. . . , 

1986 

STANDARD for 

!!p; 

... I'. 

AIR-CONDITIONING 

& REFRIGERATION 

INSTITUTE 

~~-l ":':'-' 

~ -. .' . " i\i'~Y ~ . _. I ."'V-,\ -

,.... 84-01 ,--AM-ERIC-AN-NATI-ON .......... Al 

STANDARD -

ANSI/ARI 360-86 

COMMERCIAL AND .. 

INDUSTRIAL 

UNITARY 

AIR-CONDITIONING 

EQUIPMENT 

I Standard 360 I 

1501 WILSON BOULEVARD • ARLINGTON, VIRGINIA 22209 

.. __ ----- .- ' "----::.:::t " .. , .... 

o 
TABLE OF CONTENTS 

PAGE 

PART 

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 Alternate Test Method ................................... ,. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 

Appendix B Method of Calculating IPL V ........... ;......................................................... 9 

~y 12 1993 

r:jAY 24 199: 

~\PR 1 0 !l95 

, .~p;. ~ r t-~3 

I 

I 

I 

, 

Date Due 

~ -CondttlOlling and Refrigeration Institute 

KEH-411 11-84' PrIIenI and Tradefnatl( OffICff 
36 0-86 

COMMERCIAL AND IND ~ IAL UNITARY 

AIR-CONDITIONING EQUIPMENT 

Section 1. Purpose 

1.1 Purpose. The purpose of this standard is to establish, for commercial and industrial unitary air-conditioning equipment: definitions and classification; requirements for testing and rating; 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, engineers, contractors, 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 commercial and industrial air-conditioners defined in 3.l. 

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, such as condensing units or coils. for separate use. 

2.2.1 This standard does not include standards for 

heating equipment or for the heating function of 

commercial and industrial unitary air-conditioning 

equipment. 

2.2.2 This standard does not apply to unitary airconditioners, as defined in ARI Standard 210, with 

capacities less than 135.000 Btuh, [40 kw], or to 

unitary heat-operated air-conditioning equipment, or to heat pumps, or t~ variable air volume 

units. 

Section 3. Definitions 

3.1 Commercial and Industrial Unitary AirConditioner. A commercial and industrial unitary airconditioner consists of one or more factory-made assemblies which include an evaporator or cooling coil and 

air moving device. a compressor and condenser combination. and may include a heating function as well. 

Where such equipment is provided in more than one 

assembly. the separated assemblies are to be designed to 

be used together. and the requirements of rating outlined in this standard are based upon the use of matched 

assemblies. 

3.1.1 Functions. The functions of commercial and 

industrial unitary air-conditioners, e'ither alone or 

in combination with a heating plant, are to provide 

air-circulation, air-cleaning, cooling with controlled temperature, and dehumidification, and 

may optionally include the functions of heating 

and humidifying. 

3.2 Energy Efficiency Ratio (EER). A ratio calculated ' 

by dividing the net 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). 

3.2.1 Standard Energy Efficiency Ratio. A ratio 

calculated from the capacity and power input 

values obtained at Standard Rating Conditions. 

3.3 Coefficient of Performance (COP). A. ratio calculated by dividing the net cooling capacity provided, 

(MBh) by the total power input (kw) x 3.413. 

3.3.1 Standard Coefficient of Performance. A 

ratio calculated from the capacity and power input 

values (obtained in accordance with 3.5) at Standard Rating Conditions. 

3.4 Integrated Part Load Value (IPLV). A single num-' 

ber part load efficiency figure of merit calculated per 

the method described in 5.2.2. 

3.5 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 siz~ 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 air-conditioner or published in specifications, advertising, or other literature 

controlled by the manufacturer, at stated rating conditions. 

3-:5.1 Standard Rating. A rating based on tests performed at Standard Rating Conditions. 

3.5.2 Application Rating. A rating based on tests 

performed at application rating conditions (other 

than Standard Rating Conditions). 

3.6 Rating Conditions. Any set of operating conditions 

under which a single level of performance results, and 

which causes only that level of performance of occur. 

1 
~~:~~DARD 360_86 ______ ~~~~-f---------------------------------- ~'$T.,. ,. • . 

' . ';:' '- 3:6.1 Standard Rating Conditions.. Rating condi-

~~:: '= :" qonS used-as t~e. basis of 'companson of perform-

~ ", .. :",.!. • ancc charactenstlcs. :' ~~ ~ .. , . 

