# .. 

# 1987 STANDARD 

# for

,1I1.l'; • III •

AIR-CONDITIONING 

## & REFRIGERATION I NSmUTE C. J 

# .OBSOLETE



# COMMERCIAL AND INDUSTRIAL UNITARY AIR-CONDITIONING CONDENSING UNITS 

# I Standard 365 

# I

1501 WILSON BOULEVARD. ARLINGTON, VIRGINIA 22209. ' 

### SECTION 

# RETURN TO 

# KEH-UBRARY

TCPC/E6-13

TABLE OF CONTEN I oJ 

### PAGE 1. 

### Purpose.

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1 2. Scope

................................................................................... 1 3. Definitions

............................................................................... 1 4

. Classification

............................................................................. 1 5. Testing and Rating Requirements

........................................................... 2 6. Performance Requirements

................................................................. 5 7. Safety Recommendations

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5 8. Conformance

............................................................................. 5 Appendix A "Method and Example of Calculating Integrated Part Load Valves (IPLV)

..................... 6



### Prtcen.oo**~IIIU.S.A.** 

### NOTE: This 

### standard supersedes ARI Standard 365-85



# .!!r.;; C COPYRIGHT1987, byAir-Conditioning and Refrigeration Institute

_ •• ,. Registered United States Patent and Trademark Office

# :~ 0 

### 1\'\ to

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### "t:

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# OBSOlETE('"

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# I**-----------------~._;_----** AR I STAN DA R0 365-87 

# COMMERCIAL AND INDU TRIAL UNITARY AIR-CONDITIONING CONDENSING UNITS

Section 1_ Purpose 1.1 Purpose. Thepurpose of

### this standard is to establish for commercial and industrial air-conditioningcondensing units: definitions and classifications; requirements for testing and rating; specifications, literature and advertising requirements, performance requirements; safety recommendations and conformance conditions. 1.1.1 This standardis intendedfor guidanceofthe industry,including manufacturers, distributors,installers, contractors, and consumers. 1.2 ReviewandAmendment. 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 andindustrial unitary air-conditioning condensing units defined in Section 3. 2.1.1 EnergySource. This standardappliesonlyto electrically-driven, mechanical compression type condensing units. 

### 2.2 Exclusions. This standard does not apply to condensing units with capacities less than 135,000 Btuh [40 kW]. It also does not apply to the testing and rating of condensing units for refrigeration purposes, as defined in ARI Standard 520.
Section 3. Definitions 3.1 Commercial

### ~nd Industrial Unitary AirConditioning Condensing Unit. A commercial and industrial unitary air-conditioning condensing unit is a factory-made assembly ofrefrigerating components designed to compress and liquefy a specific refrigerant. It consists of one ormore refrigerant compressors, refrigerant condensers, condenser fans and motors (where used) and factory-supplied accessories. 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 tofitits application.Thesevalues applytoall unitsoflike nominal size and type (identification) produced by the same manufacturer. As used here in, the term "published rating" includes the rating of all performance characteristics shown on the air-conditioner componentsorpublishedin specifications, advertising, orother 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 ofperformance to occur. 3.3.1 Sta';dard 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 condensing unit cooling capacity in thousands ofBtuperhour (Mbh) by the condensingunit powerinput in kilowatts (kW) at Standard Rating Conditions, expressed as Btuh/Watt. 

### 3.5 IntegratedPartLoadValue (IP LV). A single number part load efficiency figure of merit calculated per the method described in 5

.2.2. 3.6 "Shall", "Should", "Recommended", or "ItIs Recommended". "Shall", "should", "recommended", or "it is recommended" shall be interpreted as follows: 3.6.1 Shall. Where "shall" or "shall not" is used for a provision specified, that provision is mandatory if compliance with the standardis claimed. 3.6.2 Should, Recommended, or It Is Recommended. "Should", "recommended" or "itis recommended" is used to indicate provisions which are not mandatorybutwhich are desirable as good practice.Section 4. Classification 4.1 Classification. Normally, equipment covered within the scope ofthis standard may be classified as follows: Types of Commercial and Industrial Air-Conditioning Condensing Units ARI Heat Designation Type Rejection Arrangement Condensing RCU-A Air ICOMPI Unit RCU-E Evaporative COND RCU-W Water 1 

# PROPERTY OF U S

GOVERNMENTA R I STA

### NDA R D 365-87

# ------A/;~**.**-J/t....-----------------

Section 5. Testing and Rating Requirements 5.1 Stalldard RCllillgs. Standard Ratings of condensing units shall be established at the Standard Rating Conditions shown in 5.1.3. All Standard Ratings shall be verified bv tests conducted in accordance with the ASHRAE'Standard MC'fhods ofTestillgfor Ratillg Positin! Displar:emelll Condensillg Ullits (American Society of Heating. Refrigerating. and Air-Conditioning Engineers. Inc. Standard 14-80) and with the test methods and procedures as described in this standard. An alternate method of verification may be used by tests conducted in accordance with ANSI/ASHRAE "37-1978 Methods ofTestillgfor Ratillg Unitary Air-Conditioning and Heat Pump £quipmelll provided**th~t** the saturated suction temperature and actual suction"vapor temperature is determined from this procedure

