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Packaged Chillers

1.1    Scope

Packaged chillers cover products that are specifically designed to cool liquids by means of a refrigeration system that is packaged within a single factory assembled unit. Optionally products also may be designed to heat liquids 

1.2    Definitions

Packaged chillers generate chilled water that can be used to provide space cooling in summer in large air-conditioned buildings; these are comfort chillers. They can also be used as process chillers to generate chilled water or other fluids for industrial process cooling. 

Reverse cycle packaged chillers are able to heat fluids and can be used to provide space heating in winter, or for industrial process heating. Simultaneous heating and cooling packaged chillers are able to provide space heating and cooling simultaneously to meet different space conditioning needs within a building. Some air cooled packaged chillers also incorporate free cooling mechanisms that can be used to reduce the amount of electricity needed by the product to provide cooling at lower ambient temperatures.

Under the Energy Technology List (ETL) scheme, comfort chillers are defined as products which are designed to deliver a chilled water flow temperature of greater than or equal to 2°C. High temperature process chillers are defined as products that are designed to meet a process cooling load with a chilled water flow temperature of between 2°C and 12°C, inclusive.

Packaged chillers are available in a wide range of different designs and efficiencies. The ETL Scheme aims to encourage the purchase of the higher efficiency products.

1.2.1    Sub-categories 

The ETL Scheme covers seven categories of products:

  1. Air-cooled comfort chillers that provide cooling only and have a cooling capacity that is less than or equal to 1,500kW. 
  2. Air-cooled, reverse cycle, comfort chillers that provide both heating and cooling and have a cooling capacity that is less than or equal to 1,500kW. 
  3. Water-cooled comfort chillers that provide cooling only and have a cooling capacity that is less than or equal to 2,000kW. 
  4. Water-cooled, reverse cycle, comfort chillers that provide both heating and cooling and have a cooling capacity that is less than or equal to 2,000kW.
  5. Air-cooled simultaneous heating and cooling comfort chillers that are able to provide both heating and cooling simultaneously and have a cooling capacity that is less than or equal to 1,500kW.
  6. Air-cooled high temperature process chillers that have a refrigeration capacity that is less than or equal to 1,500kW. 
  7. Water-cooled high temperature process chillers that have a refrigeration capacity that is less than or equal to 2,000kW. 

To be eligible for inclusion on the ETL, products shall meet the requirements as set out below.

1.3    Requirements 

1.3.1    Eligibility requirements

To be eligible, products shall:  

  • Incorporate the following items of equipment:

a)    One or more electrically powered compressors.
b)    One or more air-cooled or water-cooled condensers.
c)    One or more evaporators.
d)    A control system that ensures the safe, reliable and efficient operation of the product.

  • Have an appropriate Conformity Assessment mark.

Where the product incorporates an integral free-cooling mechanism, it shall be:

  • Fully integrated into the packaged chiller unit during product manufacturing.
  • Directly controlled by the product’s control system in a manner that maximises the use of free cooling for outside air, dry bulb temperatures between 2.0 and 15.0°C, where the inlet and outlet water temperatures may differ from the standard rating condition specified in Table 1.2 to enable free cooling to occur at these ambient conditions.
  • Able to provide a cooling capacity at an outside air, dry bulb temperature of 2.0°C and an outlet water temperature of 7.0°C that is at least (≥) 50% of the cooling capacity obtained at the standard rating condition specified in Table 1.2.

1.3.2    Performance requirements

Products shall have a Seasonal Space Cooling Energy Efficiency (ηS,C) or Seasonal Energy Performance Ratio (SEPR) that is greater than or equal to the values set out in Table 1.1, according to the rated cooling/refrigeration capacity of the product and the product category. Products that can be used for comfort cooling and process cooling applications can be listed under both categories, provided that the applicable performance requirements for both comfort and process chillers, as set out in Table 1.1, are met.

