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# OBSOLETE 

# 1986 KEH**ll~,~~** 

## TCPC/RM;,m3.**~IW\** 

### 110

# STANDARD 

# forWATERSOURCE HEAT 

# PUMPS



# IStandard 320 

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PROPERTY OF U.S.**GOVERNI\~E"H** AIR-CONDITIONING AND REFRIGERATION INSTITUTE 1501 WILSON BOULEVARD • ARLINGTON, VIRGINIA 22209

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TABLE OF CONTENTS SEcrION 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

..... . .. . ................................ .. ........ .. ..... 3 Section 7 Safety Recommendations

.. . ............... . .......... ; :
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Section 8. Conformance

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PROPERTY OF U

.S

.**GOVERNI\~E"JT**_______________________________________________ARI STANDARD 320-86 

# WATER-SOURCE HEAT PUMPS

Section 1. Purpose 1.1 Purpose. Thepurpose ofthis standardis to establish, for water-source heat pumps: definitions and classification; requirements for testing and rating; specifications, literature and advertising requirements; performance requirements; safety requirements; and conformance conditions. 1.1.1This standard is intended for the guidance of the industry, including manufacturers, distributors, consultants, contractors, and consumers.


# . 1.2 Review andAmendment. 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 residential, commercial, and industrial water-source 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. Section 3. Definitions 3.1 Water-Source Heat Pump. A water-source heat pump consists ofone orlmore factory-made assemblies which normally include an indoor conditioningcoil with air moving means, compressor(s) and refrigerant-towater heat exchanger(s), including means to provide both cooling and heating or cooling only functions. When such equipment is provided in more than one assembly, the separatedassemblies shall 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. Water-source heat pumps shall provide the function ofair-circulating and cooling andheating with controlled temperature, and may include the functions ofair-cleaning, dehumidifying or humidifying. Models designated as "cooling only" units need not include the heating function provided the following are met: 1. The components of the air-conditioning refrigerant system (cooling system) are substantially the same on the heat pump system. 2. Switches, thermostats and/or other controls of electrical components required for the reverse cycle heating mode canbe altered ordeleted as required to provide cooling only. 3. All other chassis components, fans, motors, pumps, housings etc. must be substantially the same between both versions. 3.2 PublishedRating. A statementofthe assigned values ofthose performance characteristics,understated rating conditions, by which a unit may be chosen to fit its application. Thesevalues apply to all units oflike 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, orotherliterature 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 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 Btuh by the power input in watts 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 ofPerformance (COP). A ratio calCulated by dividing the total heating capacity provided by the refrigeration system including circulating fan heat but excluding supplementary resistance heat, (Btuh) by the total electrical input (watts) 

### x 3.412. [A ratio

.calculatedfor both cooling and heating capacities by dividing capacity in watts by power input in watts.]. 3.5.1 Standa;d Coefficientof Performance. A ratio calculated from the capacity and power input obtained in accordance with 3.5 at Standard Rating Heating Conditions. 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 standard is claimed. 3.6.2 Should, Recommended, or It is Recommended

. ..Should", "recommended", or"it is recommended" is used to indicate provisions which are notmandatorybut which are desirable as good practice. 12ARI STANDARD 320-86,

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Section 4. Classification 4.1 Classification.**Nor~ally,** water-source**heat.~umps** within the scope of this standard may be classified as shown in Table 1.

Section 5. Testing and Rating Requirements 5.1 Standard Rating. Standard ratings shall be established at the Standard Rating' Conditions specified in 5.1.3. Allstandardratings shall beverified bytests**~on** ducted in accordance with the ASHRAE Standard Methods of TestingforRating UnitaryAir-Conditioning andHeat Pump Equipment (American SocietyofHeating, RefrigeratingandAir-ConditioningEngineers, Inc. Standard 37-78), and with the test methods and procedures as described in this standard. Standard Ratings relating to cooling or heating capacities shall be net values, including the effects

..of circulating-fan heat, but not including supplementary heat. 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). 5.1.1 Values of Standard Capacity Ratings. These ratings shall be expressed only in terms ofBtu per hour (Btuh) [watts] in mUltiples of: Capacities (Btuh) [W] Less than 20,000 [5.900] 20,000-37,800 [5,900-11.000] 38,000-64,500 [11,100-18,900] 65.000 and above [19.000 and above] Multiples (Btuh) [W] 100 [30] 200 [60] 500 [160] 1,000 [300]

