01829nas a2200157   4500008004100000050001400041245011000055210006900165260002600234520122600260100002501486700002101511700003401532700002701566856007801593       1994                        eng d  aLBL-3445800aThe Design and Evaluation of Three Advanced Daylighting Systems: Light Shelves, Light Pipes and Skylights0 aDesign and Evaluation of Three Advanced Daylighting Systems Ligh  aSan Jose, CAc06/19943 a<p>We present results from the design and evaluation of three advanced daylighting systems: a light shelf, a light pipe, and a skylight. These systems use optical films and an optimizedsgeometry to passively intercept and redirect sunlight further into the building. The objectives of these designs are to increase daylighting illuminance levels at distances of 4.6-9.1 m (15-30 ft) from the window, and to improve the uniformity of the daylight distribution and the luminance gradient across the room under variable sun and sky conditions throughout the year. The designs were developed through a series of computer-assisted ray-tracing studies, photometric measurements, and observations using physical scale models. Comprehensive sets of laboratory measurements in combination with analytical routines were then used to simulate daylight performance for any solar position. Results show increased daylight levels and an improved luminance gradient throughout the year - indicating that lighting energy consumption and cooling energy due to lighting can be substantially reduced with improvements to visual comfort. Future development of the designs may further improve the daylighting performance of these systems.</p>1 aBeltran, Liliana, O.1 aLee, Eleanor, S.1 aPapamichael, Konstantinos, M.1 aSelkowitz, Stephen, E.  uhttps://facades.lbl.gov/publications/design-and-evaluation-three-advanced