-minute interval.
(4) Approximate the average power consumption of the indoor
blower motor had the frost accumulation heating mode test been
conducted at ΔPmin using linear extrapolation:
(5) Decrease the total heating capacity, Q h k(35), by the
quantity [(E fan,1−E fan,min) · (Δτ a/Δτ FR], when expressed on a
Btu/h basis. Decrease the total electrical power, Eh k(35), by the
same quantity, now expressed in watts.
3.9.2 Demand Defrost Credit
a. Assign the demand defrost credit, Fdef, that is used in
section 4.2 of this appendix to the value of 1 in all cases except
for heat pumps having a demand-defrost control system (see section
1.2 of this appendix, Definitions). For such qualifying heat pumps,
evaluate Fdef using,
where:
Δτdef = the time between defrost terminations (in hours) or 1.5,
whichever is greater. A value of 6 must be assigned to Δτdef if
this limit is reached during a frost accumulation test and the heat
pump has not completed a defrost cycle. Δτmax = maximum time
between defrosts as allowed by the controls (in hours) or 12,
whichever is less, as provided in the certification report.
b. For two-capacity heat pumps and for section 3.6.2 units,
evaluate the above equation using the Δτdef that applies based on
the frost accumulation test conducted at high capacity and/or at
the heating full-load air volume rate. For variable-speed heat
pumps, evaluate Δτdef based on the required frost accumulation test
conducted at the intermediate compressor speed.
3.10 Test Procedures for Steady-State Low Temperature Heating Mode
Tests (the H3, H32, and H31 Tests)
Except for the modifications noted in this section, conduct the
low temperature heating mode test using the same approach as
specified in section 3.7 of this appendix for the maximum and high
temperature tests. After satisfying the section 3.7 requirements
for the pretest interval but before beginning to collect data to
determine Q h k(17) and E h k(17), conduct a defrost cycle. This
defrost cycle may be manually or automatically initiated. The
defrost sequence must be terminated by the action of the heat
pump's defrost controls. Begin the 30-minute data collection
interval described in section 3.7 of this appendix, from which Q h
k(17) and E h k(17) are determined, no sooner than 10 minutes after
defrost termination. Defrosts should be prevented over the
30-minute data collection interval.
3.11 Additional Requirements for the Secondary Test Methodst 3.11.1
If Using the Outdoor Air Enthalpy Method as the Secondary Test
Method
a. For all cooling mode and heating mode tests, first conduct a
test without the outdoor air-side test apparatus described in
section 2.10.1 of this appendix connected to the outdoor unit
(“free outdoor air” test).
b. For the first section 3.2 steady-state cooling mode test and
the first section 3.6 steady-state heating mode test, conduct a
second test in which the outdoor-side apparatus is connected
(“ducted outdoor air” test). No other cooling mode or heating mode
tests require the ducted outdoor air test so long as the unit
operates the outdoor fan during all cooling mode steady-state tests
at the same speed and all heating mode steady-state tests at the
same speed. If using more than one outdoor fan speed for the
cooling mode steady-state tests, however, conduct the ducted
outdoor air test for each cooling mode test where a different fan
speed is first used. This same requirement applies for the heating
mode tests.
3.11.1.1 Free Outdoor Air Test
a. For the free outdoor air test, connect the indoor air-side
test apparatus to the indoor coil; do not connect the outdoor
air-side test apparatus. Allow the test room reconditioning
apparatus and the unit being tested to operate for at least one
hour. After attaining equilibrium conditions, measure the following
quantities at equal intervals that span 5 minutes or less:
(1) The section 2.10.1 evaporator and condenser temperatures or
pressures;
(2) Parameters required according to the indoor air enthalpy
method.
Continue these measurements until a 30-minute period
(e.g., seven consecutive 5-minute samples) is obtained where
the Table 9 or Table 16, whichever applies, test tolerances are
satisfied.
b. For cases where a ducted outdoor air test is not required per
section 3.11.1.b of this appendix, the free outdoor air test
constitutes the “official” test for which validity is not based on
comparison with a secondary test.
c. For cases where a ducted outdoor air test is required per
section 3.11.1.b of this appendix, the following conditions must be
met for the free outdoor air test to constitute a valid “official”
test:
(1) Achieve the energy balance specified in section 3.1.1 of
this appendix for the ducted outdoor air test (i.e., compare
the capacities determined using the indoor air enthalpy method and
the outdoor air enthalpy method).
(2) The capacities determined using the indoor air enthalpy
method from the ducted outdoor air and free outdoor tests must
agree within 2 percent.
3.11.1.2 Ducted Outdoor Air Test
a. The test conditions and tolerances for the ducted outdoor air
test are the same as specified for the free outdoor air test
described in Section 3.11.1.1 of this appendix.
b. After collecting 30 minutes of steady-state data during the
free outdoor air test, connect the outdoor air-side test apparatus
to the unit for the ducted outdoor air test. Adjust the exhaust fan
of the outdoor airflow measuring apparatus until averages for the
evaporator and condenser temperatures, or the saturated
temperatures corresponding to the measured pressures, agree within
±0.5 °F of the averages achieved during the free outdoor air test.
Collect 30 minutes of steady-state data after re-establishing
equilibrium conditions.
c. During the ducted outdoor air test, at intervals of 5 minutes
or less, measure the parameters required according to the indoor
air enthalpy method and the outdoor air enthalpy method for the
prescribed 30 minutes.
d. For cooling mode ducted outdoor air tests, calculate capacity
based on outdoor air-enthalpy measurements as specified in sections
7.3.3.2 and 7.3.3.3 of ANSI/ASHRAE 37-2009 (incorporated by
reference, see § 430.3). For heating mode ducted tests, calculate
heating capacity based on outdoor air-enthalpy measurements as
specified in sections 7.3.4.2 and 7.3.3.4.3 of the same ANSI/ASHRAE
Standard. Adjust the outdoor-side capacity according to section
7.3.3.4 of ANSI/ASHRAE 37-2009 to account for line losses when
testing split systems. As described in section 8.6.2 of ANSI/ASHRAE
37-2009, use the outdoor air volume rate as measured during the
ducted outdoor air tests to calculate capacity for checking the
agreement with the capacity calculated using the indoor air
enthalpy method.
3.11.2 If Using the Compressor Calibration Method as the Secondary
Test Method
a. Conduct separate calibration tests using a calorimeter to
determine the refrigerant flow rate. Or for cases where the
superheat of the refrigerant leaving the evaporator is less than 5
°F, use the calorimeter to measure total capacity rather than
refrigerant flow rate. Conduct these calibration tests at the same
test conditions as specified for the tests in this appendix.
Operate the unit for at least one hour or until obtaining
equilibrium conditions before collecting data that will be used in
determining the average refrigerant flow rate or total capacity.
Sample the data at equal intervals that span 5 minutes or less.
Determine average flow rate or average capacity from data sampled
over a 30-minute period where the Table 9 (cooling) or the Table 16
(heating) tolerances are satisfied. Otherwise, conduct the
calibration tests according to sections 5, 6, 7, and 8 of ASHRAE
23.1-2010 (incorporated by reference, see § 430.3); sections 5, 6,
7, 8, 9, and 11 of ASHRAE 41.9-2011 (incorporated by reference, see
§ 430.3); and section 7.4 of ANSI/ASHRAE 37-2009 (incorporated by
reference, see § 430.3).
b. Calculate space cooling and space heating capacities using
the compressor calibration method measurements as specified in
section 7.4.5 and 7.4.6 respectively, of ANSI/ASHRAE 37-2009.
3.11.3 If Using the Refrigerant-Enthalpy Method as the Secondary
Test Method
Conduct this secondary method according to section 7.5 of
ANSI/ASHRAE 37-2009. Calculate space cooling and heating capacities
using the refrigerant-enthalpy method measurements as specified in
sections 7.5.4 and 7.5.5, respectively, of the same ASHRAE
Standard.
3.12 Rounding of Space Conditioning Capacities for Reporting
Purposes
a. When reporting rated capacities, round them off as specified
in § 430.23 (for a single unit) and in 10 CFR 429.16 (for a
sample).
b. For the capacities used to perform the calculations in
section 4 of this appendix, however, round only to the nearest
integer.
3.13 Laboratory Testing to Determine Off Mode Average Power Ratings
Voltage tolerances: As a percentage of reading, test operating
tolerance shall be 2.0 percent and test condition tolerance shall
be 1.5 percent (see section 1.2 of this appendix for definitions of
these tolerances).
Conduct one of the following tests: If the central air
conditioner or heat pump lacks a compressor crankcase heater,
perform the test in section 3.13.1 of this appendix; if the central
air conditioner or heat pump has a compressor crankcase heater that
lacks controls and is not self-regulating, perform the test in
section 3.13.1 of this appendix; if the central air conditioner or
heat pump has a crankcase heater with a fixed power input
controlled with a thermostat that measures ambient temperature and
whose sensing element temperature is not affected by the heater,
perform the test in section 3.13.1 of this appendix; if the central
air conditioner or heat pump has a compressor crankcase heater
equipped with self-regulating control or with controls for which
the sensing element temperature is affected by the heater, perform
the test in section 3.13.2 of this appendix.
