Evaluating Daylighting Performance Within Existing Schools Expansion in Egypt

Abstract

Daylighting is an essential resource for improving the indoor quality environment in school buildings. During the last decades, Egypt has faced some problems; the increase in annual school enrollment, high classroom density, and inadequate lands manifest in public existing schools expansion. Which may cause visual discomfort in classrooms. This study aims at evaluating the daylighting performance at public school expansion classrooms in two cities of Egypt: Cairo and Aswan. This study has considered two typical design prototypes for classrooms facing south orientation. Two situations for each classroom prototype have been analyzed and evaluated. In the first one, the two studied classrooms do not face any obstructions, while in the second, they face a neighborhood building. The daylighting analysis and simulation were based on Honeybee and Ladybug. Two aspects of daylighting analysis have been used to evaluate performance; Spatial Daylight Autonomy (sDA), and Annual Sunlight Exposure (ASE). This study showed that classrooms oriented to the south without external obstruction had a high value of ASE (58.85, 55.61%), and sDA (88.49, 88.79%) for Cairo City, while in Aswan ASE values were (66.14, 62.56%), and sDA were (89.32, 89.43%), it indicates sufficient daylight levels in classrooms. Moreover, it also showed glare problems. For the existing neighborhood buildings, the sDA values were less than (75%), whereas the ASE values did not exceed (10%). It is concluded that south orientation and obstructing buildings significantly impact the amount of daylight and visual comfort.