Impact of Different Types of Glazing on Thermal Comfort of Vehicle Occupants

Due to intense peak summer temperatures and sunny summers in tropical countries like India etc., achieving the required thermal comfort of car occupants without compromising on fuel efficiency is becoming increasingly challenging. The major source of heat load on vehicle is Solar Load. Therefore, a study has been conducted to evaluate the heat load on vehicle cabin due to solar radiations and its impact on vehicle air-conditioning system performance with various combinations of door glasses and windscreen. The glasses used for this study are classified as green, dark green, dark gray, standard PVB (Polyvinyl Butyral) windscreen and PVB windscreen having infrared cut particles. For each glass, part level evaluation was done to find out the percentage transmittance of light of different wavelengths and heat flux through each glass. To verify the effectiveness of each glass, vehicle level air-conditioning system performance test was done in All Weather Chassis Dyno Facility for each retrofitted vehicle. To eliminate the effect of manufacturing variance while evaluating each retrofitted vehicle, only door glasses and windscreen were changed in the same vehicle keeping all other testing conditions such as ambient temperature, incident solar radiations, humidity and vehicle running pattern the same. The performance of each retrofitted vehicle was evaluated on the basis of its-soaking temperature, soaking time, grill temperature, and nose level temperature. On comparing the results of each configuration, the best door glass and windscreen configuration is proposed to improve the thermal comfort of the vehicle occupants.