Determining the optimum fixed solar-shading device for minimizing the energy consumption of a side-lit office building in a hot climate

Abstract

Buildings consume nearly 40% of the annual global energy consumption, with about 70% in hot climate regions. An efficient building design in every aspect is a crucial step towards minimizing such consumption. Windows system, including solar shading attachment, plays a pivotal role in designing a sustainable building. At the beginning, a survey of architectural firms was conducted to assess the current local practice of selecting the type and size of solar shading devices in different orientations. Regrettably, the survey outcomes did not consolidate the designers’ basis for choosing such solar shading devices. Therefore, the main aim of this study is to find the optimum solar shading type and size among the three most common types (simple overhang, louvers, and overhang/sided-fins) in each façade orientation (East, West, North, and South). The manipulated design parameters comprised the overhang projection from the wall base to half of the window’s height and sided-fins projection (from the wall base to half of the window’s width), as well as the overhang projection’s tilt angle (from 90° to 135°). The considered design parameters provide 4416 design options that were handled efficiently by using the simulation-based optimization technique (SBOT). The results showed that the overhang/sided-fins performed best in terms of reducing the total energy consumption in all orientations (13-28%), while louvers’ shading came second on all orientations by saving 10–21% except in the East, where the simple overhang showed slightly better performance by saving 22%. Recommended type and size for the solar shading in each orientation have been provided.