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DRAFT INDIAN STANDARD FOR LIQUID-CHILLING PACKAGES USING THE VAPOUR COMPRESSION CYCLE

METHOD OF MEASUREMENT OF PERFORMANCE AND ENERGY EFFICIENCY RATING AND TESTING FOR PERFORMANCE

ICS 97.130.20

Not to be reproduced without the permission of Last date for receipt of

BIS or used as a STANDARD comments is: 31-05-2014

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I N D E X

S. No. Content Page No.

From To

1.0 SCOPE 3 3

2.0 REFERENCES 4 4

3.0 TERMINOLOGY 5 7

4.0 CLASSIFICATION 8 8

5.0 CONSTRUCTION (GENERAL) 9 10

6.0 RATING REQUIREMENTS 11 11

7.0 Ratings 12 12

7.1 Published Ratings 12 12

7.2 Standard Rating 12 12

7.3 Application ratings 13 13

7.4 Part Load Performance 13 13

8.0 Rating tolerance 14 14

9.0 Testing 15 15

10.0 Marking, Rating plate and Published data 16 16

11.0 Basic Principles of testing 17 17

12.0 Test apparatus and installation of the test unit 18 18

13.0 Test Method 19 26

14.0 Test verification 27 28

15.0 Instrumentation 29 29

16.0 Test procedure 30 33

17.0 Fouling factor consideration for testing 34 34

Annexure – A Method for Simulating fouling factor allowance 35 37

Annexure – B Concurrent Redundant Verification test for air cooled condenser units

38 38

Annexure – C

India Seasonal Energy Efficiency Ratio 39 44

Annexure – D Sample Calculation 45 45

Annexure – E

Air distribution check procedure and check list 46 48

Annexure – F Barometric pressure adjustment 49 50

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Foreword This standard is primarily intended to introduce testing standards for Liquid cooling chillers using Vapor compression cycle. This standard is an initiative of ISHRAE (Indian Society of Heating Refrigeration and Air conditioning Engineers), Refrigeration and Air conditioning Manufacturers’ Association (RAMA). While preparing this standard considerable assistance has been drawn from standards and guidelines as listed below,

ISO 817 Organic Refrigerants – Number designation.

Proposed working draft (pwd 19298-1) liquid-chilling packages using the vapour compression cycle, Part 1 : Method of rating for performance

Proposed working draft (pwd 19298-2) liquid-chilling packages using the vapour compression cycle. Part 2 : Method of testing for performance

AHRI Guideline 1997 - Fouling Factors: A Survey Of Their Application In Today's Air Conditioning And Refrigeration Industry

ISO 9614: Acoustics – Determination of Sound Power levels of noise sources using sound intensity

IEC Standard Publication 38, IEC Standard Voltages

EN 14511 – 1: 2011: Air conditioners, liquid chilling packages and heat pumps with electrically driven compressors for space heating and cooling – Part 1: terms and definitions

EN 14511 – 2: 2011: Air conditioners, liquid chilling packages and heat pumps with electrically driven compressors for space heating and cooling – Part2: Test conditions

EN 14511 – 3: 2011: Air conditioners, liquid chilling packages and heat pumps with electrically driven compressors for space heating and cooling – Part3: Test methods

AHRI 550/590 (I-P)-2011: Performance Rating of Water-Chilling and Heat Pump Water-Heating Packages Using Vapor Compression Cycle

ANSI/ASHRAE 30-1995 – Method of Testing Liquid-Chilling Packages

ANSI/ASHRAE Standard 37-2009, Method of Testing for Ratings Electrically Driven Unitary Air Conditioning and Heat Pump Equipment.

ASHRAE Standard 116–1995, ‘‘Methods of Testing for Rating for Seasonal Efficiency of Unitary Air Conditioners and Heat Pumps.’’

ASHRAE Standard 51–1999/210–1999, ‘‘Laboratory Methods of Testing Fans for Aerodynamic Performance Rating.’’

AMCA Standard 210-99 ‘‘Laboratory Methods of Testing Fans for Aerodynamic Performance Rating.’’

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The manufacturers of factory packaged liquid chillers offer a complex array of equipment to meet the diverse applications of markets. The complexity of the product offering precludes the testing of each and every model. However, in order to promote consistency in the representation of chiller performance by all manufacturers, this standard establishes uniform rating and testing methods. In order for a manufacturer to comply with this standard, conformance to this standard is required in entirety. Only those agencies or companies that offer testing services can refer to the relevant clauses for testing method defined in this standard. This standard may also be used for customer specific tests conducted at appropriate test facilities, but it is not intended for field-testing. For the purpose of declaring and publishing the values as specified in this standard, the final value observed or calculated, expressing the result of a test or analysis, shall be rounded off in accordance with IS 2 : 1960 ‘Rules for rounding off numerical values (revised)’.

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1.0 Scope

1.1 Standard covers the method of test for the measurement of performance and energy efficiency of factory built liquid chilling units covering all types and sizes for a rated voltage up to and including 250V, 50Hz AC, for single phase and up to and including 415V, 50Hz AC for Three phase power supply.

1.2 This standard defines testing method for liquid chilling packages using the vapour compression cycle to verify the cooling capacity and power requirements at a specific set of conditions.

1.3 This standard covers full load and part load ratings testing method to allow for an

energy analysis of the unit in different applications.

1.4 It is intended that equipment testing will be done in lab where the instrumentation and load stability as defined in the standard can be provided.

Note: This standard does not provide method of testing in field installations where steady state and uniform conditions are difficult to achieve and provisions for measurements are not made.

1.5 Annex A, B & C form an integral part of this standard

1.6 This standard does not cover the testing method for:

a) Packages with Condensing unit provided with Heat reclaim b) Systems with remote condensing unit c) Systems with Evaporative cooled condenser d) Condenser less chillers

2.0 REFERENCES

Following Indian Standards are necessary adjunct to this standard. IS Number Title 101 (Part6/Sec1): 1988 Methods of sampling and test for paints, varnishes and related

products - Part 6 : Durability tests - Section 1 : Resistance to humidity under conditions of condensation

IS 101 (Part 6 : Sec 5): 1997

Method of sampling and test for paints, varnishes and related products Part 6 Durability test on Paint films section 5 Accelerated weathering test

IS 101 (Part 7 : Sec 1): 1989

Methods of Sampling and Test for Paints, Varnishes and Related Products - Part 7 : Environmental Tests on Paint Films - Section 1 : Resistance to water

IS 101 (Part 7 : Sec 2): 1990

Methods of sampling and test for paints, varnishes and related products part 7 Environmental tests on paint films Sec 2 Resistance to liquids

IS 101 (Part 7 : Sec 3): 1990

Methods of sampling and test for paints, varnishes and related products Part 7 Environmental tests on paint films Sec 3 Resistance to heat

IS 196: 1966 Atmospheric conditions for testing (revised) IS 325: 1996 Three phase induction motors (firth revision) IS 8148: 2003 Packaged Air Conditioners IS 2360 Voltage bands for electrical installations including

preferred voltages and frequency

ISO 817 Organic refrigerants – Number designation ISO 9614 – 1 Acoustics - Determination of Sound Power Levels of Noise Sources

Using Sound Intensity - Part 1: Measurement at Discrete Points First Edition

ISO 9614 – 2 Acoustics - Determination of Sound Power Levels of Noise Sources Using Sound Intensity - Part 2: Measurement by

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Scanning First Edition

PWD 19298-1 Proposed working draft liquid-chilling packages using the vapour compression cycle, Part 1 : Method of rating for performance

PWD 19298-2 Proposed working draft liquid-chilling packages using the vapour compression cycle. Part 2 : Method of testing for performance

3.0 Terminology

For the purposes of this Standard, the terms and definitions as listed below shall apply:

3.1 Bubble point

Refrigerant liquid saturation temperature at a specified pressure. (°C)

3.2 Condenser. A refrigeration system component which condenses refrigerant vapour. Sub-cooling of the refrigerant may occur as well. a) Air Cooled Condenser. A refrigeration system component that condenses

refrigerant vapor by rejecting heat to air circulated over its heat transfer surface causing a rise in the air temperature. Sub-cooling of the refrigerant may occur as well.

b) Water-Cooled Condenser. A component which utilizes refrigerant-to-water heat transfer means, causing the refrigerant to condense and the water to be heated.

3.3 Condenser Heat rejection capacity

The heat removed by the heat transfer medium of the condenser per unit of time, (kW)

3.4 Cooling capacity

Heat given off from the liquid to the refrigerant per unit of time, (kW)

3.5 Coefficient of performance (COP)

A ratio of the cooling capacity in kilo watts to the total power input in kilo watts, [kW/kW]. This is a dimensionless number.

