02308nas a2200277   4500000000100000000000100001008004100002260000900043653000900052653001300061653001300074653001600087653000800103653001800111100002300129700001500152700001800167700001700185700002100202245011600223856007100339300001200410490000800422520158600430022001402016       2016                            d  cJune10aBSDF10adaylight10aradiance10aredirection10asDA10awindow design1 aTuğçe Kazanasmaz1 aLars Grobe1 aCarsten Bauer1 aMarek Krehel1 aStephen Wittkopf00aThree approaches to optimize optical properties and size of a South-facing window for spatial Daylight Autonomy  uhttp://www.sciencedirect.com/science/article/pii/S0360132316300956  a243-2560 v1023 aThis study presents optimization approaches by a recent Climate-Based-Daylight-Modeling tool, EvalDRC, to figure out the necessary area for a daylight redirecting micro-prism film (MPF) while minimizing the glazing area. The performance of a window in terms of spatial Daylight Autonomy (sDA) is optimized by its geometry and optical properties. Data implemented in simulation model are gathered through on-site measurements and Bidirectional-Scattering Distribution Function (BSDF) gonio-measurements. EvalDRC based on Radiance with a data driven model of the film's BSDF evaluates the window configurations in the whole year. The case to achieve an sDA of at least 75% is a South-facing window of a classroom in Switzerland. A window zone from 0.90 m to 1.80 m height provides view to the outside. The upper zone from 1.80 m to 3.60 m is divided into six areas of 0.30 m height in three optimization approaches including the operation of sunshades as well. First, the size of the clear glazing is incrementally reduced to find the smallest acceptable window-to-wall ratio (WWR). Second, micro-prism films are applied to an incrementally varying fraction the initial glazed area to determine the minimum film-to-window ratio (FWR). Finally, both approaches are combined for a minimum FWR and WWR. With clear glazing and WWR of 75%, the sDA of 70.2% fails to meet the requirements. An sDA of 86.4% and 80.8% can be achieved with WWR 75%, FWR 1/9 and WWR 50%, FWR 1/2 respectively. The results demonstrate the film's potential to improve the performance of windows with reduced WWR.  a0360-1323