Ventilation Efficiency and Thermal Passenger Comfort of Novel Car Ventilation Concepts

Abstract

Three novel ventilation systems are compared regarding their static performance to mixing ventilation in a full-scale generic car cabin mock-up (GCC) under winter, spring/fall and summer conditions. Herewith, our study focuses on the air supply efficiency and the equivalent temperature as measures to quantify the achievable air quality and thermal passenger comfort, respectively. The novel ventilation systems comprise cabin displacement ventilation (CDV), ceiling based cabin displacement ventilation (CCDV) and a hybrid CDV/CCDV ventilation setting (HV). As test environment, the GCC was equipped with four thermal passenger dummies (TPDs), which provide the thermal impact of the real passengers and serve as a means to access the local equivalent temperature at the same time. Further, the mock-up was equipped with a jacket heating/cooling system to experimentally simulate different seasonal conditions. Regarding ventilation efficiency, the novel ventilation concepts perform comparable or better than MV. At breathing level, CDV shows the best performance with LVEs 50% larger as compared to MV. Concerning passenger thermal comfort, none of the systems was able to provide comfortable conditions in the winter scenario. However, during spring/fall and summer conditions CCDV and HV provide the best thermal comfort. While the cooling efficiency is largest with MV and CDV during summer conditions, the novel systems provide improved heating efficiency in the winter scenarios.