3.6 Dew point

Refrigerant vapor saturation temperature at a specified pressure. (°C)

3.7 Effective COP A ratio of the effective cooling capacity in kilo watts to the total power input in kilo watts for units with integral pumps [kW/kW].

3.8 Effective cooling capacity For units with integral pumps, the Effective Cooling Capacity includes the power input to the pumps (kW).

3.9 Fouling factor The thermal resistance due to fouling on the fluid side of the heat transfer surface (m

2 °C /kW)

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3.10 Fouling factor allowance Provision for anticipated fouling during use, specified in (m

2 °C /kW)

3.11 Liquid-chilling packages

A factory made refrigeration machine using the vapour compression cycle.

Note: Liquid-chilling packages may be operated with any type of compressor and be equipped with air-cooled and liquid-cooled, condensers. Liquid chilling packages can be supplied without condenser. Liquid chilling packages can be supplied with or without pumps.

3.12 Liquid-cooled condenser

A heat transfer device, which utilizes refrigerant-to-liquid heat transfer means, causing the refrigerant to condense and the liquid to be heated. Sub-cooling of the refrigerant may occur as well.

. 3.13 Liquid refrigerant temperature

Temperature of the refrigerant entering the expansion device. (°C)

3.14 Ratings

3.14.1 Performance rating

Performance data over the operating range of the unit at full load in the form of performance curves or catalog or output from a computer selection code.

Note: The published ratings are the ratings declared by the manufacturer in any form as defined above.

3.14.2 Application rating:

A rating based on tests performed at Application Rating Conditions other than Standard Rating Conditions (see 7.2)..

3.14.3 Standard Rating.

A rating based on tests performed at Standard Rating Conditions

3.15 Saturated discharge temperature

For single component and azeotropic refrigerants, it is the saturated temperature corresponding to the refrigerant pressure at the compressor discharge.

For zeotropic refrigerants, it is the arithmetic average of the dew point and bubble point temperatures corresponding to refrigerant pressure at the compressor discharge.

Note: The refrigerant temperature is generally measured at or immediately downstream of the compressor discharge service valve (in either case on the downstream side of the valve seat), where discharge valves are used. (°C)

3.16 Standard Barometric Pressure

Barometric pressure of 101.325 kPa (1 bar)

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3.17 Total power input of the system

Power input of all components of the unit in operation shall include:

a.) The power input for operation of the compressor, (kW)

b.) The power input of all controls, safety devices, starters, and drives of the unit,

including devices necessary for correct operation of the refrigerating circuit (e.g. oil

pump, refrigerant pump), (kW)

c.) The power for fans for air cooled liquid chillers, (kW)

d.) In case of the pump being an integral part of the unit for water cooled chillers, the

power supplied to the pumps (kW).

3.18 Sound Power Level:

Ten times the logarithm to the base 10 of the given sound power to the reference sound power which is 1 pW(10

-12 W), and expressed in decibels (dB)

4.0 CLASSIFICATION:

Liquid chilling packages shall be classified according to method of cooling of condenser.

Air cooled condenser

Water cooled condenser Note: The liquid chilling packages can also be without condensing unit. 5.0 CONSTRUCTION (GENERAL): 5.1 The unit shall be constructed with sufficient strength and rigidity to withstand normal manual

and mechanical handling, transportation and usage without damage or failure 5.2 Structural constructional parts shall be suitably provided with corrosion resistant coating.

5.3 All parts that require periodic cleaning or maintenance shall be easily accessible when the

unit is installed in accordance with manufacturer’s instructions.

5.4 Self-tapping screws shall not be used for any load bearing parts or any part that has to be removed for routine maintenance

5.5 All parts that constitute an accident hazard shall be suitably guarded.

5.6 Pipes and connections to moving or resiliently mounted parts shall be so arranged as not to

foul or to transmit undue vibrations to other parts and shall be so designed as to prevent failure due to fatigue. All other pipes and connections shall be securely anchored.

5.7 Water cooled condenser shall have cleanable water passages, either by mechanical means

or chemical or both. An adequate opening shall be provided in the casing, so as to have access to passages bearing water, from either end, for the design amenable to mechanical cleaning.

5.8 All valves and refrigeration piping shall be properly clamped so as to avoid excessive

vibration.

5.9 Safety and installation requirements

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The listed below are some of the recommended safety and minimum specifications and information to be provided by the chiller manufacturer. These requirements are basic and are not limited to the list below:

5.9.1 Safety requirements:

a. The Liquid chilling package shall be complete with flow switch, vibration isolators/cushy mounts; Emergency Power Off (EPO) switch.

b. Necessary terminal box for termination of cables to the chiller shall be a part of the chiller

panel. c. The terminal block shall be suitable for using Aluminum cables also d. Condenser heat exchanger guard shall be provided for air cooled condenser

5.9.2 Installation and commissioning requirements: a. The liquid chilling package manufacturer has to submit the dimensional drawing with point

loads and dimensions enabling the structural supporting system to be designed for installation.

b. Liquid chilling package manufacturer should advise on the minimum spacing required for

the air movement around the chillers and the suggested maintenance space including access to the liquid chilling package unit yard.

c. The liquid chilling package manufacturer shall provide shipping weight of the unit,

recommended handling and transportation method(s) including transportation from manufacturer location to the installation location.

d. Commissioning of the liquid chilling package shall be done by qualified personnel as

recommended and qualified by the manufacturer or accredited training organization. The qualified commissioning personnel shall test and provide the test data to the customer in prescribed format containing relevant electrical and refrigerant parameters for assessing the performance of the liquid chilling package.

e. Commissioning personnel shall train designated personnel of the customer / user of the

liquid chilling package on the operation and routine maintenance. f. Liquid chilling package manufacturer shall submit the required operating & maintenance

manual and safety procedures. g. Liquid chilling package manufacturer shall provide the complete details like – heat

exchanger area, dimensions and any additional information as requested by customer. h. Liquid chilling package manufacturer shall suggest the quality of water in the closed loop

evaporator and open loop condenser and the suggested make up water quality. 6.0 RATING REQUIREMENTS 6.1 Test requirements

All tests for liquid – chilling package ratings shall be conducted as defined in Clause 9.0, and Clause 11.0 to 17.0.

6.2 Standard rating conditions

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Published ratings for all liquid-chilling packages as in Clause 6 shall include the standard ratings, corresponding to the standard rating conditions shown in Table – 1 within the operating limits of the unit.

Table – 1

Liquid-cooled Air-cooled

Liquid / Air cooled condenser

Entering temperature 30°C [86.0 °F] Not applicable

Delta T 5 K [9 °R] Not applicable

Liquid-side fouling factor allowance Clean 0.000 m2 K/kW

Nominal 0.088 m2 K/kW

Not applicable

Entering dry-bulb temperature Not applicable 39°C

Air-side fouling factor allowance Not applicable 0.000 m2 K/kW

Evaporator liquid temperature

Leaving 7°C

∆ T 5 K

Evaporator fouling factor allowance

Liquid-side Clean 0.000 m2 K/kW

Nominal 0.044 m2 K/kW

Barometric pressure 101.325 kPa

Note: For all rated condition testing, Evaporator liquid-side and condenser liquid-side or air-side heat transfer surfaces shall be considered

clean during testing. Tests will be assumed to reflect fouling factors of 0.0 m2 K/W

6.3 Sound power measurement test:

The sound power measurement shall be done at rated condition specified in Table – 1 wherever feasible in the lab. In case, if the conditions as per Table – 1 cannot be maintained, the sound power measurement shall be done at possible temperature conditions and data shall be noted in the test report. The measurement shall be done in accordance with standard ISO 9614 by sound intensity method under free field condition (Part 1: Measurement by discrete points and Part 2: Measurement by scanning)

For sound power measurement test the following conditions shall be used:

Test unit shall be set to operate at full load in cooling mode

With the pump running

All fans running at nominal speed 7.0 Ratings 7.1 Published Ratings

Published ratings shall comply with this standard, performance ratings shall be based on test data or models derived from test data. Published ratings shall include the following:

a. Name and address of the manufacturer b. Refrigerant in accordance with ISO 817 c. Unit type, Model number and Serial number designations providing identification of

the liquid-chilling packages to which the ratings shall apply.

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d. Power supply in ‘……V; …. Phase; …..Hz (Rated voltage; Phase and frequency) e. Starting current in Amperes f. Full load current in Amperes g. COP at rated condition h. ISEER – Indian Seasonal Energy Efficiency Ratio i. Sound power level (dB) j. Fouling allowance - (Published ratings shall clearly state the fouling allowance).

Corrections and calculations for different fouling factors shall be made as per Annex A. Ratings shall be published using one of the following two options:

1.) Clean ratings with a correction factor on COP and capacity to yield nominal fouled conditions as per Table 1.

2.) Nominal fouled rating as per Table 1.

