Computerized Simulation of Automotive Air-Conditioning System: A Parametric Study

This paper presents results of a parametric study performed on an automotive air-conditioning (AAC) system of a passenger car. The goals are to assess the effects of varying the volumetric flow rate of supply air, number of occupants, vehicle speed, and the fractional ventilation air intake (XOA), on the dry-bulb temperature and specific humidity of the air inside the passenger’s cabin, and on the evaporator coil cooling load of the AAC system. Results of the parametric study show that increasing the supply air flow rate reduces the dry-bulb temperature of the cabin air, increases both the specific humidity of the air and the evaporator coil load. Increasing the number of occupants in the passenger cabin causes the cabin air temperature, specific humidity and the evaporator coil load to increase. Increasing the vehicle speed causes the specific humidity of the cabin air and the evaporator coil cooling load to increase but the dry-bulb temperature of the air is not significantly affected. Increasing the fractional fresh air intake (XOA) also increases the cabin air specific humidity and the evaporator coil cooling load.