Built thermal environment with multi-directional asymmetric radiations: An experimental study with real occupants

Creating a comfortable thermal environment is related to energy consumption and sustainability in buildings. The radiant cooling systems have been widely used as an energy-saving way to improve human thermal comfort. While, for indoor environments with transparent envelopes, superposition effects of multi-directional asymmetric radiation (horizontal and vertical) may also affect thermal comfort. Therefore, in this paper, thermal comfort evaluations were investigated in a room with multi-directional asymmetric radiations in a typical summer climate. The corresponding overall and local thermal responses of occupants were analyzed physiologically and psychologically. The results showed that horizontal asymmetric radiation due to solar radiation had a notable impact on occupants' thermal comfort, which caused a 0.7 degrees C difference in mean skin temperature and a 0.64-scale difference in TSV. Vertical asymmetric radiation due to the radiant cooling system had a positive effect on the skin temperature and thermal responses, with the most remarkable improvement in the forehead and back. Moreover, that also reduced 1.1 degrees C of the variation requirement of indoor setpoint temperature. The relationship between mean skin temperature and thermal sensation was studied and dissatisfaction with asymmetric radiation was analyzed. The comfort and energy-saving potentials of radiant cooling systems in nonuniform environments were also analyzed.