Optimal Window Position for Hot and Arid Environments: A Practice in Tehran based on Annual Daylight

The task of designing exterior window openings presents two main issues, namely the buildingenergy envelope and natural daylighting. The inclusion of large windows in a building can result in significantenergy loss. Hence, it is ideal to aim for an optimal opening area. This research endeavors to provideconstructors with solutions and guidelines to achieve the most efficient windows, with the optimal windowto-wall ratio for hot and arid climates, by utilizing spatial Annual Daylight calculations through DesignBuilder'sEnergyPlus software. The research model is based on an ASHRAE Standard ۱۴۰ building located in Tehran,with ۲۴ window layouts and four orientations. The findings reveal that the most efficient window layouts formaximizing annual daylight while minimizing the window-to-wall ratio are those with a sill height of ۱۲۰ cm orhigher and a window height exceeding ۶۰ cm. However, considering these setups, a height of ۱۲۰ cm issufficient for up to ۶ meters of space depth, and it is recommended to allocate the remaining window area toits width. Furthermore, in order to achieve a more balanced distribution of annual daylight with an optimalwindow-to-wall ratio, avoiding window widths of less than ۲۵% of the room’s width is recommended.

Keywords:

Optimal Window , Window Position , Hot and Arid , Annual Daylight , Tehran.