, <r:-' ·_· · .. 

1986 

: t-. .... D AMERICAN NAn .., 

OBSOLETE 

STANDARD for 

,liP; 

... 1 • 

AIR-CONDITIONING 

& REFRIGERATION 

INSTITUTE 

ANSIIARI 340-86 

COMMERCIAL AND 

.. INDUSTRIAL 

UNITARY HEAT .. 

PUMP EQUIPMENT 

I Standard 340 I 

1501 WILSON BOULEVARD. ARLINGTON, VIRGINIA 22209 

... ------. ,..- .. 
OBSOLETE 

TABLE OF CONTENTS 

PART PAGE 

Section 1. Purpose 

Section 2. Scope ................................................................................ . 

Section 3. Definitions ........................................................................... . 

Section 4. Classification .......................................................................... 2 

Section 5. Testing and Rating Requirements ........................................................ 2 

Section 6. Performance Requirements .............................................................. 6 

Section 7. Safety Recommendations ................................................. :.............. 7 

Section 8. Conformance ......................................................... . ......... " .. .".... 7 . 

: ' 

Appendix A. Method and Example of Calculating IPL V ............ . ............................................ 8 
, 

________________________ ARI STAN DAR 0 340-86 

COMMERCIAL AND INDUSTRIAL UNITARY 

HEAT PUMP EQUIPMENT 

Section 1. Purpose 

1.1 Purpose. The purpose of this standard is to establish, for commercial and industrial unitary heat pump 

equipment: definitions and classification; requirements 

for testing and rting; specifications, literature and advertising requirements; performance requirements; 

safety recommendations; and conformance conditions. 

1.1.1 This standard is intended for the guidance of 

the industry, including manufacturers, distributors, 

consultants, and consumers. 

1.2 Review and Amendment. This standard is subject to 

review and amendment as the art of the industry advances. 

Section 2. Scope 

2.1 Scope. This standard applies to factory-made airsource commercial and industrial unitary heat pumps, 

as defined in 3.1. 

2.1.1 Energy Source. This standard applies only to 

electrically-driven, mechanical compression type 

systems. 

2.2 Exclusions. This standard does not apply to the 

rating and testing of individual assemblies for separate 

use, nor to unitary heat pumps as defined in ARI Standard 240 with capacities less than 135 MBh [40 kW). or 

water-source heat pumps as defined in ARI Standard 

320. 

-Section 3. Definitions 

3.1 Commercial and Industrial Unitary Heat Pump. A 

commercial and industrial unitary heat pump consists of 

one or more factory-made assemblies which normally 

include an indoor conditioning coil, compressor(s) and 

refrigerant-to-air heat exchanger, including means to 

provide a heating function and mayor may not include a 

cooling function. When such equipment is provided in 

more than one assembly, the separated assemblies 

should be designed to be used together, and the requirements of rating outlined in the standard are based 

upon the use of matched assemblies. 

3.1.1 Functions. Commercial and industrial 

unitary heat pumps shall provide the function of 

heating with controlled temperature, and may include the functions of air-cooling, air-circulating, 

air-cleaning. dehumidifying or humidifying. 

3.2 Published Rating. A statement of the assigned 

values of those performance characteristics, under 

stated rating conditions. by which a unit may be chosen 

to fit its application. These values apply to all units of like 

nominal size and type (identification) produced by the 

same manufacturer. As used herein, the term "published 

rating" includes the rating of all performance characteristics shown on the heat pump or published in specifications, advertising. or other literature controlled by the 

manufacturer, at stated rating conditions. 

3.2.1 Standard Rating. A rating based on tests performed at Standard Rating Conditions. 

3.2.2 Application Rating. A rating based on tests 

performed at application rating conditions (other 

than Standard Rating Conditions). 

3.3 Rating Conditions. Any set of operating conditions 

under which a single level of performance -results, and 

which causes only that level of performance to occur. 

