Volume 29, Issue 4-1, December 2025
HUMAN THERMAL LOAD OF CFB CLIMATE SUMMER WEATHER BASED ON THE CONCEPT OF REQUIRED SKIN EVAPORATION
Authors: Ferenc Ács, Erzsébet Kristóf, Annamária Zsákai
Abstract: We analyzed the human thermal load of summer weather in the Cfb climate based on the results of a new model based on the human body energy balance equation and the skin surface evaporation gradient formula. The active surface of the model is the skin surface, the person is lying in a resting position, its skin type is Fitzpatrick skin type IV. For that purpose, longitudinal research method was performed in 2022 in Martonvásár, Hungary (East-Central Europe), comprising 331 observations in which weather conditions and thermal sensation types were recorded simultaneously. The main observation is that in warm climates and/or weather situations, the amount of thermal load can be very simply characterized by
latent heat flux density values of the skin evaporation. From a human point of view, the most important characteristics of summer weather in the Cfb climate are as follows: 1) The latent heat flux density of skin surface evaporation varied between 10 and 300-350 Wm-2, while the operative temperature ranged between 25 °C and 80 °C. 2) The relationship between skin surface evaporative resistance and operative temperature can be characterized by an exponential function. In cases of thermal sensation type „neutral”, skin surface evaporative resistance values are mostly above 0.5 hPa·m2·W-1. Observations made by people with different skin types are essential to generalize the results.
Keywords: Cfb climate; summer weather; human thermal load; r e quired skin evaporation; evaporative resistance of skin
Article info:
Received: July 3, 2025| Revised: December 3, 2025| Accepted: December 16, 2025