Increasing Thermal Comfort through Individual Heating Options in a German ICE Long-Distance Train

Abstract

The European Commission aims at being competitive and sustainable in passenger transport. One determinant for rail attractiveness is the passengers’ thermal comfort. Commonly, comfortable climate environments are realized by optimizing central HVAC systems. This approach neglects individual preferences and might not satisfy all passengers at best. In this paper, we investigated whether different heating devices enabling individual temperature control could be used to create a climate situation in which the passengers’ satisfaction was at least as high as in global baseline conditions, although mean air temperature was 2K cooler. The study took place in a representative ICE laboratory carriage that served as stationary test facility. In total, 84 subjects participated in four test trials. Comfort ratings were assessed via established standardized questionnaires. Results revealed that comfort variables did not differ depending on the type of temperature control. It was concluded that usage of individual heating devices compensated for 2K lower temperatures in the individual conditions but did not increase the thermal comfort. Thereby, all heating devices were perceived as being equally comfortable. Moreover, it became obvious that it is not the psychological effect of having control which accounts for the perceived comfort, but it is more important that the temperature is regulated exactly the way a passenger wants it. This finding points to options for future comfort improvements by implementing locally personalized climate environments.