A Study Of Window Daylighting With Prismatic Glass

Daylighting with prismatic glass has great potential to improve indoor lighting environment quality and save energy. As a new daylighting technology, prismatic glass has been applied gradually. Currently no existing simulation software can model the daylighting environment with prismatic glass, and thus it is difficult to predict the actual effects. As a new green building material, prismatic glass is not widely applied in the building market. Without appropriate simulation tools or guidance methods, designers cannot evaluate the daylit environment in the design phases.The study conducted questionnaire surveys regarding responses to window daylit environment quality and collected building indoor illuminance level data with window prismatic glass, separately. Using post-occupancy building performance assessment methods, the research analyzed and evaluated the actual daylighting environment quality with prismatic, and compared the illuminance levels differences between actual prismatic glass and simulated conventional flat glass. By mimicking the lighting transfer paths in glass and indoors, the research approached the methods for modeling window daylighting situations with prismatic glass, and further verified with measured actual illuminance data.The study also modeled and analyzed the indoor daylighting environment conditions with prismatic glass combined with conventional flat glass to improve daylit depth and indoor lighting environment quality. Conclusions are summarized in the end regarding the features and possible problems of using prismatic glass as window glazing. Furthermore,research suggestions are also proposed.