NBSIR 76-1029^/)

Unitary Heat Pump Specification

for Military Family Housing

C. W. Phillips

B. A. Peavy

W. J. Mulroy

Center for Building Technology

Institute for Applied Technology

National Bureau of Standards

Washington, D. C. 20234

March 1, 1976

Final Report

Issued August 1976

Prepared for Family Housing Division

Directorate of Engineering

Department of the Air Force

Washington, D. C. 20330

NBSIR 76-1029

UNITARY HEAT PUMP SPECIFICATION

FOR MILITARY FAMILY HOUSING

C. W. Phillips

B. A. Peavy

W. J. Mulroy

Center for Building Technology

Institute for Applied Technology

National Bureau of Standards

Washington, D. C. 20234

March 1, 1976

Final Report

Issued August 1976

Prepared for Family Housing Division

Directorate of Engineering

Department of the Air Force

Washington, D. C. 20330

U.S. DEPARTMENT OF COMMERCE, Elliot L. Richardson, Secretary

Edward O. Vetter, Under Secretary

Dr. Betsy Ancker-Johnson, Assistant Secretary for Science and Tec/inology

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Acting Director

Unitary Heat Pump Specification for Military Family Housing

C. W. Phillips, B. A. Peavy, and W. J. Mulroy

Center for Building Technology

Institute for Applied Technology

National Bureau of Standards

Washington, D.C. 20234

ABSTRACT

The purpose of this report is to establish, for unitary heat pump

equipment, the requirements for performance, testing, rating, design,

safety, serviceability and reliability for system and components; and

conformance conditions. This report is intended for guidance in military procurement and applies to hermetic electrically-driven vapor com10 pression unitary heat pumps of the remote (split) and packaged (integral)

types, the air-to-air and water-to-air classes, and sizes from 17,000 to

84,000 Btu/h for both heating and cooling functions.

Key Words: Heating and cooling; military family housing;

specification; unitary heat pump

i
TABLE OF CONTENTS

Page

1. Purpose, Scope and Classification 1

5 A. Purpose 1

B. Scope 1

C. Classification and Definition 1

2. Referenced Specifications and Standards 2

3. Procurement Guidelines 4

A. Prerequisite 4

B. Instructions to Purchaser 4

10

4. General Requirements 5

A. Description 5

B. Standards 6

C. Heat Pump Cooling and Heating Capacity 7

D. Heat Pump Coefficient of Performance 7 E. Operational and Reliability Requirements 8

F. Supplemental Electric Resistance Heat 8

G. Refrigerant 9

H. Indoor Temperature Control 9

I. Defrost 9

J. Protective Mechanisms, Controls and Auxiliary Equipment 9

K. Sound Rating 9

L. Hermetic Motor-Compressor Units 10

M. Moisture in Refrigerant ' 11

N. Strainer 11

0. Materials in Outdoor Unit 11

P. Air Filters 11

Q. Water-to-Air Heat Pumps 12

5. Quality Assurance Provisions 12

A. Responsibility for Inspection and Examination 12

B. Tests for Quality Conformance 12

C. Sampling for Capacity and Operational Tests 14

D. Sampling for Reliability Tests 15

2^ 6. Tests 15

A. Capacity Tests 15

B. Operational Tests 16

ii
TABLE OF CONTENTS (continued)

Page

C. Reliability Tests 16

5 7. Seasonal Performance Factor 21

8. Guaranty and Warranty 23

iii
iII
UNITARY HEAT PUMP SPECIFICATION FOR MILITARY FAMILY HOUSING

PURPOSE. SCOPE AND CLASSIFICATION

A. Purpose - The purpose of this specification is to establish, for

unitary heat pump equipment, the requirements for performance,

testing, rating, design, safety, serviceability, and reliability

for system and components; and conformance conditions. This specification is intended for guidance in military procurement.

B. Scope - This specification applies to hermetic electrically-driven

vapor-compression unitary heat pumps of the types defined in Section 1-C having suitable heating and cooling capacities for military family housing.

C. Classification and Definition - The term heat pump, applied to a year-round air conditioning system, denotes a system in which re- frigeration equipment is used in such a manner that heat is taken

from a heat source and given up to the conditioned space when heating service is desired, and heat is removed from the conditioned

space and discharged to a heat sink when cooling and dehumidification are desired. Unitary heat pumps shall be defined as con- sisting of one or more factory-made assemblies which normally include indoor conditioning coil(s), compressor (s) , outdoor coil(s)

or water-to-refrigerant heat exchanger and necessary controls to

provide both heating and cooling functions. The heating function

may be supplemented by electric resistance heaters. Unitary heat

pumps within the scope of this specification shall be classified

by:

1. Physical configuration (Type)

a. Remote (split) type - The indoor and outdoor

units are separated and remote one from the

other.

b. Packaged (integral, single) type - The indoor

and outdoor units are housed in a single cabinet assembly,

2. Heat source and sink (Class)

a. Air-to-air heat pump - Air is the heat sink

and source medium for the outdoor and indoor

units

.

b. Water-to-air heat pump - Water is the heat

sink and source medium for the outdoor unit
. or condenser and chiller. Air is the medium

providing conditioned air to spaces.

