Sunday, July 8, 2012
DOE adds warranty, lumen maintenance to Lighting Facts label
The DOE has added two optional metrics to the Lighting Facts label, indication of a warranty and a lumen maintenance metric.
In a recent DOE newsletter, the SSL Postings, Jim Brodrick, the US Department of Energy’s (DOE’s) lighting program manager explained enhancements that have been made to the LED Lighting Facts label. The label displays verified LM-79 product data including five parameters: light output in lumens, efficacy in lm/W, power required in W, correlated color temperature in K, and color rendering index. Now manufacturers can provide two additional metrics: an indication of warranty (yes/no) and lumen maintenance estimates based on LM-80 and TM-21 projections.
Brodrick noted that there is still no agreed-upon way to measure or report lifetime for solid-state lighting (SSL) products. However, in recognition of the purchaser’s need to know an expected life for an SSL product, the DOE arrived at the use of LED lumen maintenance, consistent with TM-21 and based on LM-80 measurements, as an indicator of product stability.
The decision was made not to use lumen maintenance in terms of L70, the point at which light output falls below 70 percent of initial levels, because the results may be misinterpreted as lifetime values. Instead, the metric will identify the remaining useful percentage of initial output projected to be reached any of three fixed points in time, after 25,000, 15,000 or 10,000 hours, which the manufacturer can select.
Regarding the warranty, the manufacturer can choose to list “yes” if a warranty is available. The DOE has indicated that listing a number of years associated with the warranty could also be misleading because different components in the product could be covered for different periods. For products with a "yes" designation for warranty, LED Lighting Facts has added the ability to link to the manufacturer's warranty directly from the products list.
The two new listings are optional. To date, over 4750 products are carrying the DOE’s Lighting Facts label.
It is important to differentiate the DOE Lighting Facts label from the FTC Lighting Facts label. The latter has been required on all medium screw-based bulbs sold to consumers since January 1, 2012. That label lists light output (lm), required power (W), appearance (CCT), presence of mercury, a lifetime estimate in years (based on 3 hours of usage per day) and energy cost ($/yr based on 3 hr/day, $.11/kWh).