In addition, reverse cycle products shall have a Seasonal Space Heating Energy Efficiency (ηS,H) greater than or equal to the values set out in Table 1.1. Simultaneous heating and cooling products shall have a cooling Energy Efficiency Ratio (EER) and heating Coefficient of Performance (COP) greater than or equal to the values set out in Table 1.1.

Table 1.1    Performance thresholds for packaged chillers at standard rating conditions

Product category

Rated cooling capacity

(kW)

Performance thresholds

Cooling  ηS,C (%)

Heating ηS,H (%)

1.

Air-cooled comfort chillers that provide cooling only

without integral free cooling mechanism

< 400 kW

≥ 175.0%

 

≥ 400 kW and ≤ 1500 kW

≥ 190.0%

 

with integral free cooling mechanism

< 400 kW

≥ 168.0%

 

≥ 400 kW and ≤ 1500 kW

≥ 185.0%

 

2.

Air-cooled, reverse cycle, comfort chillers that provide heating and cooling

< 400 kW

≥ 168.0%

≥ 143.0%

≥ 400 kW and ≤ 1500 kW

≥ 185.0%

≥ 143.0%

3.

Water-cooled comfort chillers that provide cooling only

< 400 kW

≥ 230.0%

 

≥ 400 kW and < 1500 kW

≥ 310.0%

 

≥ 1500 kW and ≤ 2000 kW

≥ 320.0%

 

4.

Water-cooled, reverse cycle, comfort chillers that provide heating and cooling

< 400 kW

≥ 220.0%

≥ 212.0%

≥ 400 kW and < 1500 kW

≥ 270.0%

≥ 284.0%

≥ 1500 kW and ≤ 2000 kW

≥ 284.0%

≥ 290.0%

Product category

Rated cooling capacity

(kW)

Performance thresholds

Cooling EER

Heating COP

5.

Air-cooled, simultaneous heating and cooling comfort chillers that provide heating and cooling

up to 1500kW

≥ 3.30

≥ 3.70

Product category

Rated refrigeration capacity

(kW)

Cooling SEPR performance thresholds

6.

Air-cooled, high temperature process chillers

< 400 kW

≥ 6.50

≥ 400 kW and ≤ 1500 kW

≥ 7.00

7.

Water-cooled, high temperature process chillers

< 400 kW

≥ 8.00

≥ 400 kW and < 1500 kW

≥ 9.00

≥ 1500 kW and ≤ 2000 kW

≥ 9.10

Where:

  • The seasonal space cooling energy efficiency (ηS,C) is defined as the ratio between the reference annual cooling demand pertaining to the cooling season for a product and the annual energy consumption for cooling, corrected by contributions accounting for temperature control and the electricity consumption of ground water pumps, where applicable. 
  • The seasonal space heating energy efficiency (ηS,H) is defined as the ratio between the reference annual heating demand pertaining to the heating season for a product and the annual energy consumption for heating, corrected by contributions accounting for temperature control and the electricity consumption of ground water pumps, where applicable.
  • The seasonal energy performance ratio (SEPR) is the efficiency ratio of a high temperature process chiller at standard rating conditions, representative of the variations in load and ambient temperature throughout the year, and calculated as the ratio between the annual refrigeration demand and the annual electricity consumption.
  • The cooling energy efficiency ratio (EER) is the ratio of the net cooling capacity to the effective power input when the product is cooling at full load.
  • The heating coefficient of performance (COP) is the ratio of the net heating capacity to the effective power input when the product is heating at full load.

1.4    Measurement and Calculations

1.4.1    Measurement standards

The following standards, where applicable, shall be used to determine product performance:

  • BS EN 14511:2018 “Air conditioners, liquid chilling packages and heat pumps, with electrically driven compressors, for space heating and cooling”
  • BS EN 14825:2018 “Air conditioners, liquid chilling packages and heat pumps, with electrically driven compressors, for space heating and cooling – Testing and rating at part load conditions and calculation of seasonal performance”

Please note that performance data for comfort chillers obtained in accordance with the procedures and standard rating conditions laid down in BS EN 14511:2013 will be accepted as an alternative to testing in accordance with BS EN 14511:2018 until further notice. Performance data for comfort chillers obtained in accordance with the procedures and standard rating conditions laid down in BS EN 14825:2016 will also be accepted as an alternative to testing in accordance with BS EN 14825:2018.

