NBSIR 88-3805

Revised Unitary Heat Pump

Specification for Military Family

Housing

William Mulroy

Stephen Weber

David Didion

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Building Technology

Gaithersburg, MD 20899

June 1988

Sponsored by:

U.S. Army Corps of Engineers

U.S. Department of the Army

Washington, DC 20314

Engineering Services and Utility Branch

U.S. Department of the Air Force

Washington, DC 20330-5000

Naval Facilities Engineering Command

U.S. Department of the Navy

Alexandria, Virginia 22332

75 Years Stimulating America’s Progress

1913-1988
.
NBSIR 88-3805

REVISED UNITARY HEAT PUMP

SPECIFICATION FOR MILITARY

FAMILY HOUSING

William Mulroy

Stephen Weber

David Didion

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Building Technology

Gaithersburg, MD 20899

June 1988

Sponsored by:

U.S. Army Corps of Engineers

U.S. Department of the Army

Washington, DC 20314

Engineering Services and Utility Branch

U.S. Department of the Air Force

Washington, DC 20330-5000

Naval Facilities Engineering Command

U.S. Department of the Navy

Alexandria, Virginia 22332

U.S. DEPARTMENT OF COMMERCE, C. William Verity, Secretary

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Director

Revised Unitary Heat Pump Specifications for Military Family Housing

ABSTRACT

The purpose of this report is to revise and update the unitary heat pump

specifications developed in 1976* which addressed the requirements for

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

for the system and components; and conformance conditions. The document

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-water

classes, and sizes from 12,000 to 135,000 Btu/h for both heating and

cooling functions. This report reflects changes in specifications such

that the qualified units would be compatible with current available

commercial products. It also addresses installation practices and offers

a new life cycle costing criterion for competitive selection. It is

written in the format of a draft specification.

Key Words: Heating and cooling; military family housing; specifications;

unitary heat pump

*NBSIR 76-1029
|i‘! 1

*

.

.
TABLE OF CONTENTS

Page

ABSTRACT ... .................. iii

1. PURPOSE, SCOPE AND CLASSIFICATION 1 1 . 1 Purpose 1 1 . 2 Scope 1 1.3 Classification and Definition 1

2. REFERENCED SPECIFICATIONS AND STANDARDS 3

2.1 American National Standards Institute (ANSI) 3

2.2 Air-Conditioning and Refrigeration Institute (ARI) 3

2.3 American Society of Heating, Refrigerating, and

Air Conditioning Engineers, Inc. (ASHRAE) 4

2.4 Underwriter's Laboratories, Inc. (UL) 4

2.5 Department of Defense (DoD) , 4

2.6 Air Conditioning Contractors of American (ACCA) ... 5

2.7 American Society for Testing and Materials (ASTM) 5

2.8 Department of Energy (DoE) 5

3. PROCUREMENT GUIDELINES 6

3.1 Prerequisite ...... 6

3.2 Instructions to Purchaser 7

3.3 Selection Criteria 9

3.4 Applicable Standards 9

4. GENERAL REQUIREMENTS FOR EQUIPMENT 11

4.1 Description 11

4.2 Standards 12

4.3 Heat Pump Cooling and Heating Capacity 12

4.4 Operational and Reliability Requirements 13

4.5 Supplemental Electric Resistance Heat 13

4.6 Refrigerant 14

4.7 Indoor Temperature Control 15

4.8 Defrost 15

4.9 Protective Mechanisms, Controls and Auxiliary Equipment .... 16

4.10 Sound Rating 16

4.11 Hermetic Motor-Compressor Units 16

4.11.1 Thermal Protection 17

4.11.2 Current Overload Protection 17

4.11.3 Crankcase Heating 17

4.11.4 Time Delay Mechanisms 18

4.11.5 Liquid Flood-Back 18

4.12 Moisture in Refrigerant 18

4.13 Strainer 18

4.14 Materials in Outdoor Unit 19

4.15 Air Filters 19

4.16 Water- to-Air Heat Pumps . 20

iii
Page

5. QUALITY ASSURANCE PROGRAMS .... ............ 21

5.1 Responsibility for Inspection and Examination ......... 21

5.2 Tests for Quality Conformance ................. 21

5.2.1 Capacity Tests .......... . 22

5.2.2. Operational Tests ................... 22

5.2.3 Reliability Tests ..... ... 23

5.3 Sampling for Capacity and Operational Tests . 23

5.4 Sampling for High Stress Reliability Tests . 24

5.5 Sampling for Life Cycle Reliability Tests ........... 24

6. PERFORMANCE TESTS . . .......... 25

6.1 Capacity and Efficiency Tests 25

6.2 Operational Tests 25

6.3 Reliability Tests ........ 26

6.3.1 High Stress Reliability Tests ..... 27

6.3. 1.1 Criteria for Acceptance ... 27

6. 3. 1.2 Test Specifications for Air Source Heat Pumps . 29

6. 3. 1.3 Test Specification for Water Source Heat Pumps. 30

6.3.2 Life Cycle Reliability Tests ....... .31

6. 3. 2.1 Criteria for Acceptance 31

6. 3. 2.

2

Test Specifications 33

6.3.3 Corrosion Tests 33

6. 3. 3.1 Salt Spray Test 34

6. 3. 3.

2

Indoor Unit Corrosion Test .......... 34

6. 3. 3.

3

Criteria for Acceptance ............ 35

7. LIFE CYCLE COST .......... ......... 36

8. REQUIREMENTS FOR QUALIFIED INSTALLER ................ 41

8.1 Qualification 41

8.2 Guarantee ........................... 41
1. PURPOSE. SCOPE AND CLASSIFICATION

1 . 1 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.

