This article presents the investigation of the charge optimization of a split air conditioner designed for R22 but charged with R290 as an ecofriendly alternative. Initially, a baseline test was conducted with R22 as the refrigerant. R290 was then charged, and the refrigerant quantity, capillary tube, and condenser tube optimizations were done based on a simulation study while other parameters were unchanged. Experimental results show that with propane, the optimum charge quantity of 320g (35.5%) gives a refrigerating capacity of 4.93kW, while 4.85kW was observed as the refrigerating capacity in the baseline test with R22.