Relative thermal pleasure model: A unified framework for understanding and predicting thermal comfort in dynamic environments

Abstract

Thermal comfort within dynamic environments is shaped by a combination of factors including thermal adaptation levels, short-term thermal histories, thermal expectations, and non-thermal stimuli. However, existing thermal comfort models have fallen short in providing a unified theoretical framework capable of elucidating the combined impact of these factors on thermal comfort. Here, we introduce the Relative Thermal Pleasure (RTP) model, which offers a unified theoretical framework for both elucidating and predicting thermal pleasure. The RTP model posits that the contrast between the target thermal stimulus and its reference points, in conjunction with the distribution of attention weights among these elements, together determine the emergence and intensity of thermal pleasure. To validate the model's predictions and determine model coefficients, nineteen participants were recruited to access their thermal pleasure between two warm environments with different temperatures ranged from 32 to 45 °C. The RTP model clarifies the psychological mechanisms underlying the generation of thermal pleasure and elucidates how external environmental factors and internal psychological and physiological factors influence thermal pleasure. Through theoretical and experimental analysis, we found that improving a poor thermal environment may or may not trigger thermal pleasure, depending on the improvement percentage in the thermal environment. The critical improvement percentage to induce thermal pleasure is 48.7%. The findings of this study have the potential to advance our understanding of thermal comfort and guide us in creating more comfortable thermal environments.