. Standard Cooling Capacities shall be, that obtained under Standard Rating Conditions.**Pow~r** input shall be the total power input to the compressor(s) and fanes) plus controls and other items included as part of the condensing unit. 5.1.1 Values of Standard Capacity Ratings. These ratings shall be expressed only in terms of thousandsofBtuperhour (Mbh) [kW]in multiples of 2 Mbh [0.6 kW] for units with standard ratings of 400 Mbh [117 kWJ and under. For units with standard ratings of over**~OO** Mbh [117 kW]. the ratings shall be expressed in multiples of 5 Mbh [1.5 kWJ. 

### 5.1.2 Values of Standard Efficiency Ratings. Energy Efficiency Ratios (EER) in Btuhlwatt and Integrated Part Load Values (IPLV) shall be expressed in multiples to the nearest 0.1. 5.1.3 StandardRuting Conditions. The conditions of test for Standard Rating for condensing units shall include the following:



## --- 5.1.3.1 Stalldard Rating Temperatures. Standard Capacity Ratings and correspondingpower input shall be determined at the following temperature conditions as shown in Table 1. 

### 5.1.3.2 Single Number Rating. Where single number ratings are required the reported values shall be determined by averaging the results ofthe following tests from Table 1:

For all units Refrigerant Entering condensing Unit Saturated suction temperature 50F [lO°C] and 40F [4.4°C] Actual suction temperature 65F [18.3°C] and 55F [12.8°C] Air-cooledand Evaporatively-cooled units Air entering and surrounding unit

Water-cooled units 95F [35°C] D

.B. 75F [23.9°C] W.B.· Entering water temperature 85F[29.4°C] Leaving water temperature 95F[35°C] 

### 5.1.3.3 Voltage and Frequency. Recommended nameplate voltages for 60 Hertz systems are one or more of the following utilization voltages: 200, 230, 460, 575.

"Required for Evaporatively-cooled units. Table 1. Standard Rating Conditions Air- and Evaporatively-Cooled Condensing Units Air Entering and Surrounding Unit (I) Refrigerant Entering Condensing Unit Dry Bulb (2) Wet Bulb Saturateu Suction Temp

. Actual Suction Temp

. F ·C F ·C F ·C F ·C 95 35 75 23.9 50 10**6~** Ill.] 95 35 75 23.9 40 4.'; 55 12.8 : HO 26.7 67 19.4 50 III 65 18.3 80 26.7 67 19.4 40 -1

.4

. 55 12.8 Water-Cooled Condensing Units


### .. Water Temperature Entering Leaving F ·C F ·C 85 29.4 95 35 51l 10 65 18

.3 H5 29.4 95 35 40 4.4 55 12

.8 75 23

.9 same flow rate SO 10 65 18.3 75 23

.9 as above 40 4.4 55 12.8 NOTES: (I) Theliquid temperatureandpressureleaving thecondensing unitshall bereponedby the manufacturer in his ratings. (2) Required for evaporatively-cooled condensing units only

. 2

### ----------------------------------------------__ ARI Standard Rating tests shall be performed at the nameplate rated voltage and frequency. For condensing units 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. 

### 5.1.3.4 CondenserAirQuantity. All Standard Ratings for condensing u.nits sha!l be**d~ter** 

### mined at the condenser aIr quantIty specIfied by the manufacturer where**th~ fa~**  

### dz:ive is adjustable; or where the fan dnve IS dIrect-connected, they shall be determined at the condensing unit when operated with all of the resistance elements as associated withinlet louvres and any duct work and attachments considered by the manufacturer as normal installation practice. Once established, the condenser air circuit of the condensing unit shall remain unchanged throughout all tests prescribed herein, except as altered by automatic controls. 

### 5.2 Part-LoadRating. Condensing units which are capable ofcapacity reduction shall be rated at 100% and at each step of capcity reduction provided by the condensing unit as published by the manufacturer. These rating points shall be used to calculate the IPL V (see 5.2.2). 

