Windows optimization based on the glare performance in educational building of Iran hot and dry climate

Glare is one important factor affecting the level of visual comfort and the quality of light in the spaces. The purpose of this study is to provide suitable models for optimizing windows in educational building of Iran hot and dry climate. In educational buildings in terms of space performance, glare is a significant issue that can have an impact on education. after determining the model, radiance parameters, climatic data and software validation, critical times of glare were determined at a specified point. Priority of the effect of each parameter was determined by keeping the other parameters constant. Then, using simulation, the combination of different physical parameters of the window in different percentages and dimensions was considered. Physical characteristics used in this study included window-to-wall ratio, shading length, observer position, window visibility, and percentage of colored glass. A total of 4800 different state combinations of parameters were obtained. The results show that only when the window-to-wall ratio is 30% by the variation of other factors, glare is unperceptible. Therefore, the change in the physical components of the window alone does not have the proper function of preventing glare in space. One of the proper solutions in this field is the use of lightshelves. By removing the colored glass component and adding two variables, length of lightshelves and distance to the top edge of the window, 6000 different state of composition were obtained. Using this technique at window-to-wall ratios of less than 60 percent, glare will be unperceptible.