Weather analysis applying the new clothing resistance model

A new clothing resistance model is described and applied to characterize the thermal load of weather as a function of human reactions such as activity and sweating. Weather was described by the thermal resistance (r_cl,t) and evaporative resistance (r_cl,e) of comfortable, imaginary clothing. The key input variable of the model is the rate of sweating (λE_sw). Since sweating is an individual-specific process, the model applies to the individual. Therefore, the longitudinal data collection method was applied, with observations conducted by a single individual in Martonvásár (Hungarian lowland, Central Europe) during the summer of 2023 and the winter of 2024. Furthermore, a database containing the anthropometric data of more than 3000 individuals was also analyzed. Our main findings are as follows: the model is applicable within the range of thermal neutrality when the environmental heat surplus and the rate of sweating are high, as well as when the environmental heat deficit is high, with no sweating. During large environmental heat surpluses, the r_cl,t values were found to be between 0.1 and 0.5 clo-t (clo-t = 0.155 m²·°C·W⁻¹), while the r_cl,e values fell between 0.4 and 0.8 clo-e (clo-e = 0.155 m²·hPa·W⁻¹). The values of the parameters close to 0 were caused by intense sweating (λE_sw > 200 W·m⁻²). The applicability of the model is limited and largely depends on the relationship between λE_sw and the metabolic heat flux density, while r_cl,t is also significantly dependent on human factors.