Buildings with large glazing ratios continue to be developed even within hot, sub-tropical climates such as that typical of the Mediterranean region. New builds have the benefit of incorporating better performing glazing within their building facades. Older, existing buildings with poor-performing glazing, however, would still have a potential for an upgraded façade. Previous research by the same authors has already identified the potential of incorporating both solar-PDLC (Polymer Dispersed Liquid Crystal) and SPD (Suspended Particle Device) films within the same laminate to control solar heat transfer whilst permitting a wide dynamic range of visual transparencies. This paper now identifies a novel application for such a laminate in a switchable external shading device. The switchable glazing shading device could be used in an external overhang that would cast a shadow-on-demand onto the vertical façade fenestration, thereby making it suitable for existing and future facades. This concept would also encourage the use of less raw material in achieving a controllable level of improved visual environment within an indoor space compared to adopting switchable films within the entire area of façade glazing. This study compares the degree of glare within an enclosed space achieved by a conventional opaque overhang to that achieved with a glazed shading overhang incorporating two types of switchable films. Using a physical scale model in a field test setting, indoor illumination and glare measurements are investigated under different switching states and compared to those provided by conventional static glazing, with and without ordinary external overhangs under identical field test conditions. Results show that a switchable glazed overhang in its transparent/bleached state can allow the ingress of daylight into an indoor space without creating excessive glare whereas in their translucent/tinted state, switchable shades can achieve a level of glare protection similar to that provided by an opaque shading overhang.
Etienne Magri
The Development and Performance of a Novel Switchable Shading Device.
Company: University of Malta, Malta
About the speaker:
Etienne Magri is a practicing architect and civil engineer, with over 25 years of experience in the design, detailing, and construction of buildings. He graduated from the University of Malta in 1999 with a joint degree in architecture, civil and structural engineering. In 2016 he completed a Master’s degree in Environmental Design with the University of Malta with a field test investigation on the thermal performance of spaces fitted with different types of glazing systems in a cooling-dominated climate. He is currently reading for a PhD. with the University of Malta and investigating the potential for the use of a novel switchable glazing for buildings within a Mediterranean climate for the improvement of the energetic performance of buildings and the well-being of building occupants.
