R32, Heat pump, DSH control
Since low GWP matter rise up in the market, all heat pump manufacturers are searching for the refrigerants which are attractive for environment reasons. R290 is one of the player. It has a negligible GWP. But it is flammable and danger to apply in commercial and split type of Heat pump application. Thus, R290 has been designated for Monobloc heat pump only. R32 is an alternative refrigerant for cooling application. Flammability of R32 has 80% burning velocity less than R290 and slightly flammable when compare with R410A. Although, R32 discharge gas temperature is higher than R410A around 20Â°C and this can damage compressor's motor at some heat pump condition especially at high compression zone. However Discharge superheat control[DSH] concept could be implemented in the experiment to keep discharge gas temperature within limit of 130Â°C. From the results, R32 has better heating performance 4% for BTW and 8% in ATW application when compare with both R410A and R290. Consider to the refrigerant properties the changing of R410A to R32 can keep compressors stoke volume. Meanwhile 57% stoke volume increasing of R290 must be implemented to keep the same capacity level. Consequently R32 is the candidate refrigerant for heat pump application when DSH control has been applied.