1 . 2 Scope

This specification applies to hermetic electrically-driven vapor-compression

unitary heat pumps of the types defined in Section 1.3 having suitable

heating and cooling capacities for military family housing.

1 . 3 Classification and Definition

The term heat pump, applied to a year-round air conditioning system,

denotes a system in which refrigeration 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

consisting 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:
Physical configuration (Type)

Type I - Remote (split) type - The indoor and outdoor units are

separated and remote one from the other.

Type II - Packaged (integral, single) type - The indoor and outdoor

units are housed in a single cabinet assembly.

Heat source and sink (Class)

Class A - Air-to-air heat pump - Air is the heat sink and source

medium for the outdoor and indoor units

Class 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.

Size (Capacity at ARI Standard Rating Condition)

Size 1 - 12,000 to 65,000 Btu/h (3,500 to 19,000 watts)

Size 2 - 65,000 to 135,000 Btu/h (19,000 to 39,600 watts)

2
2 . 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 required by the

reference thereto:

2 . 1 American National Standards Institute (ANSI)

ANSI/ASHRAE 15-1978 Safety Code for Mechanical Refrigeration

ANSI/ASHRAE 34-1978 Number Designation of Refrigerants

2 . 2 Air-Conditioning and Refrigeration Institute (ART)

210/240-84 Standard for Unitary Air Conditioning and Air

Source Heat Pump Equipment

240-81 Air- Source Unitary Heat Pump Equipment

260-75 Standard for Application, Installation and

Servicing of Unitary Equipment

270-84 Standard for Sound Rating of Outdoor Unitary

Equipment

275-84 Standard for Application of Sound-Rated Outdoor

Equipment

320-81 Standard for Water Source Heat Pumps

325-83 Standard for Ground Water Source Heat Pumps

520-78 Standard for Positive Displacement Refrigerant

Compressors and Condensing Units

710-80 Standards for Liquid Line Driers

3
2 .

American Society of Heating. Refrigerating, and Air-Conditioning

Engineers

36-

72

37-

78

90A-1980

116-1984

GRP158

Inc. (ASHRAE)

Methods of Testing for Sound Rating Heating, Refrigerant

and Air Conditioning Equipment

Methods of Testing for Rating Unitary AirConditioning and Heat Pump Equipment

Energy Conservation in New Building Design

Methods of Testing for Seasonal Efficiency of Unitary Air

Conditioners and Heat Pumps

Cooling and Heating Load Calculation Manual

2 .4 Underwriter's Laboratories. Inc. (UL)

559 Standard for Safety - Heat Pumps

984 Standard for Safety - Sealed (Hermetic Type) Motor-Compressors

2 . 5 Department of Defense (DoD)

4270.21-1970 Guide Specifications for Military Family Housing

Air Conditioning, Mechanical Division 15.16a

MIL-H-22547B(YD) Military Specification: Heat Pumps, Heating and

Cooling (Unitary) (8,400 to 300,000 Btu)

AFM 88-29 Engineering Weather Data

TM5-785

NAVFAC P-89

4
2 . 6 Air Conditioning Contractors of America (ACCA)

Manual G Selection of Distribution System

Manual J Load Calculation for Residential Winter and Summer Air

Conditioning

Manual 0 Equipment Selection and System Design Procedures

2 . 7 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 at 100 Percent Relative Humidity

D2247-68 (R80) Standard Method for Testing Coated Metal Specimens at 100%

Relative Humidity

G33-72 Standard Recommended Practice for Recording Data From

Atmospheric Corrosion Tests of Metallic-Coated Steel Specimens

2 . 8 Department of Energy (DoE)

DoE/NBS-0011 TI-59 Program for Calculating the Annual Energy Requirements

for Residential Heating and Cooling

DoE/CE-0076 Federal Energy Management Program Life Cycle Cost

Manual Update

5
3. PROCUREMENT GUIDELINES

3 . 1 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.

Weather data for outdoor design conditions should be in accordance

with Engineering Weather Data Air Force , Army and Navy Manual

Design sensible heating and sensible and latent cooling loads

should be determined in accordance with procedures described in

Cooling and Heating Load Calculation Manual (ASHRAE GRP 158) or

procedures given in ACCA Manual J, latest edition.

Air distribution systems should be suitable for both winter heating

and summer cooling and should conform to practices established in ACCA

Manual G, Manual D 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.

6
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, gas 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.

Also, compatibility with water pollution regulations should be ensured.

3 . 2 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:

Required voltage and related electrical characteristics.

Winter and summer design indoor and outdoor conditions and the

seasonal heating hours for 5°F (2.8°C) temperature increments as

given in the Engineering Weather Data Manual.

Required heating and cooling capacities, in Btu/h (watts), at

specified winter and summer design conditions, respectively.

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

limitations, or other special construction considerations.

Additional preproduction and/or post production capacity,

conformance and/or reliability tests as required and if any or

7
all tests are to be waived. In the area of reliability testing,

lack of data relating laboratory tests to field performance forces

some of the required operating conditions and hours of operation

to be somewhat arbitrary. If a manufacturer can demonstrate that

he is meeting the intent of the reliability tests with a testing

program of his own design (e.g. historical field reliability data),

the purchaser may choose to waive the specified reliability tests.

Specific performance data desired in addition to required test data.

Marginal cost of electricity, present value factor for life

cycle costing.

Minimum external resistance of air distribution system when

delivering the rated capacity and air quantity.

Length of warranty period. Items to be covered by warranty

(parts, labor, etc.).

When water-to-air heat pumps are specified, data covering water

quantity available in gallons per minute, summer and winter

water temperatures, water source and quality of water will be

furnished by the military services.

