COMPARATIVE CANDLEPOWER DISTRIBUTION ANALYSIS FOR COMPACT FLUORESCENTTABLE LAMP SYSTEMS

The residential lighting sector represents a significant opportunity f or energy conservation due to the almost exclusive use of inefficient incandescent sources. Compact fluorescent lamps (CFLs) have the potent ial to transform this market by using one-fourth as much power as an i ncandescent to provide the same amount of light. While technical advan ces such as triphosphors and electronic ballasts have addressed issues of color rendition, flicker, and hum, CFLs still face significant mar ket barriers, particularly their perceived brightness level in traditi onal fixture applications. When operated in fixtures originally design ed for A-lamps, CFLs with equal total lumen packages can appear dimmer due to differences in their light distributions. One such fixture, th e common table lamp, is typically operated for more than 3 hrs/day, an d thus represents a significant opportunity for energy savings. The au thors conducted a series of goniophotometric candela distribution stud ies of table lamps with the initial objective of matching with CFLs th e light distribution of the consumer-accepted A-lamp. While goniophoto metric testing was done on numerous CFL and incandescent sources, this paper focuses on three typical sources that have very different distr ibutions. Our photometric studies indicate that horizontally oriented CFLs may produce a more desirable distribution than either A-lamps or vertically oriented CFLs by minimizing shade losses and thus maximizin g the amount of useful light leaving the fixture. Optimizing fixture g eometry and lamp position can significantly increase the efficiency of these CFL fixtures. Ongoing research with the fixture industry seeks to identify and develop efficient source-fixture configurations.