A Photometric and Energy Assessment of a Novel Lighting System

This paper describes the results of a photometric and energy analysis that was conducted on a new light guide and sulfur lamp system recently installed at both the U.S. Department of Energy's Forrestal building and the Smithsonian Institutions National Air and Space Museum. This system couples high lumen output, high efficiency sulfur lamps to hollow light guides lines with a reflective prismatic film. At the Forrestal building the system lights a large roadway and plaza area that lies beneath a section of the building. It has been designed to completely replace the grid of 280 mercury vapor lamps formerly used to illuminate the space. At the National Air and Space Museum a similar system illuminates Gallery 114, which houses the large rocket displays from the U.S. Space program. This paper outlines the unique operational and design characteristics of this highly efficient distribution system and details the results of field studies that characterize the significant energy savings and increased illumination levels that have been achieved. The projected savings in maintenance costs, due to longer lamp life and a reduction of the total number of lamps, is also presented.