Additional ratings or means of determining those ratings, at other fouling factor allowances may also be published.

Note: In Air cooled condensers, if variable speed condenser fans or fan staging is used, the manufacturer shall publish the capacities and COPs taking into consideration the different performance parameters according to the fan control of the unit

7.2 Standard ratings

7.2.1 Total power input to chiller, (kW).

7.2.2 Cooling capacity, (kW) .

a. Cooling capacity for all units. b. Effective cooling capacity for units supplied with integral pumps.

7.2.3 COP at rated condition, (kW/kW). 7.2.4 ISEER – India Seasonal Energy Efficiency Ratio

7.2.5 Any two of the following:

a. Entering evaporator liquid temperature, (°C) b. Leaving evaporator liquid temperature, [°C] c. Liquid temperature difference through the evaporator, [K]

7.2.6 For all units without integral evaporator pump, evaporator liquid pressure drop, (kPa) [psi]. For units with integral pumps the available static pressure, (kPa).

7.2.7 Chilled liquid flow rate, [L/s]

7.2.8 Liquid-cooled condenser packages

a. For water cooled units without integral pump condenser liquid pressure drop (kPa) .

For units with integral pump the available static pressure (kPa). b. Any two of the following

i. Entering condenser liquid temperature, [°C] i. Leaving condenser liquid temperature, [°C]

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ii. Liquid temperature difference through the condenser, [K] 7.2.9 Air-cooled condenser units

a. Entering air dry-bulb temperature, [°C] . b. External static pressure available for ducted units, [Pa]

7.3 Application rating

Application ratings (other than standard rating) shall include Published ratings and the range of conditions within the operating limits of the equipment which shall be presented in the form of a performance curve. The conditions and the operating limits are as defined below.

All condenser types: Leaving chilled liquid temperature 4.4°C to 10.0°C in increments of 1K or less and temperature difference between 2.5K and 8K. Liquid-cooled condenser: Entering condenser liquid temperature 20°C to 35°C in increments of 1K or less and temperature difference between 2.5K and 8K. Air-cooled condenser: Entering condenser air dry-bulb temperature 20°C to 46°C dry-bulb in increments of 1°C or less and temperature difference between 2.5 K and 8 K.

Note: The rating conditions and the operating limits other than those prescribed above shall be mutually agreed upon between the manufacturer and buyer.

7.4 Part-load performance

7.4.1 Part load rating data shall be published or available upon request over the application rating conditions (defined in Annex C). These include cooling capacity, power input and ISEER.

7.4.2 100 % load refers to the full rated capacity as defined by the standard rating

conditions given in Table 1, and with the following condition for air-cooled units:

Rating condition

∆ T : 5 K For continuously variable unloading machines part load data shall be provided at a minimum of 75%, 50% and 25%, or to the minimum load point.

7.4.3 For discrete step unloading machines, part load rating data shall be provided at each

stage of capacity. 7.4.4 Method of representing part load performance as a single value shall be as described

in Annex C. The corresponding part load rating data to be required in order to calculate this single value also shall be as described.

In cases where this value is declared by the manufacturer, all part load rating data necessary for its calculation shall also be published.

8 Rating tolerances

8.1 The full load and part load permissible tolerances on capacity [kW] and COP [kW/kW] shall be

determined using the following equation:

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% FL = Percent of selected full-load rating conditions FL = Full load rating condition DTFL = Difference between entering and leaving chilled water temperature at

full-load, K (SI units)

The equation for rating tolerance for both capacity and COP has been empirically determined and recognizes three major sources of uncertainty or variation as described below.

i. Uncertainty of Measurement: Elements such as instrumentation error, set-up and

operator interaction

ii. Uncertainty in Performance Prediction: Includes the uncertainty of computing the performance of models other than tested models

iii. Manufacturing Variation: Includes the normal variation associated with heat

exchangers and compressor components Where:

8.2 Ratings published and claimed to be in compliance with this standard shall be as specified in Clause 8.1.

8.2.1. Full load capacity and full & part load COP shall not be less than 100 percent of the

rating minus the allowable tolerance as calculated in Clause 8.1. 8.2.2. Liquid pressure drop in the evaporator or condenser shall not exceed 115 percent of

the rated pressure drop at the specified liquid flow rate at any rated condition. 8.2.3. The pump head for units with integral pump(s) in the evaporator or condenser shall not

be less than 85 percent of the rated pump head at the specified liquid flow rate at any rated condition.

8.2.4. Sound power level shall be ≥ +3 dB

8.3 Typical examples on calculation are given in Annexure D for guidance only 9 TESTING: All the tests given in the standard are Type tests. The type test shall be carried out for all types, sizes and capacity. The manufacturers of factory packaged liquid chillers offer a complex array of equipment to meet the diverse applications of markets. The complexity of the product offering precludes the testing of each and every model. However, in order to promote consistency in the representation of chiller performance by all manufacturers, this standard establishes uniform rating and testing methods. In order for a manufacturer to comply with this standard, conformance to this standard is required in entirety. Only those agencies or companies that offer testing services can refer to the relevant clauses for testing method defined in this standard. This standard may also be used for customer specific tests conducted at appropriate test facilities.

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10 Marking, Rating plate and published data

10.1 Rating plate A rating plate shall be attached to each unit to provide the following essential information, in addition to the information required by applicable safety standards.

10.2 Marking and rating plate data:

The markings required by the standard shall be clearly legible and durable. Compliance is checked by inspection and by rubbing the marking by hand for 15 s with a piece of cloth soaked with water and again for 15 s with a piece of cloth soaked with petroleum spirit. The petroleum spirit to be used for the test is aliphatic solvent hexane. After all the tests of this standard, the marking shall be clearly legible. It shall not be easily possible to remove marking plates nor shall they show curling. NOTE In considering the durability of the marking, the effect of normal use is taken into account. For example, marking by means of paint or enamel, other than vitreous enamel, on containers that are likely to be cleaned

frequently, is not considered to be durable.

a) Manufacturer's name and address b) Model number designation c) Serial number d) Refrigerant designation (in accordance with ISO 817). e) Rated Voltage, phase and frequency (in accordance with IS 12360). f) Rated current in Amperes g) Published Total Power input in kW. h) Starting current in Amperes i) Refrigerant charge (kg)

10.3 Published performance data:

a) Application rating Performance curves shall be provided as specified in Clause 7.2.

b) Part load performance rating shall be provided as specified in Clause 7.3

11 Basic principles of testing

11.1 Cooling capacity (qev) The cooling capacity is the heat removed from the chilled liquid. It is determined from the measurement of the volume flow (Q) of the chilled liquid and the entering & leaving temperatures at the evaporator side, taking into consideration the specific heat capacity (cp)

and density () of the liquid. The cooling capacity shall be determined using the following equation:

Where:

- qev is the cooling capacity [kW]

- Q is the volume flow rate [m3/s]

- is the fluid density [kg/m3]

- cp is the specific heat at constant pressure [J/kg-K]

- t is the difference between inlet and outlet temperatures [K]

1000/)...( tcQq pev

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11.2 Water cooled condenser heat rejection (qcd) The condenser heat rejection capacity is the heat rejected through the condenser. It is determined from the volume flow of the liquid and the entering and leaving temperatures at the condenser, taking into consideration the specific heat capacity and density of the heat transfer medium.

The heat rejection capacity shall be determined using the following equation:

1000/)...( tcQq pcd

Where: qcd is the heat rejection capacity [kW]

Q is the volume flow rate [m3/sec

is the density [kg/m3]

cp is the specific heat at constant pressure [J/kg-K]

t is the difference between inlet and outlet temperatures [K ]

11.3 Ducted air cooled condenser heat rejection

The heat rejection capacity of a ducted air cooled condenser shall be determined using the following equation.

qcd = qv (he – hl)

Where:

qcd is the heat rejection capacity [kW]

is the density of standard air and is equal to 1.204 kg/m³ at 101.325 kPa and 20°C

qv is the standard airside volume flow rate [m³/s] (the measured volume flow rate shall

be converted into standard air)

he = enthalpy of entering air [kJ/kg]

hl = enthalpy of leaving air [kJ/kg] Note: The Airflow measurement and measuring apparatus shall be in accordance with section 6.6 of ASHRAE Standard 116–95 (RA05) Refer to Figure 12 of ASHRAE Standard 51–99/AMCA Standard 210–99 or Figure 14 of ASHRAE Standard 41.2–87 (RA 92) for guidance on placing the static pressure taps and positioning the diffusion baffle (settling means) relative to the chamber inlet.

12 Test apparatus and installation of the test unit

12.1 General requirements The test apparatus shall be designed in such a way that all requirements on adjustments of set values, stability criteria and uncertainties of measurement can be achieved according to this standard.

