Guidance

ETL769 Commercial refrigeration equipment

Updated 20 April 2020

Background

Refrigeration is the process of mechanically cooling or reducing the temperature of a space, a product or a process.

There are 2 primary applications of commercial refrigeration equipment:

• cooling, freezing and temperature maintenance during storage of food and drink products
• air conditioning systems

There are 6 sub-technologies within the commercial refrigeration technology category of the Energy Technology List (ETL):

• cellar cooling equipment
• professional refrigerated storage cabinets
• refrigerated display cabinets
• curtains, blinds, doors and covers for refrigerated display cabinets
• refrigeration compressors
• refrigeration system controls

Examples of typical cost and energy savings for each technology can be found in the technology information leaflet.

Cellar cooling systems

Cellar cooling systems maintain an indoor (cellar) environment at 10-12°C – suitable for the storage of chilled beverages and are used in pubs, restaurants and hotels.

There are 2 types of cellar cooling system eligible for the ETL:

• split systems with the evaporator in the cellar and the condensing unit external (usually outside) are the most common type
• dual split systems, comprising two evaporators and one condensing unit

Free cooling units are also eligible for the ETL. They provide “free cooling” by using a fan to draw in outdoor air when the ambient temperature is sufficiently low.

Professional refrigerated storage cabinets

Professional refrigerated storage cabinets (PRSCs) are appliances which have one or two solid doors and are typically used for the storage of food and beverages in commercial kitchens. They hold chilled food at between -1°C and 5°C and frozen food at between -18°C and -15°C.

Cabinets with single and double doors, larder and chest type, counter and under counter models for the storage of chilled and frozen food are listed on the ETL. PRSCs are fitted with solid faced lids, doors or drawers and are not used for displaying food (see instead refrigerated display cabinets section).

Refrigerated display cabinets

Refrigerated display cabinets are used by food retailers to exhibit food and beverages. The cabinet involves 1 or more evaporator/expansion device which uses a liquid refrigerant supplied by an integral condensing unit or a remote system.

All the common types of cabinet are listed on the ETL, including multi decks, chest freezers, upright freezers with glass doors and serve-over cabinets. They cover a wide range of storage temperatures from frozen food at -18°C, to chilled food at 5°C and at 10°C.

Curtains, blinds, doors and covers for refrigerated display cases

Many refrigerated display cases are open-fronted, which significantly increases the heat load on the refrigeration system. There are various components available that can be added to reduce the heat load. These include:

• strip curtains – overlapping, transparent plastic strips that fit permanent to the open front of display cases
• doors – sliding or hinged transparent doors that fit permanently to the open front of display cases
• covers (bubble lids) – rigid plastic covers that fit permanently to the top of open freezers
• blinds – roller-type blinds fitted to the front of cabinets and may incorporate a motorised control system
• enhanced air flow management devices – these guide cold air more efficiently down the front of the open fridge cabinet

To be effective in reducing the heat load, and therefore improving energy efficiency, care should be taken to ensure they are fitted correctly.

Refrigeration compressors

The compressor is part of a refrigeration system and works by compressing the refrigerant gas from a lower pressure to a higher pressure. The gas subsequently condenses, thus rejecting heat to ambient air or water in the condenser. The ETL covers the following types of refrigeration compressors:

• high temperature with HFC or HC refrigerant
• medium temperature with HFC or HC refrigerant
• low temperature with HFC or HC refrigerant
• medium temperature transcritical/subcritical with R744 refrigerant
• low temperature transcritical/subcritical with R744 refrigerant
• low temperature subcritical cascade with R744 refrigerant

Refrigeration system controls Refrigeration system controllers vary enormously in function and complexity. The simplest control is a thermostat which simply controls the temperature of the cooled space. More complex refrigeration systems, such as those with multiple compressors, ideally require more sophisticated control. When used in the right way, these controls can significantly reduce the amount of energy a refrigeration system uses.

The ETL currently includes:

• system management units that are designed to optimise an entire refrigeration system, including the operation of a refrigeration compressor(s), evaporator(s) and condenser(s)
• ‘add-on’ controllers that are designed to be used in conjunction with a specific system management unit, and enable the operation of additional refrigeration compressors, evaporators and condensers to be optimised