~; :·r!"'Sh;Ur. "Should", "Recommended", or "It Is RecI- ' . .- J d" "Shall" "should" "recommended" or . ...-... .. omm~nue . " , ~~~ ··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. 

3.7.2 Should, Recommended, or It Is Recommended. "Should", "recommended", or "it is rec-

. ommended" 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 industriai 

unitary air-conditioners within the scope of this standard 

can be classified as Shown in Table 1. 

Table 1 - Classification of Equipment 

Types or Commercial and Industrial Unitary Air-Conditioners 

ARI Heat 

Designation Type Rejection Arrangement 

Single Pack- SP-A Air 

age SP-E Evap Cond I~~~p I gg~J51 SP-W Water 

Year-Round SPY-A Air 

~~tlI2g~~1 Single SPY-E Evap Cond 

Package f?PY-W Water 

Condensing RCU-A-CB Air 

Unit, Coil RCU-E-CB Evap Cond I~~fil mI 

and Blower RCU-W-CB Water 

Year-Round RCUY-A-CB Air 

Condensing 

Unit, 

and Blower 

Coil RCUY-W-CB 

RCUY-E-CB 

Water 

Evap Cond liit~m Remote 

Condenser RC-E 

RC-A 

Evap 

Air 

Cond ~ ICONDI 

RC-W Water 

Year-Round RCY-A Air 

Remote RCY-E Evap Cond 

Condenser RCY-W Water III~ EA 

Extracted by permission from Table 1. Chapter 42. 1979 

ASHRAE Handbook. 

Section 5. Testing and Rating Requirements 

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

5.1.3. All Standard Ratings shall be verified by tests 

conducted in accordance with ASHRAE Standard 

Methods o/Testing for Rating Unitary Air-Conditioning 

and Heat Pump Equipment (The American Society of 

Heating, Refrigerating and Air-Conditioning En2 

gineers, Inc. Standard 37-78), and with the test methods 

and procedures as described in lliis standard. 

Standard Cooling Capacity shall be stated as total (sensible plus latent) cooling capacity and sensible cooling 

capacity and shall be net values, reflecting the effects of 

circulating-fan heat. Power input shall be the total power 

input to the compressor(s) and fanes) plus controls and 

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

5.1.1 Values o/Standard Capacity Ratings. These 

ratings shall be 'expressed only in terms of 

thousands of Btu per hour (MBh) in multiples of 2 

MBh [0.6 kw] for units with standard ratings of 

400 MBh [117 kw] and under. For units with standardratings'ofover400 MBh [117 kw], the ratings 

shall be expressed in. multiples of 5 MBh [1.5 kw] 

5.1.2 Values of Standard Efficiency Ratings. Energy Efficiency Ratios (EER) in Btuhlwatt shall 

be expressed in multiples tottie nearest 0.1 atuhl 

watt. Integrated Part Load Values (IPL V) and 

coefficient of performance (COP), if used, they 

shall be expressed in multiples to the nearest 0.1. 

5.1.3 Standard Rating Conditions. The conditions 

of test for Standard Ratings shall include the following: 

5.1.3.1 Standard Rating Temperatures. 

For all units 

Air temperature entering indoor portion 

of unit ............. 80 F [26.7 DC] dry bulb 

67 F [19.4D

C] wet bulb 

Air temperature surrounding 

unit ................. 95 F[35 D

C]dry bulb· 

For air-cooled units 

Air temperature entering outdoor portion 

of unit .............. 95 F [35 DC] dry bulb 

(and 75 F [23.9 C]wet bulb when condensate 

is rejected to tire airstream) 

For evaporatively-cooled units 

Air temperature entering outdoor portion 

of unit ........ : ...... 95 F [35DC] dry bulb 

75 F[23.9D

C] wet bulb 

For water-cooled units 

Water temperature entering 

condenser .................. 85 F [29.4D

C] 

Water temperature leaving 

con~~nser ....•......•....... _.95 F [35DC] 

°For units or portions thereof intended to be installed only 

indoors. this temp'eratuTe may be reduced to 80 F [26.7°C] 

dry bulb. . 
--------------__________ ARI STANDARD 360-86 

5.1.3.2 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 ~nd frequency. 

For air-conditioners 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. 

5.1.3.3 Cooling Coil Air Quantity. ,All Standard Ratings shall be determined at a cooling 

coil air quantity. delivered against at least the 

minimum external resistance required by 

5.1.3.6. as outlined below. 100 per cent recirculated air will be used except when the optional 

rating with outside air is claimed. (See 5.1.4) For 

units equipped for multizone or dual duct operation. the hot deck shall be closed off. All air 

quantities shall be expressed as cfm [Us] of 

Standard Air (density 0.075 Ib per cu ft) [1.2 

kg/m']. 