3. Size (Capacity at ARI Standard Rating Conditions)

Cooling - 17,000 to 84,000 Btu/h

(5,000 to 24,600 watts)

Heating - 17,000 to 84,000 Btu/h

REFERENCED SPECIFICATIONS AND STANDARDS

The specifications and standards of the issue listed below (including amendments, addenda, and errata), but referred to thereafter by

designation only, form a part of this specification to the extent re- quired by the reference thereto:

1. American National Standards Institute (ANSI)

B9. 1-1971 Safety Code for Mechanical Refrigeration

B79. 1-1968 Number Designation of Refrigerants

2. Air-Conditioning and Refrigeration Institute (ARI)

230-62 Application Engineering Standard for YearRound Residential Air Conditioning

240-67 Standard for Unitary Heat Pump Equipment

260-67 Standard for Application, Installation

and Servicing of Unitary Equipment

270-67 Standard for Sound Rating of Outdoor Unitary Equipment

275-69 Standard for Application of Sound-Rated

Outdoor Equipment

520-68 Standard for Positive Displacement Refrigerant Compressors and Condensing Units

710-71 Standards for Liquid Line Driers

3. American Society of Heating, Refrigerating and AirConditioning Engineers (ASHRAE)

37-69 Methods of Testing for Rating Unitary Air

Conditioning and Heat Pump Equipment
10

15

20

1972 Handbook of Fundamentals

Underwriters Laboratories, Inc. (UL)

559 Standard for Safety - Heat Pumps

984 Standard for Safety - Sealed (Hermetic type)

Motor-Compressors

Department of Defense (DOD)

4270.21-1970 Guide Specifications for Military Family Housing - Air Conditioning, Mechanical Division

15.16a

AFM 88, Chapter 6 Engineering Weather Data, Air

TM5-785

NAVFAC P-89

Force, Army and Navy Manual

National Environmental Systems Contractors Association (NESCA)

Manual G Selection of Distribution System

Manual J Load Calculation for Residential Winter

and Summer Air Conditioning

Manual K Equipment Selection and System Design

Procedures

American Society for Testing and Materials (ASTM)

B117-64 Standard Method of Salt Spray (Fog) Testing

D1654-61 Standard Method of Evaluation of Painted

or Coated Specimens Subjected to Corrosion Environments

D2247-68 Standard Method for Testing Coated Metal

Specimens at 100 Percent Relative Humidity

G33-72 Standard Recommended Practice for Recording Data From Atmospheric Corrosion Tests

of Metallic-Coated Steel Specimens

3
PROCUREMENT GUIDELINES

A. Prerequisite - Prerequisite to the use of this specification for

procurement it is necessary for the purchaser to determine weather data, design heating and cooling loads and the design for air

distribution systems of the military residential housing to be

equipped with the heat pump equipment obtained under this specification:

1. Weather data for outdoor design conditions should

be in accordance with Engineering Weather Data

Air Force, Army and Navy Manual.

2. Design sensible heating and sensible and latent

cooling loads should be determined in accordance

with procedures described in Chapters 21 and 22

(Residential Cooling Loads), ASHRAE Handbook of

Fundamentals, or procedures given in ARI 230 or NESCA Manual J.

3. Air distribution systems should be suitable for

both winter heating and summer cooling and should

conform to practices established in NESCA Manual

G, Manual K and ARI 260 for design, selection and

installation of duct system and insulation, and

registers and diffusers. Sections of DOD 4270.21

covering requirements for installation of heating

and air conditioning equipment and air distribution systems, testing of heating and air conditioning systems, etc., should be used in preparation of project specifications for military family

housing

.

4. If water-to-air heat pumps are to be considered,

an adequately proven year-round supply of water

should be available. The quality (hardness,

acidity, mineral content and bacterial count) of

the water and its temperature for both winter and summer seasons should be determined and stated in

the request for purchase.

B. Instructions to Purchaser - Items which must be specified by the

purchaser of unitary heat pump equipment in the contract or purchase order with reference to the provisions referred to in this

specification are as follows:

1. Required voltage and related electrical characteristics .
2. Winter and summer design indoor and outdoor conditions and the seasonal heating hours for 5 F (2.8 C)

temperature increments below 65 F (18.3 C) as given

in the Engineering Weather Data Manual.

3. Required heating and cooling capacities, in Btu/h

(watts), at specified winter and summer design con- ditions, respectively.

4. Type and class of heat pump required. Also size

and dimension limitations, or other special con- struction considerations.

5. Additional preproduction, postproduction capacity

tests, conformance and/or reliability tests as required. Also if any or all tests are to be waived.

6. Specific performance data desired in addition to

required test data.

7. Minimum external resistance of air distribution

system when delivering the rated capacity and air

quantity.

8. When water-to-air heat pumps are specified, data

covering water quantity available in gallons per

minute, summer and winter water temperature, water

source and quality of water will be furnished by

the military services.

9. For geographical regions of high corrosion potential, such as coastal regions with salt spray ex- posure, specify salt spray test (ASTM B117) with

720 hours of exposure for portions of heat pump

units exposed to the outdoor environment. For all

other regions specify salt spray test with 240

hours of exposure. Include special technical provisions required by the procuring military services.

GENERAL REQUIREMENTS

A. Description - Throughout this specification the term "heat pump"

will be used interchangeably with the term "unitary heat pump" as defined in Sections 1-B and 1-C. Any heat pump furnished under

this specification shall be the standard cataloged product of a manufacturer who has produced that model at least one year prior

to the date of request for procurement. Heat pumps with only minor changes resulting in a model number change may be accepted by
-the contracting officer (purchaser). Standard catalog product

heat pumps with only changes specifically required to meet this

specification may be accepted by the contracting officer. The

burden of proof that the changes do not adversely effect the

performance, reliability and safety compared to the model for

which one year of service has been demonstrated shall rest with

the heat pump manufacturer. All heat pumps of a given type,

class and size to be delivered under a specific contract or pur5 chase order shall be of the same manufacturer and model. Remote

(split) type heat pumps shall consist of a complete packaged outdoor unit and a complete packaged indoor unit. Precharged factory supplied tubing shall be furnished with remote type heat

pumps with capacities up to 44,000 Btu/h (12,900 watts). Packaged (integral) type heat pumps shall consist of a single factory-assembled sheet-metal casing complete with indoor and outdoor units piped and wired, ready for connection to duct system

and electric circuits. The complete system heating and cooling

capacity shall not be less than the design loads specified in

10 the contract or purchase order. Unless otherwise specified, the

maximum airflow and minimum external pressure shall be as required

in ARI 240. Unit components shall be readily accessible for maintenance and service. High and low side service valves shall be

provided. Self closing valves will be acceptable. Certain re- quirements in this specification, particularly current overload

protection, crankcase heating, time delay mechanisms and liquid

flood-back protection are included for system reliability needs.