12.2 Test room for the air side

The size of the test room shall be selected such that any resistance to air flow at the air inlet and air outlet of the test unit is avoided. The air flow through the room shall not be capable of initiating any short circuit between these two openings. The air velocity in the room shall not be greater than the mean velocity through the unit inlet. Unless otherwise stated by the manufacturer, the air inlet or air outlet to the test unit shall be not less than 1 m distant from

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the surfaces of the test room. Any direct heat radiation by heating units in the test room onto the unit or onto the temperature measuring points shall be avoided.

12.2.1 Appliances with duct connection The connections of a ducted air unit (test appliance) to the test facility shall be sufficiently air tight to ensure that the measured results are not influenced by exchange of air with the surroundings. The test room shall have the capability of imposing the required external static pressure.

12.2.2 Appliances with integral pumps

For appliances with integral and adjustable water or brine pumps, the pressure head and temperature difference shall be set simultaneously.

12.3 Installation and connection of the test appliance / artifact

12.3.1 General

The test appliance / artifact shall be installed and connected for the test as recommended by the manufacturer in the installation and operation manual. The accessories provided by option are not included in the test. If a back-up heater provided in option or not, it shall be switched off or disconnected and to be excluded from the testing.

When the liquid pump is an integral part of the unit and the external head pressure setting possible, the setting shall be made in order to reduce this external head pressure to approach zero.

For unit with open-type compressor, the electric motor shall be supplied for specified by the manufacturer. The compressor shall be operated at the rotational speed specified by the manufacturer.

If the manufacturer instruction indicates value for the temperature to be set on the control device for a given rating condition, then this value shall be used.

Note: if skilled personnel with knowledge of control software are required for the start of the system, the manufacturer or the nominated agent should be available when the system is being installed and prepared for tests.

12.3.2 Installation and connection of the test unit

The equipment to be tested shall be installed in accordance with the manufacturer’s installation instructions using recommended procedures and accessories. No alterations to the equipment shall be made except for the attachment of required test apparatus and instruments in the prescribed manner.

13 Test method

13.1 Conditions of heat transfer surfaces All heat transfer surfaces shall be assumed to have fouling allowances of 0.000 m

2 K/W

during the test. Tests conducted in accordance with this standard may require cleaning (in accordance with manufacturer’s instructions) of the heat transfer surfaces.

13.2 Measurements

13.2.1 Temperature and pressure measurement:

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Temperature and pressure measuring points shall be arranged in order to obtain mean values. Temperature measurements shall be made in accordance with ANSI/ASHRAE Standard 41.1. Any differences between this standard document and ANSI/ASHRAE Standard 41.1, this document shall be applicable. The accuracy and precision of the measuring instruments including read-out devices, for temperature measurements shall meet or exceed the accuracy and precision requirements defined in Table 3. To ensure adequate air distribution, thorough mixing, and uniform air temperature, the room and set up shall be properly designed and operated. The test room conditioning equipment airflow should be set such that recirculation of condenser discharged air is avoided. The recirculation of the condenser discharged air back into the condenser coil(s) shall be verified by method as below: Multiple individual reading thermocouples (at least one per sampling tree location) will be installed around the unit air discharge perimeter so that they are below the plane of condenser fan exhaust and just above the top of the condenser coil(s). The temperature difference indicated by these thermocouples shall not be greater than 5.0 K (°R) from the average inlet air. Air distribution at the test facility point of supply to the unit shall be verified prior to beginning of the test and shall be adjusted if required. Mixing fans can be used to ensure adequate air distribution in the test room. The mixing fans shall be placed such that the air from fans shall be in a direction away from air intake to the condenser and mixing fan exhaust direction is at an angle of 90°-270° to the air entrance to the condenser air inlet. Precaution to be executed to ensure no recirculation of condenser fan exhausts air back through the test unit.

Correct test shall meet the criteria for adequate air distribution and control of air temperature as defined in Table 4. Appendix A provides the check list of verification for air flow and temperature distribution. The verification shall be done before starting of any new test.

13.2.2 Air sampling device Requirements.

Air sampling device is defined as an air sampling tube assembly that draws air through sampling tubes in a manner to provide a uniform sampling of air entering the Air-Cooled Condenser coil. The design of air sampling device is described as below.

The air sampling device is designed to draw a uniform sample of the airflow entering the Air-Cooled Condenser section for measurement of air temperature. A typical configuration for the sampling device is shown in Figure 1 for a device with overall dimensions of 1.2 m by 1.2 m sample. Other dimension and rectangular shapes may be used and should be scaled accordingly as long as the aspect ratio (width to height) of no greater than 2 to 1 is maintained. The air sampling device shall be constructed of stainless steel, plastic or other suitable, durable materials. It shall have a main flow trunk tube with a series of branch tubes connected to the trunk tube. It must have from 10 to 20 branch tubes. The branch tubes shall have appropriately spaced holes, sized to provide equal airflow through all the holes by increasing the hole size as you move further from the trunk tube to account for the static pressure regain effect in the branch and trunk tubes. The number of sampling holes shall be greater than 50. The average minimum velocity through the sampling tree holes shall be 2473 m/h as determined by evaluating the sum of the open area of the holes as compared to the flow area in the aspirating psychrometer. The assembly shall have a tubular connection to allow a flexible tube to be connected to the sampling device and to the aspirating psychrometer.

The sampling device shall also be equipped with a thermocouple thermopile grid to measure the average temperature of the airflow over the sampling device. The thermopile shall have at least 16 junction points per sampling device, evenly spaced across the sampling device, and connected in a parallel wiring circuit. On smaller units with only two sampling devices it is

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acceptable to individually measure the 16 thermocouple points as a determination of room stratification. The air sampling devices shall be placed within 150–300 mm of the unit to minimize the risk of damage to the unit while ensuring that the air sampling tubes are measuring the air going into the test unit rather than the room air around the unit.

Figure 1 – Typical Air Sampling Device

Note: The 19mm by 12.5mm slots shown in Figure 1 are cut into the branches of the sampling device and are located inside of the trunk of the sampling device. They are placed to allow air to be pulled into the main trunk from each of the branches.

13.2.3 Aspirating Psychrometer:

Aspirating psychrometer is a piece of equipment with a monitored airflow section that draws a uniform airflow velocity through the measurement section and has probes for measurement of air temperature and humidity. The design of an aspirating psychrometer is as described below.

a) It consists of a flow section and a fan to draw air through the flow section and measures an

average value of the sampled air stream from air sampling device.

b) The flow section shall be equipped with two dry-bulb temperature probe connections, one of which will be used for the facility temperature measurement and one of which shall be available to confirm this measurement using an additional or a reference validation temperature sensor probe. For applications where the humidity is also required, for testing of evaporative cooled units or heat pump chillers in heating mode, the flow section shall be equipped with two wet-bulb temperature probe connection zone of which will be used for the facility wet-bulb measurement and one of which shall be available to confirm the wet-bulb measurement using an additional or a reference validation temperature wet-bulb sensor probe.

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c) The psychrometer shall include a fan that either can be adjusted manually or automatically to

maintain average velocity across the temperature sensors. A typical configuration for the aspirating psychrometer is shown in Figure 2.

d) The distance between the sensor probe and the fan shall be such that there is no abnormal impact of air velocity from the fan. Recommended distance between fan and temperature sensor shall be minimum 150mm.

e) The cup for wet bulb water shall be connected with makeup water connection to ensure minimum level of water is ensured always during testing

Figure 2: Aspirating psychrometer

13.3 Test Setup Description.

The air wet-bulb and/or dry-bulb temperature shall be measured at multiple locations entering the condenser, based on the airflow nominal face area at the point of measurement. Multiple temperature measurements will be used to determine acceptable air distribution and the mean air temperature. The use of air sampling device as a measuring station reduces the time required to setup a test and allows an additional or a reference validation temperature sensor(s) probe for redundant dry-bulb and wet-bulb temperatures. Only the dry-bulb sensors need to be used for Air-Cooled Condensers.

The nominal face area may extend beyond the condenser coil depending on coil configuration and orientation, and must include all regions through which air enters the unit. The nominal face area of the airflow shall be divided into a number of equal area sampling rectangles with aspect ratios no greater than 2 to 1. Each rectangular area shall have one air sampling device.

Velocity across

probes should be

305 ± 61 m/min Aspirating Psycrometer

header – 100mm clear

plastic tube

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Figure 3: Determination of Measurement Rectangles and Required Number of Air Sampler Trees

L

0.8L ≤ W ≤L

L

L

2L

L

3L

W

0.6 Loverall ≤ A+B+C+D+... ≤ L overall

2L

L

3L

L Legend

4L

L

5L

L H 0.8L ≤ H ≤L

6L

L

L

A B C D

Condenser Air Inlet

Nominal Face Area

Equal Area

Rectangular

Air Sampler

Tree

7L = L overall

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Figure 4: Typical Set up

A minimum of one aspirating psychrometer per side of a chiller shall have to be used. For units with three (3) sides, two (2) sampling aspirating psychrometers shall have to be used but will require a separate air sampler device for the third side. For units that have air entering the sides and the bottom of the unit, additional air sampling device should be used.