Air-conditioners employing cooling 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 [0.006 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'.1.3.6. whichever is less. 

Cooling coil air quantities as referred to herein 

apply to the air quantity experienced when the 

unit is cooling and dehumidifying under the 

Standard Rating Conditions specified in this section. Once established for the Standard Rating 

test. no further adjustment to the drive or circuit 

shaH be made. 

5.1.3.4 Condenser Air Quantity. All Standard 

Ratings for air-cooled or evaporatively-cooled 

units shall be determined at the condenser air 

quantity which is inherent to the air-conditioner 

when operated with all the resistance elements' 

Standard Ratings 

(MBh) [kwl (MBh) [kw1 

135 [39.61 thru 210 [61.61 

211 [61.71 thru 280 [82.11 

281 [82.2) thru 350 [102.61 

351 [102.71 thru 400 (117.2] 

401 [117.31 thru 500 [146.61 

501 [146.71 and over 

associated with the ,inlet or discharge attachments considered by the manufacturer as normal installation practice. Once established. the 

condenser air circuit of the air-conditioner shall 

remain unchanged throughout all tests prescribed herein. 

5.1.3.5 Requirements for Separated Assemblies. All Standard Ratings for airconditioners in which the condenser or condensing unit is separated from the cooling coil. as in 

Types Re. Rey. ReU and RCUY (Shown in 

~ection 4). shall be determined with at least 25 

feet [7.62 m] of interconnection tubing on each 

line. At least 10 feet [3.05 mlofthe 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. 

5.1.3.6 External Resistances. Commercial and 

industrial unitary air-conditioners shall be designed to work against, and tested at the following minimum external resistances when delivering the rated capacity and air quantity specified 

in 5.1.3.3. 

In interpreting this requirement, it is understood 

that filters, heating devices, and other equipment recommended as part of the airconditioner be in place and that the net external 

resistances specified below are available for 

the duct system. 

The static pressure at the return air intake of the 

unit shall not be a positive pressure. 

5.1.4 Optional Rating Conditions. Commercial 

and industrial unitary air-conditioners which incorporate an outdoor air cooling coil shall use the 

Standard Rating Conditions (see ,5.1.3 thru 

5.1.3.6) for rating, except for the following 

changes: 

a. Unit shall be adjusted to take in 20 per cent 

outdoor air 

Minimum External Resistances 

(Inches of Water) [Pal 

0.35 [87.21 

0.40 [99.61 

0.45 (112.11 

0.55 (137.01 

0.65 [161.91 

0.75 [186.81 

3 
ARI STAN DARD 360-86 _______________________ _ 

b. Return air temperature conditions shall be 

adjusted to provide 80 F [26:7 C] dry bulb. 

67 F [19.4 C] wet bulb temperatures for the 

total combined air quantity (return air plus 

outside air) to the main cooling coil. 

See Appendix A for capacity calculations. 

5.2 Part Load Rating. Systems 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 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. 

For all units 

Air temperature entering indoor portion 

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

67 F [19.4°C]wet bulb 

For air-cooled units 

Air temperature entering outdoor portion 

of unit ............. 80 F [26. 7°C] dry bulb 

(and 67 F [19.4 C] wet bulb when condensate 

is r.ejected into the air stream) 

For evaporatively-cooled units 

Air temperature entering outdoor portion 

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

67 F [19.4 °C]wet bulb 

For water-cooled units 

Water temperature entering 

condenser .................. 75 F [23.~C] 

Water flow rate (Same as Standard Rating Conditions) 

5.2.1.2 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. 

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

Figure 1 "Part-Load Factor Curve" at each 

rating point (see example in Appendix B). 

c. Use the following equation to calculate 

IPLV: 

IPL V = (PLF1 - PLF:z) (EERJ ; EER:z) . 

+ PLF:z - P~F3 (EER:z ; EER3) 

+ ........ . 

(PLF _ PLF) (EER"_J + EER") + "-1 " 2 

+ (PLF")(EER") 

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 and EER 

at part-load steps per 5.2. 

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

5.1.5 and 5.2.1. may be published as application ratings. 

and shall be based on djlta determined by the methods 

prescribed in this Section. 