If a manufacturer has alternative means to accomplish these functions, the acceptance shall be dependent on proof submitted by

15 the heat pump manufacturer, and acceptable to the contracting

officer. This proof shall include written certification that

the alternative means satisfy the functional requirements.

B. Standards - Heat pumps shall conform to the standards ARI 240,

UL 559 and ANSI B9.1, and shall meet the requirements for listing in UL Electrical Appliance and Utilization Equipment List.

Proof shall be submitted showing that the items furnished under

this specification conform to such requirements. The labels of

the ARI and the UL for the manufacturer's standard model will

20 be acceptable as sufficient evidence that the items conform to

the label-identified standards of these organizations. In lieu

of such certification, label or listing, a written certificate

from a testing laboratory or agency adequately equipped and com- petent to perform such services shall be submitted stating that

the items have been tested and that the heat pump units and as- sembled components conform to requirements specified in ARI 240,

UL 559 and ANSI B9.1. Description of test methods shall accompany certificate.

6
Heat Pump Cooling and Heating Capacity - The heat pump heating

and cooling (sensible and latent) capacities shall not be less

than that specified for the winter and summer outdoor design con- ditions of the contract or purchase order when tested in accordance with Section 5-Bl. If the sensible cooling capacity of the

heat pump at summer design conditions is more than twice the design sensible cooling load, the heat pump shall be equipped with

means to modulate or otherwise limit the design capacity-to-design-load ratio to two or less. Heat pumps with supplemental

electric resistance heat shall be sized to provide by compression

(and indoor fan heating) at least 70 percent of the calculated

annual heating requirement for the building served (see Section

7) . A method for determining the heating by compression as a percent of the annual heating requirements is given in Section

7. The minimum capacity for the supplemental heaters shall be

the difference between the design heating load and the heat output by compression at the winter design outdoor temperature.

The heat pump manufacturer shall state the rated voltage and ca- pacity of supplemental heaters. The heaters shall provide this

capacity when tested in accordance with Section 6-A4. Air-source

heat pumps shall have seasonal performance factors (SPF) , for the

heating season, including supplemental heating and defrosting

greater than:

Outdoor Design Temperature, F (C) SPF (Minimum)

35 (1.7) to 45 (7.2) 2.25

20 (-6.7) to 34 (1.1) 2.0

1 (-17.2) to 19 (-7.2) 1.5

-20 (-28.9) to 0 (-17.8) 1.25

The definition of and the method for calculating seasonal performance factors (SPF) are given in Section 7. A sample problem is

included. Forms corresponding to Table 7-1, with calculations of

seasonal performance factor for air-source heat pumps as given in

Section 7 shall be submitted with the bid .

Heat Pump Coefficient of Performance - The heat pumps shall have

coefficients of performance when tested and rated in accordance

with Sections 5 and 6 equal to or greater than the following:
Air Water

Source Source

ARI Standard Rating Condition (Cooling) 2.0 2.5

ARI Standard Rating Condition (Heating) 2.5 2.5

ARI 17 F (-8.3 C) Application Rating 1.7

Condition (Heating)

Operational and Reliability Requirements - Unless otherwise specified in the contract or purchase order at least one heat pump

of each type, class, model and size scheduled for delivery under

this specification shall be subjected to and successfully pass

the operational and reliability tests required in Section 5 of

this specification and shall conform to the requirements con- tained in Section 6 of this specification.

Supplemental Electric Resistance Heat - If supplementary heat

is needed to satisfy the heating requirements (see Section 4-C)

of this specification, supplemental electric resistance heaters

shall be provided and shall be located downstream of the indoor

coil. The electric heaters shall be electrically wired in ac- cordance with UL 559 and controlled in one or more steps so that

they shall provide sufficient additional heating capacity for

building heat demand loads in excess of the compression and indoor fan heating capacity. No single step of supplemental heating shall produce a temperature rise in the discharge air greater

than 35 F (19.4 C) . The heaters shall be controlled by means of

outdoor and indoor thermostats interlocked one with the other.

The outdoor thermostat, whose operation shall override that of

the indoor thermostat, shall prevent the supplementary heaters

from operating at outdoor temperatures above 35 F (1.7 C) except

as required to offset cooling effect during defrost operation

(Section 4-1) . For the heating operation, the indoor thermostat

shall operate in at least two steps. The first step shall initiate heat pump operation for heating by compression only. The

second step (and additional step(s), if provided) shall control

heating provided by the supplemental heaters. The cut-off temperature for the first set of supplemental heaters shall be between 0.5 (.3) and 1.5 F (.8 C) below the cut-off temperature for

the compression heating. Additional steps of supplemental heating if required shall be activated for both cut-off and cut-on,

respectively in 0.5 (.3) to 1.0 F (.6 C) steps below the first

step of supplemental heating by the thermostat. The total operating temperature differential between thermostat cut-on and cutoff of the compression heating control shall not exceed 2 F (1.1 C)

.

8
G. Refrigerant - The refrigerant shall be of Group I Classification

as described in ANSI B79.1. The type of refrigerant to be used

in the system shall be as specified in the contract or purchase

order. If not so specified, the refrigerant shall be one of the

following types: R-12, R-22, R-500, R-502.

