Experimental evaluation of the cooling and heating dynamics for a vertical ventilation concept in a generic car cabin

Abstract

The cooling and heating dynamics of vertical ventilation concepts for passenger compartments have been investigated in recent years in terms of their potential to improve thermal passenger comfort while simultaneously enhancing energy efficiency. Such ventilation concepts have equally attracted the attention of both scientists and car manufacturers because of their significance for autonomous driving. To investigate vertical ventilation concepts in a realistic measurement environment, a full-scale generic car cabin with dimensions similar to the interior of typical mid-size cars was developed and constructed at the German Aerospace Center (DLR) in Göttingen. To examine winter and summer conditions, a jacket heating/cooling based on capillary tubes was implemented in the outer layer of the cabin. The heat emission and obstruction of real passengers was simulated by thermal manikins. The system-relevant parameters were recorded by means of velocity and temperature probes at significant positions in order to examine and analyze the energy efficiency. In addition, the surface temperature of the driver manikin was captured by an infrared camera with the objective to verify the thermal comfort based on the concept of equivalent temperatures. The aim of the present study is to determine the heating and cooling dynamics of four different ventilation systems with regard to thermal comfort and efficiency for different climate scenarios representing winter and summer conditions. As a reference, a state-of-the-art dashboard ventilation for passenger cars was applied and compared to three novel ventilation systems: cabin displacement ventilation, low-momentum ceiling ventilation and a combination of them (hybrid ventilation). The results of the present study show significantly faster dynamics in case of the vertical ventilation concept compared to MV. At the conference, we will present the results and the analysis of the heating and the cooling dynamics of a car cabin in terms of thermal comfort and energy efficiency.