3.3.1 Standard Rating Conditions. Rating conditions used as the basis of comparison of performance characteristics. 

3.4 Energy Efficiency Ratio (EER). A ratio calculated 

by dividing the cooling capacity in MBh by the total 

power input in kW at any given set of rating conditions, 

expressed in Btuh per watt (Btuh/watt). 

3.4.1 Standard Energy Efficiency Ratio. A ratio 

calculated from the capacity and power input values 

-obtained at Standard Rating Conditions. 

3.5 Coefficient of Performance (COP). A ratio calculated by dividing the total heating capacity provided by 

the refrigeration system including circulating fan heat 

but excluding supplementary resistance heat, (MBh) by 

the total electrical input (kW) x 3.412. [A ratio calculated for both cooling and heating capacities by dividing 

capacity in kW by power input in kW.J 

3.6 Integrated Part Load Value (IPLV). A single number cooling part-load efficiency figure of merit calculated per the method described in 5.2.2. 

3.7 "Shall", "Should", "Recommended", or "It is Recommended". "Shall", "should", "recommended", or 

"it is recommended" shall be interpreted as follows: 

3.7.1 Shall. Where "shall" or "shall not" is used 

for a provision specified, that provision is mandatory if compliance with the standard is claimed. 
ARI STANDARD 340-86 _______________________ _ 

3.7.2 Should, Recommended, or It is Recommended. "Should", "recommended", or "it is "recommended" is used to indicate provisions which 

are not mandatory but which are desirable as good 

practice. 

Section 4. Classification 

4.1 Classification. Normally, commercial and industrial 

unitary heat pumps within the scope of this standard may 

be classified as shown in Table 1. 

Section 5. Testing and Rating Requirements 

5.1 Standard Ratings. Standard ratings shall be established at the Standard Rating Conditions specified in 

5.1.4. All standard ratings shall be verified by tests conducted in accordance with the ASHRAE Standard 

Methods o/Testing for Rating Unitary Air-Conditioning 

and Heat Pump Equipment (American Society of Heating. Refrigerating and Air-Conditioning Engineers. Inc. 

Standard 37-78). and with the test methods and procedures as described in this standard. Modifications as set 

forth in 5.1.1 may be employed. 

Standard Ratings related to cooling or heating capacities 

shall be net values, including the effects of circulatingfan heat. but not including supplementary heat. Standard Rating (Cooling) shall be stated as total (sensible 

plus latent) cooling capacity and sensible cooling capacity. Standard Input Ratings shall be the total power input 

to the compressor(s) and fan(s), plus controls and 

other items included as part of the model number(s) and 

therefore does not include power input to auxiliary 

equipment. 

5.1.1 Modified Air Flow Measuremelll Method. 

For heat pumps with Standard Ratings of 401 MBh 

[117.3 kW] and greater. indoor air flow may be 

measured in accordance with 7.6 of ASHRAE 

Standard 37-78. 

5.1.2 Values of Standard Capacity Ratings. These 

ratings shall be expressed only in terms of thousands 

of Btu per hour (MBh) [kW] in multiples of 2 MBh 

[0.6 kW] for units with Standard Ratings of 400 

MBh [117 kW].and under. For units with Standard 

Ratings of over 400 MBh [117 k WJ. the ratings shall 

be expressed in multiples of 5 MBh [1.5 kWJ. 

5.1.3 Values of Standard Energy Efficiency Ratios 

of Coefficients of Performance. Energy Efficiency 

Ratios (EER) for cooling, whenever published, 

shall be expressed in multiples of the nearest 0.1 

Btub/wall [cooling COP and Integrated Part Load 

Values (IPLV) in multiples of 0.1]; standard coefficients of performance for heating, whenever published, shall be expressed in multiples of the nearest 0.1. 

5.1.4 Standard Rating Conditions. The conditions 

of test for Standard Ratings shall include the following: 

5.1.4.1 Standard Rating Temperatures. . 

a. Cooling (Not required for heating-only units) 

Air temperature entering indoor portion 

of unit .......... 80 F [26.7°C] dry bUlb. 

