The Alliance for Solid-State Illumination Systems and Technologies (ASSIST), a program of the Lighting Research Center (LRC) at Rensselaer Polytechnic Institute, recently released a new publication that addresses the issue of how lamps should dim in terms of their “look and feel” during the dimming process. The publication, ASSIST recommends… Dimming: A Technology-neutral Definition, provides a recommended definition for lamp dimming in residential and hospitality applications, based on research of existing industry standards, laboratory evaluations of lamp and dimming control performance, and psychophysical experiments conducted to determine common user expectations and preferences.
As new replacement lamp technologies become viable for many applications, manufacturers must design for the many facets of general illumination that the consumer expects, like dimming with standard wall dimmers. LEDs are intrinsically dimmable light sources and are commonly marketed as such; however, that does not mean that all integrated LED lighting products, particularly replacement lamps for incandescent lighting, are dimmable, or that residential dimmable LED products provide the same end-user experience when coupled with the existing installed base of dimmers. Compact fluorescent lamps have similar issues as well. Thus, dimming has been often discussed as one feature that needs to work well for energy-efficient lighting to achieve widespread adoption in general lighting applications.
Even though dimming is a feature commonly expected in many lighting applications, there is no standard definition for dimming in the industry. Over a two-year period, researchers from the Lighting Research Center at Rensselaer Polytechnic Institute, on behalf of ASSIST, conducted technology performance and compatibility evaluations, human factors experiments, and reviews of existing industry standards to better understand the different aspects of lamp dimming. The results of this research led to the published ASSIST recommends, which outlines recommended minimum and maximum light levels, thresholds for dead travel, flicker, and audible noise, and definitions for dimming profile and system efficacy measurement.
Nadarajah Narendran, Ph.D., LRC director of research and organizer of the ASSIST program, notes that the goal of ASSIST’s dimming recommendation is to have manufacturers understand and meet users’ expectations for dimmed lighting, helping LED technology to gain widespread use in lighting applications. “The LRC and ASSIST’s industry members are interested in understanding the technical problems impeding market acceptance of LED lighting, and dimming is one focus area. By understanding the compatibility issues and what users want when they dim their lights, we can improve not only the dimming experience but also the likelihood that homeowners will permanently switch to energy-efficient LED lighting,” said Dr. Narendran.
The ASSIST recommends publication is available on the ASSIST website here.
An overview of the dimming research conducted by the Lighting Research Center is available here.