Evaluating a Vehicle Climate Control System with a Passive Sensor Manikin coupled with a Thermal Comfort Model

In a previous study, a passive sensor (HVAC) manikin coupled with a human thermal model was used to predict the thermal comfort of human test participants. The manikin was positioned among the test participants while they were collectively exposed to a mild transient heat up within a thermally asymmetric chamber. Ambient conditions were measured using the HVAC manikin’s distributed sensor system, which measures air velocity, air temperature, radiant heat flux, and relative humidity. These measurements were supplied as input to a human thermal model to predict thermophysiological response and subsequently thermal sensation and comfort. The model predictions were shown to accurately reproduce the group trends and the “time to comfort” at which a transition occurred from a state of thermal discomfort to comfort.

In the current study, the effectiveness of using a coupled HVAC manikin-model system to evaluate a vehicle climate control system was investigated. The test protocol prescribed a transient heat up after a cold soak of a vehicle that had been placed in a - 10 °C climate chamber. Multiple repetitions of the same scenario were run with different human subjects to reduce the influence of individual bias on the overall results and to assess the variability of test responses. The thermal sensation and comfort of the human subjects were compiled and reported in terms of average and standard deviation, which were compared to the predictions of the manikin-model system. The agreement between the manikin-model system and the human subject test results was assessed quantitatively by calculating the RMSD (root-mean-square deviation) and bias (the average error) between the predictions and the measurements.