67 F [19.4°C] wet bulb 

Air temperature surrounding unit .... 95 F 

[35.0°C] dry bulb· 

·For units or portions thereof intended to be installed only indoors. 

this temperature may be changed to be the same as the air temperature entering the indoor portion of unit. 

TABLE 1. CLASSIFICATION OF COMMERCIAL AND INDUSTRIAL UNITARY HEAT PUMPS 

Types of Commercial an~ !ndustrial Unitary Heat Pumps 

ARIType 

Heating & Heating Heat 

Designation Cooling Only Source Arrangement 

~ingle Package HSP-A HOSP-A Air FAN I COMP 

INDOOR I OUTDOOR 

COIL COIL 

Remote Outdoor HRC-A-CB HORC-A-CB Air . FAN 

Coil INDOOR OUTDOOR 

COIL COIL . COMP 

Split System HRCU-A-CB HORCU-A-CB Air I FAN COMP I 

INDOOR OUTDOOR 

COIL COIL 

2 
________________________ ARI STAN DARD 340-86 

Air temperature entering outdoor portion 

of unit .......... 95 F [35.0°C] dry bulb 

b. High Temperature Heating" 

Air temperature entering indoor portion 

of unit .... '" ... 70 F [21.1°C] dry bulb. 

60 F [15.6°C] wet bulb, max. 

~ir temperature surrounding unit .... 47 F 

[B.3°C] dry bulb* 

Air temperature entering outdoor portion 

of unit ........... 47 F [B.3°C] dry bulb, 

43 F [6.1°C] wet bulb 

c. Low Temperature Heating** 

Air temperature entering indoor portion 

of unit .......... 70 F [21.~°C] dry bulb, 

60 F [15.6°q web bulb, max. 

Air temperature surrounding unit .... 17 F 

[-B.3°C) dry bulb* 

Air temperature entering outdoor portion 

of unit ......... 17 F [-B.3°C] dry bulb, 

15 F [-9.4°C] wet bulb 

5.1.4.2 Voltage and Frequency. Recommended 

nameplate voltages for 60 Hertz.systems are one 

or more of the following utilization voltages: 200, 

230.460. 575. 

Standard Rating tests shall be performed at the 

nameplate rated voltage(s) and frequency. 

For heat pumps with dual nameplate voltage ratings, Standard Rating Tests shall be performed at 

both voltages, or at the lower of the two voltages. 

if only a single Standard Rating is to be published. 

5.1.4.3 Indoor-Side Air Quantity. All Standard 

Ratings shall be determined at an indoor-side air 

quantity, delivered against at least the minimum 

external resistance required by 5.1.4.6, as outlined below. All air quantities shall be expressed 

ascfmrUs] of Standard air (density 0.07510 per 

cu ft [1.2 kg/mll). 

Heat pumps employing indoor coil fans shall be 

rated at the air quantity specified by the manufacturer in his Standard Ratings, not to exceed 37.5 

cfm per MBh [0.06 Us per Kw] of rated cooling 

. capacity, or at the air quantity of which the drive 

is capable when operating against the external 

resistance specified in 5.1.4.6. whichever is less. 

Indoor-side air quantities as referred to herein 

apply to the air quantity experienced when the 

·For units or portions thereof intended to be installed only indoors. 

this temperature may be changed to be the same as the air temperature entering the indoor portion of unit. 

oOIf unit defrosts during the test. the indoor supply air temperature 

shall not drop below 65 F [IS.3°C] for more than one minute. 

Compliance with this requirement is not required if the control 

circuitry is such as to provide for supplementary heat during defrcst. 

unit is cooling and dehumidifying under the Standard Rating Cooling Conditions specified in this 

section. Heating-only units shall use the air quantity experienced when the unit is operating under 

the Standard High Temperature Heating Rating 

Conditions. This air quantity, except as noted in 

6.4, shall be employed in all other tests prescribed 

herein without regard to resu1ti~g external static 

pressure. 