For geographical regions of high corrosion potential, such as

coastal regions with salt spray exposure, specify salt spray test.

8
3 . 3 Selection Criteria

The unit to be purchased shall be that which meets the purchaser specified

procurement guidelines (Section 3.2), the general requirements (Section 4)

and quality assurance provisions (Section 5) of this document and which

will result in the lowest life cycle cost (Section 7)

.

3 . 4 Applicable Standards

Throughout this document reference is made to applicable current ARI

standards. These standards are those which are used for testing and

rating for listing in the most recent edition of the appropriate ARI

directory of certified products. As this document is being written (April

1988), the current applicable ARI standard for air source heat pumps is

240-81. It is recommended that units covered by ARI 240-81 that are

greater than 65,000 Btu/h (19,000 watts) in capacity shall be tested in

the same way as those less than 65,000 Btu/h (19,000 watts) in order to

provide the necessary data for calculation of local SEER and HSPF values

to allow application of the lowest life cycle cost criterion of this

standard. This requires the performance of additional "B" cooling steady

state and heating mode frost accumulation tests and either performance of

cycling tests or use of the default value of CD

.

At this time ground water source units are rated under ARI 325 and water

source heat pumps under ARI 320. It is recommended that rating under ARI

320 be allowed for units which use well water of an approximately constant

70° F (21. °C) temperature (approximately DoE zones 1 and 2) and that rating

under ARI 325 be allowed also for this application and required for all

9
other ground water source applications.

As newer Department of Energy approved methods for calculating seasonal

efficiency are developed which can be adopted to site particular energy

consumption calculations , these should be employed in lieu of the above

mentioned standards

For all other cited documents, the most recent revision shall be used for

procurement under this specification.

10
4. GENERAL REQUIREMENTS FOR EQUIPMENT

4 . 1 Description

Throughout this specification the term "heat pump" will be used

interchangeably with the term "unitary heat pump" as defined in Sections

1 . 2 and 1.3.

All heat pumps of a given type, class and size to be delivered under a

specific contract or purchase 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, on which the

capacity, operational, and reliability tests of this document have been

performed as a rated, matched set. Precharged factory supplied units and

tubing shall be furnished with remote type heat pumps whenever available.

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. Electric

resistance heaters may be field installed in either type. The cooling

capacity of the system shall not be less than the cooling design load

specified in the contract or purchase order. The resistance heating coils

shall be capable of handling a minimum of 100% of the heating design load.

Unless otherwise specified, the maximum airflow and minimum external

pressure shall be as required in the current applicable ARI standard

referenced in section 2.2. Unit components shall be readily accessible

for maintenance and service. Certain requirements in this specification,

particularly current overload protection, crankcase heating, time delay

mechanisms and liquid flood-back protection are included for system

11
reliability needs . If a bidder has alternative means to accomplish these

functions, the acceptance shall be dependent on proof submitted by the

heat pump manufacturer, and acceptable to the contracting officer,, This

proof shall include written certification that the alternative means

satisfy the functional requirements.

4 . 2 Standards

Heat pumps shall conform to current applicable ARI standards, UL 559 and

ANSI/ASHRAE 15. Proof shall be submitted showing that the items furnished

under this specification conform to such requirements. The listing and

labels (together) of the ARI and a nationally recognized safety approval

agency for the manufacturer's standard model will 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 competent to perform such services shall be

submitted stating that the items have been tested and that the heat pump

units and assembled components conform to requirements specified in

current applicable ARI standards, UL 559 and ANSI B9.1. Description of

test methods shall accompany certificate.

4 . 3 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

conditions of the contract or purchase order when tested in accordance

with Section 5.2. 1.1. The minimum capacity for the supplemental heaters

12
shall be at least equal to the heating load at the winter design outdoor

temperature

.

The heat pump manufacturer shall state the rated voltage and capacity of

supplemental heaters. The heaters shall provide this capacity when tested

in accordance with Section 6.1.4. Air source heat pumps shall meet the

minimum efficiency requirements of the current ASHRAE Standard 90, or

those which may be in effect by the local civilian authority, whichever is

more stringent. This criteria is predominate in case of conflict with

life cycle cost criteria noted later in this report.

4 . 4 Operational and Reliability Requirements

Heat pumps qualified for delivery under this specification shall meet the

operational and reliability criteria of the current applicable ARI

standards and shall have been subjected to and successfully passed the

operational and reliability tests required in Section 5 of this specification

and shall conform to the requirements contained in Section 6 of this

specification.

4 . 5 Supplemental Electric Resistance Heat

If supplementary heat is needed to satisfy the heating requirements (see

Section 4.3) 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 accordance 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

13
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 40°F (22.2°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 40° F (4.4°C) except as required to offset

cooling effect during defrost operation (Section 4.8) or in the case of

emergency (e.g., compressor failure). 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-on temperature for the

first set of supplemental heaters shall be between 0.5°F (.3°C) and 1 . 5°

(.8°C) below the cut-on 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°F (.3°C) 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 cut-off

of the compression heating control shall not exceed 2°F (1.1°C). All

quoted thermostat temperature differentials are as measured at the switch

(i.e., switch differential).

4 . 6 Refrigerant

The refrigerant shall be Group I Classification as described in ANSI/ASHRAE

34. The type of refrigerant to be used in the system shall be as specified

14
in the contract or purchase order. If not so specified, the refrigerant

shall be R-22.

4 . 7 Indoor Temperature Control

Temperature controls for heat pump operation shall be capable of being set

to control heating at any temperature at least from 55° F (12.8°C) up and

to control cooling at any temperature from at least 85° F (29.4°C) down.

The thermostat shall be factory locked to prevent setting below 42°F(5.6°C).

