AHRI research activities on low global warming potential alternative refrigerants.

This paper provides a summary of the Air-Conditioning, Heating, and Refrigeration Institute (AHRI) research activities on low global warming potential (GWP) refrigerants. First, an update on the Low-GWP Alternative Refrigerants Evaluation Program (Low-GWP AREP) is provided. This industry-wide cooperative research program identified and evaluated 38 promising alternative refrigerants’ performance over the past two years. The program, now in its second phase, is testing 15 new low-GWP refrigerant candidates. Since many of the new low-GWP refrigerants are flammable, the paper also provides an overview of regulatory barriers and potential configurations for residential heat pump systems using carbon dioxide, ammonia, and HFO-1234yf refrigerants. This paper also summarizes an AHRI research project that evaluated the material compatibility of HFO refrigerants, and HFO refrigerants blended with R-32 to better understand equipment long term reliability associated with the use of these low-GWP refrigerants.