3.13.1 This Test Determines the Off Mode Average Power Rating for
Central Air Conditioners and Heat Pumps That Lack a Compressor
Crankcase Heater, or Have a Compressor Crankcase Heating System
That Can Be Tested Without Control of Ambient Temperature During
the Test. This Test Has No Ambient Condition Requirements
a. Test Sample Set-up and Power Measurement: For coil-only
systems, provide a furnace or modular blower that is compatible
with the system to serve as an interface with the thermostat (if
used for the test) and to provide low-voltage control circuit
power. Make all control circuit connections between the furnace (or
modular blower) and the outdoor unit as specified by the
manufacturer's installation instructions. Measure power supplied to
both the furnace or modular blower and power supplied to the
outdoor unit. Alternatively, provide a compatible transformer to
supply low-voltage control circuit power, as described in section
2.2.d of this appendix. Measure transformer power, either supplied
to the primary winding or supplied by the secondary winding of the
transformer, and power supplied to the outdoor unit. For blower
coil and single-package systems, make all control circuit
connections between components as specified by the manufacturer's
installation instructions, and provide power and measure power
supplied to all system components.
b. Configure Controls: Configure the controls of the central air
conditioner or heat pump so that it operates as if connected to a
building thermostat that is set to the OFF position. Use a
compatible building thermostat if necessary to achieve this
configuration. For a thermostat-controlled crankcase heater with a
fixed power input, bypass the crankcase heater thermostat if
necessary to energize the heater.
c. Measure P2x: If the unit has a crankcase heater time
delay, make sure that time delay function is disabled or wait until
delay time has passed. Determine the average power from non-zero
value data measured over a 5-minute interval of the non-operating
central air conditioner or heat pump and designate the average
power as P2x, the heating season total off mode power.
d. Measure Px for coil-only split systems and for blower
coil split systems for which a furnace or a modular blower is the
designated air mover: Disconnect all low-voltage wiring for the
outdoor components and outdoor controls from the
low-voltage transformer. Determine the average power from non-zero
value data measured over a 5-minute interval of the power supplied
to the (remaining) low-voltage components of the central air
conditioner or heat pump, or low-voltage power, Px. This
power measurement does not include line power supplied to the
outdoor unit. It is the line power supplied to the air mover, or,
if a compatible transformer is used instead of an air mover, it is
the line power supplied to the transformer primary coil. If a
compatible transformer is used instead of an air mover and power
output of the low-voltage secondary circuit is measured, Px
is zero.
e. Calculate P2: Set the number of compressors equal to
the unit's number of single-stage compressors plus 1.75 times the
unit's number of compressors that are not single-stage.
For single-package systems and blower coil split systems for
which the designated air mover is not a furnace or modular blower,
divide the heating season total off mode power (P2x) by the
number of compressors to calculate P2, the heating season
per-compressor off mode power. Round P2 to the nearest watt.
The expression for calculating P2 is as follows:
For coil-only split systems and blower coil split systems for
which a furnace or a modular blower is the designated air mover,
subtract the low-voltage power (Px) from the heating season
total off mode power (P2x) and divide by the number of
compressors to calculate P2, the heating season
per-compressor off mode power. Round P2 to the nearest watt.
The expression for calculating P2 is as follows:
f. Shoulder-season per-compressor off mode power, P1: If the
system does not have a crankcase heater, has a crankcase heater
without controls that is not self-regulating, or has a value for
the crankcase heater turn-on temperature (as certified in the DOE
Compliance Certification Database) that is higher than 71 °F, P1 is
equal to P2.
Otherwise, de-energize the crankcase heater (by removing the
thermostat bypass or otherwise disconnecting only the power supply
to the crankcase heater) and repeat the measurement as described in
section 3.13.1.c of this appendix. Designate the measured average
power as P1x, the shoulder season total off mode power.
Determine the number of compressors as described in section
3.13.1.e of this appendix.
For single-package systems and blower coil systems for which the
designated air mover is not a furnace or modular blower, divide the
shoulder season total off mode power (P1x) by the number of
compressors to calculate P1, the shoulder season
per-compressor off mode power. Round P1 to the nearest watt.
The expression for calculating P1 is as follows:
For coil-only split systems and blower coil split systems for
which a furnace or a modular blower is the designated air mover,
subtract the low-voltage power (Px) from the shoulder season
total off mode power (P1x) and divide by the number of
compressors to calculate P1, the shoulder season
per-compressor off mode power. Round P1 to the nearest watt.
The expression for calculating P1 is as follows:
3.13.2
This Test Determines the Off Mode Average Power Rating for Central
Air Conditioners and Heat Pumps for Which Ambient Temperature Can
Affect the Measurement of Crankcase Heater Power
a. Test Sample Set-up and Power Measurement: Set up the test and
measurement as described in section 3.13.1.a of this appendix.
b. Configure Controls: Position a temperature sensor to measure
the outdoor dry-bulb temperature in the air between 2 and 6 inches
from the crankcase heater control temperature sensor or, if no such
temperature sensor exists, position it in the air between 2 and 6
inches from the crankcase heater. Utilize the temperature
measurements from this sensor for this portion of the test
procedure. Configure the controls of the central air conditioner or
heat pump so that it operates as if connected to a building
thermostat that is set to the OFF position. Use a compatible
building thermostat if necessary to achieve this configuration.
Conduct the test after completion of the B, B1, or B2 test.
Alternatively, start the test when the outdoor dry-bulb temperature
is at 82 °F and the temperature of the compressor shell (or
temperature of each compressor's shell if there is more than one
compressor) is at least 81 °F. Then adjust the outdoor temperature
at a rate of change of no more than 20 °F per hour and achieve an
outdoor dry-bulb temperature of 72 °F. Maintain this temperature
within ±2 °F while making the power measurement, as described in
section 3.13.2.c of this appendix.
c. Measure P1x: If the unit has a crankcase heater time
delay, make sure that time delay function is disabled or wait until
delay time has passed. Determine the average power from non-zero
value data measured over a 5-minute interval of the non-operating
central air conditioner or heat pump and designate the average
power as P1x, the shoulder season total off mode power. For
units with crankcase heaters which operate during this part of the
test and whose controls cycle or vary crankcase heater power over
time, the test period shall consist of three complete crankcase
heater cycles or 18 hours, whichever comes first. Designate the
average power over the test period as P1x, the shoulder
season total off mode power.
d. Reduce outdoor temperature: Approach the target outdoor
dry-bulb temperature by adjusting the outdoor temperature at a rate
of change of no more than 20 °F per hour. This target temperature
is five degrees Fahrenheit less than the temperature specified by
the manufacturer in the DOE Compliance Certification Database at
which the crankcase heater turns on. Maintain the target
temperature within ±2 °F while making the power measurement, as
described in section 3.13.2.e of this appendix.
e. Measure P2x: If the unit has a crankcase heater time
delay, make sure that time delay function is disabled or wait until
delay time has passed. Determine the average non-zero power of the
non-operating central air conditioner or heat pump over a 5-minute
interval and designate it as P2x, the heating season total
off mode power. For units with crankcase heaters whose controls
cycle or vary crankcase heater power over time, the test period
shall consist of three complete crankcase heater cycles or 18
hours, whichever comes first. Designate the average power over the
test period as P2x, the heating season total off mode
power.
f. Measure Px for coil-only split systems and for blower
coil split systems for which a furnace or modular blower is the
designated air mover: Disconnect all low-voltage wiring for the
outdoor components and outdoor controls from the
low-voltage transformer. Determine the average power from non-zero
value data measured over a 5-minute interval of the power supplied
to the (remaining) low-voltage components of the central air
conditioner or heat pump, or low-voltage power, Px.. This
power measurement does not include line power supplied to the
outdoor unit. It is the line power supplied to the air mover, or,
if a compatible transformer is used instead of an air mover, it is
the line power supplied to the transformer primary coil. If a
compatible transformer is used instead of an air mover and power
output of the low-voltage secondary circuit is measured, Px
is zero.
g. Calculate P1:
Set the number of compressors equal to the unit's number of
single-stage compressors plus 1.75 times the unit's number of
compressors that are not single-stage.
For single-package systems and blower coil split systems for
which the air mover is not a furnace or modular blower, divide the
shoulder season total off mode power (P1x) by the number of
compressors to calculate P1, the shoulder season
per-compressor off mode power. Round to the nearest watt. The
expression for calculating P1 is as follows:
For coil-only split systems and blower coil split systems for
which a furnace or a modular blower is the designated air mover,
subtract the low-voltage power (Px) from the shoulder season
total off mode power (P1x) and divide by the number of
compressors to calculate P1, the shoulder season
per-compressor off mode power. Round to the nearest watt. The
expression for calculating P1 is as follows:
h. Calculate P2:
Determine the number of compressors as described in section
3.13.2.g of this appendix.
For single-package systems and blower coil split systems for
which the air mover is not a furnace, divide the heating season
total off mode power (P2x) by the number of compressors to
calculate P2, the heating season per-compressor off mode
power. Round to the nearest watt. The expression for calculating
P2 is as follows:
For coil-only split systems and blower coil split systems for
which a furnace or a modular blower is the designated air mover,
subtract the low-voltage power (Px) from the heating season
total off mode power (P2x) and divide by the number of
compressors to calculate P2, the heating season
per-compressor off mode power. Round to the nearest watt. The
expression for calculating P2 is as follows:
4.
Calculations of Seasonal Performance Descriptors 4.1 Seasonal
Energy Efficiency Ratio (SEER) Calculations. SEER must be
calculated as follows: For equipment covered under sections 4.1.2,
4.1.3, and 4.1.4 of this appendix, evaluate the seasonal energy
efficiency ratio, where: Tj = the outdoor
bin temperature, °F. Outdoor temperatures are grouped or “binned.”
Use bins of 5 °F with the 8 cooling season bin temperatures being
67, 72, 77, 82, 87, 92, 97, and 102 °F. j = the bin number. For
cooling season calculations, j ranges from 1 to 8.