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

accompanied by. the Standard Rating plus the Part Load 

Rating (where applicable). 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 

air-conditioners rated under this standard. are to 

be expressed only in MBh [kw] at the Standard 

Rating Conditions specified in 5.1.5 plus Part 

Load Rating Conditions specified in 5.2.1. and in 

the terms described in 5.1.1 and 5.1.2. Horsepower. tons. or other units shall not be used as 

capacity designations. 

5.5 Tolerances. To comply with this standard. published cooling capacity and energy efficiency ratio shall 

be based on data obtained in accordance with the 

provisions of this section. and shall be such that any 

production unit. when tested. ~ill meet these ratings 

except for an allowance to cover testing and manufacturing variations; the amount of allowance to be minus 5 

per cent. 
--------________________ ARI STANDA RD 360-86 

PART LOAD FACTOR CURVE 

1.0 

~ ~ 

0.9 / 

/ 

0.8 

/ 

0.7 I 

I 

G:' IJ .-J 0.6 f!::. ' ) a: 

~ 0.5 I ~ I u.: 

Cl 1/ 0.4 C§ 

.-J I 

li: 0.3 / ~ V 

0.2 / 

L 

0.1 / ~ V' 

~ V 

0 

0 20 40 60 80 100 

PERCENT OF FULL-LOAD CAPACITY AT 

PART-LOAD CONDITIONS 

Note: Curve is Based on Following Equation: 

~LF = AO +-(A1xQ)+(A2xQ2)+(A3xQ3)+(A4xQ")+(A5xQS)+(A6xQ6) 

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-" 

A4 = 0.69875354 x 10- 6 

A5 = -0.76859712 x 10- 8 

A6 = 0.28918272 X 10- 10 

FIGURE 1 
ARt STAN DARD 360-86 _______________________ _ 

Section 6. Performance Requirements 

6.1 Performance Requirements. To comply with this 

standard. commercial and industrial unitary airconditioners 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. 

6.2 Maximum Operating Conditions Test. Commercial 

and industrial unitary air-conditioners shall be designed 

and produced to pass the following maximum operating 

conditions test with a cooling coil air quantity as determined under 5.1.3.3. 

6 

6.2.1 Temperature Conditions. 

For all units 

Air temperature surrounding 

unit ................ 115 F [46. 1°C] dry bulbAir temperature entering indoor 

portion of unit .......... 95 F [35"C] dry bulb 

71 F [21.7°C] wet bulb 

For water-cooled units 

Water temperature entering 

condenser .................... 90 F [32.2°C] 

Water temperature leaving 

condenser ................... 100 F [37.8°C] 

For air-cooled units 

Outside air 

temperature ......... 115 F [46. 1°C] dry bulb 

(and 75 F [23.9°C]wet bulb when condensate is 

rejected to the condenser air stream) at the 

standard condenser ?;r quantity specified and 

stated by the manufacturer. 

For evaporatively-cooled units 

Outside air 

temperature ......... 100 F [37.8°C] dry bulb 

80 F [26.7°C] wet bulb 

Make-up water temperature ...... 90 F [32.3°C] 

6.2.2 Voltages. 

6.2.2.1 Tests shall be run at 90 per cent and 110 

per cent of the unit's nameplate rated voltage at 

the unit's service connection and at rated frequency. or at a lower than 90 per cent minimum 

or a higher than 110 per cent maximum voltage. 

if listed on the nameplate. 

6.2.3 Procedure. 

-For units or ponions thereof intended to be installed only 

indoors. this temperature may be reduced to 95 F (3S·Cl 

bulb. 

6.2.3.1 The air-conditioner shall be operated 

continuously for two hours at the temperature 

conditions and voltag~(s) specified. 

6.2.3.2 All power to the air-conditioner shall be 

cut off for a period sufficient to cause the compressor to stop (not to exceed five seconds) and 

then restored. 

6.2.4 Requirements. 

6.2.4.1 During both entire tests. the airconditioner shall operate without failure of any 

of its parts. 

6.2.4.2 The unit shall resume continuous operation within one hour of restoration of power 

and shall then operate continuously for one 

hour. Operation and resetting of safety devices 

prior to establishment of continuous operation is 

permitted. 

6.2.4.3 Units with water-cooled condensers 

shall be capable of operation under these 

maximum conditions at a water-pressure drop 

not to exceed 15 psi [103.4 kPa], measured 

across the unit. 

