CFD analysis of thermal and flow physics in buildings utilizing smart glazing for mitigation of solar GAIN

Modern architectural design trends unanimously include glass facades in the construction of large buildings. An undesirable consequence of this design approach is solar gain which leads to uncontrollable space heating and an increase in interior air temperatures leading to poor thermal comfort of occupants. As glass is highly transparent in the visible and shortwave spectra, solar radiation passes easily to the building interior where the energy is absorbed by objects and surfaces and retained within the enclosed domain of the interior space. Active interventions such as air conditioning, solar control glass coatings, automated mechanical louvers, blinds, curtains etc are required to alleviate the effects of solar gain. These common methods have alarming disadvantages through poor energy efficiency, high costs, environmental impacts and poor aesthetic qualities. Switchable windows offer a contemporary smart controlled technological solution with very low electrical consumption and controlled levels of transparency/opacity through the activation of an electrically conductive inter layer between two glass panes. The current study investigates the utilization of smart glazing/switchable windows to combat the undesirable psychological and physiological effects of solar gain. Full scale CFD simulations were employed in order to investigate the fundamental thermal and flow physics in a large open space, typical of public and commercial buildings. A number of cases for varying solar loads incident on smart glazing were investigated. Results demonstrated the effectiveness of utilizing smart glazing in maintaining desirable ambient temperatures in the open spaces contributing to improved energy efficiency and occupant thermal comfort.