Design and evaluation of daylighting applications of holographic glazings
This is the final report on a study performed by Lawrence Berkeley National Laboratory for Physical Optics Corporation, under Contact Number Agreement BG-95037. The main purpose of this study was to assist Physical Optics Corporation with the design and evaluation of holographic glazings for daylighting applications. %DFNJURXQG When combined with appropriate electric lighting dimming controls, the use of daylight for ambient and task illumination can significantly reduce energy requirements in
... gy requirements in commercial buildings. While skylights can effectively illuminate any part of one-story buildings, conventional side windows can illuminate only a 15 ft -20 ft (4.6 m -6.1 m ) depth of the building perimeter. Even so, the overall efficacy of daylight is limited, because side windows produce uneven distributions of daylight. Achieving adequate illumination at distances further away from the window results in excessive illumination near the window, which increases cooling loads from the associated solar heat gain. As a result, the use of larger apertures and/or higher transmittance glazings, to introduce daylight deeper than 15 ft -20 ft (4.6 m -6.1 m), may prove ineffective with respect to saving energy, because cooling load penalties may exceed the electric lighting savings.