Addressing hourly shading effectiveness in relation to solar control devices and solar geometry under tropical climates

Abstract

In tropical climates, shading becomes an important variable to protect built environment from solar radiation. The shading performance becomes more important for windows, which are the most susceptible construction element. They perform as the major contributor to heat gain since they allow solar radiation to enter interior spaces. In order to protect windows from solar radiation, the concept of projection factor is commonly used since it facilitated the design process to determine the adequate length for shading devices, specifically overhangs. However, this approach does not account for other key factors, such as solar geometry, orientation, time of the year and hour of the day. Considering this, a simulation using an octagon model facing eight orientations is performed in order to determine the effectiveness of different overhangs configurations.