Optimizations of Roof Heat Transfer Using Computational Fluid Dynamics

In the summertime, direct sunlight is the largest component of building cooling loads. The proper addition of structures above the original roof, such as the extra roof of a building, can not only provide shade for the original roof, but also allow the heat accumulated between the roof and the structure to escape. This research focuses on this double roof design, which is a promising approach to reducing the energy consumption of the building system. In this study, the performance of double roof design to reduce the heat flux into the building is numerically investigated, with a focus on exploring the effect of the key parameters, i.e., the inclination angle and the distance between two roofs, on the heat transfer performance. The heat flux carried out from the roof system generally increases as the increase of roof inclination angle, or the separation distance. Based on the analysis, the optimal design of the double roof is determined. The present work shows that a well-designed double roof could greatly reduce the energy consumption of the building.