19 March 2025
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Neil Roberts, Technical Sales Director at Climalife, explains the importance of ensuring longevity with the correct selection of refrigerant.
The F-Gas phasedown, in whichever nation’s form, is a significant driver for the adoption of very low Global Warming Potential (GWP) refrigerants across various refrigeration applications. This phasedown aims to reduce the environmental impact of refrigerants by encouraging the use of alternatives with lower GWPs.
Retrofitting existing systems designed for high or moderate GWP refrigerants to very low GWP alternatives is challenging and often impractical. Therefore, it is crucial for new equipment to use refrigerants with a low, or preferably very low GWP, to ensure longevity and compliance with future regulations.
System specifics
For hermetically sealed commercial refrigerators and freezers, the use of refrigerants with a GWP of 150 or higher has been banned since January 2022. This regulation significantly limits the options available for these applications. A common choice for this type of equipment are hydrocarbons such as isobutane (R-600a), propane (R-290) and propylene (R-1270), which are highly flammable and are assigned the A3 safety class. Safety standards, such as IEC 60335-2-89, limit the maximum charge of A3 class refrigerants to 500g. Despite this limitation, R-290 is often chosen for its excellent energy efficiency.
Although not currently applicable in Great Britain, the EU F-gas regulation has extended this restriction to include self-contained stationary refrigeration systems (except where safety exemptions exist) which may involve much larger refrigerant charge sizes and potentially make the use of A3 (e.g. R-290, R-1270) difficult within the current safety standards. A2L safety class alternatives to A3 refrigerants include R-454C and R-455A, both with GWP < 150, as well as R-1234yf and R-1234ze. Carbon dioxide (R-744) is a non-flammable option with a GWP <150, however in some applications the equipment cost can be prohibitive, and it is important to compare the complete system energy efficiency, in some systems this can be considerably lower than other <150 GWP options.
In single compressor or non-retail commercial remote condensing unit systems, the existing F-Gas regulation for Great Britain banned the use of virgin refrigerants with a GWP of 2500 or higher for new stationary equipment, with a charge of 40 tonnes carbon dioxide equivalents (TCO2e) or more, since 2020. This led to the adoption of alternatives such as R-448A and R-449A, both with GWP <2500 but >1300. The HFC TCO2e phase down has reduced by 50% since 2020 and will continue to significantly reduce over the next few years raising the question as to whether R-448A and R-449A should still be used for new installations. Viable alternatives to R-448A/R-449A include R-454A, R-454C and R-455A, all with GWP <300. R-744 is also an option, but as previously mentioned, a full assessment compared to other very low GWP options should be made to ensure the most eco-efficient choice is made.
Since January 2022, new multi-compressor retail or food service systems with a cooling capacity of 40kW or more must use refrigerants with a GWP <150. Although in general, centralised systems can show performance benefits over distributed systems, modular distributed direct expansion systems with low GWP A2L refrigerants have proven to be cost-efficient and have lower total CO2 emissions in a retail environment. Studies have shown that A2L systems, such as those using R-454A, R-454C and R-455A offer lower 10-year total tCO2e emissions and life cycle costs compared to some other low GWP technologies.
Refrigerants in action
Using very low GWP A2L refrigerants is nothing new. One of the first retail applications was installed by Central England Co-op in 2019 using the very low GWP A2L refrigerant R-454C at their Langley Park store in Derbyshire, UK. This installation achieved an 11% energy saving compared to a similar store operating with <2500 GWP A1 refrigerant. The analysis indicated that using R-454C led to lower capital expenditure, maintenance costs, and total emissions compared to an equivalent R-744 installation.
Also in 2019, Asda, a major UK supermarket chain that had already moved away from traditional centralised plant architecture in favour of a modular distributed system design, installed a low GWP A2L refrigeration system using R-454A at their Trafford Park Manchester store.
Since then, Central England Co-op and Asda have continued to install very low GWP A2L systems, demonstrating energy savings and lower emissions without significantly increasing system complexity or installation costs.
In industrial refrigeration, ammonia is widely used due to its high efficiency and low GWP. However, where ammonia is not feasible due to safety concerns, carbon dioxide (R-744) is often used as an alternative. Low GWP A2L refrigerants are also viable options for smaller industrial systems. For example, in 2017 Park Cake Bakeries installed a new refrigeration system using R-454A in a low-temperature warehouse at their site in Oldham, UK. The system, designed and installed by Dawson Rentals, demonstrated the feasibility and efficiency of using R-454A in industrial applications.
In 2022 a single circuit centralised refrigeration system was installed in a 15,000m³ chilled cold store using very low GWP R-454C. The system used 414kg of refrigerant and was estimated to cost 28-32% less than other low GWP technologies, have an energy efficiency ~20% higher and annual emissions ~17% lower than an equivalent R-744 system.
Compliance and safety
Compliance with EN 378 and the Pressure Equipment Safety Regulation (PE(S)R) is essential for the safe and legal use of all refrigerants. Based on the location and access categories of the installation, EN 378 can be used to determine suitable design and what additional protective measures can used, covering a wide range of application needs. The PE(S)R is a legal requirement, and non-compliance can lead to prosecution. System design can help avoid more rigorous requirements, such as minimising the size or eliminating liquid receivers.
Risk assessments need to incorporate the requirements of The Dangerous Substances and Explosive Atmospheres Regulation (DSEAR) and are necessary for all refrigerants. DSEAR is often thought to only apply to flammable refrigerants but this not true. Any refrigerant which has the hazard code H280 on the safety data sheet (which is virtually all refrigerants) must comply with DSEAR. Compliance with EN 378 and PE(S)R is a crucial part of this process. Compliance with EN 378 guidance will in many cases prevent the formation of flammable atmospheres, but if this is not possible, risk assessments using the principles within EN 60079 (Explosive Atmosphere Standards) must be performed. Guidance documents on the safe use of flammable refrigerants are available from organisations such as the Institute of Refrigeration and the Federation of Environmental Trade Associations (FETA) and help is always available from responsible refrigerant suppliers such as Climalife.
Final words
In conclusion, legislation is driving the refrigeration industry towards the adoption of very low-GWP refrigerants. To avoid obsolescence and ensure long-term viability, new systems should be designed for use with very low GWP refrigerants. A thorough assessment of compliance, costs, and total emissions is crucial when choosing a very low GWP refrigerant. Support and tools are available from responsible refrigerant suppliers such as Climalife, to help navigate the transition to very low GWP technologies, ensuring that the industry can meet regulatory requirements while minimising cost and environmental impact.
