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Department for Energy Security and Net Zero

Retrofit Measures for Open Fronted Refrigerated Display Cabinets

1.1    Scope

Retrofit measures for open fronted refrigerated display cabinets are products which create either a physical or an invisible barrier that reduces the infiltration of ambient air (and heat flow) into refrigerated display cabinets, thereby reducing the energy consumption of the cabinet. 

1.2    Definitions

Retrofit measures for open fronted refrigerated display cabinets are products that are specifically designed to reduce the infiltration of ambient air into a refrigerated display cabinet.  

The Energy Technology List (ETL) scheme covers five categories of product: 

  1. Strip curtains that consist of transparent, flexible strips hung adjacent to each other, and fastened at both ends to neighbouring strips, in a manner that allows temporary openings to be made in the curtain for the purpose of removing items from the cabinet. 

  2. Blinds that consist of a flexible fabric mounted on a roller mechanism that enables the blind to be deployed across the display window of the cabinet when the retail outlet is closed or during trading. The blind may also incorporate a motorised control system. 

  3. Transparent sliding doors that consist of doors with a heat reflective coating, mounted in a mechanism (that is designed to be installed in the window of the cabinet) that enables the doors to be opened when items need to be removed from the cabinet. 

  4. Transparent hinged doors that consist of doors with a heat reflective coating, mounted in a mechanism (that is designed to be installed in the window of the cabinet) that enables the doors to be opened when items need to be removed from the cabinet. 

  5. Enhanced air flow management systems designed to optimise the descending air curtain at the front of an open refrigerated display cabinet in order to reduce the infiltration of ambient air. This solution may include, but it is not limited to, modifications or attachments to the shelves of the cabinet. 

These criteria relate only to measures/products which are installed to existing cabinets that are already operational. Eligible products are referred to as retrofit measures or retrofit products. Refrigerated display cabinets with these measures/products installed at the point of manufacturer and then shipped are in scope of the ETL criteria for Refrigerated Display Cabinets[1].

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 in categories 1, 2, 3 and 4 shall: 

  • Be of fixed design and dimensions with a unique product code.
  • Provide a flexible or rigid barrier that can be used to reduce the infiltration of ambient air (and heat flow) through the open display window of a refrigerated display cabinet.
  • Be designed to fit one or more specific types or models of refrigerated display cabinet in a manner that ensures that when fitted there is no air gap around the edges of the product’s rigid barriers, and an air gap of less than 20mm around the edges of the product’s flexible barriers.

Products in category 5 shall:

  • Be designed to guide and stabilise the air flow(s) more closely down the entire front of a refrigerated display cabinet in order to reduce the infiltration of ambient air.

1.3.2    Performance requirements

1.3.2.1     Product temperatures


Eligible products shall:

  • Maintain the product temperature classification of the refrigerated display cabinet the measures are installed on. For example, classification M0, M1 or M2 when tested to BS EN ISO 23953-2 in climate class III (25°C, 60% RH). See Table 1.1 below.  

Table 1.1 Temperature Classifications for Refrigerated Display Cabinets

Class Highest temperature θah of the warmest M-package colder than or equal to (°C) Lowest temperature θb of the coldest M-package warmer than or equal to (°C) Lowest temperature θal of the warmest M-package colder than or equal to (°C)
M0 +4 -1 -
M1 +5 -1 -
M2 +7 -1 -

 

1.3.2.2     Integrated lighting equipment


Eligible products that contain integrated lighting shall have a minimum luminaire efficacy of (≥) 95 Lm/W.

1.3.3    Information requirements 

Suppliers shall report the following parameters for each model, which will be published on the ETL Product Search:

  • The energy saving [%] achieved against the ETL Method for Testing Retrofit Measures for Open Fronted Refrigerated Display Cabinets.

1.4    Measurement and Calculations 

The product’s energy saving [%] shall be determined in accordance with the method and test conditions set out in:

  • ETL Method for Testing Retrofit Measures for Open Fronted Refrigerated Display Cabinets.

1.5    Verification for ETL Listing 

Manufacturers shall provide sales and technical brochures to evidence the conformity of their products against the requirements from section 1.3.1. 

Any of the following testing routes may be used to demonstrate the conformity of products against the requirements from section 1.3.2 and 1.3.3 

  • 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 three routes can be found in the ETL Testing Framework.

1.5.1    Representative testing

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

  • Are in the same product category
  • Have the same constructional design that do not affect materially the product functionality or energy performance, for example: 

          - for night blinds – to consider materials specification, components and subassemblies, type of fitting, etc.
          - for doors – to consider the transparent material - perspex or glass, single or double glazing 
          - for shelf edge technology – to consider the proximity of the front of shelf to the air-discharge of the cabinet[2]

Any product modifications and enhancements should be clearly identified, and differences of any kind should be explained. 

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 is scheduled to be reviewed during the 2024/25 review cycle.

1.7.2  Illustrative future direction of the requirements

The next technical review will consider the eligibility requirements and the availability of the currently recognised retrofit measures for open fronted refrigerated display cabinets as well as the inclusion of any new verified retrofit technology.

It will also look at the potential inclusion of a performance threshold following the collection of relevant energy performance data which is expected to become available thanks to the new ETL method for testing retrofit measures for open fronted refrigerated display cabinets.

Furthermore, the ETL method for testing retrofit measures for open fronted refrigerated display cabinets will be reviewed once again with regards to the door opening frequency of closed cabinets in light of the availability of more robust data from UK trading stores. A consultation on the topic in July 2022 with a significant response rate concluded that the door opening data is still inconclusive and inconsistent to render deviation from the 10 openings per hour that are prescribed in the BS EN ISO 23953-2 standard.

The next technical review will also assess any impact the new ETL testing standard has had on the industry stakeholders and their participation levels in the ETL.

The technical review should also consider feedback from the users of the ETL Product Search Pages and whether the newly added performance and information requirements helped them to better inform their decisions when choosing retrofit measures for open fronted refrigerated display cabinets.


[1] https://etl.energysecurity.gov.uk/products/refrigeration-equipment/refrigerated-display-cabinets

[2] Suppliers will be required to report the model and the details of the cabinet on which the testing was conducted as per the ETL Method for Testing Retrofit Measures for open fronted refrigerated display cabinets.