This study evaluates the performance of a residential air conditioner (A/C) using R32 as a retrofit for R410A. One of the biggest challenges in the retrofitting is to determine the ideal mass of refrigerant, which eventually lead to optimum performance of the system. The theoretical mass of refrigerant charging in this retrofitting analysis was determined using the density ratio of alternative (R32) to the existing (R410A) refrigerants. To achieve the optimum performance, the mass of

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... charging was varied between 90, 95, 100 and 105% from the theoretical mass of refrigerant charging. The experiments were carried out using a 2.5 kW split type A/C. The results show that the replacement of R410A with R32 decreases the COP at all refrigerants charging. The highest COP of A/C with R32 was achieved during mass of refrigerant charging of 95%. In this condition, the COP only decreased by 5.1%. The decrement in COP is caused by an increase in input power of the A/C. Consequently, it is not recommended replacing R410A with R32 in the A/Cs that originally is designed for R410A.