Thermal Characteristics and Energy Performance of Double Skin Façade System in the Hot Summer and Cold Winter Zone

Double skin façade (DSF) system is used in high-rise buildings increasingly in the hot summer and cold winter zone in China, due to its advantages in sound proof, aesthetic appearance and energy efficiency. This paper demonstrated a method of obtaining the thermal characteristics of the double skin façade system using computational fluid dynamics (CFD) techniques, and evaluated the energy performance of the DSF system. Based on the CFD simulation results using climatic data of Hangzhou city, a linear relation between the room heat gain and two other variables, the solar radiation and the temperature difference between the room and the ambient, can be confirmed. This linear relation shows two important characteristics of the DSF system: solar heat gain coefficient (SHGC) and effective heat transfer coefficient or U value. Effects of four DSF parameters were analyzed that included the glazing properties, the cavity width, the vent opening size, and the cavity height. The results show that the cavity width and the cavity height appear to have little effect on the thermal performance. Increasing the vent opening can improve the thermal performance up to a certain extent. Using the linear relations, the total cooling load can be easily evaluated as demonstrated. Such capability can be of great help during the DSF design and optimization process.