H. Indoor Temperature Control - Temperature controls for heat pump

operation shall be capable of being set to control heating at

5 any temperature at least from 55 F (12.8 C) to 75 F (23.9 C) and

to control cooling at any temperature from 75 F (23.9 C) to at

least 85 F (29.4 C) . The thermostat shall be factory locked to

prevent setting above 85 F or below 55 F. When the heat pump

system is operating (except during defrost operation) , the temperature control shall be capable of regulating the indoor temperature at the thermostat to within 1 F (.6 C) of the control

setting when only compression heating is being provided and to

within 2 F (1.1 C) of the control setting when compression and

supplemental heating is required. For control of supplemental

10 heat see Section 4-F. The thermostat shall contain or a sub-base

shall be provided containing selector switches for COOL-OFF-HEAT

and FAN-AUTO-ON.

I, Defrost - Air-source heat pumps designed to operate with a defrost cycle shall include positive actuation and termination

means for defrosting the coils and fins of the outdoor unit automatically with suitable drain provisions to remove condensate

and meltage without freeze-up or other malfunctions throughout

the entire range of application temperatures.

15

J. Protective Mechanisms, Controls and Auxiliary Equipment - The

heat pump system shall contain the necessary components; protective mechanisms, controls and auxiliary equipment for it to meet

the requirements and tests set forth in this specification.

Safety devices and protective controls shall be used to limit or terminate abnormal operating conditions and shall not be used to

control normal heat pump operations. Also refer to Section 4-B.

K. Sound Rating - All outdoor unitary heat pump equipment shall be

sound rated and tested in accordance with ARI 270 and ARI 275

and shall not exceed a sound rating of 20 as defined in these

standards. The ARI label will be acceptable as sufficient evidence of compliance. In lieu of such certification or label, a written certificate from a testing agency or laboratory adequately

equipped and competent to perform such services shall be submitted

stating that the equipment has been tested and conforms to re- quirements specified in ARI 270 and to the requirements of this

specification.

9
L. Hermetic Motor-Compressor Units - Hermetic motor-compressor units

shall conform to the standards of UL 984 and ARI 520 with regards

to construction, performance and testing. The requirements for

motor-compressor protection systems of these standards shall also

apply in addition to the following:

1. Thermal Protection - An internal motor-winding temperature-sensing protection device of the automatic

5 reset type for the compressor motor shall be provided to prevent motor operation under excessive

motor winding temperatures. The heat pump manufacturer's recommended maximum motor winding temperature shall not be exceeded when the heat pump is

operating under any of the tests prescribed in ARI

240, and in no case shall winding temperature under

any of these test conditions exceed 300 F (149 C)

,

when measured as described in paragraph 7.2 of ARI

520. The heat pump manufacturer's recommended max10 imum motor winding temperature shall be stated in

the bid submission.

2. Current Overload Protection - Motor running-current

overload protection of the manual or automatic reset type, conforming to the National Electric Code

(refer to UL 984) , shall be provided for the com- pressor motor. If manual reset is provided it shall

be readily accessible and the reset means clearly

marked

.

15

3. Crankcase Heating - Means shall be provided for heating the compressor crankcase during "off" cycles to

minimize liquid foaming and prevent consequent liquid slugging under compressor starting conditions

caused by retention of refrigerant by oil in the

compressor. Crankcase heaters either external or internal (except for motor windings used as heaters) shall be readily replaceable from the exterior

2Q without breaking the refrigerant seal.

4. Time Delay Mechanism - The motor protection system

shall contain a device or means that delays operation of the compressor motor for a period of at

least 3 but not more than 6 minutes after compressor operation is called for when shut-down for any

reason, inadvertent or otherwise has occurred.

(Note: This is needed to diversify startup loads

in housing areas after power interruption and to

guard against short cycling of individual units.)

10
5. Liquid Flood-Back - A means shall be provided for

protecting the compressor from liquid flood-back,

under all design conditions of operation, including defrost. Properly designed and sized accumulators will satisfy this requirement. Accumulators

must provide for return of oil to the compressor.

Moisture in Refrigerant - The system shall contain a filter-drier

in the liquid line to both the indoor and outdoor coils, conforming to ARI 720. Filter driers shall be so installed as to be

easily removed for replacement. Refrigerant piping shall be circuited such that backwashing of the filter-drier by reversal of

refrigerant flow does not occur. The moisture content in the

refrigerant shall not exceed 30 ppm at time of heat pump installation and at conclusion of the Reliability Tests (see Section

6-C).

Strainer - If the heat pump system uses capillary tubes as a re- frigerant expansion device, strainer (s) shall be installed in

the line ahead of each capillary tube assembly capable of stopping passage of scale and other particulate matter of minor dimension greater than 20% of the bore size of the smallest tube.

Materials in Outdoor Unit - The materials of which the components

in the outdoor unit are fabricated and the method of fabrication

shall be such that when a heat pump system is subjected to the

Reliability Tests (Section 6-C) of this specification, it shall

pass the tests and retain its physical and structural integrity.

The use of dissimilar metals in intimate contact with each other

shall be avoided wherever these joints are exposed to moisture

in normal operation in order to minimize galvanic corrosion between the metals. When the use of dissimilar metals cannot be

avoided, construction methods shall be utilized which minimize

or eliminate the galvanic effect. Coils and fins of the outdoor

coil shall be corrosion resistant or treated to resist corrosion.

All materials in both indoor and outdoor sections shall be of

such type or construction that the unit can satisfactorily pass

the applicable salt spray/humidity tests in Section 6-C. Coils,

fins and fan shall be protected from physical damage by means of

a suitable grill or other means which do not lower the airflow

through the coil enough to prevent the specified performance of

the system.

