Performance benefits of highly reflective diffuse materials in lighting fixtures

Fixture designers make a tradeoff between low glare, which is achieved by recessing lamp sources, and high efficiency Diffuse reflective materials are often used behind lamp sources in highly recessed fixtures to improve light output uniformity, but their diffuse nature and low reflectance degrades efficiency even further. A highly reflective (98-99 percent) diffuse material suitable for use in architectural fixtures is available which enables significant increase in fixture efficiency while maintaining low glare and uniform output. The material is a highly stable fluoropolymer, which does not degrade or yellow over time when exposed to heat or UV energy. Testing on a variety of commercially available fixture types showed a 10-20 percent increase in total lumen output when incorporating a small insert made of the material behind the lamp source. Light intensity generally increased uniformly within the area illuminated by the fixture, without increasing cutoff angle, generally resulting in larger spacing criteria. Further analysis showed a linear relationship between this increase in light output demonstrated by the material and reduction of fixture counts in an architectural environment. This reduction of fixture counts can even be achieved in architectural spaces with low ceilings due to increases in spacing criteria.