Thermal comfort and energy saving in a vehicle compartment using a localized air-conditioning system

A localized air-conditioning system is expected to decrease energy consumption by avoiding extra cooling on the vacant seats. However, the energy saving of the localized air-conditioning system with satisfactory thermal comfort has seldom been quantified. In this study, both thermal comfort in the vehicle compartment and energy saving of the localized air-conditioning system with the front and ceiling vents were investigated. Thermal comfort in the vehicle compartment with the front and ceiling vents was analyzed using computational fluid dynamics with empirical correlations for thermal indices. In addition, the performance of the air-conditioning unit was measured at various air flow rates and air temperatures. The energy consumption of the localized air-conditioning system with the optimized front and ceiling vents decreased by 20.8% and 30.2%, respectively, against the baseline, while satisfying the neutral thermal comfort at the vent air temperature of 9 °C.