Air Filters - Air filters mounted on the air return to the indoor unit shall be furnished. The air filter installation shall

preferably be integral with the indoor unit and if mounted re- motely in the house duct system, the duct must be leak tight to

the unit. The air filter shall be readily accessible for removal

from the indoor unit for cleaning or replacement after residential installation. The air filter installation shall have no unplugged holes or cracks allowing air to bypass the filter prior

to reaching indoor coil.

11
Q. Water-to-Alr Heat Pumps - Water-to-air heat pumps shall be designed to meet the following performance requirements:

1. The water temperature leaving the condenser during

cooling operation shall not exceed 100 F (37.8 C)

.

2. The water temperature leaving the water-to-refrigerant heat exchanger during heating operation shall

Xiot be less than 45 F (7.2 C) .

.r''> >

!

, 3. ' -A low pressure cut-out device with a manually reset

lockout relay shall be installed near the inlet to

the compressor to prevent freezing during the heating operation.

4. - The water-to-refrigerant heat exchanger, internal

piping and connections shall be composed of cupronickel alloy or the equivalent corrosion resistance.

5. Construction and/or piping for water-to-refrigerant

heat exchangers shall include provision for isolation and access valving for the purposes of chemi-

.

' cal cleaning or physical access for mechanical cleaning of the water side of heat exchange surfaces.

QUALITY ASSURANCE PROVISIONS

A. Responsibility for Inspection and Examination - The contractor

(supplier) shall be responsible for the fulfillment of all inspection requirements as specified herein. The contractor shall

be responsible for insuring that the components of the system, even though manufactured by a secondary supplier, are tested, and

examined, and are satisfactory for inclusion in the heat pump

system. The supplier shall also be responsible for the fulfillment of requirements of the referenced applicable documents for

any components of the heat pump system. Unless otherwise specified in the contract or purchase order, the Government (purchaser) reserves the right to perform any of the inspections to determine if the requirements set forth in Section 4 are fulfilled.

If the Government so desires it may contract this responsibility

to any qualified commercial or Government laboratory.

B. Tests for Quality Conformance - Three types of tests required by

this specification shall be performed, or shall have been performed for each type, class, model and size of heat pump to be

supplied in the contract or purchase order; namely, 1) Capacity,

2) Operational, and 3) Reliability Tests. The data required

shall be obtained from tests described in Section 6, with regard

12
to all inspections and capacity, operational and reliability

tests. The Government reserves the right to make any or all in

spections and tests necessary in addition to those required in

the contract or purchase order to assure conformance with specification requirements at any time prior to final acceptance.

If such additional testing indicates failure to conform, the

cost of the unit or component tested and the cost of testing

will be borne by the supplier. If such additional testing indicates conformance, the cost of the unit or component tested

and the cost of testing will be borne by the Government.

la. Capacity Tests - Heating - For air-source heat

pumps, the supplier shall provide manufacturer '

s

performance data sufficient to establish curves

of heating capacity and power input (including

defrost effects, but not including supplemental

heat) versus outdoor air temperature, with re- turn indoor air temperature between 70 and 75 F

(21.1 and 23.9 C) . The outdoor temperature range

should be from 62 F (16.7 C) to the winter outdoor design temperature specified in the contract

or purchase order or to the lowest temperature at

which the heat pump will operate to satisfy the

seasonal performance factor calculation required

in Section 4-C. Certified performance data shall

be provided for the heating capacity and power

input at the standard rating condition and the

application rating condition as described in ARI

240.

For water-source heat pumps manufacturer '

s

performance data shall be provided showing heating

capacity and power input versus (1) entering

winter design water temperature, if the entering

winter design water temperature specified in the

contract or purchase order is lower than 60 F

(15.6 C) . Return indoor air temperature shall

be between 70 and 75 F (21.1 and 23.9 C) . Certified performance data showing heat capacity

and power input shall be provided for the standard rating conditions described in ARI 240.

lb. Capacity Tests - Cooling - Air air-source heat

pumps, manufacturer '

s

performance data showing

the cooling capacity and power input shall be

provided for the design summer outdoor temperature, and certified performance data shall be

provided for the standard rating condition described in ARI 240. For water-source heat pumps,

manufacturer '

s

performance data shall be provided

showing cooling capacity versus entering water

13
temperature and minimum water flow rate (or leaving water temperature) if the entering summer design water temperature specified in the contract

or purchase order is warmer than 75 F (23.9 C)

.

Certified performance data shall be provided showing cooling capacity at standard rating conditions

described in ARI 240. For all cooling tests re- turn indoor air conditions shall be as described

in ARI 240.

For the heating and cooling capacity tests above,

if, in the contract or purchase order an air system distribution resistance or airflow different

from the values listed in Section 4.1.9 of ARI

240, is specified, the performance data required

shall be adjusted accordingly.

Manufacturer '

s

performance data is data based on tests of which the accuracy is attested to by the

unit manufacturer. Certified performance data is

data of which the accuracy is attested to either

by an independent testing laboratory or by a cer- tification program such as that of ARI.

2. Operational Tests - The heat pump system shall operate satisfactorily under standard and maximum

operating conditions (refer to Section 4-E) . Heat

pumps scheduled for delivery under this specification shall meet all requirements of ARI 240, Section 6, Performance Requirements. The ARI label

will be accepted as evidence of meeting this re- quirement. In lieu of such certification or label,

a written certificate from a testing agency or laboratory adequately equipped and competent to perform such services shall be submitted stating that

the equipment conforms to requirements specified

in ARI 240.

3. Reliability Tests - The heat pump shall be subjected to the reliability tests listed in Section

6-C of this specification and shall conform to the

listed requirements, and shall perform without damage to any part.