5.1.4.4 Outdoor-side Air Quantity. All Standard 

Ratings for air-source units shall be determined 

at the outdoor-side air quantity specified by the 

manufacturer where the fan drive is adjustable; 

or, where the fan drive is non-adjustable, they 

shall be determined at the outdoor-side air quantity inherent in the heat pump when operated 

with all of the resistance elements associated with' 

inlet louvers and any ductwork and attachments 

considered by the manufacturer as normal installation practice. Once established. the outdoorside air circuit of the heat pump shall remain 

unchanged throughout all tests prescribed herein. 

5.1.4.5 Requirements for Separated Assemblies. 

All Standard Ratings for heat pumps in which the 

outdoor section is separated from the indoor section, as in Types HRC. HORC. HRCU and 

HORCU (shown in Section 4). shall be determined with at least 25 feet [7.62 m] of interconnection tubing on each line, of the size recommended by the manufacturer. Such heat pumps in 

which the interconnection tubing is furnished as 

an integral part ofthe machine not recommended 

for cutting to length shall be tested with the complete length of tubing furnished, or with 25 feet 

[7.62 m] of tubing. whichever is greater. At least 

10 feet [3.05 m] of the interconnection tubing 

shall be exposed to the outside conditions. with 

'the rest of the tubing exposed to the inside conditions. The line sizes, insulation, and details of 

installation shall be in accordance with the manufacturer's published recommendations. 

5.1.4.6 External Resistances. Indoor air-moving 

equipment intended for use with field installed 

duct systems shall be designed to operate against, 

and tested at not less than, the minimum external 

resistance shown in Table 2 when delivering the 

rated capacity and air quantity specified in 

5.1.4.3. Indoor air-moving equipment not intended for use with field installed duct systems 

shall be tested at 0 in. water [0 Pal external pressure. 

In interpreting this requirement, it is understood 

that the most restrictive filters, supplementary 

heating coils. and other equipment recommended as optional parts of the heat pump be in 

place and that the net external resistances 

3 
ARI STANDARD 340-86 ________________________________________________ _ 

TABLE 2. MINIMUM EXTERNAL RESISTANCE 

Minimum 

·Standard Capacity Ratings External 

Resistance 

(Inches of 

(MBh) [kW] Water) [Pal 

135 thru 210 39.6 thru 61.6 0.35 87.2 

211 thru 280 61.7 thru 82.1 0.40 99.6 

281 thru 350 82.2 thru 102.6 0.45 112.1 

351 thru 400 102.7 thru 117.2 0.55 137.0 

401 thru 500 117.3 thru 146.6 0.65 161.9 

501 and over 146.7 and over 0.75 186.8 

·Cooling Capacity for units with cooling function; High Tern· 

perature Heating Capacity for heating-only units (See 5.~.4.3) 

specified above'are available for the external duct 

system. 

5.2 Part Load Rating. Heat pumps which are capable 

of capacity reduction shall be rated at 100% and at each 

step of capacity reduction provided by the refrigeration 

system(s) as published by the manufacturer. These rating points (cooling only) shall be used to calculate the 

IPLV (see 5.2.2). 

5.2.1 Part Load Rating Conditions. The conditions 

of test for part load ratings are the same as for the 

Standard Ratings (See 5.1) except for the following: 

5.2.1.1 Part Load Rating Temperatures (Cooling) 

Air temperature entering indoor portion 

of unit ............ 80 F [26.7°q dry bulb, 

67 F [19.4°C] wet bulb 

Air temperature surrounding unit . . ..... 80 F 

[26.7°q dry bulb 

Air temperature entering outdoor portion 

of unit ....... . ..... 80 F [26.7°C] dry bulb 

5.2.1.2 Part Load Rating Temperatures (Heating): All temperatures are the same as those 

shown in 5.1.4.1b High Temperature Heating. 

5.2.1.3 The capacity reduction means may be 

adjusted to obtain the specified step of unloading. 

