Retrofit of R-410A in Air to Water Heat Pumps: Test of Two Low GWP Candidates

This paper presents an experimental evaluation of two low GWP refrigerants candidates for the replacement of R-410A in an "air to water" heat pump. The baseline is evaluated following the ANSI/AHRI Standard 551/591. For both low GWP candidates (ARM-70 alpha and DR-5), tests are performed following the same standard for three refrigerant charges. Both heat capacity and coefficient of performance are compared for the baseline and the tests with the low GWP refrigerants. The results show that for the best refrigerant charge, both heat capacity and COP are improved by 5 to 10%. The best refrigerant charge is found for both replacement candidates.