Sampling for Capacity and Operational Tests - Unless otherwise

required in the contract or purchase order, one heat pump of

each type, model and size scheduled for delivery and picked at

random shall have been or shall be subjected to all listed ca- pacity tests and operational tests and shall satisfactorily con- form to all test requirements. The tests on each heat pump shall

14
be made sequentially with the capacity tests being performed

first. The heat pump tested as representative of each type,

model and size shall pass all tests described in Section 5-B,

and as specified under Sections 6-A and 6-B,

D, Sampling for Reliability Tests - Unless otherwise required in

the contract or purchase order, at least one heat pump of each

type, class, model and size scheduled for delivery and picked

5 at random shall be subjected to and successfully pass the re- liability tests (Section 6-C) conducted in accordance with the

following plan. If there are no failures in the first specimen, the type, class, model and size will be considered satisfactory with respect to the reliability tests and the unit tested

can be included in the lot for delivery. If there are not more

than two failures, a second trial, using three additional specimens of the same type, class, model and size, picked at random

by a Government inspector shall undergo a test for conformance

to all listed reliability requirements. If there is not more

10 than one failure of the same kind, or not more than three failures altogether from that total of four specimens tested, the

lot will be considered satisfactory with respect to the reliability tests. Any unit failing shall not be included in the lot

for delivery. If there are two or more failures of the same

kind, or four or more failures altogether from the total of four

specimens tested, all heat pumps of that type, class, model and

size shall be rejected.

15 6. TESTS

A. Capacity Tests - This section describes tests of heat pumps for

determination of capacity and coefficient of performance. Test

data required in Section 5 are derived from the tests described

in Section 6. All of these tests shall be performed without the

indoor thermostat in the system or with the thermostat set to

call for continuous operation of the compression system. The

resistance heaters shall be turned off during these tests. Both

cooling and heating tests shall be performed as described in the

following paragraphs. Testing procedures shall be as described

in ASHRAE 37. Unless otherwise specified, test conditions shall

be as set forth in ARI 240.

1. Heating Tests - A heating test at the standard rating and testing conditions specified by ARI 240

shall be performed. In addition, heating tests at

the application rating conditions specified by ARI

240 and in Section 5=-B of this specification shall

be performed in accordance with ASHRAE 37.

15
2. Cooling Tests - Cooling tests at the standard rating conditions specified in ARI 240 and at application rating conditions in Section 5-B shall be

performed on the heat pump in conformance with

ASHRAE 37.

3. Coefficient of Performance - At rating and application conditions, the coefficient of performance

of the heat pump for heating and cooling (see Section 4-D) shall be calculated from the test data.

The definition of coefficient of performance given

in ARI 240 shall apply. The test shall be performed without the supplemental- heaters in operation.

4. Heating Capacity of Supplemental Heater - The heating capacity of the supplemental heaters shall be

determined by the measurement of the electrical

power usage of the supplemental heater (s). The

electrical power usage shall be measured at specified voltage and at room temperature of 70 F

(21.1 C) with suitable instrumentation accurate

to within 2 percent of the measured value. The

test data shall be used to determine compliance

with Section 4-F.

Operational Tests - As stated in Section 5-B. 2, required operational tests are the following tests described in the Performance

Requirements of ARI 240:

1. Maximum Operating Condition Test

2. Low Temperature Operation Test for Cooling

3. Insulation Efficiency Test

4. Condensate Disposal Test

Reliability Tests - Temperature tolerances for the reliability

test shall be as specified in performance requirements of ARI

240. Voltage tolerances shall be + 3 volts. The tests will be

conducted sequentially in the order given in Table 6-1. All of

these tests shall be performed without the indoor thermostat in

the system or with the thermostat shunted to call for continuous

operation. All manual-reset operating, protective, and limit

controls/devices shall be reactivated within 30 minutes following trip-out or similar operation throughout each test. Supplemental heaters shall not be operated in any of the reliability

tests. Indoor unit air inlet temperature shall be held in the

range from 70 (21.1) to 80 F (26.7 C) for tests (except for test

-16
8). For all tests, the portion of the tests that call for unit

operation implies continuous compressor operation except as con- trolled by protective/limit devices.

The portions of the heat pump that are normally exposed to the

outdoor environment shall be tested in a corrosive environment

(see 7 of Table 6-1) as described in ASTM B117 (salt spray test)

Unless otherwise specified in the contract or purchase order,

the duration of this test shall be 240 hours. The portions of

the heat pump that are normally exposed to the indoor environment shall be tested as described in ASTM D2247 (100 percent

relative humidity test) . The time duration of this test shall

be 240 hours. The extent of area of indoor and outdoor exposure

to salt spray/humidity environment for corrosion testing of pack

aged (integral) type heat pumps shall be determined from size,

dimension and construction considerations. Data to be taken before and after corrosion tests shall be recorded and results

photographed as given in Section 3.3 of ASTM G33. For painted

and all coated surfaces refer to ASTM D1654 for testing procedure where marks shall be scribed on vertical, horizontal, ex- ternal and internal painted or coated surfaces. Rating Schedule

No. 2 of ASTM D1654 shall be reported. The rating number shall

not be less than 6 and there shall be no rust creep greater than

1/8" (3.18 mm) normal to the scribe marks for acceptance. Blistering or flaking of paint or coating and rust creep at screw

holes shall be reported and rated as above. Oxidation and cor- rosion of bare metal parts and at joints of dissimilar metals

shall be reported and photographed.

As applicable, the following requirements must be met for acceptance :

a. No impairing damage shall occur to any component

during these tests.

b. The temperature of the oil sump remote from the

suction line inlet to the compressor shall at no time during operation of the compressor motor be

less than 25 F (13.9 C) warmer than that of the

suction line within 6 inches (.152 m) of the com- pressor shell.

c. The temperature of the discharge line within 6

inches (.152 m) of the compressor shall at no time

during operation of the compressor motor be less

than 20 F (11.1 C) warmer than the saturation temperature corresponding to the discharge pressure

for more than 5 minutes. Thermocouples shall be

used for these measurements, shall be physically

bonded to the respective surfaces (including at

least 1 inch (.0254 m) of the leads) and shall be

insulated from ambient conditions.