A minimum total of two (2) air sampling device should be used in any case, in order to assess air temperature uniformity.

The air sampling device shall be located such that it is at geometric centre of each rectangle condenser coil; either horizontal or vertical orientation of the branches is acceptable. The sampling device shall cover at least 80% of the height and 60% of the width of the air entrance to the unit (for long horizontal coils), or shall cover at least 80% of the width and 60% of the height of the air entrance (for tall vertical coils). The sampling device shall not extend beyond the face of the air entrance area. It is acceptable to block all branch inlet holes that extend beyond the face of the unit. Refer to Figure 3 for examples of how an increasing number of air sampling devices are required for longer condenser coils.

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A maximum of only four (4) sampling devices shall be connected to each aspirating psychrometer. The sampling device should be connected and routed to the aspirating psychrometer using insulated flexible tubing so that heat transfer to the air stream is prevented. In order to proportionately divide the flow stream for multiple sampling devices for a given aspirating psychrometer, the flexible tubing should be of equal lengths for each sampling device. Refer to Figure 4 for some typical examples of air sampling device and aspirating psychrometer setups.

Care must be taken to ensure that the liquid temperatures are the average bulk stream temperatures. This shall include provisions for mixing of the fluid.

For free air intake temperature measurements, it is required:

a.) Either to have at least one sensor per m² and not less than four measuring points equally distributed on the air surface

b.) Or to use a sampling device. It shall be complemented with a minimum of four sensors for checking uniformity if the surface area is greater than 1 m².

13.3.1 Units with integral pumps

Units that include an integral evaporator fluid pump, and / a condenser fluid or heat reclaim fluid pump shall have to be tested for both condition A and Test condition B as defined below.

13.3.2 Test condition A : integral liquid pumps operating

The unit shall be run with the integral pumps running and the external loop resistance of the test facility adjusted to obtain the desired rating fluid flow rates. The following values shall then be measured;

Evaporator and/or condenser and/or heat reclaim condenser entering and leaving

liquid temperatures [°C] Evaporator and/or condenser and/or heat reclaim condenser liquid flow rates [m

3/sec]

Evaporator and/or condenser and/or heat reclaim condenser external water static pressure [kPa]

Total power input to the unit (compressor + pumps + controls) [kW] The calculated test capacities for this test will represent the Net Cooling capacity, Net condenser heat rejection and Net Heat Reclaim capacity.

13.3.3 Test condition B: liquid pumps turned off

A second test shall be run with the integral pumps turned off. The following values shall be measured; Evaporator and Condenser and heat reclaim condenser Entering and Leaving liquid

Temperatures [°C] Evaporator and Condenser liquid Flow rates [m

3/s]

Total power input to the unit (compressor + controls) [kW]

The calculated test capacities for this test will represent the Gross Cooling capacity and Gross condenser heat rejection. The following figures 1 and 2 are representing typical arrangements of test facility and measurement locations for the test conditions A and B respectively.

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F Figure 5: Test A configuration - Unit under test with integral liquid pumps on.

Figure 6: Test B configuration – Unit under test with integral liquid pumps off.

14 Test verification

Heat Balance method as defined in clause 14.1 and 14.2 shall be used for units of the following types:

evaporator

unit evaporator

pump

loop

heat exchanger

condenser

unit condenser

pump

loop evaporator

pump

loop condenser

pump

loop

heat exchanger

compressorECDWT

W_PRESS

FLOW

LCDWT

W_PRESS

ECLWT

W_PRESS

FLOWLCLWT

W_PRESS

UNIT KW

(COMP+PUMPS)

on

on

on

on

adjust valve to

obtain rated gpm

adjust valve to

obtain rated gpm

evaporator

unit evaporator

pump

loop

heat exchanger

condenser

unit condenser

pump

loop evaporator

pump

loop condenser

pump

loop

heat exchanger

compressorECDWT

FLOW

LCDWT

W_PRESS

ECLWT

W_PRESS

FLOWLCLWT

W_PRESS

UNIT KW

(COMP)

off

on

off

on

adjust pump to obtain

rated flow rate

adjust pump to obtain

rated flow rate

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a. Liquid cooled condensers,

b. Ducted air cooled condensers, and

For the chiller units with air cooled condenser, concurrent redundant instrumentation method as specified in Annexure B shall be used for units of below type:

14.1 Heat balance-substantiating test

14.1.1 Calculation of the heat balance.

Heat losses or gains through radiation, convection, bearing friction, oil cooler etc. in most cases is negligible and hence are not be considered in the overall heat balance. By omitting the effects of the negligible heat losses and gains mentioned above, the general heat balance equation shall be as follows:

qev + W input = qcd

Where: qev = Cooling capacity qcd = Heat rejection capacity Winput = Compressor work input as defined in 14.1.2 through 14.1.4.

14.1.2 In a hermetic package, where the compressor motor is cooled by refrigerant, chilled

liquid or condenser liquid, the motor cooling load will be included in the measured condenser load, hence

Winput = Electrical power input to the compressor motor, expressed in kW.

14.1.3 In packages using an open-type compressor with prime mover and external gear drive :

Winput = qprime mover - qgear

Where:

Winput = Power input to the compressor shaft, expressed in kW qprime mover = Power delivered by prime mover, expressed in kW qgear = Friction loss in gear box, expressed in kW

The value of qprime mover shall be determined from the power input to prime mover using certified data from the prime mover manufacturer.

The value of qgear shall be determined from certified gear losses provided by the gear manufacturer.

14.1.4 In a package using an open-type compressor with direct drive and the prime mover not

furnished by the manufacturer:

For determination of W input for turbine or engine operated machines, the turbine or engine manufacturer's certified power input/output data shall be used.

Winput = power input to the compressor shaft, expressed in kW

In the case of motor drive: Winput = power measured at motor terminals plus power to auxiliaries.

14.1.5 Percent heat balance. Heat balance, in percent, is defined as:

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100

hrccd

hrccdinputev

qq

qqWq

The heat balance (percent) shall be within the tolerance calculated per Clause 15. For the applicable conditions for any test of a liquid chilling package unit to be acceptable.

14.2 Verification test tolerance on heat balance.

The verification test tolerance shall be determined from the following equation.

)%

830()%07.0(34.10

FLDTFL

FL

Where:

% FL = Percent Full-load FL = Load factor DTFL = Difference between entering and leaving chilled liquid temperature at full-load in K.

15 Instrumentation 15.1 Uncertainties of measurement (Permissible variation in measurement)

The uncertainties of measurement shall not exceed the values specified in Table 3.

Table 3 – Uncertainties of measurement for indicated values

Measured quantity Unit Uncertainty of measurement

Water Temperature Temperature difference Volume flow Static pressure difference

°C K m³/s [cfm] Pa [psi]

0.1 °C [ 0.18 °F]

0.1 °C [ 0.18 °F]

1.0 % of reading

5 pa [0.0196 in]

(p < 100 Pa)[ p < 0.393 in]

5 Pa [0.0196 in]

(p > 100 Pa)[ p > 0.393 in]

Air Dry bulb Wet bulb Static pressure difference

°C °C Pa [in. of WC]

0.2 °C [ 0.36°F]

0.2 °C [ 0.36°F]

5 pa [0.0196 in]

Refrigerant Temperature Pressure

°C kPag [psig]

0.5 °C [0.9°F]

1 % of reading

Concentration Chilled liquid, other than water.

%

2 %

Electrical quantities Electric power Voltage Current Frequency

W V A Hz

1 % of reading

0.5 % of reading

1 % of reading

0.5 % of reading

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Compressor rotational speed (for open drive only)

s-1 0.5 % of reading

The cooling capacity shall be determined with a maximum uncertainty of 5% independent of the individual uncertainties of measurement including the uncertainties on the properties of fluids.

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16 Test procedure 16.1 General

If chilled liquid other than water is used, the specific heat capacity and density of such liquid shall be determined and taken into consideration in the evaluation. If supplied with the liquid chilling package the test shall include simultaneous determination of the heat reclaim condenser capacity by obtaining the data as defined in Table 4 for heat reclaim condensers.

The test shall not be started until all non-condensable have been removed from the system.

16.2 Steady state conditions

Steady state conditions is considered obtained and maintained when all the measured quantities remain constant without having to alter the set values, for a minimum duration of 15 minutes, with respect to the tolerances given in Table 4. Periodic fluctuations of measured quantities caused by the operation of regulation and control devices are permissible. However, the mean value of such fluctuations shall not exceed the permissible deviations listed in Table 4.