6.2.5 Optional Maximum Operating Conditions 

Test. Commercial and industrial unitary airconditioners which incorporate an outdoor air 

cooling coil shall use the conditions, voltages and 

procedure (see 6.2 thru 6.2.3) and meet the requirements of 6.2.4. except for the following 

changes: 

a. Outdoor air set as in 5.1.4a. 

b. Return air temperature conditions shall be 

adjusted to provide 95 F [35°C] dry bulb. 

71 F [21. 7°C] wet bulb temperatures for the 

total combined air quantity (return air plus 

outside air) to the main cooling coil. 

c. Outdoor air entering outdoor air cooling coil 

shall be 115 F [46.1°CJ dry bulb and 75 F 

[23.9"C] wet bulb temperatures. 

6.3 Low- Temperature Operation Test. Commercial and 

industrial unitary air-conditioners shall be designed and 

produced to pass the following low-temperature operation test when operating with initial air quantities as 

determined in 5.1.3.3. 5.1.3.4 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: 

6.3.1 Temperature COllditions. 

For all units 

Air temperature entering indoor portion 

of unit ............... 67 F [19.4°C] dry bulb 

57 F [13.9.0C] wet bulb 
---------_______________ ARI STAN DARD 360-86 

For water-cooled units 

Water temperature leaving 

condenser .................... 70 F [2 I. 1°C] 

For air-cooled and evaporatively-cooled units 

Outside air temperature .. 67 F [19.4°C] dry bulb 

57 F [13.9°C] wet bulb· 

6.3.2 Voltage and Frequency. This test shall be 

performed at nameplate rated voltage and frequency. 

6.3.3 Procedure. The test shall be continuous with 

the unit on the cooling cycle for not less than four 

hours after establishment of the specified temperature conditions. The unit will be peqnitted to start 

and stop under control of an automatic limit device, if provided. 

6.3.4 Requirements. 

6.3.4.1 During the entire test. the airconditioner shall operate without damage to the 

equipment. 

6.3.4.2 During the entire test, the air quantity 

*The wei-bulb lemperalure condilion is nol required when testing 

air-cooled condensers which do not evaporale condensalc. 

shall not drop more than 25 per cent from that 

determined under the Standard Rating Test. 

6.3.4.3 During the test. and during the defrosting period after the completion of the test. all ice 

or meltage must be caught and removed by the 

drain provisions. 

6.4 Tolerances. The conditions for the tests outlined in 

6.2 and 6.3. are average values subject to tolerances of 

:t 1.0 F [:to.S6°C] for air wet-bulb and dry-bulb temperatures. :to.S F [:to.28°C] for water temperatures. and 

:t 1.0 per cent of the reading for voltages. 

Section 7. Safety Recommendations 

7.1 It is strongly recommended that the product be 

designed, constructed, assembled and installed in ac-. 

cordance with nationally recognized safety standards 

and codes appropriate for products covered by this 

standard. 

Section 8. Conformance 

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

implied for products or equipment within. i~ purpose 

(section 1) and scope (section 2) unless such claims 

meet all of the requirements of the standard. 

APPENDIX A 

ALTERNATE TEST METHOD 

Section A 1. Capacity Calculation for Unitary 

Equipment Using an Outdoor Air Cooling Coil 

Al.l To determine the capacity of unitary equipment 

using an outdoor air cooling coil (See Fig. A.l for test 

facility). the following equation shall be used: 

Where: 

qu = 

woa = 

W ra = 

hon = 

net capacity of unit, Mbh [k W] 

weight of outside make-up air, Ib per hr [kg/s] 

weight of return air, Ib per hr [kg/s] 

enthalpy of outside air, Btu per Ib of dry air 

[J/kg] . 

enthalpy of return air, Btu per lb of dry air 

[J/kg] 

enthalpy of supply air, Btu per lb of dry air 

[J/kg] 

7 
CD 

CD 

I 

o 

CD 

C') 

c 

a: 

« 

c 

z 

« 

t-

(J) 

a: 

« 

-

OUTSIDE AIR 

~===11 P---ll 

-

OUTDOOR AIR COIL 

RETURN AIR 

CODE TESTER 

--

MAIN COOLING COIL 

ALTERNATE TEST METHOD . ELIMINATE RETURN AIR CODE TESTER 

AND MEASURE OUTSIDE AIR WITH A 

SEPARATE CODE TESTER. 