17
No audible knocking or hammering of mechanical

parts shall occur in excess of that occurring in

normal continuous operation at standard rating

conditions in ARI 240.

Average motor winding temperatures measured as described in paragraph 7.2 of ARI 520 shall not

exceed 300 F (149 C) at any time during any of

the reliability tests.

Discharge refrigerant line temperature within 6

inches (.152 m) of the compressor shall not ex- ceed 300 F (149 C) during the reliability tests.

Upon completion of the reliability tests, the

moisture content of the refrigerant shall be determined and the moisture content shall not ex- ceed 30 ppm.

Table 6-1 Reliability Test Specifications

1. Heating and cooling test

Voltage as specified in the contract or purchase order

Outdoor air dry-bulb temperature 70 F

(21.1 C) to 80 F (26.7 C)

Indoor air dry-bulb temperature 70 F

(21.1 C) to 80 F (26.7 C)

100% operation - 50% cooling and 50%

heating

Cycle reversal every hour

48 hours total test duration

2 . High temperature test (cooling)

Voltage 90% of specified

Outdoor air dry-bulb temperature 130 F

(54.4 C) to 140 F (60 C)

Indoor air dry-bulb temperature 70 F

(21.1 C) to 80 F (26.7 C)

18
100% unit operation

24 hours total test duration

Low temperature test (heating)

Voltage 110% of specified

Outdoor air dry-bulb temperature 5 F

(-15 C) (or lowest recommended manufacturer's operating temperature if

higher than 5 F)

Indoor dry-bulb temperature 70 (21.1)

to 80 F (26.7 C)

Operation: Off 24 hours, On 8 hours,

Off 24 hours, On 8 hours

64 hours total test duration

Fan motor failure blocked air filter

test (cooling)

Voltage as specified

Outdoor air dry-bulb temperature 95 F

(35 C) to 105 F (40.6 C)

Indoor dry-bulb temperature 70 F (21.1 C)

to 80 F (26.7 C)

100% unit operation: 12 hours at 50% of

normal airflow across indoor coil, 12

hours with no airflow across indoor coil

(indoor fan inoperative and filter face

blocked for this test)

24 hours total test duration

Low refrigerant charge test (cooling)

Voltage as specified

Outdoor air dry-bulb temperature 95 F

(35 C)

Indoor air dry-bulb temperature 70 F

(21.1 C) to 80 F (26.7 C)

19
50% of manufacturer's recommended re- frigerant charge

100% unit operation

24 hours total test duration

Low refrigerant charge test (heating)

Conditions same as 5 above, except outdoor air temperature 20 F (-6.7 C) to

35 F (1.7 C)

Salt-spray test - ASTM B117 (cooling

operation one hour at conclusion)

Outdoor air dry-bulb temperature 97 +

2 F (36.1 +1.1 C) (atmospheric pressure in salt-spray chamber)

Indoor air dry-bulb temperature 70 F

(21.1 C) to 80 F (26.7 C) (for one hour

operation at conclusion of salt-spray

test)

Compressor motor shall not be operated

except for one hour at conclusion of

salt-spray test

Voltage as specified

Outdoor unit fan 100% operation except

as noted below

At the 24th and 96th hour of salt

spray exposure, the heat pump fan

and salt spray are turned off and

the chamber door is left open for

a period of 8 hours

At the end of the 8 hour period the

test is resumed

At the conclusion of the final hour

of actual salt-spray exposure, the

spray shall be discontinued, the

chamber door opened and the compressor turned on and operated in the

cooling mode for one hour

20
Total duration of actual salt spray

exposure shall be 240 hours (or 720

hours if specified in the contract

or purchase order)

8. 100 percent relative humidity test - ASTM D22A7

Indoor air temperature 85 F (29.4 C)

Indoor fan operation 100% (no heating or cooling coil operation)

Voltage as specified

Interruption conditions at the 24th and

96th hour as specified in test 7 above

240 hours total 100 percent relative humidity exposure

SEASONAL PERFORMANCE FACTOR

The seasonal performance factor (SPF) of air-source heat pumps, for

the heating season, shall take into account all system energy re- quirements, including defrost operation, all fan motors, supplemental heat, etc., and shall be calculated from the relationship

where X = heat delivered to building during heating season, kWh

Y = energy input to all motors during heating season, kWh

Z = supplemental heat during heating season, kWh

Values for X, Y and Z are calculated in tabular form from the following information (see Table 7-1)

A - Outdoor temperature range, F; outdoor air temperature increments of 5 F (2.8 C) below 65 F (18.3 C)

B - Seasonal heating hours for A, hrs; found in the Engineering Weather Data Manual or is available from the U. S.

Weather Bureau

21
C - Average building heat loss for A, 10 Btu/h

3

D - Average heat pump capacity for A, 10 Btu/h; compressor

and indoor fan heating, no supplemental heating

E - Percent running time for heat pump, %; if C > D, E = 100,

otherwise E = 100 x C/D

F - Rate of energy input to heat pump for A, kW

G - Energy input to heat pump, kWh; G = B x E x F/lOO

H - Energy input from electric resistance heaters, kWh; if

C < D, H = 0; otherwise H = B x (C-D)/3.412

J - Energy input to building from heat pump, kWh; J = B x E

X D/341.2

Summing over the outdoor air temperature increments gives

X = EJ + ZH

Y = EG

Z = EH

for substitution in the definition for SPF.