1.4.2    Performance metrics

1.4.2.1    Calculation of ηS,C

The seasonal space cooling energy efficiency (ηS,C) shall be calculated using the equation below:

$$ \eta_{S,C}=\frac{1}{CC}\times SEER-\sum{F(i)} $$

Where:

  • The Seasonal Energy Efficiency Ratio (SEER) is defined as the overall energy efficiency ratio of the product, representative for the cooling season and shall be calculated in accordance with the methods described in BS EN 14825:2018.
  • The value of the Conversion coefficient (CC), which accounts for the estimated 40% average EU generation efficiency, shall be 2.5.
  • ΣF(i) is the sum of the space cooling correction factors, of which there are two:
    •  F(1), the temperature controls correction factor, shall be 3%
    • F(2), the brine and water pumps correction factor, which is only applicable for water-cooled cooling only and reverse-cycle comfort chillers, shall be 5%.

The seasonal space cooling energy efficiency shall be calculated based on the part load Energy Efficiency Ratios (EER) at the 24 outdoor temperature conditions of the reference cooling season, as defined in BS EN 14825:2018. Each part load EER shall be weighted by the number of hours in a year during which each outdoor temperature condition occurs, as defined by the reference cooling season.

The part-load EER values shall be measured at four of the 24 part-load conditions; A, B, C and D, which are defined in BS EN 14825:2018 – see Table 1.3. The remainder of the EER values shall be determined via interpolation of the EER values at part-load conditions A, B, C and D. For ambient temperatures above the part load A ambient temperature, the same EER value as for part load condition A shall be used. For ambient temperatures below the part load D ambient temperature, the EER value for part load condition D shall be used.

The methods for calculating the ηS,C and SEER are described in full in Clause 5 of BS EN 14825:2018, with a worked example in Annex G of the same test standard. 

1.4.2.2    Calculation of ηS,H

The seasonal space heating energy efficiency (ηS,H) shall be calculated using the equation below, in accordance with the methods described in BS EN 14825:2018.

$$ \eta_{S,H}=\frac{1}{CC}\times SCOP-\sum{F(i)}$$

Where:

  • The Seasonal Coefficient of Performance (SCOP) is defined as the overall energy efficiency ratio of the product, representative for the heating season.
  • The value of the Conversion coefficient (CC), which accounts for the estimated 40% average EU generation efficiency, shall be 2.5.
  • ΣF(i) is the sum of the space heating correction factors, of which there are two:
    • F(1), the temperature controls correction factor, shall be 3%
    • F(2), the brine and water pumps correction factor, which is only applicable for water-cooled reverse-cycle comfort chillers, shall be 5%.

The seasonal space heating energy efficiency shall be calculated for a low temperature application with a water supply temperature of 35°C. ηS,H shall be based on the part load Coefficient of Performance (COP) at the 46 outdoor temperature conditions of the reference heating season, as defined in BS EN 14825:2018. Each part load COP shall be weighted by the number of hours in a year during which each outdoor temperature condition occurs, as defined by the reference heating season.

The part-load COP values shall be measured at four of the 46 part-load conditions; A, B, C and D, which are defined in BS EN 14825:2018 – see Table 1.3. The remainder of the COP values shall be determined via interpolation/extrapolation of the COP values at part-load conditions A, B, C and D. For ambient temperatures above the part load D ambient temperature, the COP and capacity shall be extrapolated from the values for part load conditions C and D.

The methods for calculating the  ηS,H and SCOP are described in full in Clause 8 of BS EN 14825:2018, with a worked example in Annex H of the same test standard.

1.4.2.3    Calculation of SEPR

The SEPR shall be determined in accordance with the test conditions and calculation method described in Clause 10 of BS EN 14825:2018. 