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 2°F (1.1°C) of the control setting when only

compression heating is being provided and to within 3°F (1.7°C) of the

control setting when compression and supplemental heating is required.

For control of supplemental heat see Section 4.5. The thermostat shall

contain or a sub-base shall be provided containing selector switches for

COOL-OFF-HEAT and FAN-AUTO-ON.

4 . 8 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 and other malfunctions

throughout the entire range of application temperatures.

15
4 . 9 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 operation. Also refer

to Section 4.2.

4 . 10 Sound Rating

All outdoor unitary heat pump equipment shall be sound rated and tested in

accordance with ARI 270 and shall not exceed a sound rating of 8.4 bels for

units below 38,000 Btu/h (11,100 watts), 8.6 bels for units between 38,000

Btu/h (11,100 watts) and 65,000 Btu/h (19,000 watts) and 8.8 bels for units

between 65,000 Btu/h (19,000 watts) and 135,000 Btu/h (39,600 watts) in

capacity as defined in these standards. The ARI label will be acceptable

as sufficient evidence of compliance with the test method of ARI 270. 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 requirements specified in ARI 270 and to the requirements of this

specification.

4.11 Hermetic Motor-Compressor Units

Hermetic motor-compressor units shall conform to the requirements of UL 984

with regard to construction, performance and testing. The requirements for

motor-compressor protection systems of this standard shall also apply in

16
addition to the following.

4.11.1 Thermal Protection

An internal motor-winding temperature-sensing protection device of the

automatic reset type for the compressor motor shall be provided to prevent

motor operation under excessive motor winding temperatures. The heat pump

compressor manufacturer's recommended maximum average motor winding

temperature shall not be exceeded when the heat pump is operating under

any of the tests prescribed in ARI 210/240, and in no case shall winding

temperature under any of these test conditions exceed 300°F (149°C). The

heat pump compressor manufacturer's recommended maximum average motor

winding temperature shall be stated in the bid submission.

4.11.2 Current Overload Protection

Motor running- current overload protection conforming to the National

Electric Code (refer to UL 984) , shall be provided for the compressor

motor. If manual reset is provided it shall be readily accessible and

reset means clearly marked.

4.11.3 Crankcase Heating

Means shall be provided for heating the compressor crankcase of units with

outdoor compressors which equalize crankcase pressure to suction pressure,

so that liquid slugging as a result of liquid foaming under compressor

starting conditions is prevented. Crankcase heaters either external or

internal (except for motor windings used as heaters) shall be readily

replaceable from the exterior without breaking the refrigerant seal.

17
4 . 11.4 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 three but not

more than six 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.)

4.11.5 Liquid Flood-Back

A means shall be provided for protecting the compressor of air source

units from liquid flood-back, under all design conditions of operation,

including defrost. Properly designed and sized accumulators or a

sufficiently large oil sump within the hermetic shell will satisfy this

requirement. Accumulators must provide for return of oil to the compressor.

4 . 12 Moisture in Refrigerant

The system shall contain a filter-drier conforming to ARX 710. Refrigerant

piping shall be circuited such that backwashing of the filter-drier by

reversal of refrigerant flow does not occur unless the filter is designed

for bidirectional operation. The moisture content in the refrigerant

shall not exceed 60 ppm at time of heat pump installation and 30 ppm at

conclusion of the Reliability Tests (see Section 6.3).

4 . 13 Strainer

If the heat pump system uses capillary tubes as a refrigerant expansion

device, a strainer shall be installed in the line ahead of the capillary

18
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.

4. 14 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 6.3) of this specification,

it shall pass the tests and retain its physical and structural integrity.

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. 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.

4 . 15 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 remotely 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 the indoor

coil

.

19
4.16 Water- to-Air Heat Pumps

Water-to-air heat pumps shall be capable of meeting the following performance

requirements

1. The water temperature leaving the condenser during cooling

operation shall not exceed the maximum water temperature

recommended by the manufacturer.

2. The water temperature leaving the water- to-refrigerant heat

exchanger during heating operation shall not be less than 40°

(4.4°C) for open loop systems and the manufacturer's recommended

temperature with the manufacturer's recommended circulating

fluid (brine) for closed loop systems.

3.

A low pressure cut-out device with a manually reset lockout or a

freezestat shall be installed so as to prevent freezing during

the heating operation.

4.

Construction and/or piping for water- to-refrigerant heat

exchangers of open loop systems shall include provision for

isolation and access valving for the purposes of chemical

cleaning or physical access for mechanical cleaning of the

water side of heat exchange surfaces. Water piping and valving

may be installed.

20
5. QUALITY ASSURANCE PROCEDURES

5 . 1 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 component 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.

5 . 2 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 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 to all inspections and

capacity, operational and reliability tests. The Government reserves the

right to make any or all inspections 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

21
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.

5.2.1 Capacity Tests

The supplier shall provide manufacturer '

heating and cooling data which

shall be obtained in accordance with the current applicable ARI standard

and certified as required in paragraph 4.2. Certified performance data

shall include capacity and power input at the standard rating condition

and the application rating condition as described in the current applicable

ARI standard.

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 the current applicable ARI standard is specified,

the performance data required shall be adjusted accordingly.

Manufacturer '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 certification program such as that of ARI.

5.2.2 Operational Tests

The heat pump system shall operate satisfactorily under standard and

maximum operating conditions (refer to Section 4.4). Heat pumps scheduled

for delivery under this specification shall meet all requirements of the

22
current applicable ARI standard. The ARI label and listing in the current

ARI directory will be accepted as evidence of meeting this requirement.

In lieu of such certification and 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 the current applicable ARI standard.