Table 1. Classification of Water-Source Heat Pumps Types of Water-Source Heat Pumps ARI Designation Type •Arrangement Single Package HSP-W 

### I FAN 

### I COMPI

(Dueted) IEVAP I COND/ Split System HRCU-W 

# I FAN I/COMP/ (Dueted) EVAP**~** Single Package HSP-W-O I FAN I COMPI

(Free Delivery) IEVAP I CONDI Split System HRCU-W-O 

# I FAN //COMP/ (Free Delivery) EVAP \CONDJ
"Denotes cooling mode function. 5.1.2 Values of StandardEnergyEfficiencyRatios or Coefficients of Performance. Standard ratios of energy efficiency for cooling, wheneverpublished, shall be expressed in multiples of the nearest 0.1 Btuhlwatt [cooling C.O.P. in multiples of 0.1]; standard coefficients of performance for heating, whenever published, shall be expressed in multiples of the nearest 0.1. 5.1.3 StandardRating Conditions. Theconditions of test for Standard Ratings shall include the following:

- 5.1.3.1. Standard Rating Temperatures. a. Cooling Air temperature entering indoor. portion of unit..

... 80 F [26.7D

### C] dry bulb, 67 F [19.4D

### C] wet bulb Air temperature surrounding unit

................. 80 F [26.7 D

### C] wet bulb Water temperature entering refrigerant-to-water heat exchanger

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

### C] Water temperature leaving refrigerant-to-water heat exchanger

............... 95 F [35.0D

### C] b. Healing (not required for cooling onlymodels) Air temperature entering indoor portion ofunit.

.....70 F 

### [21.1DC] dry bulb, 60 F [15.6D

### C] bulb, max. Air temperature surrounding unit

..................70 F 

### [21.1

### DC] dry bulb Water temperature entering refrigerant-to-water heat exchanger

.._ .........._ ..70 F 

### [21.1DC] Water flow rate

._ .._ ........ as determined in Standard Rating Cooling Test 5.1.3.2 Electrical Conditions. Recommended nameplate voltages for 60 Hertz systems are one or more of the utilization voltages shown in Table 1 of ARI Standard 110 for AirConditioning and Refrigerating Equipment Nameplate Voltages. 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. ifonly a single Standard Rating is to be published. 5.1.3.3 Indoor-SideAirQuantity. All Standard Ratings shall be determined at an indoor-side air quantity, delivered against at least the • minimum external resistance required by

### ________________________________________________ARI STANDARD 320-86 5.1.3.5, as outlined below. All air quantities shall be expressed as cfm [Us] of Standard Air (density 0.075 Ib per cu ft [1.2 kg/mll).

a. Heatpumps shallberated at theindoor-side air quantity delivered when operating against the minimum external resistance specified in 5.1.3.5 orat a lower indoor-side airquantity, ifso specified by manufacturer.
Indoor-side air quantities as referred to herein apply to the air quantity experienced when the unit is cooling and dehumidifying under the Standard Rating Cooling Conditions specified in this section.This airquantity, except as noted in 6.3, shall be employed in all oO ther tests prescribed herein without regard to resulting external static pressure. 

### 5.1.3.4 Requirements for Separated Assemblies. All Standard Ratings for heat pumps in which the outdoor section is separated from theindoorsection, as in Type HRCU (shown in Section 4), shall be determined with at least 25 feet [7.62 m] ofinterconnection tubing on each line, ofthe size recommended by the manufacturer. Such heat pumps in which the interconnection tubing is furnished as an integral part of the machine not recommended for cutting to length shall be tested with the complete length oftubing furnished, or with 25 feet [7.62 m] of tubing, whicheverisgreater.Theline sizes,insulation, and details ofinstallation shall be in accordance with the manufacturer's published recommendations.


### 5.1.3.5 Minimum 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 whendeliveringthe ratedcapacityandairquantity specified in 5.1.3.3. Indoor air-moving equipment not intended for use with field installed ductsystems shall be tested at0 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 pumpbe in place and that the net external resistances specified above are available for the external duct system. 

