An original R22 wall room air conditioner with a cooling capacity of 2.4 kW and energy
efficiency ratio (EER) of 3.2 is retrofitted with a compressor of a 20% larger displacement to
charge R290 and R1270 for performance experiments. The results show that for R1270, only
adopting a same kind mineral lubricant of higher viscosity would supply 2.4% higher
cooling capacity and 0.8% higher EER than those of the original R22 system under normal
condition, and for R290, adopting the larger displacement compressor simultaneously
would also obtain better performance. Alternative systems all have higher increase rate
and greater increment in both cooling capacity and EER than the original R22 system when
outdoor temperature decreases. The R1270 system has great increase in cooling capacity
and negligible decrease in EER. Refrigerant charge distribution is also investigated and it
indicates that the charge within both heat exchangers and compressor ought to be
reduced.0