The Effect of Retrofitted Refrigerant and Environmental Temperature on the Performance of Air Conditioner: An Experimental Study

Abstract

There are several factors that influence the efforts to increase the performance of an air conditioner (AC), one of which is the selection of working fluid, environmental condition, and device components. Refrigerant is the most vital substance which determines the efficiency of the cooling machine. In addition, ambient air temperature and humidity are other important factors that affect the performance of the cooling machine. Therefore, it is extremely crucial to calculate the environmental condition, which is the air temperature, so that the cooling machine can work optimally. Currently, the refrigeration system uses R-22 refrigerant. However, the use of R-22 has a high ODP (ozone depletion potential) value, thus having a risk of damaging the ozone layer. As a safer alternative, the use of hydrocarbon refrigerants, such as R134a and R290, can solve this problem as they do not have any ODP. This study was conducted by retrofitting the synthetic refrigerant in Air Conditioner (AC) 1 HP with various types of hydrocarbon refrigerant. The outside air temperatures used were 30°C, 50°C, 60°C, and 70°C, while the airflow velocity across the condenser also varied, namely 4.8 m/s, 5.8 m. /s, 6 m/s, and 6.6 m/s. From the results of this study, it is known that retrofitting synthetic refrigerants into hydrocarbon refrigerants can increase the coefficient of performance (COP) of the air conditioner. The uses of R134a and R290 hydrocarbon refrigerants increase the COP by 19% and 24.5%, respectively. In addition, lower ambient temperature will reduce the required electrical power. R290 Refrigerant has the best COP value compared to R22 and R134a.