International. Recently, the results of an evaluation of R32 (HFC, GWP = 675), HFO1234yf (GWP = 4), HFO1234ze (GWP = 6) and various HFO mixtures (with around 500 GWP) were analyzed as an alternative to R410A in air conditioning (AA) and heat pump systems (BC).
Theoretically, R32 has 3-14% higher capacity than R410A in the evaporation operation range of AA (7-13°C) and 7-16% higher capacity in the evaporation operating range in BC (-23-34°F).
Likewise, R32 theoretically has a -1% to +5% higher energy efficiency radius (EER) in the cooling operating range of AA and 0% to 7% higher EER in the operating range of a heating BC.
In tests performed on R410A systems, the actual relative capacity of the compressor is considered to have on average around 3-4% lower than the theoretical and the current relative compressor EER is around 2-3% lower than the theoretical one, due to lower isotropic efficiency overall. However, these tests were performed using an optimized R410A compressor and not an optimized R32 product.
According to this study, despite their very low GWP, HFOs are comparable to R32. However, HFO is hampered by its relatively high costs, and no visible advantages beyond R32 were observed in these results. The authors believe that R32 could serve as an initial candidate for new equipment and thus satisfy any proposal for a gradual decrease in HFC power, at least until 2020.
