Design of a passive device for a maximum shadow on roofs in a warm humid climate

Abstract

Buildings and homes in warm humid climates are major sources of energy consumption, and roofs are generally exposed to the greatest solar gain, leading to overheating. Shading devices are passive solutions that reduce solar irradiance gains. However, the shape of these devices is based on reused materials or fixed geometries, considering aspects such as orientation. In the present work, we analyze the geometric configuration of a shading device that can control the incoming solar gain on roofs by the maximum shading length. The optimal device design is derived from the application of solar geometry and the principles of the constructal design methodology. The shading device’s optimal geometric configuration maximizes the shading length in summer and winter in a warm humid climate. The shading device arrangement on the roof of a low-income house was analyzed by numerical simulation for different aspect ratios of the devices, reducing the temperature by an average of C for an aspect ratio of . This configuration offers a    reduction compared with the case without shading devices. The shading devices contribute to the set of passive solutions to achieve adequate conditions (energy and habitability) in warm humid climates.