16.3 Output measurement of cooling capacity

For the output measurement it is necessary to record all the meaningful data continuously. In the case of recording instruments which operate on a cyclic basis, the sequence shall be adjusted such that a complete recording is effected at least once every 30 s. The output shall be measured in the steady state condition. The duration of measurement shall be not less than 35 min

Table 4 – Permissible deviations from set values

Quantity Permissible deviation of the arithmetic mean

values from set values

Permissible deviation of individual measured

values from set values

Liquid entering temperature leaving temperature volume flow static pressure difference

0.2 K

0.3 K

2 % -

0.5 K

0.6 K

5 %

10 % Air Dry bulb temperature Wet bulb temperature Static pressure

0.3 K

0.3 K -

1 K

1 K

10 % Refrigerant Saturated discharge temperature Liquid refrigerant temperature

0.5 K

1 K

1 °C

2 °C Voltage Single / Three phase Frequency

3 %

3 %

3 %

3 %

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16.4 Calculation of Test results

16.4.1. Cooling capacity and heat reclaim capacity

Cooling and heat reclaim capacities shall be determined from the average of the capacities calculated from the six sets of data collected as described in 13.3.

16.4.2. Power consumption

a) For test units with a frequency conversion device or motor starter furnished as part of the

compressor circuit, the compressor power input shall be measured at the input terminals of the frequency converter or motor starter. For liquid-chilling package units for testing not supplied with the starter or frequency converter furnished for it, then a starter or frequency converter of similar type shall be used for the test.

b) Power consumed by auxiliaries, during normal operation of the package shall be included in the total power consumption for test units which are supplied as part of the unit.

c) In case of open-type compressors, where the motor and/or gear set is not supplied by the manufacturer, or for engine or turbine drives, the compressor shaft input shall be determined as stated in Clause 11.3.5 or Clause 11.3.6.

d) In case of air-cooled condensers, the power consumption of condenser fan shall be included in the total power consumption of the package.

16.5 Data to be recorded

16.5.1 Measurement data

The data to be recorded for the capacity tests are as described in Table 5. The table provides the general information required but is not intended to limit the data to be obtained.

Table 5 – Data to be recorded

Measured quantity or result Unit Liquid

cooled condenser

Air cooled condenser

Ambient conditions - Air temperature, dry bulb - Atmospheric pressure

°C

kPa [in Hg]

X X

X X

Electrical quantities - Voltage - Total power input (per Clause 3.16) - Frequency

V W Hz

X X X

X X X

Chilled liquid - Inlet temperature - Outlet temperature - Volume flow - Pressure drop / ESP - Concentration (For fluids other than water)

°C °C

m³/s [lb/m] kPa [psi]

%

X X X X X

X X X X X

Condenser liquid - Inlet temperature - Outlet temperature - Volume flow - Pressure drop / ESP

°C °C

m³/s[lb/m] kPa [psi]

X X X X

NA

Air - Dry bulb inlet temperature - Wet bulb inlet temperature

°C °C

X X

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- Static pressure (ducted units) kPa [in WC] X

Refrigerant - Discharge pressure leaving compressor - Liquid refrigerant temperature entering expansion device

- Refrigerant charge (if adjusted)

kPag [psig]

°C kg

X

X

Heat balance % X

Cooling capacity kW X X

COP kW / kW X X

16.5.2 Supplementary data to be recorded for general information

Following additional information shall also be recorded and reported along with Test report.

a) Nameplate data which includes but not limited to make, model, size and type of refrigerant, sufficient to completely identify the liquid chiller.

b) For units with open-type compressors where motor and or gear set are not supplied by manufacturer, or for engine or turbine drives, record compressor driver or input rotational speed.

c) Wherever applicable:

i. Motor, engine or turbine nameplate data.

ii. Pressure, temperature and exhaust pressure from steam turbine nameplate data.

iii. Fuel gas specification for gas turbine drives, including pressure, kPa.

iv. For non-electrically driven units, additional data such as steam consumption, gas consumption, or fuel consumption, etc. sufficient to calculate input power.

d) Date, place and time of test.

e) Names of test Engineer (or) technician. And witnessing personnel, if the test being witnessed by a 3

rd party or customer.

17 Fouling factor considerations for testing

17.1 For all rated condition testing, Evaporator liquid-side and condenser liquid-side or air-side heat transfer

surfaces shall be considered clean during testing. Tests will be assumed to reflect fouling factors of 0.000

m2 K / kW.

17.2 To determine the capacity of the chiller package at the nominal fouling conditions, the procedure defined

in Annex A shall be used to determine an adjustment for the evaporator and or condenser liquid

temperatures.

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Annexure- A (normative)

Method for simulating fouling factor allowance

A.1 Purpose A.1.1 This Annex describes the method for adjusting the operating conditions of a test unit to

simulate the required rating liquid side fouling allowance.

It is assumed that all heat transfer surfaces have a fouling allowance of 0.0000 m2 K / kW

during the test. The procedure below defines a way to adjust the liquid cooled condenser liquid temperatures and the evaporator liquid temperatures to simulate a desired field fouling allowance.

The procedure below is only applicable to the waterside of evaporators and condensers and excludes air cooled condensers.

A.2 Fouling allowance procedure A.2.1 Obtain the log mean temperature difference (LMTD) for the evaporator and/or

condenser using the following equation at the specified field fouling allowance (ff).

S

R

RLMTD

1ln

(E1)

R = liquid temperature range = absolute value (twl - twe), K

S = small temperature difference

= absolute value (tscd - twl), °C, for condenser

= absolute value (tsev - twl), °C, for evaporator

A.2.2 Derivation of LMTD:

The Incremental LMTD (ILMTD) is determined using the following equation:

)(A

qffILMTD (E2)

Note that the A (area) is the surface area on the liquid side.

A.2.3 The liquid temperature difference TDa needed to simulate the additional fouling, TDa, can now be calculated: TDa = S - Sc (E3)

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1

ze

RSTDa

(E4)

Where:

ILMTDLMTD

RZ

(E5)

1

ze

RcS (E6)

Sc = small temperature difference as tested in clean condition

The liquid temperature difference, TDa, is then added to the condenser and heat reclaim condenser entering liquid temperature or subtracted from the evaporator leaving liquid temperature to simulate the additional fouling factor.

A.3 Example-condenser fouling:

Fouling factor allowance ff = 0.088 m2 K/kw

Condenser load, q = 850 kW Condenser leaving liquid temp, Twl = 35°C Condenser entering liquid temp, Twe = 28 °C Liquid surface area, A = 50 m

2

Saturated condensing temperature. tscd = 40 °C

S = tscd - twl = 40 - 35 = 5 ° C

R = twl - twe = 35 - 28 = 7 ° C

ILMTDLMTD

RZ

97.0

748.0966.7

7

1

za

e

RSTD

1

0.70.5

97.0

e = 0.7 K

The entering condenser liquid temperature for testing is then raised 0.7 °C to simulate the fouling factor allowance of 0.088 m

2 K/kW. The entering condenser liquid temperature will be

28 + 0.7 or 28.7°C.

A.4 The meaning of Symbols and subscripts. The symbols and subscripts used in equations E1 through E6 are as follows:

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Symbols:

A = Liquid heat transfer surface, m2, for evaporator or condenser or heat reclaim

condenser

e = Base of natural logarithm

q = Capacity in kW

R = Liquid temperature range

S = Small temperature difference

t = Temperature, °C

ff = Fouling factor allowance (m2 °C / kW)

tscd = Saturated vapor temperature entering the condenser for single component or azeotrope refrigerants and equal dew point for zeotropic refrigerants [at compressor discharge pressure].

tsev = saturated vapor temperature leaving the evaporator for single component or azeotrope refrigerants and average dew point for zeotropic refrigerants [at compressor average suction pressure].

Subscripts:

a = Additional fouling e = Entering (eg.: twe – Water entering temperature) ev = Evaporator c = Cleaned cd = Condenser f = Fouled or fouling l = Leaving (eg.: twl – Water leaving temperature) w = Liquid s = Saturation

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Annexure- B (Informative)

Concurrent redundant verification test for air cooled condenser units

B.1 The concurrent redundant verification may be used for air cooled condenser units for which a heat balance substantiating test cannot be realised.

B.2 Capacity calculation method. Calculate the capacity of the evaporator using one set of instrumentation. Also calculate the

capacity of the evaporator using the redundant set of instrumentation. For a valid test, these two calculated values must agree within the tolerance specified in Clause 8.

B.3 Power calculation method.

The power measured by the two sets of instruments must be within 2% at all loads.

B.4 Efficiency calculation method.

Efficiency shall be calculated using the measured (averaged) values and should comply with the tolerances of Clause 8.