### 5.2.1 Part Load Rating Conditions. The conditions of test for part load rating are the same for the Standard Ratings (See 5.1) except for the following: 

### 5.2.1.1 Part LoadRating Temperatures. For all units Refrigerant Entering Condensing Unit Saturated suction temperature 50F[100] Actual suction temperature 65F[18.3°C] 

### For air-cooled units Airtemperature entering and surrounding unit ofunit.

............... 80 F [26.7°C] dry blub (and67 F [19.4°C] wetbulb when condensate is rejected into the air stream) 

### For evaporatively-cooled units Airtemperature entering and surroundingunit ofunit

................ 80 F [26.7°C] dry bulb 67 F [19.4°C] wet bulb 

### For water-cooled units Water temperature entering condenser

..................**~** 

### ....75F [23.9°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 ofunloading. No manual adjustment of condenser air' quantities from those of the Standard Rating Conditions shall be made. However. automatic adjustment ofcondenser air quantities by condensing unit function is permissible. 

### 5.2.2 Integrated Part Load Value (IPLV). For. equipment covered by this standard. the IPL V (in EER) shall be calculated as follows: 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: (EER 

### + EER.) IPL V = 

### (PLF1 - 

### PLF 2) 1 

### 2 -
(EER2 

### + EERJ) 

## + (PLF1 - 

### PLF J ) 

### 2 

### +
..... . .. . (EERn

_ 1 

### + EERn) 

## + (PLFn

_ 1 - 

### PLF n ) 

### 2 

## + (PLF,,)(EER,,) where: PLF = 

### Part-LoadFactordetermined from Figure 1 n = 

### Total number ofcapacity steps Subscript 1 = 

### 100% capacity and EER at part-load rating conditions Subscript 2; 3 etc. = 

### specific capacity and EER at part-load steps per 5.2 

### 5.3 Publication of Ratings. Wherever application ratings are published or printed, they**s~all** 

### include, or**~e** 

### accompanied by, the Standard RatlOg clearly**~c:slg** 

### nated as such, including a statement of the condItIons at which the ratings apply. 

### 5.3.1 Capacity Designations. The capacity. designations used in published specifications, literature or advertising, controlled by the manufacturer shall be expressed only in Mbh [kW] at the StandardRating Conditions specified in 5.1.3 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. 

### 5.4 Tolerances. To comply with this**stand~rd,** 

### publishedcoolingcapacityratings and energyeffiCIency**r~t** 

### ings shall be based on data obtainedin**accorda~ce W1~h**  

### this section. and shall be such that any prod,!ctlon urnt. when tested. will meet or exceed these ratIngs**exc~pt** 

### for an allowance to cover testing and man'!factunng variations; the amount of allowance to be mmus 5 per cent. 3

# ~ 

# , ARI STANDARD 365-87 ; 

## U

PART LOAD FACTOR CURVE

1.0 ,/ 

### I--""'"
0.9 

### / 

# / 0.8 

## I 0.7 

# I 

# I L2 0.6 

# , -l a.. 

# J a:: 

# f2 0

.5 

# I**~** 

# I u: 

### I 0 0.4

### ~ 

# I -l**~** 

# / a:: 0.3**~** 

# 1/
0.2 

### j 

# '/
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: PLF 

## = AO 

### + (AI x Q)

### +(A2 X Q2)

### +(A3 X Q3)

### +(A4 X Q4)

### +(AS X Q5)

### +(A6 X Q6) 

### where: PLF 

## = Part-Load Factor Q 

## = Percent offull-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

FIGURE 1 4________________________ ARI STANDARD 365-87

Section 6. Performance Requirements 6.1 Performance Requirements. To comply with this standard, commercial and industrial unitary**air~** conditioning condensing units shall be designed and produced in accordance with the provisions of this section insuch a mannerthat any productionunit will meet the appropriate requirements detailed herein. 6.2 Maximum Operating Conditions Test. Commercial and industrial unitary air-conditioning condensing units shall be designed and produced to pass the following maximum operatingconditions tests. Formulti-capacity units. this test shall beconductedwith unit controlsetfor maximum capacity. 6.2.1 Temperature Conditions. For aI/units Air temperature surrounding unit 115 F [46.1°C] dry bulb· Refrigerant Entering Condensing Unit Saturated suction temperature
... 50 F [1 DoC] Actual suction temperature
.... 65 F [IS.3°C] 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 condensateis rejected to the condenser air stream) at the standard condenser air quantity specified and stated by the manufacturer. For**evaporatively~cooled** units Outside air temperature
........ 100 F [37.S0C) dry bulb SO 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 berun at 90percent and 110 per cent ofthe unit's nameplate rated voltage at

·For units or portions thereor intended to be installed only indoors. this temperature may be reduced to 9S F [3soq dry bulb. the unit's service connection and at rated frequency. orat a lower than 90 per cent minimum ora higher than 110 percent maximum voltage. if listed on the nameplate. 6.2.3 Procedure. 6.2.3.1 The condensing unit shall be operated continuously for two hours at
.t
. he temperature conditions and voltage(s) specified. 6.2.3.2 All power to the condensing unit 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 Requiremellls

. 6.2.4.1 During both entiretests, the condensing unit 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 priorto establishmentofcontinuousoperationis 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. 6.3 Tolerances. The conditions for the tests outlined in 6.2 are average values subject to tolerances of :t1.0 F [:to.56°C] for air**wet~bulb** and dry-bulb temperature, and :t1.0 per cent ofthe reading for voltages.
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**stan~** dards and codes, appropriate for the product covered by this standard. Section 8. Conformance 8.1 Conformance. While conformance with this**stan~** dard is voluntary, conformance shall not be claimed or implied for products or equipment within its Purpose (Section 1) orScope (Section 2) unless such claimsmeet all ofthe requirements ofthe Standard.



