Investigation of human thermal comfort under highly transient conditions for automative applications Part 1 : experimental design and human subject testing implementation

This paper focuses on the experimental research of developing models to effectively predict the dynamic whole body and local thermal comfort under highly transient conditions. Two approaches were taken subsequently. The first step was to collect environmental data with a testing vehicle under transient and non-uniform conditions. An environmental chamber was used to simulate 16 typical winter and summer conditions, which fully covered the range of thermal conditions necessary
for comfort evaluations in a vehicle. A testing vehicle was instrumented to measure air temperature, globe radiant temperature, air velocity, and relative humidity at 20 locations by a measurement device developed in-house called StickMan.
A real-time environmental control system was also developed to provide the desired airflow rate and supply air temperature for the transient conditions. The environmental data were input into a transient thermoregulation model to calculate peoples physiological responses to the environment, such as whole body and local skin temperatures, heat fluxes, core temperature, sweat rate, and so on. Secondly, human subject testing was performed to collect subjective thermal comfort responses
under the same conditions. Finally, the physiological and thermal sensation data were combined to develop the thermal comfort model. This model expands the range of applications from fast warm-up or cool-down transients to steady-sate conditions, and the scope of the model was expanded to include a range of initial conditions rather than being limited to standard initial conditions. Coupled with the Interior Comfort Engineering (ICE) software developed by the automotive industry, this vehicle modeling software allows designers to implement tests with a virtual prototype on a virtual trip and determine how well the climate control system is going to work during the design phase of a new automobile. It will reduce the design cycle and eliminate the need for a large number of
human subjects to evaluate thermal comfort satisfaction in real vehicle prototypes.