No manual adjustment of indoor and outdoor air 

quantities from those of the Standard Rating 

Conditions shall be made. However, automatic 

adjustment of outdoor air quantities by system 

function is ' permissible. 

5.2.2 Integrated Part Load Value (IPLV). For equipment covered by this standard, the IPLV (in EER) shall 

be calculated as follows: 

4 

a. Determine the capacity and EER at the conditions specified in 5.2. except 5.2.1.2. 

b. Determine the part-load factor (PLF) from ') 

Figure 1 "Part-Load Factor Curve" at each 

rating point (see example in Appendix A). 

c. Use the following equation to calculate 

IPLV: 

IPL V = (PLF1 - PLF2) (EERJ ; EER2) 

+ PLF2 - PLF.J (EER2 ; EER.J) 

+ ....... . . 

+ (PLF - PLF) (EER,,_1 + EERn) n-l n 2 

+ (PLFn)(EERnr 

where: PLF = Part-Load Factor determined from 

Figure 1 

n = Total number of capacity steps 

Subscript 1 = 100% capacity and EER at partload rating conditions 

Subscript 2; 3 etc. = specific capacity steps per 

5.2. 

5.3 Application Ratings. Ratings at conditions of temperature or air quantity other than specified in 5.1.4 or 

5.2. I. may be published as application ratings, and shall 

be based on data determined by the methods prescribed 

in 5.1. 

5.4 Publication of Ratings. Wherever application ratings are published or printed, they shall include, or be 

accompanied by, the Standard Capacity Ratings and 

their corresponding power inputs clearly designated as 

such, including a statement of the conditions at which 

the ratings apply. 

5.4.1 Capacity Designation. The capacity designation used in published specifications, literature or 

advertising, controlled by the manufacturer, for 

heat pumps rated under this standard, are to be 

expressed only in MBh [kW] at the Standard Rating 

Conditions specified in 5.1.4 and in the terms described in 5.1.2 through 5.1.3. Horsepower, tons or 

other units shall not be used as capacity designa-

-tions. 

5.5 Tolerances. To comply with this standard, published 

cooling capacity, heating capacity(s) and energy efficiency ratings, shall be based on data obtained in accordance with the provisions of this section, and shall be 

such that any production unit, when tested, will meet 

these ratings except for an allowance to cover testing and 

manufacturing variations; the amount of allowance to be 

minus 5 per cent. 

t 

I 
· ... ·~ ::~r.;..!:=":· 

.:::.--:t :\:: 

----------------------------------------______ ARI STANDARD 340-86 

PART LOAD FACTOR CURVE 

to ~ ~ 

/ , 

0.9 / 

0.8 

/ 

0.7 / 

I 

L2 0.6 'I ...J 

e:. J a: 

g 0.5 I 

() I Lf 

Cl 0.4 1 

c5 

...J I 

h: 0.3 I ~ / 

0.2 I 

/ 

0.1 / 

~ 

~ /' 

0 

0 20 40 60 80 100 

PERCENT OF FULL-LOAD CAPACITY AT 

PART-LOAD CONDITIONS 

Note: Curve is Based on Following Equation: 

PLF = AO + (A1 XQ)+(A2xQ2

)+(A3 xQ3 )+(A4xQ4)+(ASx Q5) + (A6 X Q6) 

where: PLF = Part-Load Factor 

Q = Percent of full-load capacity at part-load rating 

conditions. 

AO = -0.12773917 X 10- 6 

'A1 = -0.27648713 x 10-3 

A2 = 0.50672449 X 10-3 

A3 = -0.25966636 x 10-4 

A4 = 0.69875354 x 10-6 

AS = -0.76859712 X 10-8 

A6 = 0.28918272 x 10- 10 

FIGURE 1 

5 
ARI STAN DARD 340-86 ________________________ _ 

Section 6. Performance Requirements 

6.1 Performance Requirements. To comply with this 

standard. commercial and industrial unitary heat pumps 

shall be designed and produced in accordance with the 

provisions of this section in such a manner that any 

production unit will meet the requirements detailed herein. 