### 5ARI STANDARD 365-87

________________________________________________ _ 

### APPENDIX A METHOD AND EXAMPLE OF CALCULATING INTEGRATED PART LOAD VALUES (IPLV) Section A1. Purpose and Scope 

### Al.I Purpose. 

### A.I.I.I This appendix shows examplecalculations for determining Integrated Part Load Values (IPLV).


### AI.2 Scope. 

### A.I.2.1 This appendix is for equipment covered by this standard. 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% offull load 

### • SO% offull load' 

### • 25% offull load 

### A3.1.2 Obtain partloadfactors from Figure 

### 1 (see Figure Al Example).

Section A2. Equations and Definitions ofTerms



### ,Al.I General Equation. 

### 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 2 = 

### 0.9 PLF3 = 

### 0.4 PLF 4 = 

### 0.1 EERI = 

### 8.9 EER2 

## = 7.7 EER3 = 

### 7.1 EER4 = 

### S.O IPLV = 

### (PLF 1 - PLF 2 ) 

# (EERI ; EER2)



### + (PLF 2 - PLF J) (EER2 ; EERJ)


### + ........ . 

### + (PLF

- PLF)

# (EER n

_ 1 

### + EERn) n-l n 

### 2 

### + (PLFn)(EERn)

, Where: PLF 

### = Part-Load Factor determined from Figure 1



### 6 n = Total number ofcapacity steps Subscript 

### 1 

### = 100% capacity and EER at part-load rating conditions Subscript 

### 2; 3, etc. = specific capacity steps per S.2. Enterthe 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) 

### )(7.1 +S.O) 

### + (0.4-0.1 2 

### +(0.1 

### xS.O)

= 

### (0.1 

### x 8.3) 

### + (O.S 

### x7.4) 

### + (0.3 

### x 6.0) 

### + 0.5

= 

### 0.83 

### + 3.70 

### + 1.80 

### + 0.5 IPLV = 

### 6.8 Tofurtherillustratethe calculationprocess seeFigure A2 Example.________________________ ARI STANDARD 365-87

1.0
0.9

0.8

0.7 

### LL ...J 0.6**~** 

### a:

### ~ 0.5

### ~ u.: CJ 0.4 

### C5 ...J

### ~ 0.3**~** 0.2

0.1

0**~**

0 PART LOAD FACTOR CURVE



# - - ./ 

### / 

# ,

... 

## I 

# / 

# I 

# I I 

# I I I 'I



# - j 

# / / 

# J 

# / /**~ ~**  

### ;/**~,** 20 40 60 80

PERCENT OF FULL-LOAD CAPACITY AT PART-LOAD CONDITIONS ".,-

100



### Note: Curve is Based on Following Equation: PLF = 

### AO + (AI xQ)+(A2x Q2)+ (A3x Q3)+(A4x Q4)+(A5XQS)+(A6xQ6) 

### where: PLF 

## = Part-Load Factor Q = 

### Percent offull-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 A1 EXAMPLE 

### 7ARI STANDARD 

### 365-87

_______________________ _

FIGURE A-2 EXAMPLE

IPLV CALCULATION 

### Using information from A3.1.i; A3.1.2 and A3.1.3

Capacity Mfrs. Net % Full PLP Mfrs.Part Avg. Part PLFDiff

. Step Cap. (Tons) Load Cap.2 LoadEER LoadEER (For R Only)
1 50.0 100% 1.0 8.!r = 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 S.O = 5.01 (0.1-0

.0)=0.1



## - 0% 0.0 

## -

NOTES Avg. EER x PLFDiff. =

8.3 x 0.1 = 7.4 x 0.5 = 6.0 x 0.3 = 5.01 x 0.1 = Single number IPLV
"Rounded to IFor the range between 0% capacity and the last capacity step, use EER ofthe last capacity step for the average EER. 2"Jbe 100% capacity and EER are to be determined at the part-load rating conditions. 3Part-Ioad factor from Figure AI.



### 8 Weighted Avg.

0.83 3.70 1.80 0.50 6

.83"
'6

.8



# •