Free-running temperature of room equipped with pipe-embedded double skin facade: A case study in Guangzhou

Pipe-embedded double-skin facades (PDSFs) have proved to be among the best approaches to solve the overheating problem confronted in conventional double-skin facades (DSFs). Although the heat transfer characteristics of PDSF have been investigated by numerical methods in previous research, the free-running temperature and economic operating strategy of a room with PDSF have not been studied. In this study, a prediction method for the free-running temperature of a room equipped with PDSF is established. The performance of PDSF in different types of rooms under different operating strategies in Guangzhou was obtained. The results show that (1) the proposed method could be used to accurately predict the free-running temperature of a room with PDSF; (2) heat gain reduction of PDSF over DSF is strongly dependent on the solar intensity; thus, it is appropriate to operate PDSF for both efficiency and economy when the solar intensity exceeds 100 W/m(2) and the room is occupied; and (3) free-running temperature of PDSF can be decreased by approximately 3.5 degrees C compared with DSF, and the time when the indoor temperature is below 28 degrees C can be extended to 34% in residential buildings with PDSF.