Demonstration of Recessed Downlight Technologies: Power and Illumination Assessment
ph: (865) 576-8401, fax: (865) 576-5728 email: email@example.com Available to the public from the National Technical Information Service, U.S. Department of Commerce, 5285 Port Royal Rd., Springfield, VA 22161 ph: (800) 553-6847, fax: (703) 605-6900 email: firstname.lastname@example.org online ordering: http://www.ntis.gov/ordering.htm This document was printed on recycled paper. Executive Summary Solid state lighting (SSL), specifically light-emitting diodes (LED), has been advancing at a
... pace, and there are presently multiple products available that serve as direct replacements for traditional luminaires. In this demonstration, conventional recessed lights in a conference room were used to compare conventional incandescent A-lamps, incandescent reflector R-lamps, dimming compact fluorescent lamps (CFL), to an LED replacement product. The primary focus during the study was on light delivered to the task plane as provided by the power required by the lighting system. Vertical illuminance, dimming range, and color shift are also important indicators of lighting quality and are discussed in the report. The results clearly showed that LEDs, with dimming-capable drivers, are much more efficient than incandescent and CFLs. Further, LEDs provide much smoother and consistent dimming than dimmable CFLs. On the potential negative side, it is important that the dimming switch be identified as compatible with the LED driver. A wide variety of dimmer switches are capable of dimming LEDs down to 15% of full light output, while select others can be capable of dimming LEDs down to 5%. In addition, LEDs can be intensive light sources, which can result in uncomfortable glare in some applications and to some occupants. Higher ceiling (9-foot or greater) or non-specular reflectors can act to alleviate the potential for glare. * Assumes 2,000 hours per year operation, $0.10/kWh, 0.25-h/lamp labor, $50/h labor rate. † Only includes the cost of the replaceable LED module.