Additionally, for sections 4.1.2, 4.1.3, and 4.1.4 of this
appendix, use a building cooling load, BL(Tj). When referenced,
evaluate BL(Tj) for cooling using,
where:
Q ck=2(95) = the space cooling capacity determined from the A2
test and calculated as specified in section 3.3 of this appendix,
Btu/h.
1.1 = sizing factor, dimensionless.
The temperatures 95 °F and 65 °F in the building load equation
represent the selected outdoor design temperature and the zero-load
base temperature, respectively.
4.1.1 SEER Calculations for a Blower Coil System Having a
Single-Speed Compressor and Either a Fixed-Speed Indoor Blower or a
Constant-Air-Volume-Rate Indoor Blower, or a Coil-Only System Air
Conditioner or Heat Pump
a. Evaluate the seasonal energy efficiency ratio, expressed in
units of Btu/watt-hour, using:
SEER = PLF(0.5) * EERB where: PLF(0.5) = 1 − 0.5
· CD c, the part-load performance factor evaluated at a cooling
load factor of 0.5, dimensionless.
b. Refer to section 3.3 of this appendix regarding the
definition and calculation of Q c(82) and E c(82). Evaluate the
cooling mode cyclic degradation factor CD c as specified in section
3.5.3 of this appendix.
4.1.2 SEER Calculations for an Air Conditioner or Heat Pump Having
a Single-Speed Compressor and a Variable-Speed
Variable-Air-Volume-Rate Indoor Blower 4.1.2.1 Units Covered by
Section 3.2.2.1 of This Appendix Where Indoor Blower Capacity
Modulation Correlates With the Outdoor Dry Bulb Temperature
The manufacturer must provide information on how the indoor air
volume rate or the indoor blower speed varies over the outdoor
temperature range of 67 °F to 102 °F. Calculate SEER using Equation
4.1-1. Evaluate the quantity qc(Tj)/N in Equation 4.1-1 using,
where:
Q c(Tj) =
the space cooling capacity of the test unit when operating at
outdoor temperature, Tj, Btu/h. nj/N = fractional bin hours for the
cooling season; the ratio of the number of hours during the cooling
season when the outdoor temperature fell within the range
represented by bin temperature Tj to the total number of hours in
the cooling season, dimensionless.
a. For the space cooling season, assign nj/N as specified in
Table 19. Use Equation 4.1-2 to calculate the building load,
BL(Tj). Evaluate Q c(Tj) using,
where:
the space
cooling capacity of the test unit at outdoor temperature Tj if
operated at the cooling minimum air volume rate, Btu/h. the space cooling
capacity of the test unit at outdoor temperature Tj if operated at
the Cooling full-load air volume rate, Btu/h.
b. For units where indoor blower speed is the primary control
variable, FPck=1 denotes the fan speed used during the required A1
and B1 tests (see section 3.2.2.1 of this appendix), FPck=2 denotes
the fan speed used during the required A2 and B2 tests, and FPc(Tj)
denotes the fan speed used by the unit when the outdoor temperature
equals Tj. For units where indoor air volume rate is the primary
control variable, the three FPc's are similarly defined only now
being expressed in terms of air volume rates rather than fan
speeds. Refer to sections 3.2.2.1, 3.1.4 to 3.1.4.2, and 3.3 of
this appendix regarding the definitions and calculations of Q
ck=1(82), Q ck=1(95), Q ck=2(82), and Q ck=2(95).
where:
PLFj = 1 − CD c · [1 − X(Tj)], the part load factor, dimensionless.
E c(Tj) = the electrical power consumption of the test unit when
operating at outdoor temperature Tj, W.
c. The quantities X(Tj) and nj/N are the same quantities as used
in Equation 4.1.2-1. Evaluate the cooling mode cyclic degradation
factor CD c as specified in section 3.5.3 of this appendix.
d. Evaluate E c(Tj) using,
e. The parameters FPck=1, and FPck=2, and FPc(Tj) are the same
quantities that are used when evaluating Equation 4.1.2-2. Refer to
sections 3.2.2.1, 3.1.4 to 3.1.4.2, and 3.3 of this appendix
regarding the definitions and calculations of E ck=1(82), E
ck=1(95), E ck=2(82), and E ck=2(95).
4.1.2.2 Units Covered by Section 3.2.2.2 of This Appendix Where
Indoor Blower Capacity Modulation Is Used To Adjust the Sensible to
Total Cooling Capacity Ratio. Calculate SEER as specified in
section 4.1.1 of this appendix.
4.1.3 SEER Calculations for an Air Conditioner or Heat Pump Having
a Two-Capacity Compressor
Calculate SEER using Equation 4.1-1. Evaluate the space cooling
capacity, Q ck=1 (Tj), and electrical power consumption, E ck=1
(Tj), of the test unit when operating at low compressor capacity
and outdoor temperature Tj using,
where Q ck=1 (82)
and E ck=1 (82) are determined from the B1 test, Q ck=1 (67) and E
ck=1 (67) are determined from the F1 test, and all four quantities
are calculated as specified in section 3.3 of this appendix.
Evaluate the space cooling capacity, Q ck=2 (Tj), and electrical
power consumption, E ck=2 (Tj), of the test unit when operating at
high compressor capacity and outdoor temperature Tj using,
where Q ck=2(95)
and E ck=2(95) are determined from the A2 test, Q ck=2(82), and E
ck=2(82), are determined from the B2test, and all are calculated as
specified in section 3.3 of this appendix.
The calculation of Equation 4.1-1 quantities qc(Tj)/N and
ec(Tj)/N differs depending on whether the test unit would operate
at low capacity (section 4.1.3.1 of this appendix), cycle between
low and high capacity (section 4.1.3.2 of this appendix), or
operate at high capacity (sections 4.1.3.3 and 4.1.3.4 of this
appendix) in responding to the building load. For units that lock
out low capacity operation at higher outdoor temperatures, the
outdoor temperature at which the unit locks out must be that
specified by the manufacturer in the certification report so that
the appropriate equations are used. Use Equation 4.1-2 to calculate
the building load, BL(Tj), for each temperature bin.
4.1.3.1 Steady-State Space Cooling Capacity at Low Compressor
Capacity Is Greater Than or Equal to the Building Cooling Load at
Temperature Tj, Q ck=1(Tj) ≥BL(Tj) where: Xk=1(Tj) =
BL(Tj)/Q ck=1(Tj), the cooling mode low capacity load factor for
temperature bin j, dimensionless. PLFj = 1 − CD c · [1 − Xk=1(Tj)],
the part load factor, dimensionless.
Obtain the fractional bin hours for the cooling season, nj/N,
from Table 19. Use Equations 4.1.3-1 and 4.1.3-2, respectively, to
evaluate Q ck=1(Tj) and E ck=1(Tj). Evaluate the cooling mode
cyclic degradation factor CD c as specified in section 3.5.3 of
this appendix.
Table 19 - Distribution of Fractional Hours
Within Cooling Season Temperature Bins
Bin number,
j
Bin
temperature
range
°F
Representative temperature
for bin
°F
Fraction of of total
temperature
bin hours,
nj/N
1
65-69
67
0.214
2
70-74
72
0.231
3
75-79
77
0.216
4
80-84
82
0.161
5
85-89
87
0.104
6
90-94
92
0.052
7
95-99
97
0.018
8
100-104
102
0.004
4.1.3.2 Unit Alternates Between High (k=2) and Low (k=1) Compressor
Capacity To Satisfy the Building Cooling Load at Temperature Tj, Q
ck=1(Tj) BL(Tj) Q ck=2(Tj) Xk=2(Tj) = 1 −
Xk=1(Tj), the cooling mode, high capacity load factor for
temperature bin j, dimensionless.
Obtain the fractional bin hours for the cooling season, nj/N,
from Table 19. Use Equations 4.1.3-1 and 4.1.3-2, respectively, to
evaluate Q ck=1(Tj) and E ck=1(Tj). Use Equations 4.1.3-3 and
4.1.3-4, respectively, to evaluate Q ck=2(Tj) and E ck=2(Tj).
4.1.3.3 Unit Only Operates at High (k=2) Compressor Capacity at
Temperature Tj and Its Capacity Is Greater Than the Building
Cooling Load, BL(Tj) Q ck=2(Tj). This section applies to units that
lock out low compressor capacity operation at higher outdoor
temperatures. where: Xk=2(Tj) =
BL(Tj)/Q ck=2(Tj), the cooling mode high capacity load factor for
temperature bin j, dimensionless. PLFj = 1 − CDc(k =
2) * [1 − Xk=2(Tj) the part load factor, dimensionless.
4.1.3.4
Unit Must Operate Continuously at High (k=2) Compressor Capacity at
Temperature Tj, BL(Tj) ≥Q ck=2(Tj)
Obtain the fractional bin hours for the cooling season, nj/N,
from Table 19. Use Equations 4.1.3-3 and 4.1.3-4, respectively, to
evaluate Q ck=2(Tj) and E ck=2(Tj).
4.1.4 SEER Calculations for an Air Conditioner or Heat Pump Having
a Variable-Speed Compressor
Calculate SEER using Equation 4.1-1. Evaluate the space cooling
capacity, Q ck=1(Tj), and electrical power consumption, E ck=1(Tj),
of the test unit when operating at minimum compressor speed and
outdoor temperature Tj. Use,
where Q ck=1(82) and E ck=1(82) are determined from the B1 test,
Q ck=1(67) and E ck=1(67) are determined from the F1 test, and all
four quantities are calculated as specified in section 3.3 of this
appendix.
