Use of A2L refrigerants increasing
The use of A2L refrigerants for supermarket applications seems to be increasing. A2L refrigerants are mildly flammable and exhibit low toxicity. They have lower flammability than hydrocarbons. However, it is still necessary to avoid components that may provide an ignition source. Extensive safety assessment (using standards such as BS EN378) is required to make sure the refrigeration system is safe.
The use of A2L refrigerants enables supermarkets to comply with F-Gas regulations that stipulate that for new products:
- From 2020: HFCs with a GWP above 2,500 are banned in stationary refrigeration equipment (except for systems that cool products to below -50°C).
- From 2022: any F gas with a GWP of above 150 is banned in central pack systems with a rated cooling capacity of 40 kW or more.
Therefore from 2022 unless a supermarket uses refrigeration packs of less than 40 kW the refrigerant must have a GWP of less than 150. This currently predisposes a natural refrigerant or an ultra-low GWP A2L refrigerant.
ASDA were the first supermarket to apply an A2L refrigerant in their Trafford Park store. HFO R454A was used which has a GWP of 238 (https://www.racplus.com/news/asda-claims-breakthrough-with-world-first-very-low-gwp-a2l-store-system/10044666.article?blocktitle=Most-popular&contentID=-1).
The Central England Co-op has also just installed R454C in a new convenience store at Langley Park, Derbyshire. R454C has a GWP of 148. The Co-op also plan to test the refrigerant in another trial store (https://www.racplus.com/news/central-england-co-op-installs-very-low-gwp-hfo-in-first-convenience-store-trial/10044981.article).
A recent report from Wave Refrigeration (https://www.coolingpost.com/features/are-hfo-hfc-blends-the-best-option-for-supermarkets/) also examined the use of A2L refrigerants. Wave modelled the impact of seven different refrigeration technology options:
- Water-cooled integrals
- Air-cooled integrals
- Propane/glycol secondary systems
- R134a/pumped CO2 secondary MT/sub-critical cascaded LT Systems
- Non-flammable R449A systems
- Transcritical CO2 booster systems
- Lower GWP A2L HFC/HFO blends R454C and R454A.
They examined the 10 year total emissions from these systems in the UK and Seville in Spain. In the analysis 2 store formats were examined; a standard supermarket of around 2000 m² sales area and a small supermarket with 300-500 m². Their conclusion was that the lowest 10 year CO2eq emissions were from R454C. The use of R454A generated slightly higher 10 year CO2eq emissions but this was still less than all the other systems analysed.
For further information on refrigerant choices please contact Alan Foster at RD&T (email@example.com).