Assessment of the overall energy performance of an SPD smart window in a hot desert climate

Abstract

In this study, the overall energy consumption and visual comfort of a switchable suspended particle device (SPD) smart window were investigated as part of the glazing integration of an adaptive building designed to consume less energy in a hot desert climate. A typical floor of a commercial office building in Riyadh was chosen for the energy and visual comfort simulation, which was based on Energy-Plus and Diva-for-Rhino software for cardinal orientation. A comprehensive simulation analysis of various state of SPD glazing, namely opaque (OFF), transparent (ON) and automated controlled (based on solar radiance: from 100w/m2 – 900w/m2), was conducted and the results were compared against traditional single glazing and double-glazing low emissivity (DG low-e) coated windows for reference. The simulation results indicated that switchable SPD smart windows (in the OFF and automated states) achieved a promising reduction of net energy by up to 58% against DG low-e, apart from at the northern orientation. Conversely, the opaque (OFF state) had a counterproductive impact on lighting energy consumption and visual comfort. Acceptable daylight autonomy (DA300lux) and Useful daylight illuminance (UDI100lux–2000lux) was observed for the SPD smart window in the ON and automated controlled states; moreover, it offered a significant reduction in daylight glare probability (DGP). Thus, controlled switchable SPD glazing can be a good alternative to standard glazing in a hot desert climate in terms of reducing energy use and providing visual comfort.