Evaluate the space cooling capacity, Q ck=2(Tj), and electrical
power consumption, E ck=2(Tj), of the test unit when operating at
full compressor speed and outdoor temperature Tj. Use Equations
4.1.3-3 and 4.1.3-4, respectively, where Q ck=2(95) and E ck=2(95)
are determined from the A2 test, Q ck=2(82) and E ck=2(82) are
determined from the B2 test, and all four quantities are calculated
as specified in section 3.3 of this appendix. Calculate the space
cooling capacity, Q ck=v(Tj), and electrical power consumption, E
ck=v(Tj), of the test unit when operating at outdoor temperature Tj
and the intermediate compressor speed used during the section 3.2.4
(and Table 8) EV test of this appendix using,
where Q ck=v(87) and E ck=v(87) are determined from the EV test
and calculated as specified in section 3.3 of this appendix.
Approximate the slopes of the k=v intermediate speed cooling
capacity and electrical power input curves, MQ and ME, as
follows:
Use Equations 4.1.4-1 and 4.1.4-2, respectively, to calculate Q
ck=1(87) and E ck=1(87).
4.1.4.1 Steady-State Space Cooling Capacity When Operating at
Minimum Compressor Speed Is Greater Than or Equal to the Building
Cooling Load at Temperature Tj, Q ck=1(Tj) ≥BL(Tj) where: Xk=1(Tj) =
BL(Tj)/Q ck=1(Tj), the cooling mode minimum speed load factor for
temperature bin j, dimensionless. PLFj = 1 − CD c · [1 − Xk=1(Tj)],
the part load factor, dimensionless. nj/N = fractional bin hours
for the cooling season; the ratio of the number of hours during the
cooling season when the outdoor temperature fell within the range
represented by bin temperature Tj to the total number of hours in
the cooling season, dimensionless.
Obtain the fractional bin hours for the cooling season, nj/N,
from Table 19. Use Equations 4.1.3-1 and 4.1.3-2, respectively, to
evaluate Q c k=l (Tj) and E c k=l (Tj). Evaluate the cooling mode
cyclic degradation factor CD c as specified in section 3.5.3 of
this appendix.
4.1.4.2 Unit Operates at an Intermediate Compressor Speed (k=i) In
Order To Match the Building Cooling Load at Temperature Tj,Q
ck=1(Tj) BL(Tj) Q ck=2(Tj) where: Q ck=i(Tj)
= BL(Tj), the space cooling capacity delivered by the unit in
matching the building load at temperature Tj, Btu/h. The matching
occurs with the unit operating at compressor speed k = i. EERk=i(Tj) = the
steady-state energy efficiency ratio of the test unit when
operating at a compressor speed of k = i and temperature Tj, Btu/h
per W.
Obtain the fractional bin hours for the cooling season, nj/N,
from Table 19. For each temperature bin where the unit operates at
an intermediate compressor speed, determine the energy efficiency
ratio EERk=i(Tj) using,
EERk=i(Tj) = A + B · Tj + C · Tj 2.
For each unit, determine the coefficients A, B, and C by
conducting the following calculations once:
where: T1
= the outdoor temperature at which the unit, when operating at
minimum compressor speed, provides a space cooling capacity that is
equal to the building load (Q ck=l(Tl) = BL(T1)), °F. Determine T1
by equating Equations 4.1.3-1 and 4.1-2 and solving for outdoor
temperature. Tv = the outdoor temperature at which the unit, when
operating at the intermediate compressor speed used during the
section 3.2.4 EV test of this appendix, provides a space cooling
capacity that is equal to the building load (Q ck=v(Tv) = BL(Tv)),
°F. Determine Tv by equating Equations 4.1.4-3 and 4.1-2 and
solving for outdoor temperature. T2 = the outdoor temperature at
which the unit, when operating at full compressor speed, provides a
space cooling capacity that is equal to the building load (Q
ck=2(T2) = BL(T2)), °F. Determine T2 by equating Equations 4.1.3-3
and 4.1-2 and solving for outdoor temperature. 4.1.4.3 Unit Must
Operate Continuously at Full (k=2) Compressor Speed at Temperature
Tj, BL(Tj) ≥Q ck=2(Tj). Evaluate the Equation 4.1-1 Quantities
as
specified in section 4.1.3.4 of this appendix with the
understanding that Q ck=2(Tj) and E ck=2(Tj) correspond to full
compressor speed operation and are derived from the results of the
tests specified in section 3.2.4 of this appendix. 4.1.5 SEER
Calculations for an Air Conditioner or Heat Pump Having a Single
Indoor Unit With Multiple Indoor Blowers
Calculate SEER using Eq. 4.1-1, where qc(Tj)/N and ec(Tj)/N are
evaluated as specified in the applicable subsection.
4.1.5.1 For Multiple Indoor Blower Systems That Are Connected to a
Single, Single-Speed Outdoor Unit
a. Calculate the space cooling capacity, Q
ck=1(Tj), and electrical power consumption, E
ck=1(Tj), of the test unit when operating at the cooling
minimum air volume rate and outdoor temperature Tj using the
equations given in section 4.1.2.1 of this appendix. Calculate the
space cooling capacity, Q ck=2(Tj), and electrical
power consumption, E ck=2(Tj), of the test unit when
operating at the cooling full-load air volume rate and outdoor
temperature Tj using the equations given in section 4.1.2.1 of this
appendix. In evaluating the section 4.1.2.1 equations, determine
the quantities Q ck=1(82) and E ck=1(82) from the B1
test, Q ck=1(95) and E ck=1(95) from the Al test,
Q ck=2(82) and E ck=2(82) from the B2 test,
andQ ck=2(95) and E ck=2(95) from the A2 test.
Evaluate all eight quantities as specified in section 3.3 of this
appendix. Refer to section 3.2.2.1 and Table 6 of this appendix for
additional information on the four referenced laboratory tests.
b. Determine the cooling mode cyclic degradation coefficient,
CDc, as per sections 3.2.2.1 and 3.5 to 3.5.3 of this appendix.
Assign this same value to CDc(K=2).
c. Except for using the above values of Q
ck=1(Tj), E ck=1(Tj), E
ck=2(Tj), Q ck=2(Tj), CDc, and CDc (K=2),
calculate the quantities qc(Tj)/N and ec(Tj)/N as specified in
section 4.1.3.1 of this appendix for cases where Q
ck=1(Tj) ≥BL(Tj). For all other outdoor bin temperatures,
Tj, calculate qc(Tj)/N and ec(Tj)/N as specified in section 4.1.3.3
of this appendix if Q ck=2(Tj) >BL (Tj) or as
specified in section 4.1.3.4 of this appendix if Q
ck=2(Tj) ≤BL(Tj).
4.1.5.2 Unit Operates at an Intermediate Compressor Speed (k=i) In
Order To Match the Building Cooling Load at Temperature Tj,Q
ck=1(Tj) <BL(Tj) <Q ck=2(Tj) where, Q ck=i(Tj)
= BL(Tj), the space cooling capacity delivered by the unit in
matching the building load at temperature Tj, Btu/h. The matching
occurs with the unit operating at compressor speed k = i. EERk=i(Tj), the
steady-state energy efficiency ratio of the test unit when
operating at a compressor speed of k = i and temperature Tj, Btu/h
per W.
Obtain the fractional bin hours for the cooling season, nj/N,
from Table 19. For each temperature bin where the unit operates at
an intermediate compressor speed, determine the energy efficiency
ratio EERk=i(Tj) using the following equations,
For each temperature bin where Q ck=1(Tj) <BL(Tj) <Q
ck=v(Tj),
For each temperature bin where Q ck=v(Tj) ≤BL(Tj) <Q
ck=2(Tj),
Where:
EERk=1(Tj) is the steady-state energy efficiency ratio of the test
unit when operating at minimum compressor speed and temperature Tj,
Btu/h per W, calculated using capacity Q ck=1(Tj) calculated using
Equation 4.1.4-1 and electrical power consumption E ck=1(Tj)
calculated using Equation 4.1.4-2; EERk=v(Tj) is the steady-state
energy efficiency ratio of the test unit when operating at
intermediate compressor speed and temperature Tj, Btu/h per W,
calculated using capacity Q ck=v(Tj) calculated using Equation
4.1.4-3 and electrical power consumption E ck=v(Tj) calculated
using Equation 4.1.4-4; EERk=2(Tj) is the steady-state energy
efficiency ratio of the test unit when operating at full compressor
speed and temperature Tj, Btu/h per W, calculated using capacity Q
ck=2(Tj) and electrical power consumption E ck=2(Tj), both
calculated as described in section 4.1.4; and BL(Tj) is the
building cooling load at temperature Tj, Btu/h. 4.2 Heating
Seasonal Performance Factor (HSPF) Calculations
Unless an approved alternative efficiency determination method
is used, as set forth in 10 CFR 429.70(e), HSPF must be calculated
as follows: Six generalized climatic regions are depicted in Figure
1 and otherwise defined in Table 20. For each of these regions and
for each applicable standardized design heating requirement,
evaluate the heating seasonal performance factor using,
where:
e2(Tj)/N = The ratio of the electrical energy consumed by the heat
pump during periods of the space heating season when the outdoor
temperature fell within the range represented by bin temperature Tj
to the total number of hours in the heating season (N), W. For heat
pumps having a heat comfort controller, this ratio may also include
electrical energy used by resistive elements to maintain a minimum
air delivery temperature (see 4.2.5). RH(Tj)/N = The ratio of the
electrical energy used for resistive space heating during periods
when the outdoor temperature fell within the range represented by
bin temperature Tj to the total number of hours in the heating
season (N), W. Except as noted in section 4.2.5 of this appendix,
resistive space heating is modeled as being used to meet that
portion of the building load that the heat pump does not meet
because of insufficient capacity or because the heat pump
automatically turns off at the lowest outdoor temperatures. For
heat pumps having a heat comfort controller, all or part of the
electrical energy used by resistive heaters at a particular bin
temperature may be reflected in eh(Tj)/N (see section 4.2.5 of this
appendix). Tj = the outdoor bin temperature, °F. Outdoor
temperatures are “binned” such that calculations are only performed
based one temperature within the bin. Bins of 5 °F are used. nj/N=
Fractional bin hours for the heating season; the ratio of the
number of hours during the heating season when the outdoor
temperature fell within the range represented by bin temperature Tj
to the total number of hours in the heating season, dimensionless.