6.1.1 Heating-only units are not intended to meet 

the requirements of performance tests pertaining to 

the cooling mode. 

6.2 Maximum Operating Conditions Test. Commercial 

and industrial unitary heat pumps shall be designed and 

produced to pass the following maximum operating conditions test with an indoor side coil air quantity as determined under 5.1.4.3: 

6.2.1 Temperature Conditions. 

6.2.1.1 Cooling. 

Air temperature surrounding 

unit ............. 115 F [46.1°C] dry bulb· 

Air temperature entering indoor portion 

of unit ............ 80 F [26.7°C] dry bulb, 

67 F [19.4°C] wet bulb 

Outside air temperature ...... 115 F [46.1°C] 

dry bulb (and at the standard condenser air 

quantity specified and stated by the manufacturer) 

6.2.1.2 Heating. 

Air temperature entering indoor portion 

of unit ............. 80 F [26.7°C] dry bulb 

Air temperature surrounding . 

unit .............. 75 F [23.9°C] dry bulb.· 

Outside air temperature ............... 75 F [23.9°C] dry bulb, 

65 F [18.3°q ~et bulb 

6.2.2 Voltages. Tests shall be run at"the minimum 

and maximum utilization voltages of Voltage Range 

A as shown in Table 1 of ARI Standard 110 at the 

unit's service connection and at rated frequency. 

6.2.3 Procedure. 

6.2.3.1 The heat pump shall be operated for one 

hour at the temperature conditions and voltage(s) specified. 

6.2.4 Requirements. During both entire tests, the 

heat pump shall operate continuously and without 

failure of any of its parts. 

6.3 Voltage Tolerance Test. Air-source unitary heat 

pumps shall be designed and produced to pass the fol-

·F~r units or ponions thereof intended to be installed only indoors. 

this tcmre,rature ~ay be cha~l:!ed to be the same as the air tempera. 

ture entenng the mdoor porllon of unit. 

6 

lowing voltage tolerance test with a cooling coil air quantity as determined under 5.1.4.3. 

6.3.1 Temperature Conditions. Temperature conditions shall be maintained as shown in 5.1.4.1.a (or 

in 5.1.4.1.b for heating only units). 

6.3.2 Voltages. 

6.3.2.1 Tests shall be run at the Range B 

minimum and maximum utilization voltages from 

ARI Standard 110, Table 1, based upon the unit's 

nameplate rated voltage(s). These voltages shall 

be supplied at the unit's service connection and at 

rated frequency. A lower or a higher voltage shall 

be used, if listed on the nameplate. 

6.3.2.2 The power supplied to the heat pump 

shall be adjusted just prior to the shut down 

period (See 6.3.3.2) so that the resulting voltage 

at the unit's service connection is 86 per cent of 

nameplate rated voltage when the compressor is 

on locked rotor. For the purpose of this standard, 

the compressor nameplate locked-rotor amperes 

may be used to determine this voltage. The 

proper value of no-load voltage which will give 

the specified voltage at locked-rotor conditions 

should be determined prior to the test. . 

The locked-rotor current value of any motor shall 

be measured as follows: 

a. All hermetic compressor motors shall be 

tested as a compressor assembly. 

b. The motor winding temperature shall not 

exceed 77 F [25°C] when the voltage is 

applied. 

c. The current reading shall be taken within 

four seconds after the voltage is applied. If 

the test is repeated, the motor winding shall 

be allowed to cool to 77 F [25°C] or lower 

before the current is reapplied. 

d. The voltage at the unit service connection, 

at the time the current reading is taken, 

shall be the manufacturer's nameplate rated 

voltage. 

e. The locked-rotor current shall be measured 

with an ammeter, with the rotor actually 

locked. 

6.3.2.3 Within one minute after the heat pump 

has resumed continuous operation (See 6.3.4.3), 

the voltage shall be restored to the values 

specified in 6.3.2.1. 

