Impact of glazing type and orientation on the optimum dimension of windows for office room in hot climate

Abstract

This study aims to show the impact of orientation and glazing type on optimum window size in hot climate using genetic algorithms. In winter the optimization of window size is obtained thanks to thermal gains from solar radiation, taking into account this free heat gains from the sun reduces heating demand of the building. In summer the optimization of window size is complex, in this case, the window is considered as a heat gains element. For a hot climate, the sun can be used as a passive strategy to reduce energy consumption. An optimal window size allows avoiding problems of glare and overheating. ASHRAE proposed a Window to Wall Ratio (WWR) which is considered as the optimal window size that ensures minimum annual thermal loads, this coefficient neglect different parameters such as (Glazing type, the orientation, daytime). A typical office room located in Ghardaia (South of Algeria) is selected as a case study. The results show that daylight is a key factor in limiting the window size in hot climate. The WWR cannot be considered as optimal for the whole year; this study shows that the optimal window size varies with daytime.