Obtain nj/N values from Table 20. j = the bin number,
dimensionless. J = for each generalized climatic region, the total
number of temperature bins, dimensionless. Referring to Table 20, J
is the highest bin number (j) having a nonzero entry for the
fractional bin hours for the generalized climatic region of
interest. Fdef = the demand defrost credit described in section
3.9.2 of this appendix, dimensionless. BL(Tj) = the building space
conditioning load corresponding to an outdoor temperature of Tj;
the heating season building load also depends on the generalized
climatic region's outdoor design temperature and the design heating
requirement, Btu/h.
Table 20 - Generalized Climatic Region
Information
Region No.
I
II
III
IV
V
VI
Heating Load
Hours, HLH
750
1,250
1,750
2,250
2,750
*2,750
Outdoor Design
Temperature, TOD
37
27
17
5
−10
30
j Tj ( °F)
Fractional Bin
Hours, nj/N
1 62
.291
.215
.153
.132
.106
.113
2 57
.239
.189
.142
.111
.092
.206
3 52
.194
.163
.138
.103
.086
.215
4 47
.129
.143
.137
.093
.076
.204
5 42
.081
.112
.135
.100
.078
.141
6 37
.041
.088
.118
.109
.087
.076
7 32
.019
.056
.092
.126
.102
.034
8 27
.005
.024
.047
.087
.094
.008
9 22
.001
.008
.021
.055
.074
.003
10 17
0
.002
.009
.036
.055
0
11 12
0
0
.005
.026
.047
0
12 7
0
0
.002
.013
.038
0
13 2
0
0
.001
.006
.029
0
14 −3
0
0
0
.002
.018
0
15 −8
0
0
0
.001
.010
0
16 −13
0
0
0
0
.005
0
17 −18
0
0
0
0
.002
0
18 −23
0
0
0
0
.001
0
* Pacific Coast Region.
Evaluate the building heating load using
Where:
TOD = the outdoor design temperature, °F. An outdoor design
temperature is specified for each generalized climatic region in
Table 20. C = 0.77, a correction factor which tends to improve the
agreement between calculated and measured building loads,
dimensionless. DHR = the design heating requirement (see section
1.2 of this appendix, Definitions), Btu/h.
Calculate the minimum and maximum design heating requirements
for each generalized climatic region as follows:
where Q h
k(47) is expressed in units of Btu/h and otherwise defined as
follows:
a. For a single-speed heat pump tested as per section 3.6.1 of
this appendix, Q h k(47) = Q h(47), the space heating capacity
determined from the H1 test.
b. For a section 3.6.2 single-speed heat pump or a two-capacity
heat pump not covered by item d, Q h k(47) = Q hk=2(47), the space
heating capacity determined from the H1 or H12 test.
c. For a variable-speed heat pump, Q h k(47) = Q hk=N(47), the
space heating capacity determined from the H1N test.
d. For two-capacity, northern heat pumps (see section 1.2 of
this appendix, Definitions), Q kh(47) = Q k=1h(47), the space
heating capacity determined from the H11 test.
For all heat pumps, HSPF accounts for the heating delivered and
the energy consumed by auxiliary resistive elements when operating
below the balance point. This condition occurs when the building
load exceeds the space heating capacity of the heat pump condenser.
For HSPF calculations for all heat pumps, see either section 4.2.1,
4.2.2, 4.2.3, or 4.2.4 of this appendix, whichever applies.
For heat pumps with heat comfort controllers (see section 1.2 of
this appendix, Definitions), HSPF also accounts for resistive
heating contributed when operating above the
heat-pump-plus-comfort-controller balance point as a result of
maintaining a minimum supply temperature. For heat pumps having a
heat comfort controller, see section 4.2.5 of this appendix for the
additional steps required for calculating the HSPF.
4.2.1 Additional Steps for Calculating the HSPF of a Blower Coil
System Heat Pump Having a Single-Speed Compressor and Either a
Fixed-Speed Indoor Blower or a Constant-Air-Volume-Rate Indoor
Blower Installed, or a Coil-Only System Heat Pump Where: whichever is less;
the heating mode load factor for temperature bin j, dimensionless.
Q h(Tj) = the space heating capacity of the heat pump when
operating at outdoor temperature Tj, Btu/h. E h(Tj) = the
electrical power consumption of the heat pump when operating at
outdoor temperature Tj, W. δ(Tj) = the heat pump low temperature
cut-out factor, dimensionless. PLFj = 1 − C D h · [1 −X(Tj)] the
part load factor, dimensionless.
Use Equation 4.2-2 to determine BL(Tj). Obtain fractional bin
hours for the heating season, nj/N, from Table 20. Evaluate the
heating mode cyclic degradation factor C D h as specified in
section 3.8.1 of this appendix.
Determine the low temperature cut-out factor using
Where:
Toff = the outdoor temperature when the compressor is automatically
shut off, °F. (If no such temperature exists, Tj is always greater
than Toff and Ton). Ton = the outdoor temperature when the
compressor is automatically turned back on, if applicable,
following an automatic shut-off, °F.
Calculate Q h(Tj) and E h(Tj) using,
where Q h(47) and
E h(47) are determined from the H1 test and calculated as specified
in section 3.7 of this appendix; Q h(35) and E h(35) are determined
from the H2 test and calculated as specified in section 3.9.1 of
this appendix; and Q h(17) and E h(17) are determined from the H3
test and calculated as specified in section 3.10 of this appendix.
4.2.2 Additional Steps for Calculating the HSPF of a Heat Pump
Having a Single-Speed Compressor and a Variable-Speed,
Variable-Air-Volume-Rate Indoor Blower
The manufacturer must provide information about how the indoor
air volume rate or the indoor blower speed varies over the outdoor
temperature range of 65 °F to −23 °F. Calculate the quantities
in
Equation 4.2-1 as specified in section 4.2.1 of this appendix with
the exception of replacing references to the H1C test and section
3.6.1 of this appendix with the H1C1 test and section 3.6.2 of this
appendix. In addition, evaluate the space heating capacity and
electrical power consumption of the heat pump Q h(Tj) and E h(Tj)
using where the
space heating capacity and electrical power consumption at both low
capacity (k=1) and high capacity (k=2) at outdoor temperature Tj
are determined using
For units where indoor blower speed is the primary control
variable, FPhk=1 denotes the fan speed used during the required H11
and H31 tests (see Table 12), FPhk=2 denotes the fan speed used
during the required H12, H22, and H32 tests, and FPh(Tj) denotes
the fan speed used by the unit when the outdoor temperature equals
Tj. For units where indoor air volume rate is the primary control
variable, the three FPh's are similarly defined only now being
expressed in terms of air volume rates rather than fan speeds.
Determine Q hk=1(47) and E hk=1(47) from the H11 test, and Q
hk=2(47) and E hk=2(47) from the H12 test. Calculate all four
quantities as specified in section 3.7 of this appendix. Determine
Q hk=1(35) and E hk=1(35) as specified in section 3.6.2 of this
appendix; determine Q hk=2(35) and E hk=2(35) and from the H22 test
and the calculation specified in section 3.9 of this appendix.
Determine Q hk=1(17) and E hk=1(17) from the H31 test, and Q
hk=2(17) and E hk=2(17) from the H32 test. Calculate all four
quantities as specified in section 3.10 of this appendix.
4.2.3 Additional Steps for Calculating the HSPF of a Heat Pump
Having a Two-Capacity Compressor
The calculation of the Equation 4.2-1 quantities differ
depending upon whether the heat pump would operate at low capacity
(section 4.2.3.1 of this appendix), cycle between low and high
capacity (section 4.2.3.2 of this appendix), or operate at high
capacity (sections 4.2.3.3 and 4.2.3.4 of this appendix) in
responding to the building load. For heat pumps that lock out low
capacity operation at low outdoor temperatures, the outdoor
temperature at which the unit locks out must be that specified by
the manufacturer in the certification report so that the
appropriate equations can be selected.
a. Evaluate the space heating capacity and electrical power
consumption of the heat pump when operating at low compressor
capacity and outdoor temperature Tj using
b. Evaluate the space heating capacity and electrical power
consumption (Q hk=2(Tj) and E hk=2 (Tj)) of the heat pump when
operating at high compressor capacity and outdoor temperature Tj by
solving Equations 4.2.2-3 and 4.2.2-4, respectively, for k=2.
