| Keywords |
Anidolic Ceiling Daylighting System ; RADIANCE ; Photon Map ; School Classroom ; Visual Environment |
| Abstract |
The visual environment in school classrooms is an important design element, because visual tasks are the primary activities in classrooms. Proper quantity of light should be guaranteed and glare should be avoided at the same time. In addition, since most classrooms in regular schools are mostly occupied during daytimes, daylighting is strongly recommended not only to improve the quality of light by the full spectrum but also to save electric lighting energy. One of the effective daylighting systems for classrooms is anidolic daylighting system which collects direct sunlight by the anidolic element of parabolic reflector installed outside building, transfers the collected light through the light duct installed inside the ceiling space, and distributes the transferred light on to the work planes by the light diffuser installed on the ceiling near the back wall. In this study, the daylighting performance of an anidolic ceiling daylighting system was evaluated by RADIANCE program coupled with photon map algorithm in order to identity an optimum configuration of the light diffuser. Various geometries and sizes of the light diffuser were evaluated in terms of illuminance levels and uniformity of illuminance. The simulations were conducted for 10:00 a.m., 12:00 noon, 2:00 p.m. and 4:00 p.m. on the equinoxes (3/21 and 9/21), summer solstice (6/21) and winter solstice (12/21) under clear sky conditions. Additional simulation was conducted for an overcast sky condition. The results were examined with the average illuminance and the uniformity of illuminance and it was identified that the designs R4 and R5 were the optimum geometries and sizes. |