6.3.3 Procedure. 

6.3.3.1 The heat pump shall be operated for one 

hour at the temperature conditions and voltage(s) specified. 
_________________________ ARI STANDARD 340-86 

6.3.3.2 All power to the heat pump shall be cut 

offfor a period sufficient to cause the compressor 

to stop (not to exceed five seconds) and then 

restored. 

6.3.4 Requirements. 

6.3.4.1 During both entire tests, the heat pump 

shall operate without failure of any of its parts. 

6.3.4.2 The heat pump shall operate continuously without interruption for any reason for the 

one hour period preceding the power interruption. 

6.3.4.3 The unit shall resume continuous operation within two hours of restoration of power and 

shall then operate continuously for one half hour. _ 

Operation and resetting of safety devices prior to 

establishment of continuous operation is permitted. 

6.4 Low-Temperature Operation Test (Cooling). 

Commercial and industrial unitary heat pumps shall be 

designed and produced to pass the following lowtemperature operation test when operating with initial 

air quantities as determined in 5.1.4.3 and 5.1.4.4, and 

with controls, and dampers set to produce the maximum 

tendency to frost or ice the evaporator, provided such 

settings are not contrary to the manufacturer's instructions to the user: 

6.4.1 Temperature Conditions. 

Air temperature entering indoor portion 

of unit ...... . ....... 67 F [19.4°q dry bulb, 

57 F [13.~q wet bulb 

Outside air temperature ................. 67 F [19.4°q dry bulb 

6.4.2 Voltage and Frequency. This test shall be performed at nameplate rated voltage and frequency. 

6.4.3 Procedure. The test shall be continuous with 

the unit on the cooling mode, for not less than four 

hours after establishment of the specified temperature conditions. The unit will be permitted to operate under control of a limit device, if provided. 

6.4.4 Requirements. 

6.4.4.1 During the entire test, the heat pump 

shall operate without damage to the equipment. 

6.4.4.2 During the entire test, the air quantity 

shall not drop more than 25 per cent from that 

determined under the Standard Rating Test. 

6.4.4.3 During the test, and during the defrosting period after the completion of the test, all ice 

or meJtage must be caught and removed by the 

drain provisions. 

6.5 Tolerances. The conditions for the tests outlined in 

6.2,6.3 and 6.4 are average values subject to tolerances 

of ± 1.0F [±osq for air wet bulb and dry bulb 

temperature, ± 0.5 F [±0.3°q for water temperatures 

and ± 1.0 per cent of the reading for voJrages. 

SectIon 7. Safety Recommendations 

7.1 Safety. It is strongly recommended that the product 

be designed, constructed, assembled and installed in 

accordance with nationally recognized safety standards 

and codes appropriate for products covered by this 

standard. 

Se(4tion 8. Voluntary Conformance ' 

8.1 Conformance. While conformance with this standard is voluntary, conformance shall not be claimed or 

implied for products or equipment within itsPurpose 

(Section 1) and Scope (Section 2) unless such claims 

meet all the requirements of the standard. 

7 
ARI STANDARD 340-86 ________________________________________________ _ 

APPENDIX A 

METHOD AND EXAMPLE OF 

CALCULATING INTEGRATED PART LOAD VALUES 

(IPLV) 

Section A 1. Purpose and Scope 

AI.I Purpose. 

A.I.I.I This appendix shows example calculations 

for determining Integrated Part Load Values 

(IPLV). 

. AI.2 Scope. 

A.I.2.1 This appendix is for equipment covered 

by this standard. 

Section A2. Equations and Definitions of Terms 

A2.1 General Equation. 

IPLV = (P~Fl - PLFz) (EERJ ; EER2) 

+ PLFz - PLFJ (EERz ; EER3) 

+ ........ . 

(PLF _ PLF) (EERn_J + EERn) + n-J n 2 

+ (PLFn}(EERn) 

where: PLF = Part-Load Factor determined from 

Figure 1 

8 

n = Total number of capacity steps 

Subscript 1 = 100% capacity and EER at partload rating conditions 

Subscript 2; 3 etc. = specific capacity steps per 

S.2. 