5.2.3 Reliability Tests

The heat pump shall be subjected by the manufacturer to either the high

stress or the life cycle reliability tests listed in Section 6.3 of this

specification (unless waived by the purchaser) and shall conform to the

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

as permitted herein. Reliability test data shall be made available to

the purchaser by the manufacturer if requested.

5 . 3 Sampling for Capacity and Operational Tests

Unless otherwise required in the contract or purchase order, the heat pump

type, class, model and size to be provided for delivery shall have its

certified data for all listed capacity tests and operational tests and

shall satisfactorily conform to all test requirements. Units which are

identical but not necessarily the same physical units may be used for the

capacity and operational tests and the reliability tests. The heat pump

tested as representative of each type, model and size shall pass all tests

described in Section 5.2, and as specified under Sections 6.1 and 6.2.

23
5 . 4 Sampling for High Stress Reliability Tests

If the high stress reliability test option is chosen, at least one heat

pump of each type, class, model or closely related models to be provided

under this contract and picked at random shall have been subjected to and

successfully passed the reliability tests (Section 6.3.1) conducted in

accordance with the following plan. If there are no failures in this

first specimen, the type, class, model and size will be considered

satisfactory with respect to the reliability tests. If there are not

more than two failures, three additional specimens picked at random shall

undergo a test for conformance to all listed reliability requirements. If

there is not more 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. 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. Sampling

under this option applies to each type, class, model or worst case

condition of closely related models, and worst size condition within

models which are to be provided under this contract. A failure shall be

considered to be an inability to meet any of the criteria for acceptance

of 6. 3. 1.1.

5 .Sampling for Life Cycle Reliability Tests

Sampling for the life cycle reliability test option shall be at random and

shall be sufficiently large as to be statistically significant as defined

in Section 6. 3. 2.1. Sampling under this option applies to each type,

24
class, model or worst case condition of closely related models, and worst

size condition within models which are to be provided under this contract.

6. PERFORMANCE TESTS

6 . 1 Capacity and Efficiency Tests

This section describes tests of heat pumps for determination of capacity and

coefficient of performance. Testing procedures shall, where applicable, be

as described in the current applicable ASHRAE test procedure for all sizes

of heat pumps procured under this document. Unless otherwise specified, test

conditions shall be as set forth in the current applicable ARI standard. At

rating and application conditions, the efficiency of the heat pump for heating

and cooling shall be calculated from the test data in a manner as defined

by the current applicable ARI standard. This determination shall act as input

to the Life Cycle Cost procedure described in Section 7 of this document.

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 Sections 4.5 and 4.3.

6 .

2

Operational Tests

As stated in Section 5.2.2, required operational tests are the following

tests described in the Performance Requirements of the current applicable

ARI standard:

25
1. Maximum Operating Condition Test

2. Voltage Tolerance Test

3. Low Temperature Operation Test (Cooling)

4. Insulation Efficiency Test (Cooling)

5. Condensate Disposal Test (Cooling)

6 . 3 Reliability Tests

For the purpose of this specification, reliability tests for air source

heat pumps will be considered in two separate programs: (1) high stress

tests and (2) life cycle tests. The high stress test program is intended

to take the system beyond its normal operating limits to ensure that there

are adequate safety devices that will shut the system down in order to

protect the essential, more expensive components (i.e„, compressor). The

life cycle tests are designed to have the unit operate under simulated

field conditions near or slightly beyond the worst expected climatic

conditions for an extended period of time. The contractor must submit the

manufacturer's data that proves the specific model or a closely related

model to that being offered has successfully completed either one or the

other of these programs (high stress or life cycle) as defined in the

following sections.

In addition to either of these test programs the purchaser may specify one

or both of the corrosion tests described in Section 6.3.3; depending on

the climatic conditions of the installation site.

26
6.3.1 High Stress Reliability Tests

Temperature tolerances for the reliability tests shall be as specified in

performance requirements of ARI 210/240. Voltage tolerances shall be + 3

volts. 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°F (21.1°C) to 80°F (26.7°C) for tests.

For all tests, the portions of the tests that call for unit operation

imply continuous compressor operation except as controlled by protective/limit

devices. High stress reliability tests for water source heat pumps shall

be performed with water, not freezing inhibited brine, as the circulating

fluid.

6. 3. 1.1 Criteria for Acceptance

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

1. No impairing damage shall occur to any component during these tests.

2. The temperature of the oil sump remote from the suction line

inlet to the compressor shall at no time during steady-state

operation be less than 40° F (22. 2° C) warmer than that of the

suction line within 6 inches (.152 m) of the compressor shell.

During the off cycle this temperature difference may decrease

27
to 10°F (5.6°C). On start up this temperature difference must

constantly increase toward its steady state value.

3. The temperature of the discharge line within six inches (.15 m)

of the compressor shall at no time during steady state operation

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 sufaces (including at least

one inch (.025 m) of the leads) and shall be insulated from

ambient conditions.

4. No audible knocking or hammering of mechanical parts shall occur

in excess of that occurring in normal continuous operation at

standard rating conditions in the current applicable ARI standard.

5. Trip-out of operating, protective, and limit controls/devices

shall not constitute a failure.

6. Average motor winding temperature shall not exceed 300° F (149°C)

at any time during any of the reliability tests. Use of a

Seely bridge is recommended for measurement of the average

winding temperature while the motor is running.

7. Discharge refrigerant line temperature within 6 inches (.15 m)

of the compressor shall not exceed 250°F (121°C) during the

28
reliability tests.

8. Upon completion of the reliability tests, the moisture content

of the refrigerant shall be determined and the moisture content

shall not exceed 30 ppm with filter drier included in the system.

6.3. 1.2 Test Specifications for Air Source Heat Pumps

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)

100% unit operation

24 hours total test duration

3

.

