Berkeley thermal comfort models: Comparison to people votes and indications for user-centric HVAC strategies in car cabins

Abstract

New heating and cooling strategies can be adopted in a smart way to bring thermal comfort while reducing energy requirements. UCB thermal sensation and comfort models can be viewed as an alternative to the PMV standard to investigate frugal and local strategies for namely electric vehicles. In the present investigation, people votes are recorded while they were experiencing transient and quasi-homogeneous scenarios in cool and warm automotive-like environments and compared to the UCB Zhang model predictions. Quite good qualitative agreements are found between model predictions and actual votes particularly in warm environments. On the strength of these results, a parametric investigation is carried out and interesting trends about thermal preferences are brought to light for each body part. It is observed that body parts have, depending on the global thermal ambiance, different expectations in terms of thermal preferences. For instance, one can mention that the pelvis should only be cooled slightly even in extreme hot environments, otherwise the comfort is strongly deteriorated. Based on this investigation body parts that have to be focused in priority have been identified for different global thermal ambiances (very cold So=−4, cold So=−2, neutral So=0, warm So=2 and very hot So=4) and suggestions for comfort-oriented and energy saving-oriented strategies have been proposed.