The Air-Conditioning, Heating, and Refrigeration Institute (AHRI) announced an industry-wide cooperative research program to evaluate alternative refrigerants that have low global warming potential (GWP). This paper presents testing results for the performance of an air conditioner and a heat pump using three low GWP refrigerants (R32, D2Y-60 and L-41A) and R410A. The results show R32 and L-41A are good replacement candidates for R-410A. The paper also presents thermophysical property differences the four refrigerants. The paper also presents the cycle modeling which was used to investigate soft-optimization for D2Y60.