Experimental Evaluation of Innovative Wall Daylighting Systems

Abstract

Daylighting offers the potential to save electrical energy and reduce peak demand for lighting, the major consumer of energy in a variety of buildings. However, widespread adoption of daylighting techniques is hampered by the lack of both daylight resource information and simple, reliable methods of testing daylighting designs. To surmount these obstacles, facilities for collecting illuminance data and for testing small-scale and full-size models have been established. These are (1) an extensively instrumented resource measurement station, (2) a sun angle simulator for exploring the geometries of the sun and the building during the early stages of design, (3) a heliodon to allow detailed illuminance and luminance distribution measurements in scale models, and (4) a rotating test building for quantitative and qualitative assessments of full-scale components. The current research efforts have been using these facilities to seek ways of projecting light admitted through walls deep into interior spaces. Sidelighting systems are of interest because the wall is the only available source of daylight in many commercial buildings. Innovative static and dynamic reflector assemblies have been examined and proven effective. Compared with typical sidelighting designs, the systems examined in this study project light deeper and produce more uniform illuminance across the space.