R32 vs HFOs as alternatives to R410A

During the IIR-co-sponsored 14thInternational Refrigeration and Air Conditioning Conference at Purdue, USA, in July 2012, H. Pham and R. Rajendran presented the results of an evaluation of R32, HFO1234yf, HFO1234ze and various HFO blends as alternatives to R410A in air-conditioning and heat pump systems.
During the IIR-co-sponsored 14thInternational Refrigeration and Air Conditioning Conference at Purdue, USA, in July 2012, H. Pham and R. Rajendran presented* the results of an evaluation of R32 (HFC, GWP = 675), HFO1234yf (GWP= 4), HFO1234ze (GWP= 6) and various HFO blends (GWP around 500) as alternatives to R410A in air-conditioning (AC) and heat pump (HP) systems.

Theoretically, R32 has 3-14% higher capacity than R410A in the AC evaporating operating range (7-13°C) and 7-16% higher capacity in the HP evaporating operating range (-23 -34°F). Correspondingly, R32 has theoretically -1% to +5% higher energy efficiency ratio (EER) in the AC cooling operating range and 0% to 7% higher EER in the heat pump heating operating range.
In practical drop-in tests in R410A systems, the actual relative compressor capacity was seen to have on average about 3-4% lower than theoretical and the actual relative compressor EER was on average about 2-3% lower than theoretical due to lower overall isentropic efficiency. However, these tests were conducted using an R410A optimized compressor and not a R32 optimized product.

According to this study, in terms of LCCP, despite their very low GWPs, HFOs are comparable to R32. However, HFOs are hampered by their relatively high costs, and no visible advantages over R32 were observed in these early drop-in system test results. The authors consider that R32 could serve as an initial candidate for new equipment to meet any potential HFC phase-down proposals, at least until 2020.

*R32 and HFOs as low-GWP refrigerants for air conditioning, H. Pham, R. Rajendran

This paper can be downloaded wia the IIR’s Fridoc database. You just have to login and search for the paper via the Fridoc database.