Overall thermal sensation and comfort prediction with different model combinations: Cold and hot step-change environments in winter.

Currently, numerous thermal comfort models have been proposed; however, research on the combination of different models is lacking. This study aims to predict the overall thermal sensation (OTS*) and thermal comfort (OTC*) with different model combinations under hot and cold step changes. Three cold- and hot-shock processes are designed in the climate chamber. Accordingly, the skin temperature, thermal sensation, and thermal comfort votes of 16 participants are collected. The impacts of winter hot and cold step changes on subjective votes and skin temperatures are evaluated. Further, the OTS* and OTC* values are calculated, and their accuracy under different model combinations is analyzed. The results reveal that thermal sensation changes in human body exhibit distinct asymmetry under the cold and hot step-changes, except for the cycle of "15-30-15 °C" (I15). The parts farther from the core area become more asymmetrical after the step changes. The single models exhibit the highest accuracy in different model combinations. The combined form of a single model is recommended for thermal sensation or comfort prediction.