Thermal insulated PVC windows for residential buildings: feasibility of insulation performance improvement by various elemental technologies

Herein, we aimed to improve the thermal insulation of polyvinyl chloride (PVC) windows to reduce the energy consumption of buildings. Currently, the gold standard PVC window is triple glazed and has a thermal transmittance of 0.7 W/(m2·K). However, further reduction in the thermal transmittance of the windows via quadruple glazing is not feasible because this would make the windows too heavy and expensive. We searched for an alternative method for reducing the thermal transmittance without increasing the weight. The window frame, glazing, and glazing edge parts of a PVC window significantly affect the overall thermal insulation; thus, we evaluated the insulation contribution of each of the above to identify their optimal conditions. Using these optimal conditions, we were able to create a window having a thermal transmittance of 0.46 W/(m2·K). However, these optimal conditions make their production difficult. Hence, we manufactured an alternative using practical specifications more suited for actual production. This window achieved a thermal transmittance of 0.63 W/(m2·K).