Low and ultra-low GWP refrigerants to replace R-404A and R-134a in commercial and industrial refrigeration.

Each year, the world uses more than 90 million tonnes of refrigerant to keep food fresh in 240,000 supermarkets and to cool more than 300,000 buildings. New regulations that control emissions from fluorinated gases (F-gases) to combat climate change are putting HFCs under pressure for phasedown globally. Market dynamics will drive the move towards low and ultra-low GWP alternatives. R-134a and R-404A are the main HFCs used in commercial and stationary refrigeration, after the phase-out of R22. Objective of this work is to analyse performance of potential alternative refrigerants with reduced GWP that are commercialized or in development to be used as retrofit, or for new build. HFOs (hydro-fluoro-olefins) present a global warming potential (GWP) of up to 99 % lower than currently used alternatives and offer excellent performance, efficiency, serviceability and safety and deliver a greener way to reduce carbon footprint. New blends based on HFOs cover stationary refrigeration, transport refrigeration and a/c. For low temperatures, R-448A is a nonflammable (A1) direct replacement for R-404A in industrial/commercial refrigeration with increased operating envelope compared to other alternatives. It allows for lower discharge temperature when operating at low temperature conditions, that helps to reduce cost of application and minimise energy consumed. R-455A is a developmental A2L refrigerant planned to be used by components manufacturers and OEMs in condensing units where R-404A is currently used. It matches the capacity and has the same or better efficiency relative to R-404A, with GWP<150. For medium temperatures, R-1234ze (GWP<1)[0] is a mildly flammable (A2L), group PED 2 alternative refrigerant to 134a for new systems with proven records in chillers, heat pumps, district cooling&heating, CO2 cascade systems. R-450A is a non-flammable, high efficiency alternative with proven records as primary stage of CO2 cascades and DX refrigeration. Non-flammable refrigerant R-1233zd (GWP=1)[0], with higher capacity and efficiency similar to R-123, is a good replacement in centrifugal chillers and other low-pressure uses.