An Evaluation of Light Quantity and Quality in Reading Rooms, and Suggestions for Amendments; the Case of Shahid Beheshti University libraries

Assistant Professor, Faculty of Architecture and Urban Planning, Shahid Beheshti University
Daylight reception in built environments is one of the main performance indicators for the quality of life. This is even more important in certain spaces such as study rooms. There are a variety of measurement indices for assessing daylight. The present paper assesses daylight availability and visual comfort in seven libraries at Shahid Beheshti University, Tehran, through software simulation using DIVA. The corresponding performance indices are then evaluated against recommended values in national and international standards. In order to improve visual conditions a series of solutions are proposed, and then applied in studied cases, to demonstrate their effectiveness in improving the quantity and quality of daylight.  The simulated models are tested for validity, and used in order to study their respective effect in sufficiency and distribution of light, visual comfort and required energy. In the end, a series of suggestions are made in each case based on simulation results and costs. According to initial assessments, the main problem was low levels of daylight availability in five cases, and high levels in another. The Useful Daylight Illuminance index (UDI300-3000) are increased from 6–59% to 24–100% by implementing improvement strategies. In addition, the lighting energy in the studied spaces, have been improved by 4–58%. The most effective improvement measures are
1. increasing the reflectance of walls and ceilings (changing colours),
2. using skylight, and
3. increasing the light transmittance of windows by substituting them with more transparent windows or by regularly cleaning them.