Effect of solar radiation on human thermal sensation and physiological parameters in a convection–radiation air conditioning environment

This study focused on the effect of glass structures of modern architecture on the indoor thermal environment during summer. In particular, this study examined how solar radiation significantly altered people’s thermal sensations. Laboratory tests on convection–radiation air conditioning systems were conducted, encompassing 12 different scenarios, including diverse indoor open areas, terminal forms, and levels of solar radiation. These tests aimed to explore the physiological and psychological responses of the human body to solar radiation penetrating through windows into the inner room. During the experiments, the participants’ subjective thermal sensations and thermal comfort were recorded, along with continuous monitoring of their physiological and environmental parameters. Results showed that solar radiation significantly increased local skin temperature, with a maximum rise of 2.15 ℃. Operative temperature is a reliable indicator of human skin temperature and thermal sensation vote (TSV). This study established two models that could predict the skin temperature of individuals indoors through operative temperature under conditions without or with solar radiation, and identified sensitive ranges of operative temperature for both models, to be specific, 26.32 ℃ to 28.43 ℃ and 28.51 ℃ to 34.11 ℃, respectively. Furthermore, this study established the relationship between skin temperature and TSV under conditions with and without solar radiation. The results indicate that solar radiation enhances the human body’s adaptability to indoor environmental parameters; a convection–radiation system (FC+RF) could be used to optimize indoor thermal control under solar radiation, achieving more stable environmental temperatures and improved indoor comfort.