### 5.2 Part-LoadRating. Heatpumpswhich arecapableof capacity control shall be rated at each step of capacity Table 2. Minimum External Resistance Minimum External Standard Cooling Capacity Ratings Resistance (Inchesof (Thousands ofBtuh) [kwj Water) [Paj Up thru 28 Up thru 8.2 0.10 24.9 29thru 42 8.5 thru 12.3 0.15 37

.4 43 thru 70 12.6thru 20.5 0.20 49.8 71 thru 105 20.8thru 30.8 0.25 62.3 106thru 134 31.1thru 39.3 0.30 74.7 135 thru 210 39.6thru 61.6 0.35 87.2 211 thru 280 61.7thru 82

. 1 0.40 99.6 281 thru 350 82.2 thru 102.6 0.45 112.1 351 thru 400 I02.7thru 117.2 0.55 137.0 401 thru 500 117.3thru 146.6 0.65 161.9 501 and over 146

.7 and over 0

.75 186.8

reductionprovidedby theheatpump and allowed bythe controls.

0 

### S.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-LoadRating Temperatures (Cooling). Air temperature entering indoor

portion ofunit

..... 80 F[26,7°C] dry bulb, 67 F[19.4°C] wetbulb Watertemperature entering refrigerantto-waterheat exchanger

.....75 F[23.9°C] Waterflow rate

...... Same as determined in Standard Rating Cooling Test 

### 5.2.1.2 Part-Load Rating Temperatures (Heating-not**r~quired**

### for cooling only models).



## ' Air temperature enteringindoor

portion ofunit

.....70 f[21.1°C] drybulb,

o 60 F[15.6°C] wet bulb max. Air temperature surrounding unit

...............70 F[21.1°C] dry bulb Watertemperature entering refrigerantto-water heat exchanger

..... 75 F[23.9°C] Water flow rate

........... as determined in

o Standard Rating Cooling Test 5.2.1.3 The capacity reduction means may be adjusted to obtain the specified step ofunloading. 

### 5.3 Application Ratings. Ratings at conditions of temperature or air quantity other than those specified in 5.1.3 and 5.2.1,maybepublished as applicationratings, and shall be based on data determined by the methods prescribed in 5.1. 3ARI STANDARD 320-86

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5.4 Publication ofRatings. Wherever application ratings are published or printed. they shall include. or be accompanied by. theStandard Capacity Ratings plusthe Part-Load Rating (where applicable), and their corresponding power inputs, clearly designated as such, includinga statementofthe conditions atwhich theratings apply. 5.4.1 Capacity Designation. Thecapacitydesignation used in published specifications, literature or advertising, controlled by,the manufacturer, for heat pumps rated under this standard, are to be expressed only in Btuh [watts] at the Standard Rating Conditions specified in 5.1.2 plus PartLoad Rating Conditions specified in 5.2.1, and in the termsdescribed in 5.1.1 through 5.1.2: Horsepower, tons, or other units shall not be used as capacity designations. 5.5 Tolerances. To comply with this standardpublished cooling capacity ratings. heating capacity ratings. ratios of energy efficiency for cooling. and coefficients ofperformance for heating. shall be based on data obtained in accordance with the provisions of this section. and shall be such that anyproduction unit, when tested, will meet or exceed these ratings exceptfor an allowance tocover testing and manufacturing variations; the amount of allowance to be minus 5 percent.
Section 6. Performance Requirements 6.1 Performance Requirements. To comply with this standard. water-source heat pumps shall be designed and produced in accordance with the provisions of**thi~** section in such a manner that any production unit will meet the requirements detailed herein. 6.2 Maximum Operating Condifions Tesf. Watersource heat pumps shall be designed and produced to pass the following maximum operating conditions test with an indoor·side coil air quantityas determined under 5.1.3.3:

4 6.2.1 Temperature Conditions. 6.2.1.1 Cooling. Air temperature surrounding unit

.................... 95 F [35.0°C] dry bulb Air temperature entering indoor portion of unit

................ 95 F [35.0°C] dry bulb, 71 F [21.2°C] wet bulb Water temperature entering refrigerantto water heat exchanger

......... 90 F [32.3°C] Water flow rate

.................Maintained same as in 5.1.3.1 6.2.1.2 Heatillg (nol reqlliredfor cooling only models). Air temperature entering indoor portion of unit..

