Façade elements for room illumination with integrated microstructures for daylight redirection and LED lighting

Abstract

Lowering energy consumption of buildings is a common task, which is addressed in this presented research by the development and application of a micro structured system that successfully redirects daylight in order to light an office room instead of blocking it by shading systems. Designed as a common three-pane window compound and built utilizing manufacturing methods for mass production, namely hot embossing and UV imprinting, it can be handled as a common façade element. Measurements in the equipped office room prove a significant lowering of energy consumption for artificial lighting. This research is accompanied by the development of another façade element integrating an artificial luminaire to take care of situations in which no daylight is available, but without changing the location of the illumination source. The luminaire realized as micro structured surface emitter is incorporated as a window compound together with the LEDs used in a test façade, while offering a clear view to the outside. The view through the system is measured by a setup that partly mimics human perception. This transparent façade element emits light to the rooms ceiling for indirect illumination. Not yet being as efficient as standard lighting solutions, it offers new design options in reducing the use of common luminaires and in opening up new usable space at the ceiling and interior.