A new simplified model for evaluating non-uniform thermal sensation caused by wearing clothing

In the standard thermal sensation models such as Fanger's and Gagge's models, the clothing system is simulated as an overall insulation covering the whole body. But under actual conditions, some segments of body are bare and other parts are covered by clothing. In addition, there is a significant difference between thermal sensation of the bare and that of covered segments. Moreover, to use a more complex multi-segmented model, large amount of empirical data is required to simulate each segment of the body. The data, then, must be numerically analyzed to determine the thermal parameters for each segment and its subdivided layers. In this study, a simplified three-node and easy-to-implement thermal sensation model is presented based on Gagge's standard model. In the present model the human body is subdivided into three lumped compartments: core, bare skin, and clothed skin. Thermoregulatory parameters of each compartment are determined by the relative energy balance equation of the compartment. The present model accurately estimates the thermal sensation of the bare as well as the clothed parts of the body. The model has been verified against the analytical and experimental results where a good agreement was found.