The effects of shading on thermal performance of DSF in hot-arid climate of Iran

Due to the expansion of glass usage in the facade of buildings, there is a risk of increased energy consumption due to the heat exchange between the facades and the environment. A double skin facade is optimally one of the best options in managing the interaction between the outdoors and the internal spaces. The aim of these façades is, on one hand, to increase internal comfort and, on the other hand, to decrease energy consumption. However, in hot-arid climates, when the amount of radiation on the surface of façade increases, the overheating in the upper floors becomes a major problem. One of the primary ways to solve this problem is to develop natural ventilation in cavity. But this method cannot alone reduce the intensity of overheating in the upper floor. Due to the increase of air temperature in double skin façade, the temperature of internal skin and the amount of heat transferred to the living space is increased. In this research, it has been attempted to reduce the rate of Incensement of temperature on the internal skin of the façade by placing blinds with the tilt angle of 35. The blinds are placed in the middle of air cavity to allow proper air circulation between two skins. The inner skin temperature of the system and the shadow effect on façade has been predicted under overheating scenario with the ANSYS Fluent software. The model was tested with natural ventilation in the warmest day of July. According to the result of this study, in the model of DSF with aluminum blinds, the temperature of inner skin at 9 and 27 m height is reduced by 19.5 and 28 (K) compared to the model without blinds, respectively.

Keywords:

Double skin façade , Shading , Overheating , Temperature of the inner skin , Heat transfer