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Annexure- C (Informative)

INDIA SEASONAL ENERGY EFFICIENCY RATIO (ISEER)*

C 1 Purpose

The purpose of this annex is to define a uniform procedure for the calculation of a single value number that is a representation of the part load efficiency of a chiller. The single value number will be called an India Seasonal Energy Efficiency Ratio or ISEER. It is somewhat like highway and city fuel efficiency for cars, which both are intended to be typical efficiency number, but will likely not exactly match actual efficiencies obtained under actual operating conditions.

C 2 Scope

This annex procedure is only for equipment covered by this standard. The ISEER equation and procedure are intended to be an average representation of a single chiller in a typical commercial application with conventional operating parameters. The procedure is intended to provide a consistent uniform method for calculating the single number for part load operation. A fixed set of operating load points and conditions are defined to allow for equal comparison of products. But allowances have been made for regional values to be defined to allow for correlation to regional ambient and building operational and construction standards. The intent is that this single value metric be used by efficiency standards and certification programs around the world that require more than a full load efficiency level. The equation has been derived to provide a representation of the average part load efficiency for a single chiller only. However, for operating cost and energy analysis it is best to use a comprehensive analysis tool that reflects the actual weather data, building load characteristics, operational hours, economizer capabilities and energy drawn by auxiliaries such as pumps and cooling towers when calculating the applied chiller system efficiency. This becomes increasingly important with multiple chiller systems because individual chillers operating within a multiple chiller systems can have significantly different load profiles than a single chiller.

C 3 Equation and Definition of Terms C 3.1 The single value part load rating shall be determined by using the following equation; ISEER = A x COP 100% + B x COP 75% + C x COP 50% + D x COP 25%

where:

COP100% = COP at full load rating point and operating conditions COP75% = COP at 75% load rating point and operating conditions COP50% = COP at 50% load rating point and operating conditions COP25% = COP at 25% load rating point and operating conditions A= weighting factor for 100% load B= weighting factor for 75% load C= weighting factor for 50% load D= weighting factor for 100% load

The values of A, B, C, and D are based on the weighted average of the most common building types across climatic zones of India. Values that have been developed are shown in Table C1.

*Note: ISEER is an equivalent term to IPLV and ESEER.

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Table C 1: Weighting coefficients A to D for calculation of ISEER

Load rate (%) 100 75 50 25

Weighting coefficients A= 6 B= 48 C= 36 D= 10

The ISEER rating requires that the unit efficiency be determined at 100%, 75%, 50% and 25% at the conditions specified in Table C2.

Table C2: India Seasonal Energy Efficiency Rating Conditions

Liquid Cooled Air Cooled

Evaporator Liquid temperature

Leaving 7 °C

Flow Flow rate equal to a 5 K Delta Temperature at 100% rating point

Evaporator fouling factor allowance

Liquid Side 0.044 m2 .K /Kw

Condenser fouling factor allowance

Liquid Side 0.088m

2 .K / kW

0.000 m

2 .K / kW

Condenser Flow Flow rate equal to a 5 K Delta

temperature at 100% rating point

Airflow equal to the full load rating

Condenser Entering Temperature

100% Load 75% Load 50% Load 25% Load

30.0 °C 26.0 °C 23.0 °C 20.0 °C

39.0 °C 32.0 °C 26.0 °C 20.0 °C

For units with proportional unloading performance should be obtained at the 25%, 50%, 75% and 100% points to calculate the ISEER.

If the unit has discrete steps of unloading, but due to its capacity control logic cannot be operated at 75%, 50% or 25% capacity, then the unit should be operated at other load points and the 75%, 50%, or 25% capacity efficiencies should be determined by interpolating between the two operating points that frame the rating point. The required condenser entering temperature at the requested load point should be used and a capacity test run at each unloading stage on either side of the desired part load rating point then should be interpolated to obtain the desired part load point rating. For example if the unit has capacity stages at 33% and 66% nominal displacement, then the 50% point can be determined by obtaining the capacity and efficiency at the 66% unloading stage at 50% entering temperature and another test, at the 33% unloading stage at the 50% entering temperature. Extrapolation of data shall not be used and the desired rating point must be framed by two actual operating points. An actual chiller capacity point, equal to or less than the required rating point must be used to plot the data. For example, if the minimum actual capacity is 33%, then the curve can be used to determine the 50% capacity point, but not the 25% capacity point.

If a unit cannot be unloaded to the 25%, 50%, or 75% capacity point, then the unit should be run at the minimum step of unloading at the condenser entering temperature based on Table C2 for 25%, 50% or 75% capacity points as required. The efficiency shall then be determined by using

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the following equation:

min

mind

CapacityCOP

C Power

Where: Capacitymin and Powermin are the values from the lowest stage of unloading running at the desired part load rating point. Cd is a degradation factor to account for cycling of the compressor for capacities less than the minimum step of capacity. Cd should be calculated using the following equation:

( 0.13 ) 1.13D

C LF

The factor LF should be calculated using the following equation:

%( )

100

LoadFull Load Unit Capacity

LFPart Load Unit Capacity

Where: %Load is the standard rating point i.e. 75%, 50% and 25%. Full load capacity is the capacity at the full load 100% rating point as defined in Table 1 The part load capacity of the unit is the capacity obtained when the machine is run at it’s lowest stage of capacity at the desired load point rating conditions. For water cooled units where a unit has been selected for operating conditions that will not allow operation at the full load condenser entering fluid conditions, then an ISEER cannot be calculated. For these applications an NISEER (Non-standard India Seasonal Energy Efficiency Ratio) can be determined, using the same procedures as defined above except that for the full load rating point the machine will be run at the maximum design entering condenser temperature. The 75%, 50% and 25% points will then be run at the temperatures defined in Table C2 unless the unit will not operate at these conditions and then the maximum option temperature shall be used. For example if a chiller was selected for 30°C full load condenser enter fluid temperature then the 100% point would be determined at a 30°C entering conditions. For ISEER rating the 75% would then be determined at a 26 °C entering temperature, the 50% at 23°C and the 25% point at 20°C

C 4 Sample Calculation

The following is an example of an ISEER calculation for an air cooled machine with 3 discrete stages of capacity with an ISEER determined for the Average profile.

Chiller Part Load Values Data Rating Step Capacity (kW) % Load Ent Air (°C) Input (kW) COP 100% 1(100%) 350.0 100% 39.0 92.3 3.79

100% 1 (100%) 392.0 112% 32.0 101.8 3.85

75% 2(66%) 245.0 70% 32.0 56.3 4.35

50% 2(66%) 256.0 73% 26.0 57.5 4.45

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50% 3(33%) 141.0 40% 26.0 30.7 4.59

25% 3(33%) 146.9 42% 20.0 33.3 4.41

Using the above data the part load COP value can be calculated.

Part Load Values Adjusted

Point Load % Capacity(kw) EER

COP100% 100% 350.0 3.79

COP75% 75% 262.5 4.29

COP50% 50% 175.0 4.54 The 75% load point is determined by interpolating between the 100% and 72.3% load point.

75%

(75 70)(3.85 4.35) 4.35 4.29

(112 70)COP

The 50% load point is determined by interpolating between the 73% and 42% load points.

50%

(50 40)(4.45 4.59) 4.59 4.54

(73 40)COP

Because the unit cannot unload to 25% capacity or less, the following additional calculations are required to determine the COP25%. Using the minimum capacity data point listed above, that was determined at the minimum step of capacity at the 20 °C ambient conditions the following calculations can be made.

(.25) (350)0.60

146.9LF

( 0.13 0.60) 1.13 1.05D

C

146.94.20

1.05 33.3COP

Using the A, B, C and D efficiencies the EBV can then be calculated as follows: ISEER (COP) = (0.06 X 3.79) + (0.48 X 4.29) + (0.36 X 4.54) + (0.10 X 4.20) = 4.34 C5 Approach adopted for ISEER coefficient calculations:

(I) Weather data is taken from bin weather file used for energy simulation of buildings available through ISHRAE.

(II) Following building types have been analysed through simulation for studying the chiller load variation:

a. Office Building – Large, 24 hour use b. Office building- Large, daytime use

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c. Office building – small, 24 hour use d. Office building – small, daytime use e. Retail shopping building, daytime use f. Hotel building, 24 hour use g. Hospital – 24 hour use

(III) Building envelopes, occupancy, LPD, EPD etc. are the taken from recently built modern buildings

(IV) Models of all seven types have been simulated for representative cities of various climatic zones: hot & dry, composite, warm & humid, and moderate.

(V) Grouping of data as per bin method for computation of ISEER coefficients is done on the basis of load on chiller.

(VI) Bin group is selected in such a way that average of peak bin group should be 75% load and similarly average of low bin group and min bin group should be 50% and 25% load respectively.