Determine Q hk=1(62) and E hk=1(62) from the H01 test, Q hk=1(47)
and E hk=1(47) from the H11 test, and Q hk=2(47) and E hk=2(47)
from the H12 test. Calculate all six quantities as specified in
section 3.7 of this appendix. Determine Q hk=2(35) and E hk=2(35)
from the H22 test and, if required as described in section 3.6.3 of
this appendix, determine Q hk=1(35) and E hk=1(35) from the H21
test. Calculate the required 35 °F quantities as specified in
section 3.9 of this appendix. Determine Q hk=2(17) and E hk=2(17)
from the H32 test and, if required as described in section 3.6.3 of
this appendix, determine Q hk=1(17) and E hk=1(17) from the H31
test. Calculate the required 17 °F quantities as specified in
section 3.10 of this appendix.
4.2.3.1 Steady-State Space Heating Capacity When Operating at Low
Compressor Capacity is Greater Than or Equal to the Building
Heating Load at Temperature Tj, Q hk=1(Tj) ≥BL(Tj) Where: Xk=1(Tj) =
BL(Tj)/Q hk=1(Tj), the heating mode low capacity load factor for
temperature bin j, dimensionless. PLFj = 1 − CD h · [ 1 −
Xk=1(Tj) ], the part load factor, dimensionless. δ′(Tj) = the low
temperature cutoff factor, dimensionless.
Evaluate the heating mode cyclic degradation factor CD h as
specified in section 3.8.1 of this appendix.
Determine the low temperature cut-out factor using
where
Toff and Ton are defined in section 4.2.1 of this appendix. Use the
calculations given in section 4.2.3.3 of this appendix, and not the
above, if:
a. The heat pump locks out low capacity operation at low outdoor
temperatures and
b. Tj is below this lockout threshold temperature.
4.2.3.2 Heat Pump Alternates Between High (k=2) and Low (k=1)
Compressor Capacity To Satisfy the Building Heating Load at a
Temperature Tj, Q hk=1(Tj) <BL(Tj) <Q hk=2(Tj) Xk=2(Tj) = 1 −
Xk=1(Tj) the heating mode, high capacity load factor for
temperaturebin j, dimensionless.
Determine the low temperature cut-out factor, δ′(Tj), using
Equation 4.2.3-3.
4.2.3.3 Heat Pump Only Operates at High (k=2) Compressor Capacity
at Temperature Tj and its Capacity Is Greater Than the Building
Heating Load, BL(Tj) <Q hk=2(Tj)
This section applies to units that lock out low compressor
capacity operation at low outdoor temperatures.
If the H1C2 test described in section 3.6.3 and Table 13 of this
appendix is not conducted, set CD h (k=2) equal to the default
value specified in section 3.8.1 of this appendix.
Determine the low temperature cut-out factor, δ(Tj), using
Equation 4.2.3-3.
4.2.3.4 Heat Pump Must Operate Continuously at High (k=2)
Compressor Capacity at Temperature Tj, BL(Tj) ≥Q hk=2(Tj) 4.2.4 Additional
Steps for Calculating the HSPF of a Heat Pump Having a
Variable-Speed Compressor
Calculate HSPF using Equation 4.2-1. Evaluate the space heating
capacity, Q hk=1(Tj), and electrical power consumption, E hk=1(Tj),
of the heat pump when operating at minimum compressor speed and
outdoor temperature Tj using
where Q hk=1(62)
and E hk=1(62) are determined from the H01 test, Q hk=1(47) and E
hk=1(47) are determined from the H11 test, and all four quantities
are calculated as specified in section 3.7 of this appendix.
Evaluate the space heating capacity, Q hk=2(Tj), and electrical
power consumption, E hk=2(Tj), of the heat pump when operating at
full compressor speed and outdoor temperature Tj by solving
Equations 4.2.2-3 and 4.2.2-4, respectively, for k=2. For Equation
4.2.2-3, use Q hcalck=2(47) to represent Q hk=2(47), and for
Equation 4.2.2-4, use E hcalck=2(47) to represent E hcalck=2(47) -
evaluate Q hcalck=2(47) and E hcalck=2(47) as specified in section
3.6.4b of this appendix.
where Q hk=v(35)
and E hk=v(35) are determined from the H2V test and calculated as
specified in section 3.9 of this appendix. Approximate the slopes
of the k=v intermediate speed heating capacity and electrical power
input curves, MQ and ME, as follows: 4.2.4.1
Steady-State Space Heating Capacity When Operating at Minimum
Compressor Speed Is Greater Than or Equal to the Building Heating
Load at Temperature Tj, Q hk=1(Tj ≥BL(Tj)
Evaluate the Equation 4.2-1 quantities
as
specified in section 4.2.3.1 of this appendix. Except now use
Equations 4.2.4-1 and 4.2.4-2 to evaluate Q hk=1(Tj) and E
hk=1(Tj), respectively, and replace section 4.2.3.1 references to
“low capacity” and section 3.6.3 of this appendix with “minimum
speed” and section 3.6.4 of this appendix. Also, the last sentence
of section 4.2.3.1 of this appendix does not apply. 4.2.4.2 Heat
Pump Operates at an Intermediate Compressor Speed (k=i) in Order To
Match the Building Heating Load at a Temperature Tj, Q hk=1(Tj)
<BL(Tj) <Q hk=2(Tj) and δ(Tj) is
evaluated using Equation 4.2.3-3 while, Q hk=i(Tj) = BL(Tj), the
space heating capacity delivered by the unit in matching the
building load at temperature (Tj), Btu/h. The matching occurs with
the heat pump operating at compressor speed k=i. COPk=i(Tj) = the
steady-state coefficient of performance of the heat pump when
operating at compressor speed k=i and temperature Tj,
dimensionless.
For each temperature bin where the heat pump operates at an
intermediate compressor speed, determine COPk=i(Tj) using the
following equations,
For each temperature bin where Q hk=1(Tj) <BL(Tj) <Q
hk=v(Tj),
For each temperature bin where Q hk=v(Tj) ≤BL(Tj) <Q
hk=2(Tj),
Where:
COPhk=1(Tj) is the steady-state coefficient of performance of the
heat pump when operating at minimum compressor speed and
temperature Tj, dimensionless, calculated using capacity Q hk=1(Tj)
calculated using Equation 4.2.4-1 and electrical power consumption
E hk=1(Tj) calculated using Equation 4.2.4-2; COPhk=v(Tj) is the
steady-state coefficient of performance of the heat pump when
operating at intermediate compressor speed and temperature Tj,
dimensionless, calculated using capacity Q hk=v(Tj) calculated
using Equation 4.2.4-3 and electrical power consumption E hk=v(Tj)
calculated using Equation 4.2.4-4; COPhk=2(Tj) is the steady-state
coefficient of performance of the heat pump when operating at full
compressor speed and temperature Tj, dimensionless, calculated
using capacity Q hk=2(Tj) and electrical power consumption E
hk=2(Tj), both calculated as described in section 4.2.4; and BL(Tj)
is the building heating load at temperature Tj, Btu/h. 4.2.4.3 Heat
Pump Must Operate Continuously at Full (k=2) Compressor Speed at
Temperature Tj, BL(Tj) ≥Q hk=2(Tj)
Evaluate the Equation 4.2-1 Quantities
as
specified in section 4.2.3.4 of this appendix with the
understanding that Q hk=2(Tj) and E hk=2(Tj) correspond to full
compressor speed operation and are derived from the results of the
specified section 3.6.4 tests of this appendix. 4.2.5 Heat Pumps
Having a Heat Comfort Controller
Heat pumps having heat comfort controllers, when set to maintain
a typical minimum air delivery temperature, will cause the heat
pump condenser to operate less because of a greater contribution
from the resistive elements. With a conventional heat pump,
resistive heating is only initiated if the heat pump condenser
cannot meet the building load (i.e., is delayed until a
second stage call from the indoor thermostat). With a heat comfort
controller, resistive heating can occur even though the heat pump
condenser has adequate capacity to meet the building load
(i.e., both on during a first stage call from the indoor
thermostat). As a result, the outdoor temperature where the heat
pump compressor no longer cycles (i.e., starts to run
continuously), will be lower than if the heat pump did not have the
heat comfort controller.
4.2.5.1 Blower Coil System Heat Pump Having a Heat Comfort
Controller: Additional Steps for Calculating the HSPF of a Heat
Pump Having a Single-Speed Compressor and Either a Fixed-Speed
Indoor Blower or a Constant-Air-Volume-Rate Indoor Blower
Installed, or a Coil-Only System Heat Pump
Calculate the space heating capacity and electrical power of the
heat pump without the heat comfort controller being active as
specified in section 4.2.1 of this appendix (Equations 4.2.1-4 and
4.2.1-5) for each outdoor bin temperature, Tj, that is listed in
Table 20. Denote these capacities and electrical powers by using
the subscript “hp” instead of “h.” Calculate the mass flow rate
(expressed in pounds-mass of dry air per hour) and the specific
heat of the indoor air (expressed in Btu/lbmda · °F) from the
results of the H1 test using:
where V
s, V mx, v′n (or vn), and Wn are defined following Equation 3-1.
For each outdoor bin temperature listed in Table 20, calculate the
nominal temperature of the air leaving the heat pump condenser coil
using,
Evaluate eh(Tj/N), RH(Tj)/N, X(Tj), PLFj, and δ(Tj) as specified
in section 4.2.1 of this appendix. For each bin calculation, use
the space heating capacity and electrical power from Case 1 or Case
2, whichever applies.
Case 1. For outdoor bin temperatures where To(Tj) is equal to or
greater than TCC (the maximum supply temperature determined
according to section 3.1.9 of this appendix), determine Q h(Tj) and
E h(Tj) as specified in section 4.2.1 of this appendix
(i.e., Q h(Tj) = Q hp(Tj) and E hp(Tj) = E hp(Tj)). Note:
Even though To(Tj) ≥Tcc, resistive heating may be required;
evaluate Equation 4.2.1-2 for all bins.
