Improving Circadian Light Exposure Through Architectural Daylighting Design in School Classrooms

Recent studies reveal light exposure in architectural spaces impacts human biological functions and overall health including circadian rhythms, functions, sleep quality, and alertness. These "non-visual" effects go beyond what frequent studies associate with visual lighting. Hence, understanding circadian responses is becoming increasingly important in spaces like schools where performance and alertness are critical. However, effective architectural daylighting design guidelines targeting circadian needs remain underdeveloped. This study aims to improve Daylight-driven circadian lighting aligned with visual requirements in schools through an architectural approach, by modifying five architectural features in school classrooms located in Helwan, Egypt, and investigating their impact on indoor daylight characteristics. The study conducted simulations to analyze daylight illuminance and the circadian effect of light during their occupancy hours across the year, using Design Builder v7. Results are based on a comparative analysis between base case classrooms and proposed circadian-architecture modifications case simulations. Initial base-case simulations revealed illuminance values and Equivalent melanopic lux outside the recommended range; indicating visual and circadian discomfort. The adaptive circadian approach improved light distribution, minimized glare, and enhanced dark zone illumination during critical working hours, with an average improvement from 21% in the morning to 93% in the afternoon. Overall, this study highlights the importance of architectural features for circadian lighting wellness in classroom design, to enhance student well-being and productivity.