Critical overview of heat balance, adaptive, local discomfort models to predict thermal comfort in buildings

The importance of ensuring comfort in indoor environments is becoming increasingly relevant. Thermal comfort can largely influence the thermal perception of occupants and is particularly complex to evaluate, as it includes environmental, physiological, and psychological aspects. For its assessment, several models based on laboratory and field studies have been developed. However, most of the studies often refer to the heat-balance or the adaptive approach, which are commonly used in thermal comfort research. The current availability of databases including objective and subjective measurements of thermal comfort from all over the world gave the possibility to discuss the validity of these models. After a first investigation of the two main currents in thermal comfort research, which include thermal physiology and human behaviour, this paper analyses the heat balance and the adaptive models with their strengths and lacks. It results that these two models present several potentials that should be considered for going towards an integrated model of thermal comfort. Indeed, instead of considering them as alternatively, it is necessary to combine their strengths to provide healthy and comfortable buildings.