Case 2. For outdoor bin temperatures where To(Tj) >Tcc,
determine Q h(Tj) and E h(Tj) using,
Note:
Even though To(Tj) Tcc, additional resistive heating may be
required; evaluate Equation 4.2.1-2 for all bins.
4.2.5.2 Heat Pump Having a Heat Comfort Controller: Additional
Steps for Calculating the HSPF of a Heat Pump Having a Single-Speed
Compressor and a Variable-Speed, Variable-Air-Volume-Rate Indoor
Blower
Calculate the space heating capacity and electrical power of the
heat pump without the heat comfort controller being active as
specified in section 4.2.2 of this appendix (Equations 4.2.2-1 and
4.2.2-2) for each outdoor bin temperature, Tj, that is listed in
Table 20. Denote these capacities and electrical powers by using
the subscript “hp” instead of “h.” Calculate the mass flow rate
(expressed in pounds-mass of dry air per hour) and the specific
heat of the indoor air (expressed in Btu/lbmda · °F) from the
results of the H12 test using:
where V
S, V mx, v′n (or vn), and Wn are defined following Equation 3-1.
For each outdoor bin temperature listed in Table 20, calculate the
nominal temperature of the air leaving the heat pump condenser coil
using,
Evaluate eh(Tj)/N, RH(Tj)/N, X(Tj), PLFj, and δ(Tj) as specified
in section 4.2.1 of this appendix with the exception of replacing
references to the H1C test and section 3.6.1 of this appendix with
the H1C1 test and section 3.6.2 of this appendix. For each bin
calculation, use the space heating capacity and electrical power
from Case 1 or Case 2, whichever applies.
Case 1. For outdoor bin temperatures where To(Tj) is equal to or
greater than TCC (the maximum supply temperature determined
according to section 3.1.9 of this appendix), determine Q h(Tj) and
E h(Tj) as specified in section 4.2.2 of this appendix (i.e.
Q h(Tj) = Q hp(Tj) and E h(Tj) = E hp(Tj)). Note: Even though
To(Tj) ≥TCC, resistive heating may be required; evaluate Equation
4.2.1-2 for all bins.
Case 2. For outdoor bin temperatures where To(Tj) TCC, determine
Q h(Tj) and E h(Tj) using,
Note:
Even though To(Tj) Tcc, additional resistive heating may be
required; evaluate Equation 4.2.1-2 for all bins.
4.2.5.3 Heat Pumps Having a Heat Comfort Controller: Additional
Steps for Calculating the HSPF of a Heat Pump Having a Two-Capacity
Compressor
Calculate the space heating capacity and electrical power of the
heat pump without the heat comfort controller being active as
specified in section 4.2.3 of this appendix for both high and low
capacity and at each outdoor bin temperature, Tj, that is listed in
Table 20. Denote these capacities and electrical powers by using
the subscript “hp” instead of “h.” For the low capacity case,
calculate the mass flow rate (expressed in pounds-mass of dry air
per hour) and the specific heat of the indoor air (expressed in
Btu/lbmda · °F) from the results of the H11 test using:
where V
s, V mx, v′n (or vn), and Wn are defined following Equation 3-1.
For each outdoor bin temperature listed in Table 20, calculate the
nominal temperature of the air leaving the heat pump condenser coil
when operating at low capacity using,
Repeat the above calculations to determine the mass flow rate (m
dak=2) and the specific heat of the indoor air (Cp,dak=2) when
operating at high capacity by using the results of the H12 test.
For each outdoor bin temperature listed in Table 20, calculate the
nominal temperature of the air leaving the heat pump condenser coil
when operating at high capacity using,
Evaluate eh(Tj)/N, RH(Tj)/N, Xk=1(Tj), and/or Xk=2(Tj), PLFj,
and δ′(Tj) or δ″(Tj) as specified in section 4.2.3.1. 4.2.3.2,
4.2.3.3, or 4.2.3.4 of this appendix, whichever applies, for each
temperature bin. To evaluate these quantities, use the low-capacity
space heating capacity and the low-capacity electrical power from
Case 1 or Case 2, whichever applies; use the high-capacity space
heating capacity and the high-capacity electrical power from Case 3
or Case 4, whichever applies.
Case 1. For outdoor bin temperatures where Tok=1(Tj) is equal to
or greater than TCC (the maximum supply temperature determined
according to section 3.1.9 of this appendix), determine Q hk=1(Tj)
and E hk=1(Tj) as specified in section 4.2.3 of this appendix
(i.e., Q hk=1(Tj) = Q hpk=1(Tj) and E hk=1(Tj) = E
hpk=1(Tj).
Note:
Even though Tok=1(Tj) ≥TCC, resistive heating may be required;
evaluate RH(Tj)/N for all bins.
Case 2. For outdoor bin temperatures where Tok=1(Tj) TCC,
determine Q hk=1(Tj) and E hk=1(Tj) using,
Note:
Even though Tok=1(Tj) ≥Tcc, additional resistive heating may be
required; evaluate RH(Tj)/N for all bins.
Case 3. For outdoor bin temperatures where Tok=2(Tj) is equal to
or greater than TCC, determine Q hk=2(Tj) and E hk=2(Tj) as
specified in section 4.2.3 of this appendix (i.e., Q
hk=2(Tj) = Q hpk=2(Tj) and E hk=2(Tj) = E hpk=2(Tj)).
Note:
Even though Tok=2(Tj) <TCC, resistive heating may be
required; evaluate RH(Tj)/N for all bins.
Case 4. For outdoor bin temperatures where Tok=2(Tj) <TCC,
determine Q hk=2(Tj) and E hk=2(Tj) using,
Note:
Even though Tok=2(Tj) <Tcc, additional resistive heating may
be required; evaluate RH(Tj)/N for all bins.
4.2.5.4 Heat Pumps Having a Heat Comfort Controller: Additional
Steps for Calculating the HSPF of a Heat Pump Having a
Variable-Speed Compressor. [Reserved] 4.2.6 Additional Steps for
Calculating the HSPF of a Heat Pump Having a Triple-Capacity
Compressor
The only triple-capacity heat pumps covered are triple-capacity,
northern heat pumps. For such heat pumps, the calculation of the
Eq. 4.2-1 quantities
differ
depending on whether the heat pump would cycle on and off at low
capacity (section 4.2.6.1 of this appendix), cycle on and off at
high capacity (section 4.2.6.2 of this appendix), cycle on and off
at booster capacity (section 4.2.6.3 of this appendix), cycle
between low and high capacity (section 4.2.6.4 of this appendix),
cycle between high and booster capacity (section 4.2.6.5 of this
appendix), operate continuously at low capacity (4.2.6.6 of this
appendix), operate continuously at high capacity (section 4.2.6.7
of this appendix), operate continuously at booster capacity
(section 4.2.6.8 of this appendix), or heat solely using resistive
heating (also section 4.2.6.8 of this appendix) in responding to
the building load. As applicable, the manufacturer must supply
information regarding the outdoor temperature range at which each
stage of compressor capacity is active. As an informative example,
data may be submitted in this manner: At the low (k=1) compressor
capacity, the outdoor temperature range of operation is 40 °F ≤ T ≤
65 °F; At the high (k=2) compressor capacity, the outdoor
temperature range of operation is 20 °F ≤ T ≤ 50 °F; At the booster
(k=3) compressor capacity, the outdoor temperature range of
operation is −20 °F ≤ T ≤ 30 °F.
a. Evaluate the space heating capacity and electrical power
consumption of the heat pump when operating at low compressor
capacity and outdoor temperature Tj using the equations given in
section 4.2.3 of this appendix for Q hk=1(Tj) and E hk=1 (Tj)) In
evaluating the section 4.2.3 equations, Determine Q hk=1(62) and E
hk=1(62) from the H01 test, Q hk=1(47) and E hk=1(47) from the H11
test, and Q hk=2(47) and E hk=2(47) from the H12 test. Calculate
all four quantities as specified in section 3.7 of this appendix.
If, in accordance with section 3.6.6 of this appendix, the H31 test
is conducted, calculate Q hk=1(17) and E hk=1(17) as specified in
section 3.10 of this appendix and determine Q hk=1(35) and E
hk=1(35) as specified in section 3.6.6 of this appendix.
b. Evaluate the space heating capacity and electrical power
consumption (Q hk=2(Tj) and E hk=2 (Tj)) of the heat pump when
operating at high compressor capacity and outdoor temperature Tj by
solving Equations 4.2.2-3 and 4.2.2-4, respectively, for k=2.
Determine Q hk=1(62) and E hk=1(62) from the H01 test, Q hk=1(47)
and E hk=1(47) from the H11 test, and Q hk=2(47) and E hk=2(47)
from the H12 test, evaluated as specified in section 3.7 of this
appendix. Determine the equation input for Q hk=2(35) and E
hk=2(35) from the H22, evaluated as specified in section 3.9.1 of
this appendix. Also, determine Q hk=2(17) and E hk=2(17) from the
H32 test, evaluated as specified in section 3.10 of this
appendix.
c. Evaluate the space heating capacity and electrical power
consumption of the heat pump when operating at booster compressor
capacity and outdoor temperature Tj using
Determine
Q hk=3(17) and E hk=3(17) from the H33 test and determine Q hk=2(5)
and E hk=3(5) from the H43 test. Calculate all four quantities as
specified in section 3.10 of this appendix. Determine the equation
input for Q hk=3(35) and E hk=3(35) as specified in section 3.6.6
of this appendix. 4.2.6.1 Steady-State Space Heating Capacity when
Operating at Low Compressor Capacity is Greater than or Equal to
the Building Heating Load at Temperature Tj, Q hk=1(Tj) ≥BL(Tj).,
and the heat pump permits low compressor capacity at Tj.
