The Effect of Reflectors and Delamping Upon Light Levels

Abstract

In the 1987 Georgia Institutional Conservation Program ICP), recommendations for installation of reflectors in fluorescent fixtures accompanied by delamping totaled $5.4 million. Concerned with that effects of these recommendations on light levels, the Governor's Office to Energy Resources asked the Georgia Tech Research Institute to quantify the change in light levels. This paper summarizes the study and its findings, and suggests what conditions favor the use of reflectors. The study found that installing specular reflectors in fluorescent fixtures accompanied by 50 percent delamping resulted in reduced light levels of 60 to 80 percent of design light levels. The continuous row fixtures in the study showed the greatest variation in light levels raging from 52 percent between rows to 80 percent under rows for an average of nearly 70 percent. Light levels in rooms with fixtures on an even grid spacing ranged from 73 percent between fixtures to 86 percent under fixtures for room averages of 75 to 80 percent. Reflectors in rooms with higher ceilings gave more uniform light distributions but resulted in slightly lower average light levels. The study concluded that fluorescent fixture reflectors accompanied by delamping is a viable means to reduce lighting energy consumption if a reduction in design light levels is acceptable.