Experimental evaluation of indoor thermal environment with modularity radiant heating in low energy buildings

The air conditioning system in low-energy buildings should be high-efficient because of its limitation on energy consumption and requirement for thermal comfort. This study proposed a novel modularity radiant terminal which can be moved freely in the vertical direction. A series of field experiments on the optimal design scheme of modularity radiant heating terminal was conducted in a laboratory in hot summer and cold winter region of China. Indoor thermal performance with different installation position and area of modularity radiant heating panel were investigated. Results indicated that the modularity radiant heating system can maintain a comfortable indoor environment which the operative temperature can reach 21 degrees C, the vertical temperature difference below 3 degrees C and the radiation asymmetry below 4 degrees C. The design scheme of the modularity radiant heating has significant effects on indoor thermal environment, in which the installation position was a key factor. The modularity radiant panel installed in the middle of the wall and close to the floor can effectively improve the response lag of indoor thermal environment in the operation period and reduce the heat attenuation speed in the shutdown period. The response time of operative temperature at the start period can be reduced for more than 1.5 h and the thermal lag can be increased for more than 2 h at the shutdown period. Besides, the operative temperature can be increased by 1.5 K and the vertical temperature difference and the radiation asymmetry can be reduced by approximately 1 K, respectively. The optimal design of modularity radiant system can simultaneously further improve thermal comfort and realize energy consumption for low energy buildings. (C) 2020 Elsevier Ltd and IIR. All rights reserved.