Section A3. Calculation Example for a Four 

Capacity Step System 

A3.1 Unit Performance Data & Sample Calculation. 

A3.1.1 Assume equipment has four capacity steps 

as follows: 

• 100% (full load} 

• 7S% of full load 

• SO% of full load 

• 25 % of full load 

A3.1.2 Obtain part load factors from Figure 1 (see 

Figure Al Example). 

A3.1.3 Obtain EER at each capacity step per S.2. 

A3.1.4 Calculate IPL V using the general equation 

with: 

n=4 

PLF1 = 1.0 

PLF:z = 0.9 

PLF3 = 0.4 

PLF4 = 0.1 

EERI = 8.9 

EER:z = 7.7 

EER3 = 7.1 

EER4 = S.O 

Enter the above values in the general equation, (A2.1). 

IPLV = (1.0_0.9}(8.9 ; 7.7) 

+ (0.9-0.4}e.7 ; 7.1) 

+ (0.4-0.1}C· 1;S.0)+(0.lXS.0) 

= (0.1 x 8.3) + (O.S X7.4) 

+ (0.3 x 6.0) + 0.5 

= 0.83 + 3.70 + 1.80 + O.S 

IPL V = 6.83 rounded to 6.8 

To further illustrate the calculation process see Figure A2 Example. 
~ 

________________________ AR I STAN DARD 340-86 

PART LOAD FACTOR CURVE 

1.0 r- - " / ~ 

100" 

0.9 l- / 

i 

0.8 I II' 

0.7 I 

il 

w:- 0.6 'I 

..J 

e:. j JI' 

II: 

Q 0.5 I ~ I u.; I 0 0.4 c5 - J ..J 

~ 0.3 7 j~ 

~ [7 

0.2 j 

/ 

/ 0.1 ...... 1" 

0 -' VJ 

0 20 40 60 80 100 

PERCENT OF FULL-LOAD CAPACITY AT 

PART-LOAD CONDITIONS 

Note: Curve is Based on Following Equation: 

PLF = AO + (AI XQ)+(A2xQ2)+(A3xQ3)+(A4xQ4)+(ASX QS)+(A6x Q6) 

where: PLF = Part-Load Factor 

Q = Percent of full-load capacity at part-load rating 

conditions . 

. AO = -0.12773917 X 10- 6 

Al = -0.27648713 x 10- 3 

A2 = 0.50672449 X 10- 3 

A3 = -0.25966636 x 10- 4 

A4 = 0.69875354 x 10- 6 

AS = -0.76859712 X 10- 8 

A6 = 0.28918272 x 10- 10 

FIGUREA1 

9 
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e 

FIGURE A-2 EXAMPLE 

IPLV CALCULATION 

Using information from B3.1.1; B3.1.2 and B3.1.3 

Capacity MCrs. Net % Full PLF1 Mfrs. Part Avg. Part PLF DiCr. 

Step Cap. (Tons) Load Cap.2 Load EER Load EER . ' 

(For R Only) 

1 50.0 100% 1.0 8.92 

= 8.3 (1.0-0.9)=0.1 

2 37.5 75% 0.9 7.7 

= 7.4 (0.9-0.4)=0.5 

3 25.0 50% 0.4 7.1 as 6.0 (0.4-0.1)=0.3 

4 12.5 25% 0.1 5.0 ~ 5.01 (0.1-0.0)=0.1 

---- 0% 0.0 ----

Weighted 

Avg. EER x PLF Diff. = Avg . 

8.3 x 0.1 = 0.83 

7.4 x 0.5 = 3.70 

6.0 x 0.3 = 1.80 

5.01 x 0.1 = 0.50 

Single number IPL V 6.83· 

·Rounded to 6.8 

NOTES 

IFor the range between 0% capacity and the last capacity step. use EER of the last capacity step for the average EER. 

2The 100% capacity and EER are to be determined at the part-load rating conditions. 

3Part-load factor from Figure AI. 

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