Thermal Performance of Vacuum Insulated Window Shutter Systems

Windows are a major area of heat loss in buildings losing up to 10 times more energy compared to other building elements. Thermal shutters are used to improve the energy performance of windows in both hot and cold climatic conditions. The performance of thermal shutters however greatly depends on the thermal insulation and construction detailing, specifically cold-bridging, through the shutter, as well as between the shutter and window frames. This study evaluates the effects of cold-bridging, trickle ventilation and the size of the air cavity, between the vacuum insulated shutter and the window, on the performance of window thermal shutters. Thermal simulations are conducted in VOLTRA (Thermal analysis software) to assess the conditions. The results indicate that although thermal shutters reduce heat-loss through windows, their performance could be significantly affected by cold-bridging by up to 90%. The additional thermal resistance due to the air cavity and the ventilation through the trickle vent appeared to be much less significant compared to the effects of thermal bridging.