1.4.2.4    Calculation of EER

The cooling Energy Efficiency Ratio (EER) at full load shall be calculated using the following equation:

$$ EER=\frac{net\ cooling\ capacity\ (kW)}{effective\ power\ input\ \left(kW\right)\ when\ cooling}
$$

1.4.2.5    Calculation of COP

The heating Coefficient of Performance (COP) at full load shall be calculated using the following equation:

$$ COP=\frac{net\ heating\ capacity\ (kW)}{effective\ power\ input\ \left(kW\right)\ when\ heating}
$$

1.4.3    Test Requirements

All products shall be tested to determine product performance under laboratory conditions in accordance with the procedures set out in BS EN 14511:2018.

The product’s cooling/refrigeration capacity (kW), EER (at full load) and COP shall be determined at the standard rating conditions set out in Table 1.2 below, which vary by product category.

Table 1.2    Standard rating conditions for Packaged Chillers

Product category

Cooling EER and Cooling/refrigeration capacity (kW)

Heating COP

1.

Air-cooled comfort chillers that provide cooling only

BS EN 14511-2:2018 Table 16, Standard rating conditions, Water (for intermediate temperature heating application and comfort chillers)

 

2.

Air-cooled, reverse cycle, comfort chillers that provide heating and cooling

BS EN 14511-2:2018 Table 16, Standard rating conditions, Water (for intermediate temperature heating application and comfort chillers)

BS EN 14511-2:2018 Table 12, Standard rating conditions, Outdoor air

3.

Water-cooled comfort chillers that provide cooling only

BS EN 14511-2:2018 Table 11, Standard rating conditions, Water-to-water (for intermediate temperature heating applications) from cooling tower and comfort chillers

 

4.

Water-cooled, reverse cycle, comfort chillers that provide heating and cooling

BS EN 14511-2:2018 Table 11, Standard rating conditions, Water-to-water (for intermediate temperature heating applications) from cooling tower and comfort chillers

BS EN 14511-2:2018 Table 7, Standard rating conditions, Water

5.

Air-cooled, high temperature, process chillers

BS EN 14511-2:2018 Table 25, Cooling capacity conditions for air-cooled, water-cooled process chillers

 

6.

Water-cooled, high temperature, process chillers

BS EN 14511-2:2018 Table 25, Cooling capacity conditions for air-cooled, water-cooled process chillers

 

The product’s cooling/refrigerating capacity (kW) and EER at part load; and heating capacity (kW) and COP at part load, shall be determined at the part load conditions shown in Table 1.3 below and in accordance with the procedures detailed in BS EN 14825:2018  for comfort and process chillers. 

For comfort chillers, where cooling capacity (kW) and EER test data is available at four part load conditions other than those stated in Table 1.3, these can be used to calculate the cooling capacity and EER at part load ratios A, B, C and D as below. In this scenario, test data in accordance with BS EN 14825:2013 will also be accepted as an alternative to testing in accordance with BS EN 14825:2018 until further notice.

Table 1.3    Part Load Conditions for Packaged Chillers

Product category

Cooling EER and cooling/refrigerating capacity (kW) at part load

Heating COP and heating capacity (kW) at part load

Air-cooled comfort chillers

BS EN 14825:2018 Table 4, Part load ratios A, B, C and D, fan coil application, fixed or variable outlet

BS EN 14825:2018 Table 8, Part load ratios A, B, C and D low temperature application, average reference heating season, fixed or variable outlet

Water-cooled comfort chillers

 BS EN 14825:2018 Table 5, Part load ratios A, B, C and D, cooling tower application, fan coil application, fixed or variable outlet

BS EN 14825:2018 Table 12, Part load ratios A, B, C and D low temperature application, average reference heating season, ground water, fixed or variable outlet

Air-cooled high temperature process chillers

BS EN 14825:2018 Table 16, Part load ratios A, B, C and D, high temperature application

 

