Experimental performance of daylighting systems based on nonimaging optics

Abstract

Non imaging optics has established a reliable and sound framework for the design of efficient lighting systems in different application fields (nuclear physics, solar concentrators, electric lighting appliances,etc.). Based on its outstanding features, novel daylighting devices (anidolic daylighting systems)were designed in order to achieve efficient collection and redistribution of the diffuse component of daylight within deep office rooms. Several devices were set up, optimised through computer numerical simulations, built at different scales (1:10 scale models, 1:1 scale test modules)and finally monitored under different weather conditions (clear and overcast skies). An overview of the high luminous performance achieved by these daylighting devices --a zenithal anidolic collector, an anidolic ceiling and facade integrated anidolic systems --in 6 to 7 meters deep rooms under typical Central European weather conditions will be given in this communication. It will be shown that a very significant improvement of daylight factors monitored at a 5 meter distance from the facade is achieved by theses systems in comparison to a conventional double glazing reference facade (doubling of the daylight factors on the work plane), which corresponds to a substantial improvement of the daylight provision in the deeper part of the room.A daylighting system (anidolic slats) that shows the limits of building integration for such systems,will be considered as well.