Evaluate the quantities
using
Eqs. 4.2.3-1 and 4.2.3-2, respectively. Determine the equation
inputs Xk=1(Tj), PLFj, and δ′(Tj) as specified in section 4.2.3.1
of this appendix. In calculating the part load factor, PLFj, use
the low-capacity cyclic-degradation coefficient CD h, [or
equivalently, CD h(k=1)] determined in accordance with section
3.6.6 of this appendix. 4.2.6.2 Heat Pump Only Operates at High
(k=2) Compressor Capacity at Temperature Tj and Its Capacity Is
Greater Than or Equal to the Building Heating Load, BL(Tj) <Q
hk=2(Tj)
Evaluate the quantities
as
specified in section 4.2.3.3 of this appendix. Determine the
equation inputs Xk=2(Tj), PLFj, and δ′(Tj) as specified in section
4.2.3.3 of this appendix. In calculating the part load factor,
PLFj, use the high-capacity cyclic-degradation coefficient, CD
h(k=2) determined in accordance with section 3.6.6 of this
appendix. 4.2.6.3 Heat Pump Only Operates at High (k=3) Compressor
Capacity at Temperature Tj and Its Capacity Is Greater Than or
Equal to the Building Heating Load, BL(Tj) ≤Q hk=3(Tj) where:
Xk=3(Tj) = BL(Tj)/Q hk=3
(Tj) and PLFj = 1−CDh (k = 3) *
[1−Xk=3 (Tj) Determine the low temperature cut-out
factor, δ′(Tj), using Eq. 4.2.3-3. Use the booster-capacity
cyclic-degradation coefficient, CD h(k=3) determined in accordance
with section 3.6.6 of this appendix. 4.2.6.4 Heat Pump Alternates
Between High (k=2) and Low (k=1) Compressor Capacity to Satisfy the
Building Heating Load at a Temperature Tj, Q hk=1(Tj) <BL(Tj)
<Q hk=2(Tj)
Evaluate the quantities
as
specified in section 4.2.3.2 of this appendix. Determine the
equation inputs Xk=1(Tj), Xk=2(Tj), and δ′(Tj) as specified in
section 4.2.3.2 of this appendix. 4.2.6.5 Heat Pump Alternates
Between High (k=2) and Booster (k=3) Compressor Capacity To Satisfy
the Building Heating Load at a Temperature Tj, Q hk=2(Tj)
<BL(Tj) <Q hk=3(Tj) and Xk=3(Tj) =
Xk=2(Tj) = the heating mode, booster capacity load factor for
temperature bin j, dimensionless. Determine the low temperature
cut-out factor, δ′(Tj), using Eq. 4.2.3-3. 4.2.6.6 Heat Pump Only
Operates at Low (k=1) Capacity at Temperature Tj and Its Capacity
Is Less Than the Building Heating Load, BL(Tj) > Q hk=1(Tj)
where the
low temperature cut-out factor, δ′(Tj), is calculated using Eq.
4.2.3-3. 4.2.6.7 Heat Pump Only Operates at High (k=2) Capacity at
Temperature Tj and Its Capacity Is Less Than the Building Heating
Load, BL(Tj) > Q hk=2(Tj)
Evaluate the quantities
as
specified in section 4.2.3.4 of this appendix. Calculate δ″(Tj)
using the equation given in section 4.2.3.4 of this appendix.
4.2.6.8 Heat Pump Only Operates at Booster (k=3) Capacity at
Temperature Tj and Its Capacity Is Less Than the Building Heating
Load, BL(Tj) > Q hk=3(Tj) or the System Converts to Using Only
Resistive Heating where δ″(Tj) is
calculated as specified in section 4.2.3.4 of this appendix if the
heat pump is operating at its booster compressor capacity. If the
heat pump system converts to using only resistive heating at
outdoor temperature Tj, set δ′(Tj) equal to zero. 4.2.7 Additional
Steps for Calculating the HSPF of a Heat Pump Having a Single
Indoor Unit With Multiple Indoor Blowers
The calculation of the Eq. 4.2-1 quantities eh(Tj)/N and
RH(Tj)/N are evaluated as specified in the applicable
subsection.
4.2.7.1 For Multiple Indoor Blower Heat Pumps That Are Connected to
a Singular, Single-Speed Outdoor Unit
a. Calculate the space heating capacity, Q hk=1(Tj), and
electrical power consumption, E hk=1(Tj), of the heat pump
when operating at the heating minimum air volume rate and outdoor
temperature Tj using Eqs. 4.2.2-3 and 4.2.2-4, respectively. Use
these same equations to calculate the space heating capacity,
Q hk=2(Tj) and electrical power consumption, E
hk=2(Tj), of the test unit when operating at the heating full-load
air volume rate and outdoor temperature Tj. In evaluating Eqs.
4.2.2-3 and 4.2.2- 4, determine the quantities Q hk=1(47)
and E hk=1(47) from the H11 test; determine Q hk=2
(47) and E hk=2(47) from the H12 test. Evaluate all four
quantities according to section 3.7 of this appendix. Determine the
quantities Q hk=1(35) and E hk=1(35) as specified in
section 3.6.2 of this appendix. Determine Q hk=2(35) and
E hk=2(35) from the H22 frost accumulation test as
calculated according to section 3.9.1 of this appendix. Determine
the quantities Q hk=1(17) and E hk=1(17) from the H31
test, and Q hk=2(17) and E hk=2(17) from the H32
test. Evaluate all four quantities according to section 3.10 of
this appendix. Refer to section 3.6.2 and Table 12 of this appendix
for additional information on the referenced laboratory tests.
b. Determine the heating mode cyclic degradation coefficient,
CDh, as per sections 3.6.2 and 3.8 to 3.8.1 of this appendix.
Assign this same value to CDh(k = 2).
c. Except for using the above values of Q hk=1(Tj),
E hk=1(Tj), Q hk=2(Tj), E hk=2(Tj), CDh, and
CDh(k = 2), calculate the quantities eh(Tj)/N as specified in
section 4.2.3.1 of this appendix for cases where Q hk=1(Tj)
≥ BL(Tj). For all other outdoor bin temperatures, Tj, calculate
eh(Tj)/N and RHh(Tj)/N as specified in section 4.2.3.3 of this
appendix if Q hk=2(Tj) > BL(Tj) or as specified in
section 4.2.3.4 of this appendix if Q hk=2(Tj) ≤ BL(Tj).
4.2.7.2 For Multiple Indoor Blower Heat Pumps Connected to Either a
Single Outdoor Unit With a Two-capacity Compressor or to Two
Separate Single-Speed Outdoor Units of Identical Model, calculate
the quantities eh(Tj)/N and RH(Tj)/N as specified in section 4.2.3
of this appendix. 4.3 Calculations of Off-mode Power Consumption
For central air conditioners and heat pumps with a cooling
capacity of:
Less than 36,000 Btu/h, determine the off mode represented
value, PW,OFF, with the following equation:
greater
than or equal to 36,000 Btu/h, calculate the capacity scaling
factor according to: where Q
C(95) is the total cooling capacity at the A or A2 test condition,
and determine the off mode represented value, PW,OFF, with
the following equation: 4.4 Rounding of
SEER and HSPF for Reporting Purposes
After calculating SEER according to section 4.1 of this appendix
and HSPF according to section 4.2 of this appendix round the values
off as specified per § 430.23(m) of title 10 of the Code of Federal
Regulations.
Table 22 - Representative Cooling and
Heating Load Hours for Each Generalized Climatic Region
Climatic region
Cooling load hours
CLHR
Heating load hours
HLHR
I
2,400
750
II
1,800
1,250
III
1,200
1,750
IV
800
2,250
Rating Values
1,000
2,080
V
400
2,750
VI
200
2,750
4.5 Calculations of the SHR, Which Should Be Computed for Different
Equipment Configurations and Test Conditions Specified in Table 23
Table 23 - Applicable Test Conditions For
Calculation of the Sensible Heat Ratio
Equipment configuration
Reference
table Number of
appendix M
SHR computation with
results
from
Computed values
Units Having a
Single-Speed Compressor and a Fixed-Speed Indoor blower, a Constant
Air Volume Rate Indoor blower, or No Indoor blower
4
B Test
SHR(B).
Units Having a
Single-Speed Compressor That Meet the section 3.2.2.1 Indoor Unit
Requirements
5
B2 and B1 Tests
SHR(B1), SHR(B2).
Units Having a
Two-Capacity Compressor
6
B2 and B1 Tests
SHR(B1), SHR(B2).
Units Having a
Variable-Speed Compressor
7
B2 and B1 Tests
SHR(B1), SHR(B2).
The SHR is defined and calculated as follows:
Where
both the total and sensible cooling capacities are determined from
the same cooling mode test and calculated from data collected over
the same 30-minute data collection interval. 4.6 Calculations of
the Energy Efficiency Ratio (EER).
Calculate the energy efficiency ratio using.
where
Q ck(T) and E ck(T) are the space
cooling capacity and electrical power consumption determined from
the 30-minute data collection interval of the same steady-state wet
coil cooling mode test and calculated as specified in section 3.3
of this appendix. Add the letter identification for each
steady-state test as a subscript (e.g.,EERA2) to
differentiate among the resulting EER values. [82 FR 1476, Jan. 5,
2017]