(VII) ISEER coefficients for 25%, 50%, 75% and 100% load are first computed separately for each building type in each representative city. Average of all the cases has led to the final set of ISEER coefficients.

A sample ISSER calculation for a large office building situated at Chennai having 24x7 operating hours is presented in table below:

Table – C 3

ISEER data and calculation for large office building Chennai (24*7)

% Load

Average %

Load

No of

HRS Ton hr min bin low bin peak bin

design

bin

100 to 87.5 93.75 237 222.2 0 0 0 222.2

87.5 to 81.25 84.37 353 297.8 0 0 297.8 0.0

81.25 to 75 78.125 511 399.2 0 0 399.2 0

75 to 68.25 71.87 642 461.4 0 0 461.4 0

68.25 to 62.5 65.625 718 471.2 0 0.00 471.2 0

62.5 to 56.25 59.375 1360 807.5 0 807.5 0 0

56.25 to 50 53.125 1404 745.9 0 745.9 0 0

50 to 43.75 46.875 1411 661.4 0 661.4 0 0

43.75 to 37.5 40.625 846 343.7 0 343.7 0 0

37.5 to 31.25 34.375 522 179.4 179.4 0 0 0

31.25 to 25 25.125 364 91.5 91.5 0 0 0

25 to 18.75 21.875 235 51.4 51.4 0 0 0

18.75 to 12.5 15.625 116 18.1 18.1 0 0 0

12.5 to 6.25 9.375 37 3.5 3.5 0 0 0

6.25 to 0 3.125 4 0.1 0.1 0 0 0

8760 4754.3 344.0 2558.5 1629.6 222.2

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weightage 7.2% 53.8% 34.3% 4.7%

D C B A

Annexure- D (informative)

SAMPLE CALCULATIONS

D 1 Purpose:

The purpose of this annex is to provide guidance for calculation of rating tolerance as described in Clause 8. To calculate permissible tolerances on capacity (kW) and COP

)%

830()%07.0(34.10

FLDTFL

FL

D 1.1 Full-load example in COP: Rated capacity = 35 kW Rated power input = 9.230 kW Cooling DTFL = 5 K [9°R] COP = 35 = 3.79 9.230 Tolerance = 10.34 – (0.07 x 100%) + 830 =10.34 – 7 + 1.66 = 5.0% 5 x 100%

Min. allowable capacity = kW250.33000.35x100

0.5100

6.3x3.79100

0.5100

D 1.2 Part-load example in COP

Minimum allowable COP =

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Assume a part load of 69.5% of the rated capacity.

Part load capacity = 24.325 kW

Part load power input = 5.960 kW DTFL = 5.0 K [9°F]

COP = 08.4960.5

325.24

Tolerance (SI units) = %5.695

830%)5.6907.0(34.10

= 10.34 - 4.87 + 2.39 = 7.86%

Tolerance (British units) = 695.09

150.0)695.007.0(105.0

Min. allowable COP = 3.764.08100

86.7100

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Annexure E (Informative)

Air Distribution Check procedure and check list

Following procedure shall be adopted for verification of the air and temperature distribution within the lab. This may be conducted at every test set up to verify the air and temperature distribution with in the specified limits.

Set up the air sampler device and the aspirating around the chiller condensing unit based on the unit configuration as shown in Figure 4. Keep the aspirating psychrometer’s air mixing fan on.

Ensure all the thermocouples mounted on the air sampler device measures same value and measures ambient. The measured values shall be within the allowable tolerance as per Table 4.

Start the chiller and conditioning equipment of the lab. Once the appropriate stable conditions have been achieved, record the temperature values as simultaneously as possible prior to start of data collection. Note the data in the table below.

Calculate the Mean Air Dry-Bulb temperature (MADBT)

Confirm that each of the aspirating psychrometer values are within ±1°C (for units ≤ 703.4 kW or ±1.7°C (for units ≥ 703.4 kW ) of MADBT

Confirm that each thermocouple values are within ±1°C of each Aspirating psychrometer.

Confirm each recirculating thermocouple values shall be with in ±2.7°C of the MADBT

Note the values in a sketch (Figure 7) as shown below. The data shall be noted as shown in the Figure 8.

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FIGURE 7

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FIGURE 8

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Annexure F (Normative)

BAROMETRIC PRESSURE ADJUSTMENT

F 1 Purpose.

The purpose of this appendix is to prescribe a method of adjusting measured test data according to the local

barometric pressure.

F 2 Background.

In order to ensure that performance can be uniformly compared from one unit to another and from one

manufacturer to another, performance testing for air-cooled chillers shall be corrected for air density variations.

To accomplish this, use the following two (2) correction factors (CFQ, CFɳ) to correct test data at 100% load

points back to standard barometric pressure at sea level. These correction factors use an empirical method of

correction based on industry average values across a wide variety of chillers. The correction factors are based on

pressure rather than altitude, in order to include the effects of weather variations. Test data shall be corrected to

Standard Air conditions for comparison to Published Ratings. The correction multiplier for efficiency and capacity

at the 0% load point will be 1.0. Intermediate correction multipliers at part-load points will be a linear interpolation

of values between the 0 and 100% load points where the % load value is based on the measured capacity

divided by the design capacity.

Note: These factors are not intended to serve as selection code correction factors. For selection codes it is best

to use component models that properly adjust for variation in barometric pressure as related to fan, heat

exchanger and compressor power and capacity.

The correction factors (CFQ, CFɳ) will be limited to a value corresponding to a barometric pressure of 12.23 psia

(approximately 5000 feet elevation). Correction factors for measured barometric readings below the minimum will

be equal to the value determined at 12.23 psia.

F 3 Procedure.

Air-cooled chillers are tested at the local conditions. The data is then corrected to sea level and standard

pressure by multiplying the measured data by the appropriate correction factor (CF). Both factors are in the form

of a second order polynomial equations, Table F2.

DQ = AQ · P2 + BQ · P + CQ

Dɳ. = Aɳ. · P

2 + Bɳ. · P + Cɳ.

CFQ = 1 + (DQ – 1) · e

[-0.35 · (Dɳ · ɳ test, FL

– 9.6)]

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CFɳ = 1 + (Dɳ – 1) · e

[-0.35 · (Dɳ · ɳ test, FL

– 9.6)]

Qcorrected = Qtest · CFQ ɳcorrected = ɳtest · CFɳ Where: Variables are defined in Tables F1 and F2.

Table F 1 Terms

Variable or Subscript

Description Unit of Measure

P Pressure, absolute Psia Q Capacity TonR ɳ Efficiency

1 EER

ɳ Efficiency measured in Full Load Test EER CFQ Capacity Correction Factor - CFɳ Efficiency Correction Factor - A, B, C Polynomial Constants - Test Actual measured Value during test at local conditions - Corrected Adjusted value equivalent to operation at sea level with standard pressure -

If efficiency is expressed in kW/tonR

then divide, Equation B6, by the correction factor CFη instead of

multiplying.

Table F2. Terms Correction Factor (CF) coefficients Variable or Subscript

Description Unit of Measure

Capacity DQ Capacity Dɳ Units of Measure for P

AQ BQ CQ Aɳ Bɳ Cɳ

IP (psia) 1.1273E-03

-4.1272E-02

1.36304E+00

2.4308E-03

-9.0075E-02

1.79872E+00

Note: E indicates scientific equation, example 1E-02 = 0.01

100% Load Point Example: A chiller has published ratings of 200.0 tons

R and 10.500 EER at sea level. The chiller is tested at an

elevation of about 3500 feet with overcast skies. The measured test results: Capacity Q

tested = 198.50 Tons

R

Efficiency η

tested = 10.350 EER

Air pressure P = 13.00 psia Correction factor D

Q

= 0.0011273∙13.00² –0.041272∙13.00 + 1.36304 = 1.0170

Correction factor Dη = 0.0024308∙13.00²–0.090075∙13.00 + 1.79872 = 1.0386 Correction factor CFq = 1+(1.0170 – 1) ∙exp[-0.35∙(1.0386∙10.350 – 9.6)] = 1.0114 Correction factor CFη = 1+(1.0386 – 1) ∙exp[-0.35∙(1.0386∙10.350 – 9.6)] = 1.0258 Corrected capacity Q

corrected

= 198.50∙1.0114= 200.76 tonsR

Corrected efficiency η

corrected = 10.350∙1.0258 = 10.62 EER

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Part load efficiency and capacity correction factors for the above example are determined using a linear interpolation method based on the 0 and 100% correction values: With a part load measured capacity of 160 tons

R

and a 200 tonR

rating point,

CFη = 1 + (160/200)∙(1.0258 – 1) = 1.0206

CFQ

= 1 + (160/200)∙(1.0114 – 1) = 1.0091