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Department for Business, Energy and Industrial Strategy

Cellar Cooling Equipment

1.1           Scope

Cellar cooling equipment covers refrigeration products that are specifically designed to maintain, by means of a refrigeration system, an indoor environment at a condition suitable for the storage of chilled beverages below 12°C, and free cooling units that ensure free cooling is utilised when the outside ambient temperature is sufficiently low.

1.2           Definitions

Cellar cooling refrigeration equipment is permanently installed and uses the standard refrigeration cycle of evaporation, compression and condensation to cool a cellar or other storage space.

Cellar cooling refrigeration equipment is available in a range of different designs and efficiencies. The Energy Technology List (ETL) Scheme aims to encourage the purchase of higher efficiency products. It also encourages the purchase of free cooling units that utilise free cooling in order to reduce the energy consumption of the cellar cooling refrigeration equipment when weather conditions are suitable.

1.2.1       Sub-categories

The ETL Scheme covers three categories of cellar cooling equipment:

  • Single split systems with the equipment supplied in two parts (evaporator and condensing unit) to be connected on installation.
  • Dual split systems with the equipment supplied in three parts (two evaporators and one condensing unit) to be connected on installation.
  • Free cooling units for cellar cooling.

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, cellar cooling refrigeration equipment products shall:

  • Have a cooling capacity of between 2 kW and 12 kW at the standard rating conditions for ambient air temperature of 32°C and a cellar air temperature of 10°C.
  • Consist of two or three factory-built sub-assemblies that are designed to be connected during installation.
  • Conform with the requirements of The Pressure Equipment (Safety) Regulations 2016

To be eligible, free cooling unit products shall:

  • Utilise a fan to draw in ambient air from outdoors to provide free cooling when the ambient temperature is sufficiently below the required indoor temperature.
  • Incorporate a fan which meets the minimum energy efficiency requirements for fans driven by motors with an electric input power between 125 W and 10 kW as given in eco-design regulation (EU) No 327/2011.
  • Include a damper which is designed to close when the free cooling unit is not in operation in order to prevent air leakage from outdoors into the cooled space.
  • Incorporate an automatic control system which controls both the free cooling unit and cellar cooling equipment as follows:
    • The free cooling unit is in operating mode when the outside ambient temperature is below a set temperature.
    • Air is circulated within the cooled space by using one or two fans of the cellar cooling unit evaporator when the free cooling unit is in operating mode, the remaining one or more evaporator fans being switched off.
    • The free cooling unit fan starts and draws ambient air into the cooled space when the temperature rises to a given setpoint and the outside ambient temperature is below the set temperature.
    • When the temperature of the cooled space reduces to the setpoint temperature minus the set temperature differential, the free cooling unit fan switches off.
    • If the outside temperature rises above the set temperature, the free air cooling system goes into standby mode and the cellar cooling equipment resumes normal operation.
  • Have an appropriate Conformity Assessment mark.

1.3.2       Performance requirements

Cellar cooling refrigeration products (currently listed on the ETL[1]) shall have a Coefficient of Performance (COP) equal to or greater than the figures shown in Table 44.1 below.

For new applicants, a Seasonal Energy Performance Ratio (SEPR) shall be declared using the ETL calculation tool derived from BS EN 14825:2018.

Table 1.1    Coefficient of Performance thresholds for cellar cooling equipment

Product category


Single split systems

≥ 3.30

Dual split systems

≥ 3.30

“≥” means “greater than or equal to”

The refrigerant used in the testing and resulting declaration of the equipment’s COP/SEPR shall be stated on application.

1.4           Measurement and Calculations

1.4.1       Measurement standards

Either of the following standards shall be used to determine product performance:

For ETL listed products (through August 2020): BSI Publicly Available Specification PAS 57:2003 “Cellar cooling equipment – Procedure for determining performance and calculating energy efficiency”

After August 2020: 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.

  • To be used in conjunction with the ETL Cellar Cooling Equipment SEPR calculation tool (see below). 

1.4.2       Performance metrics

The Coefficient of Performance (COP) at full load shall be calculated using the following equation, in accordance with BSI PAS 57:2003.

$$COP=\frac{(system\ cooling\ capacity\ (kW))}{(system\ energy\ consumption\ (kW))}$$

The Seasonal Energy Performance Ratio (SEPR), shall be calculated using the ETL Cellar Cooling Equipment SEPR Calculation Tool in conjunction with BS EN 14825:2018, which is based upon four rating point measurements of COP (32, 25, 15 and 5oC ambient temperatures).  

1.4.3       Test Requirements

Testing (after August 2020) shall use the calorimeter test method defined in Annex A of BS EN 14511‑3:2018.

1.4.4       Rounding 

For the avoidance of doubt test data should be presented to 2 decimal places. As an example, a COP of 3.29 would be deemed to not meet the performance requirements.

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-tested and verified or cross-checked by an independent body
  • Witnessed testing
  • Independent testing
  • Representative testing (see clause 44.5.1 below)

Further information regarding the first four routes can be found in Guidance Note 5 on the ETL product testing framework[2].

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.
  • Have the same sub cooling arrangement as the representative model.
  • Have the same number of evaporators.
  • Fit within the same product category (e.g. are all split systems).

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 the lowest quartile of predicted performance in each group. The performance of each model in the group shall be predicted using a validated mathematical model. As a minimum, at least two models shall be tested in each range of products and in each laboratory used for product testing.

It should be noted that:

  • If a manufacturer voluntarily removes the representative model from the Energy Technology List (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 2022/23 ETL review cycle.

1.7.2       Illustrative future direction of the requirements 

Future changes to the Specification may include:

  • Transition to SEPR as the basis for performance thresholds, using BS EN 14825:2018.
  • Removal of BSI PAS 57:2003 as a measurement standard, testing requirement, and associated COP thresholds.
  • Define an SEPR performance threshold and reassess all listed products against this requirement, ensuring only models with an SEPR are listed on the ETL from April 2023.


[1] August 2020