Energy and exergy analysis of an R410A small vapor compression system retrofitted with R290

Abstract This study analyzes the energy and exergy of a small vapor compression system by retrofitting R410A working fluid with R290. The study was conducted on a split air conditioner by maintaining the air temperature through the condenser at 308 K and the air temperature through the evaporator at 300 K. The full charge amount of R410A was 340 g and the produced refrigerating capacity, power compressor, and coefficient of performance (COP) were 1899 W, 333 W, and 4.6, respectively. Subsequently, by varying the retrofit charging amount of R290, the optimum charging amount was obtained in the range of 45–55% from the full charge amount of R410A according to the COP and exergy efficiency; it exhibited the highest COP of 4.9. However, the refrigerating capacity and power consumption of the compressor decreased by 31.3 and 35.7%, respectively, compared with the system's condition of full charge amount R410A. Finally, the total exergy destruction and highest exergy efficiency were sequentially determined, where R410A exhibited 549.2 W and 0.26, and R290 exhibited 338 W and 0.21, respectively.