Low temperature test (heating)

Voltage 110% of specified

Outdoor air dry-bulb temperature the higher of the lowest recorded

temperature for the region or the unit cut-off temperature

Indoor dry-bulb temperature 70°F (21.1°C) to 80°F (26.7°C)

Operation: Off 24 hours, On 8 hours, Off 24 hours, On 8 hours

64 hours total test duration

4

.

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

29
5 . 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)

50% of manufacturer's recommended refrigerant charge

100% unit operation

24 hours total test duration

6 . Low refrigerant charge test (heating)

Conditions same as 5 above, except outdoor air temperature 20°

(-6 . 7°C) to 35° F ( 1 . 7° C)

6. 3. 1.3 Test Specifications for Water Source Heat Pumps

1

Heating and cooling test

Voltage as specified in the contract or purchase order

Entering Water temperature 70° F (21.1°C) to 50° F (10.0°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

Entering Water temperature 85°F (29.4°C) to 95°F (35.0°C)

Indoor air dry-bulb temperature 70° F (21.1°C) to 80° F (26. 7° C)

100% unit operation

24 hours total test duration

3 . Low temperature test (heating)

Voltage 110% of specified

Outdoor air dry-bulb temperature for split system units the higher of

the lowest recorded temperature for the region or the unit cut-off

temperature

Entering water temperature 36°F (2.2°C) to 32°F (0°C)

Indoor dry-bulb temperature 70°F (21.1°C) to 80°F (26„7°C)

Operation: Off 24 hours, On 8 hours, Off 24 hours, On 8 hours

64 hours total test duration

30
4

.

Blocked air filter test (cooling)

Voltage as specified

Entering water temperature 65°F (18.3°C) to 75°F (23.9°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

5

.

Low refrigerant charge test (cooling)

Voltage as specified

Entering water temperature 65°F (18.3°C) to 75°F (23.9°C)

Indoor air dry-bulb temperature 70 F (21.1°C) to 80° F (26. 7° C)

50% of manufacturer's recommended refrigerant charge

100% unit operation

24 hours total test duration

6

.

Low refrigerant charge test (heating)

Conditions same as 5 above, except entering water temperature 45°

F

(7 . 2° C) to 55° F ( 1 . 28° C)

6.3.2 Life Cycle Reliability Tests

Temperature tolerances for the reliability tests shall be as specified in

performance requirements of the current applicable ARI standard. Voltage

tolerances shall be +3 volts. Supplemental heaters shall not be operated

during any reliability tests.

6. 3. 2.1 Criteria for Acceptance

Criteria for acceptance shall be those of 6. 3. 1.1 with the addition that

trip-out or similar operation of any manual-reset operating, protective,

or limit control/device shall constitute a failure.

Additional criteria for acceptance for the Life Cycle Reliability Test

option shall be compressor mean time between failures of at least 38,990

31
hours of test time and system mean time between failures of at least 3,910

hours of test time, both for the 2,000 hour test cycle of Section 6. 3. 2. 2,

with 80% confidence, assuming a constant failure rate. Reliability

computations are to take all failures without any exceptions into account.

A system failure is the occurrence of any condition which renders the heat

pump system incapable of operating satisfactorily, within the specified

performance limits, on a thermostat demand. A compressor failure constitutes

a system failure requiring that the compressor be removed and replaced to

restore satisfactory system operation.

The minimum number of units to be tested to meet the above 80% confidence

criteria may be calculated by satisfying equation 6.1 or may be read from

table 6.1 which lists the minimum number of units to be tested for various

numbers of compressor failures and the maximum number of unit failures

consistent with each listed test sample size.

n -m x

e m

E

x=0

x!

< 0.2 (6.1)

where m =

No. of units tested * No. of test hours per unit

mean time between failure

n = Total number of failures allowed

32
Table 6.1 Minimum number of test units and maximum number of compressor

failures and system failures required for life cycle reliabi lity

testing

Maximum Number of

Compressor Failures

0

12

3

4

Minimum Number of

Test Units

32

59

84

108

132

Maximum Number of

Unit Failures

12

25

36

48

60

6. 3. 2.

2

Test Specifications

1 . High temperature test (cooling)

Outdoor air dry-bulb temperature 95° F (35.0°C) or higher

Indoor air dry-bulb temperature 70°F (21.1°C) to 80°F (26.7°C)

Indoor relative humidity 50%

Operation: off 15 minutes/on 15 minutes

Voltage 110% of specified, 350 hours duration

Voltage 90% of specified, 350 hours duration

2 . Defrost test (heating)

Outdoor air dry-bulb temperature 38°F (3.3°C) to 32°F (0°C)

Outdoor relative humidity 80%

Indoor air dry-bulb temperature 70°F (21.1°C) to 80°F (26.7°C)

Operation: off 10 minutes/on 10 minutes

800 hours duration

3 . Low temperature test (heating)

Outdoor air dry-bulb temperature the higher of the local design

temperature region or the unit cut-out temperature

Indoor air dry-bulb temperature 70° F (21.1°C) to 80° F (26. 7° C)

Operation: off 1 hour/on 1 hour

Voltage 110% of specified, 250 hours duration

Voltage 90% of specified, 250 hours duration

6.3.3 Corrosion tests

Under extreme climatic conditions at the application site, the purchaser

may find it appropriate to require the heat pump outdoor and/or indoor

unit to pass the following tests.

33
6. 3. 3.1 Salt Spray Test

If a salt spray test is specified by the purchaser, portions of the heat

pump that are normally exposed to the outdoor environment shall be tested

in a corrosive environment 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.

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. Total duration of actual salt spray exposure shall be 240

hours (or 720 hours if specified in the contract or purchase order)

6. 3. 3.Indoor Unit Corrosion Test

If the 100% relative humidity test is specified by the purchaser, 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.

