Research on evaporative cooling to improve the performance of automobile air conditioners

In this study, an evaporative cooling device (ED) was developed using the evaporative cooling pad (EP) made of cellulose-based materials with related accessories to actually install on a condenser of the automotive air conditioner (MAC) to improve the operating performance of HR-12 MAC. The ED was used to pre-cool the air entering the condenser by evaporative cooling instead of directly spraying water to cool the condenser. This approach can effectively reduce the risk of condenser corrosion and contamination. The HR-12 MAC performance was assessed at three different outdoor ambient temperatures (T_oa: 30 °C, 35 °C, and 40 °C) and EP thicknesses (3 cm, 5 cm, and 7 cm). The configuration of the optimum EP thickness was identified through the results of HR-12 MAC performance experiments. The operating performance of HR-12 MAC with ED improved with the increase in T_oa and EP thickness. However, according to most test results, ED could not effectively improve the performance of HR-12 MAC at the T_oa of 30 °C. Under optimal conditions, the coefficient of performance (COP) of the refrigeration system and the energy efficiency ratio (EER) of the air conditioning system of HR-12 MAC with ED were respectively 7.76% and 13.09% higher than the original HR-12 MAC at the T_oa of 40 °C, and the EP thickness of 7 cm.