Fig. A1 ARI Test set-up for units using an 'outdoor coli 

SUPPLY AIR 

CODE TESTER 

-

--

00 
________________________ ARI STAN DARD 360-86 

APPENDIX 8 

METHOD AND EXAMPLE OF 

CALCULATING INTEGRATED PART LOAD VALUES 

(IPLV) 

Section B1. Purpose and Scope 

B1.1 Purpose. 

B.1.1.1 This appendix shows example calculations 

for determining Integrated Part Load Values 

(IPLV). ' ' 

B1.2 Scope. 

B.1.2.1 This appendix is for equipment covered by 

this standard. 

Section 82. Equations and Definitions of Terms 

B2.1 General Equation. 

IPL V = (PLF1 - PLF2

) (EERI ; EER}) 

+ PLF2 - PLFJ (EER2 ; EERJ) 

+ ........ . 

(PLF - PLF) (EER"_1 + EER") + n-l n 2 

+ (PLF")(EER") 

Where: PLF = Part-Load Factor determined from 

Figure 1 

n = Total number of capacity steps 

Subscript 1 = 100% capacity and EER at 

part-load rating conditions 

Subscript 2; 3, etc. = specific capacity steps 

per 5.2. 

Section B3. Calculation Example 'for a Four 

Capacity Step System 

B3.1 Unit Performance Data & Sample Calclliation. 

B3.1.1 Assume equipment has four capacity steps 

as follows: 

• 100% (full load) 

• 75% of full load 

• 50% of full load 

• 25% of full load 

B3.1.2 Obtain part load factors from Figure 1 (see 

Figure B1 Example). 

B3.1.3 Obtain EER at each capacity step per 5.2. 

B3.1.4 Calculate IPL V using the general equation 

with: 

n=4 

PLF1 = 1.0 

PLF2 = 0.9 

PLF3 = 0.4 

PLF4 = 0.1 

EERl = 8.9 

EERz = 7.7 

EER3 = 7.1 

EER4 = 5.0 

Enter the above values in the general equation, (B2.1). 

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

+ (0.9_0.4)(7.7 ; 7.1) 

(

7.1+5.0) ( 50) + (0.4-0.1) 2 + 0.1 x . 

= (0.lX8.3) + (0.5x7.4) 

.. + , (0.3 x 6.0) + 0.5 

= 0.83 + 3.70 + 1.80 + 0.5 

IPL V = 6.83 rounded to 6.8 

To further illustrate the calculation process see Figure B2 Example. 

9 
10 

ARI STAN DARD 360-86 ------------------------

PART LOAD FACTOR CURVE 

1.0 " .JIll'" ",..,-

/ ~ 

0.9 J 

'" j 

0.8 

I . -

0.7 lI 

u::-

...J 0.6 

e:. j cr: 

12 0.5 I 

0 I 'I' 

if 

C 0.4 - ~ If 

C§ .... ...J - J 

~ 0.3 I ~ V 

0.2 I 

/ 

0.1 - ,/ 

~ V 

--' /' ~~ 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 + (AlxQ)+(A2xQ2)+(A3xQ3)+(A4xQ4)+(A5xQS)+(A6xQ6) 

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 

A5 = -0.76859712 x 10- 8 

A6 = 0.28918272 x 10- 10 

FIGURE 81 EXAMPLE 
\

1\\ 

\L 

CJ 

--

FIGURE B2 EXAMPLE 

IPLV CALCULATION 

Using information from B3.I.!; B3.1.2 and B3.I.3 

Capacity Mfrs. Net % Full PLFJ Mfrs. Part Avg. Part PLF Difr. 

Step Cap. (Tons) Load Cap.l Load EER Load EER 

(For R Only) 

1 50.0 100% 1.0 8.91 

= 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 

= 6.0 (0.4-0.1)=0.3 

4 12.5 25% 0.1 5.0 

= 5.0' (0.1-0.0) =(). I 

---- 0% 0.0 --_.-

- - - -

Weighted 

Avg. EER x PLF om. = Avg. 

8.3 x 0.1 = 0.83 

7.4 x 0.5 = 3.70 

6.0 x 0.3 = 1.80 

5.0' x 0.1 = 0.50 

Single numbl!r IPLV 6.83· 

----- - -- -

·Rounded to 6.8 

NOTES 

'For the range between 0% capacity and the last capacity step. use EER of the last capacity step for the aVl!rage EER. 

7The 100% capacity and EER Drc to be dctl!rminl!d lit the purt-Iolld rolting conditions. 

lPart-load factor from Figure B 1. 

-

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(J) 

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Z 

C 

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C 

Co) 

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I 

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