Water-cooled high temperature process chillers

BS EN 14825:2018 Table 17, Part load ratios A, B, C and D, high temperature application

 

 

Test results may be submitted in summary form provided that: 

  • Sufficient data is included to confirm that the cooling/refrigerating capacity (kW), EER, COP and SEPR, as applicable for each product was determined in accordance with the test procedures in BS EN 14511: 2018 and determined at, or corrected to, the standard rating conditions outlined in Table 1.2 and the part load conditions outlined in Table 1.3. 
  • At least one detailed test report is submitted for each range of products and for each laboratory used.  The data to be recorded in a detailed test report for the test at standard rating conditions is defined in Table 6 of BS EN 14511-3: 2018.  The test report shall include details of the data recording period and duration of performance measurement.  
  • Detailed test reports have been prepared for each product tested and are available on request for inspection, where not submitted with the application. 

Where the same product can be used for comfort and process cooling applications, a single test report demonstrating that the ηS,C performance threshold for comfort chillers is achieved may be provided. For these products, evidence that the SEPR performance threshold for process chillers is achieved may be provided by calculation using a validated mathematical model.

1.4.4    Rounding

For the avoidance of doubt test data should be presented to one decimal place. As an example, a water-cooled, reverse cycle, comfort chiller with a cooling capacity of 100kW, and a seasonal space cooling energy efficiency of 219.9, or a seasonal space heating energy efficiency of 211.9, would be deemed to not meet the performance requirements.  

1.4.5    Uncertainties of measurement

All measurements used for the calculation of the SEER shall have a maximum level of uncertainty as stated in BS EN 14825:2018.

1.5    Verification for ETL Listing 

Any of the following testing routes may be used to demonstrate the conformity of products against the requirements:

  • In-house testing – Self-certified
  • In-house testing – Self-tested and verified or cross-checked by an independent body
  • Witnessed testing
  • Independent testing
  • Representative testing (see clause 1.5.1 below)

Further information regarding the first four routes can be found in Guidance Note 5 on the ETL product testing framework . 

1.5.1    Representative Testing  

Where applications are being made for a range of two or more products that are variants of the same basic design, test data may be submitted for a representative selection of models, provided that all variants:

  • Use the same refrigerant as the representative model.
  • Have the same compressor type (i.e. manufacturer, method of compression (e.g. reciprocating or scroll) and type of enclosure (e.g. hermetic or semi-hermetic)) as the representative model.
  • Fit within the same product category (e.g. are all water-cooled comfort chillers).

The representative models shall be selected by dividing the range of products into groups of models with similar design characteristics, and testing a model in each group. The performance of each model in the group shall be predicted using a validated mathematical model. As a minimum, at least one model shall be tested in each range of products.

For air-cooled comfort chillers that provide cooling only, test data for representative models that incorporate free cooling can only be used to represent variants of similar design that incorporate free cooling. Test data for representative models that do not incorporate free cooling can only be used to represent variants of similar design that do not incorporate free cooling.

It should be noted that:

  • If a manufacturer voluntarily removes the representative model from the ETL then other products linked with that representative model may or may not be permitted to remain on the ETL.
  • If any product submitted under these representative model rules is later found not to meet the performance criteria when independently tested, then all products based on the same representative model will be removed from the ETL.

1.6    Conformity Testing

Products listed on the ETL may be subject to the scheme’s conformity testing programme in order to ensure listed models continue to meet the ETL requirements. 

1.7    Review 

1.7.1    Indicative review date 

This specification will be reviewed during the 2021/22 ETL review cycle.

1.7.2    Illustrative future direction of the requirements

When the Tier 2 minimum energy performance standards of Commission Regulation (EU) 2016/2281 come into force for packaged chillers on 1 January 2021, the market average product performance will rise. Future requirements will therefore see a tightening of thresholds to reflect the top 25% of products with regards to energy efficiency.  

Also, as the use of new low Global Warming Potential (GWP) refrigerants becomes more widespread in the packaged chillers market, the requirements will be reviewed to assess their impact on product performance.