Pande et al. (1996) tested three refrigerants, R32, R410A (R32/R125, 50/50 wt.%) and R410B (R32/R125, 45/55
wt.%), in a residential heat pump system and compared their performance with R22. It was found out that R32
yielded the best performance. R32 showed cooling seasonal performance 5% better than R22 and heating seasonal
performance 3% to 4% better than R22. R410A and R410B showed 2% to 3% better cooling seasonal performance,
and equivalent heating seasonable performance than those of R22. Yajima et al. (2000) investigated the performance
and total equipment warming impact (TEWI) of a 16 kW prototype with a variable speed compressor. Test results
showed that the COP of R32 was higher than that of R410A not only under the rated capacity condition, but also
under the capacity reduction condition by compressor speed control