34
The extent of area of indoor and outdoor exposure to salt spray/humidity

environment for corrosion testing of packaged (integral) type heat pumps

shall be determined from size, dimension and construction considerations.

100% Relative Humidity Test

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% relative humidity exposure

Flaking, perforation, or penetration of metal parts shall be

considered a failure.

6. 3. 3.

3

Criteria for Acceptance

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, external 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" (3.2 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 corrosion of bare

metal parts and at joints of dissimilar metals shall be reported and

photographed. Flaking, perforation, or penetration of metal parts shall

35
be considered failure. Impairing damage to any mechanical or electrical

components shall be considered failure.

7. LIFE CYCLE COST

For purposes of this heat pump specification, the definition of the Life

Cycle Cost (LCC) of a contract bid is given by the following expression:

LCC = C + P * F * E ( 1 )

where C = installed cost of the heat pump equipment based on the

contract bid ($)

P = current local unit price of electricity ($/kWh)

F = Modified Uniform Present Worth Factor, which takes into

account the discount rate and the expected increases in

electricity prices, and which assumes a fifteen year life

for the heat pumps

E = total annual electric energy estimated to be consumed by

the heat pump equipment for both heating and cooling (kWh/year)

The first term, C, on the right-hand side of expression (1) represents the

total dollar investment cost associated with installing the heat pump

equipment specified in the contract. This cost should include acquisition,

delivery, installation, start up, and initial testing of the heat pump

equipment and of the associated controls and distribution system. This

cost may be structured to include an initial or an extended period

warranty for parts and/or labor. To assure that all of the contract bids

36
are compared on an equal basis, the request for bids should specify the

same warranty period to be offered by all the bidders. Comparability

across bids also requires that the engineering specifications for the heat

pump equipment be adequate to satisfy the heating and cooling loads of the

target housing units specified in the request for bids. In this way,

comparison of bids focuses on the effects of the only two variables still

permitted to vary across bids: 1) the investment cost, C; and 2) the

seasonal heating and cooling efficiency ratings used to compute total

annual electric energy use, E.

The second term of expression (1), P, represents the current local unit

price of electricity stated in $/kWh. Given the objective of minimizing

the LCC of supplying heating and cooling to housing on a particular

military base, the theoretically correct value to be used for P is the

marginal cost savings that would result from reducing electricity consumption

one kWh below the current level of consumption on the base. Data on

current base consumption can be used to determine this marginal cost

savings from the current rate schedule of the local utility. Alternatively,

P can be approximated by using the average price given in column (3) of

Table 7-1 for the particular Department of Energy (DoE) Region in which

the military base is located. For example, if the base were in Nevada,

which is in DoE Region 9, the appropriate average price to use to approximate

P would be $0,072 per kWh. These average electricity prices for the

various regions are derived from Tables Ca-1 through Ca-11 of a report

issued annually in support of the Federal Energy Management Program of the

37
Table 7-1. Average Electric Energy Price, P, and Modified Uniform

Present Worth Factors, F, for the 10 DoE Regions and the

United States Average for 1987

Region

Number States Included

Average

Price

($/kWh)

Modified Uniform Present

Worth Factor

(7%, 15 Years) (10%, 15 Years)

(1) (2) (3) (4) (5)

1 ME , NH , VT , MA , CT , RI 0.099 8.42 7.08

2 NY, NJ, PR, VI 0.087 8.74 7.31

3 PA , MD , WV , VA , DC , DE 0.068 8.52 7.12

4 KY,TN,NC,SC,MS,AL

GA, FL, CZ

0.066 7.90 6.64

5 MN , WI , MI , IL , IN , OH 0.077 8.01 6.74

6 TX , NM , OK , AR , LA 0.064 9.62 7.99

7 KS S M0, IA,NE 0.071 8.38 7.02

8 MT , ND , SD , WY , UT , CO 0.071 8.10 6.78

9 CA , NV , AZ , HI

,

Pac . Trust Terr .

,

Samoa, Guam

0.072

) 8.10 6.79

10 WA , OR , ID , AK 0.035 9.45 7.85

11 UNITED STATES AVE. 0.071 8.41 7.04

Source

Barbara C. Lippiatt and Rosalie T. Ruegg, "Energy Prices; and

Discount Factors for Life Cycle Cost Analysis: Annual Supplement

to NBS Handbook 135 and NBS Special Publication 709, "NBSIR 85-

3273-2 (Rev. 6/87) U.S. Dept, of Commerce, National Bureau of

Standards, Gaithersburg, MD 20899. The prices given in the

report in $/million Btu were converted to $/kWh by assuming 3413

Btu/kWh

.

38
Department of Energy. 1 The prices specifically refer to electricity

supplied to the commercial sector in 1987. Updates are available on an

annual basis from the DoE Federal Energy Management Program.

The term F in expression (1) represents the Modified Uniform Present Worth

Factor that converts a future stream of variable annual cash payments to

its equivalent present value. This factor is designed to take into

account three elements: (1) the discount rate, (2) the duration of the

cash payments, and (3) variations in the annual cash payments that may

result from electricity price fluctuations. The discount rate is the

rate of interest that reflects the decision maker's time value of money.

For evaluating energy conservation investments made by Federal agencies,

the Energy Security Act of 1980 (P.L. 96-294) requires that a discount

rate of 7 percent be used. 2 For evaluating Federal investments that are

not primarily intended to conserve energy, the U.S. Office of Management and

Budget requires that a discount rate of 10 percent be used (except for a

few types of investments such as for water resources and capital asset

leasing.) 3 Thus, if the heat pump procurement is being undertaken

primarily to conserve energy, the 7 percent discount rate should be used;

otherwise, the 10 percent discount rate should be used.

