Retrofit assessment of window air conditioner

This study investigates the feasibility of replacing R22 window air conditioners with hydrocarbon refrigerants (propane, R290) for various charged masses (25–70%), and analyzes the performance at different outside air temperatures (26, 29, 32 °C). Results indicate that the optimal charged mass for refilling a window air-conditioning unit with R290 refrigerant is approximately 50–55% of the R22 refrigerant at different outside air temperatures. In addition, a comparison of R22 and R290 refrigerants shows that the EER of the R290 refrigerant exhibits an upward trend as the outside air temperature increases, improving the EER by approximately 20% under ideal conditions. The refrigerant in most window air conditioners can be changed from R22 to R290, and the ODP and GWP of R290 are negligible comparable with those of R22 refrigerant. Replacing R22 window air conditioners with R290 can effectively enhance EER values and reduce carbon emissions.

► We investigate the feasibility of replacing R22 window air conditioners with R290.
► The optimal charged mass is approximately 50–55% of the R22 refrigerant.
► The EER of the R290 refrigerant can enhance about 20% under optimal conditions.