Selecting Glass Window with Film for Buildings in a Hot Climate

Abstract

This article is about the developing parameters and relationships for selecting a proper glass window applied with film as building envelopes for buildings located in a hot climate based on its thermal performances. Thermal comfort of the occupants sitting near the glass window is the thermal performance that needed to be considered besides the heat transmission in selecting a proper type of glass to use as a glass window for the building. The predicted percentage of dissatisfied (PPD) is chosen as a thermal comfort index. 45 types of film and 1280 glass windows with film are investigated in this study. It can be shown that the thermal comfort index is dependent on the optical properties (total transmittance and total absorptance) and the overall heat transfer coefficient of glass windows with film. Glass window with film which has high transmittance shall have more discomfort due to solar radiation effect. Glass window with film which has high absorptance shall have more discomfort due to surface temperature effect. The discomfort from the surface temperature effect for double pane glass window with film is also dependent on the glass thickness other than the absorptance and the change in overall heat transfer coefficient. Expressions for predicting the performance of the glass windows with film in terms of thermal comfort are developed.