1 Barbara C.Lippiatt and Rosalie T.Ruegg, "Energy Prices and Discount

Factors for Life Cycle Cost Analysis: Annual Supplement to NBS Handbook

135 and NBS Special Publication 709," NBSIR 85-3273-2 (Rev. 6/87) U.S.

Dept, of Commerce, National Bureau of Standards, Gaithersburg, MD 20899.

2 Energy Security Act, P.L. 96-294, 94 STAT 611, sec. 405 (1980).

3 U.S. Office of Management and Budget, "Discount Rates to be Used in Evaluating

Time-Distributed Costs and Benefits," (Washington, DC: U.S. Office of

Management and Budget, Circular A-94, March 27, 1972).

39
The second element affecting the value of F, the duration of the cash

payments, is determined by the expected service life of the heat pump

equipment being installed. This specification assumes that the service

life of every heat pump alternative being proposed is the same 15 year period.

The third element that determines the appropriate value of F in expression

(1) is the expected price of electricity during the 15 year life of the

equipment. The DoE Energy Information Administration provides projections

of electricity prices. These projections serve as the basis for the

computed F values published in Tables .B-la through B-lla and B-lb through

B-llb of "Energy Prices and Discount Factors for Life-Cycle Cost Analysis,"

referenced above. The F values in these tables cover a range of study

periods for both 7 and 10 percent discount rates. Table 7-1 presents these

F values for a study period of 15 years for each of the 10 DoE regions and

the United States Average in Columns (4) and (5)

.

The final term in expression (1) is E and represents the total annual

electricity estimated to be consumed by the heat pump for an entire year

of heating and cooling. The value of E for each contract proposal is

determined by separately estimating annual electricity consumption for the

cooling season and for the heating season and then summing the two estimates.

The procedure for calculating E shall be one which qualifies as an

acceptable evaluation technique under the U.S. Department of Energy's

Building Energy Performance Standards. The method of DoE/NBS-0011 is

recommended. The heat pump efficiencies to be used in this calculation

40
shall be the manufacturers' values for SEER for the cooling season and

HSPF for the heating season of the DoE region in which the installation

site lies. For water source units that do not require resistance heat to

meet the building load, the SEER and the HSPF shall be equal to their

respective steady-state efficiencies for the local seasonal average ground

water temperature times a factor of 0.9 in the cooling mode and 0.85 in the

heating mode to take into account cyclic degradation. If resistance heat

is required to meet the building load with a water source unit the HSPF

shall be calculated by a bin calculation on which the steady-state efficiency

shall be degraded by a constant part load factor of 0.85 in all bins.

When published, a DoE method for water source units shall replace this method.

8. REQUIREMENTS FOR QUALIFIED INSTALLER

8 . 1 Qualification

Dealer/Installer shall be certified by the heat pump manufacturer as having

his senior mechanics successfully passed their factory sponsored installation

course in the past ten years. The Dealer/Installer shall be local; that

is, the military base shall lie within his normal radius of service.

Dealer/Installer shall guarantee that his installation and charging method

is completely in accordance with the manufacturer's procedures and provide

a demonstration of the procedure on site.

8 .

2

Guarantee

Dealer/Installer shall provide a five year service contract guaranteeing

normal preventative maintenance as well as parts and labor for repairs.

This contract shall offer the first year all parts and labor free of charge

41
and service contract for the next four years , the cost of which shall be

included in item C of equation (1) in Section 7.

42
NBS-114A (REV. 2-80

U.S.-DEPT. OF COMM.

/

-BIBLIOGRAPHIC DATA

SHEET (See instructions)

1. PUBLICATION OR

REPORT NO.

NBSIR 88-3805

2. Performing Organ. Report No. 3. Publication Date

JUNE 1983

4. TITLE AND SUBTITLE

Revised Unitary Heat Pump Specification for Military Family Housing

5. AUTHOR(S)

William Mulroy, Stephen Weber, David Didion

6. PERFORMING ORGANIZATION (If joint or other than NBS. see instructions)

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20234

7. Contract/Grant No.

8. Type of Report & Period Covered

9. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street. City. State. ZIP)

Army Corps of Engineers Engineering Services and Naval Facilities Engineering

Department of the Army Utility Branch Command

Washington, D.C. 20314 Department of the Air Force Department of the Navy

Washington, D.C. 20330-5000 Alexandria, Virginia 22332

10. SUPPLEMENTARY NOTES

Document describes a computer program; SF-185, FIPS Software Summary, is attached.

11. ABSTRACT (A 200-word or less factual summary of most significant information. If document includes a significant

bibliography or literature survey, mention it here)

The purpose of this report is to revise and update the unitary heat pump specifications

developed in 1976* which addressed the requirements for performance, testing, rating,

design, safety, serviceability and reliability for the system and components; and

conformance conditions. The document 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-water classes,

and sizes from 12,000 to 135,000 Btu/h for both heating and cooling functions. This

report reflects changes in specifications such that the qualified units would be compatible with current available commercial products. It also addresses installation

practices and offers a new life cycle costing criteria for competitive selection.

It is written in the format of a draft specification.

12. KEY WORDS (Six to twelve entries; alphabetical order; capitalize only proper names; and separate key words by semicolon s) leating and cooling; military family housing; specifications; unitary heat pump

13. AVAILABILITY 14. NO. OF

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1 Order From Superintendent of Documents, U.S. Government Printing Office, Washington, D.C.

20402. 15. Price

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! Order From National Technical Information Service (NTIS), Springfield, VA. 22161 $11.95

USCOMM-DC 6043-P 80