....... 80 F [26.7°C] dry bulb Air temperature surrounding unit

.................... 80 F [26.7°C] dry bulb Water temperature entering refrigerantto-water heat exchanger

........ 90 F [32.3°C] Water flow rate

................Maintained same as in 5.1.3.1 6.2.2 Voltages. 6.2.2.1 Testsshall be run at 90percentand 110 percent ofthe unit's nameplate ratedvoltage at the unit's service connection and at rated frequency, orat a lowerthan 90percent minimum ora higherthan 110percent maximum voltage. iflisted on the nameplate. 6.2.2.2 The power supplied to the heat pump shall be adjusted just prior to the shut down period(See 6.2.3.2)sothat the resultingvoltage at the unit's service connection is 86 percent of nameplate ratedvoltage when the compressoris on locked rotor. (Forthose dual voltage units so specified on**eir** specification sheets for a minimum voltage 5 per cent below the lower rated voltage. this locked-rotor voltage setting shall be 91 per cent ofthe lowerrated voltage.) 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. Ifthe 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. 6.2.2.3 Within one minute after the heat pump has resumed continuous operation (See 6.2.4.3), the voltage shall be restored to the values specified in 6.2.2.1. 6.2.2.4 Single phase dual voltage units whose lower voltage is 208v., which specify on their 

# •________________________ARI STANOAR 0 320-86
specification sheets a minimum voltage to be applied at the unit service connection for the maximum operating conditions test, shall be tested at this minimum voltage in accordance with 6.2.2.1, 6.2.2.2 and 6.2.2.3.This provision applies only when the minimum voltage does not exceed 19Sv. 6.2.3 Procedure. 6.2.3.1 The heat pump shall be operated for two hours at the temperature conditions and voltage(s) specified. 6.2.3.2 All powerto the heat pump shall be cut offfor a period sufficient to cause the compressortostop (notto exceed five seconds) and then restored. 6.2.4 Requirements. 6.2.4.1 Duringboth entire tests, the heat pump shall operate without failure ofany ofits parts. 6.2.4.2 The heat pump shall operate continuouslywithoutinterruptionfor anyreason for the two-hour period preceding the power interruption. 6.2.4.3 The unit shall resume continuous operation within two hours 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.
6.3 Low- Temperature Operation Test (Cooling). Water-source heat pumps 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 and with controls and dampers set to produce the maximum tendency to frost or ice the evaporator, provided**su~h** settings are not contrary to the manufacturer's instructions to the user: '

,6.3.1 Temperature Conditions. Air temperature entering indoor portion ofunit.

........67 F [19.4°C] dry bulb, 57 F [13.9°C] wet bulb Water temperature entering refrigerantto-water heat exchanger

......... 65 F [lS.3°C] Water flow rate

...............'

..Maintained same as in 5.1.3.1 6.3.2 Procedure. Thetest shall be continuouswith the unit on the cooling mode,for notless than four hoursafterestablishmentofthespecified temperature conditions.Theunit will bepermittedto operate underthe control ofa limit device, ifprovided. 6.3.3 Requirements. 6.3.3.1 During the entire test, the heat pump shall operatewithoutdamage tothe equipment. 6.3.3.2 During the entire test, the air quantity shall not drop more than 25 per cent from that determined under the Standard Rating Cooling Test. 6.3.3.3 Duringthe test, and during the defrostingperiodafterthecompletionofthetest,all ice or meltage must be caught and removed by the' drain provisions. 6.4 Insulation Efficiency Test (Cooling). Water-source heat pumps shall be designed and produced to pass the following insulation efficiency test when operating with air quantities as determined in 5.1.3.3 with controls, fans, dampers and grilles set to produce the maximum tendency to sweat, provided such settings are not contrary to the**~anufacturer's** instructions to" he" user. 6.4.1 Temperature Conditions. Air temperature entering and surrounding indoor portion ofunit

......... :
.... SO F r26.7°C] dry bulb, 75 F [23.9°C] wet bulb Water temperature entering refrigerantto-water heat exchanger

....... SO 

### F [26.

## rq Water flow rate

.............. Maintained same as in 5.1.3.1 6.4.2 Procedure. After establishment of the specified temperature conditions, the unit shall be operated

.continuously for a period offour hours. 6.4.3 Requirements. During the test, no condensed water shall drop, run or blow offfrom the unit casing. 6.S Tolerances

.. The conditions for the tests outlined in 6.2, 6.3 and 6.4 are average values subject to tolerances of ± 1.0 F [±0.56°C] for

. air wet bulb and dry bulb temperatures, ±0.5 F [±0.2S°C] for water temperatures and ± 1.0 per cent ofthe reading for voltages.

5ARI STAN DA RD 320-86

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Section 7. Safety Recommendations 

### 7.1 Safety. Itis strongly recommended that the product be designed, constructed, assembled and installed in accordance with nationally recognized safety standards and codes, appropriate for the product covered by this standard.

6 Section 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 its 

### Purpose (Section 1) or

### Scope (Section 2) unless such claims meet all ofthe requirements ofthe standard.



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