A sample calculation for SPF is shown in Table 7-1. For a location

at Forbes AFB, Kansas, the seasonal heating hours of column B are

found in the Engineering Weather Data Manual, and the winter design

temperature is 3 F (-16.1 C) . The heating load is assumed to be

90,000 Btu/h (26,377 watts) with an indoor temperature of 70 F

(21.1 C) and a design temperature difference of 67 F (37.2 C) . The

average heating loads (column C) are computed from the relationship:

Q = ^^0^3^^ (65-T) where T is the average temperature for the temperature range in column A. Columns D and F are assumed values for heat

pump performance for the temperature range in column A. Performing

the indicated calculations given above, a SPF equal to 2.09 is found.

The heating by compression as a percent of the total heat supplied

is 81.4 percent. The percent of heating by compression shall be calculated for the water-source heat pump where columns D and F of Table

7-1 are assumed as constants when operating at the winter design temperature and design flow rates of the water source.

22
GUARANTY AND WARRANTY

A. Guaranty - The heat pump(s) to be furnished under this specification shall be guaranteed for a period of one (1) year from the

date of acceptance thereof, either for beneficial occupancy or for final acceptance, whichever is earlier, against defective

materials, design or workmanship. Upon receipt of notice from

the Government of failure of any part of guaranteed equipment

during the guaranty period, the affected part or parts shall be

replaced promptly with new parts by and at the expense of the

contractor (supplier)

.

B. Warranty - If the hermetic motor compressor becomes inoperative

as a result of defects in material or workmanship within four

(4) years next following the expiration of one (1) year after

the date of installation for use, the manufacturer shall furnish

a new motor compressor. Labor, for replacement, and cost of re- frigerant are not included as a part of this additional fouryear warranty.

23
Table 7-1

Sample Calculation for Seasonal Performance Factor

A B C D E F G H J

60/64 675 4.0 75.2 5.3 6.57 235.9 791.3

55/59 585 10.7 71.6 14.9 6.30 550.8 1,834.6

50/54 568 17.5 67.5 25.9 6.02 886.5 2,913.2

45/49 542 24.2 63.4 38.2 5.75 1.189.6 3,844.2

40/44 572 30.9 59.0 52.4 5.43 1.626.7 5,180.2

35/39 600 37.6 49.5 76.0 5.15 2,347.2 6,612.0

30/34 612 44.3 45.2 98.0 4.86 2,915.1 7,946.0

25/29 417 51.0 41.5 100.0 4.60 1,918.2 1,161.0 5,071.9

20/24 326 57.8 37.2 100.0 4.40 1,434.4 1,968.2 3,554.3

15/19 222 64.5 34.0 100.0 4.23 939.1 1,984.5 2,212.2

10/14 155 71.2 30.5 100.0 4.10 635.5 1,848.9 1,385.6

5/9 96 77.9 27.6 100.0 3.90 374.4 1,415.2 776.6

0/4 47 84 6 24 0 1 00 0 3 77 177? o . o

-5/-1 20 91.3 21.0 100.0 3.62 72.4 412.1 123.1

-10/-6 3 98.1 18.0 100.0 3.51 10.5 70.4 15.8

E = 15,313.5 9,695.1 42,591.6

X = EJ + EH = 42,591.6 + 9,695 .1 = 52,286 .7

Y = EG 15,313.5

Z = EH 9,695.1

SPF = - X 52. 286.7

-r- = 2.09 + Z 15,313.5 + 9,695

Heat by compression as percent of total heat supplied =

42 591 6 + 9 695 1 ^^'^^

24
NBS-114A (REV. 7-73)

U.S. DEPT. OF COMM. BIBLIOGRAPHIC DATA

SHEET

1. PUBLICATION OR REPORT NO. NBSIR 76-1029

2. Gov't Accession

No.

3. Recipient's Accession No.

4. TITLE AND SUBTITLE

Unitary Heat Pump Specification for Military Family Housing

5. Publication Date March 1, 1976

6. Performing Organization Code

7. AUTHOR(S)

C. W. Phillips, B, A, Peavy, and W. J. Mulrov

8. Performing Organ. Report No.

9. PERFORMING ORGANIZATION NAME AND ADDRESS

NATIONAL BUREAU OF STANDARDS

UtrAK 1 Men 1 Ur L.UMMCK^C

WASHINGTON, D.C. 20234

10. Project/Task/Work Unit No. 4624142

11. Contract/Grant No.

12. Sponsoring Organization Name and Complete Address (Street, City, State, ZIP)

Family Housing Division

Department of the Air Force

Washington, D. C. 20330

10. 1 ype or Keport & reriod Covered

Final

14. Sponsoring Agency Code

15. SUPPLEMENTARY NOTES

16. ABSTRACT (A 200-word or less {actual sunmary of most sigftificant information. If document includes a significant

bibliography or literature survey, mention it Irere.)

The purpose of this report is to establish, for unitary heat pump equipment, the

requirements for performance, testing, rating, design, safety, serviceability and re- liability for system and components; and conformance conditions. This report is intended for guidance in military procurement and applies to hermetic electrically-driven

vapor-compression unitary heat pumps of the remote (split) and packaged (integral)

types, the air-to-air and water-to-air classes, and sizes from 17,000 to 84,000 Btu/hr

for both heating and cooling functions.

17. KEY WORDS (six to twelve entries; alphabetical order; capitalize only the first letter of tfie first key word unless a proper name; separated by semicolons)

Heating and cooling; military family housing; specification; unitary heat pump

18. AVAILABILITY Unlimited 19. SECURITY CLASS

(THIS REPORT)

21. NO. OF PAGES

1 X' For Official Distribution. Do Not Release to NTIS

UNCL ASSIFIED 27

1

' Order From Sup. of Doc, U.S. Government Printing

Washington. D.C. 20402. SD Cat. No. CI

Office 20. SECURITY CLASS

(THIS PAGE)

22. Price

1 ! Order From National Technical Information Service

Springfield, Virginia 22151 (NTIS)

UNCLASSIFIED

USCOMM-DC 29042-P74