EPA is requesting comments by Friday March 27 on two specific areas that were not specifically addressed in the previous version (4.2) of the RLF specification. These are the limits on correlated color temperature (CCT) and minimum light output requirements.
In the draft version 4.3, EPA says it is appropriate to include CCT values up to and including 4000K, and that are consistent with ANSI C78.377-2008. This will, says EPA, ensure “residential consumer satisfaction while allowing design flexibility for fixture manufacturing partners.” The previous specification has now been modified to remove the four values greater than 4000K.
Version 4.2 of the RLF specification did not set a minimum light output level, so that efficient fixtures with very low light output could still qualify. EPA has now amended this to require a minimum LED light engine output of 250 lumens (exceeding the output of a 25W incandescent lamp), and low output products will not be eligible.
Another change is that version 4.3 now includes an expanded reference to the industry standard for lumen maintenance, IESNA LM-80.
However, the specification does not reference LM-79, another industry standard that describes electrical and photometric measurements of solid-state lighting (SSL) products. Instead, the EPA specification references a document developed by ASSIST that describes the measurement of LED light engines. See ASSIST recommends: LED Light Engines and Integrated LED Lamps.
Two routes to Energy Star qualification
This highlights one of the major differences between the EPA’s Energy Star specifications for LED lighting and the alternative specification (Solid State Lighting version 1.1) from the Department of Energy (DOE).
The DOE SSL v1.1 specifications require testing of the light output of the whole fixture, i.e. delivered lumens, for reasons explained in a recent LEDs Magazine article by Jim Brodrick, who runs the DOE SSL program. See Time to stop ignoring light losses from residential fixtures.
In contrast, the EPA specifications are based on an evaluation of the enclosed LED light engine (LEDs + heat sink + driver). The same qualifying LED light engine can be incorporated into multiple fixtures, although in-situ thermal testing is required for each fixture design. This also means that the fixture itself can be aesthetically pleasing while not necessarily using materials that are optically efficient.
The fact that there are two Energy Star specifications covering solid-state lighting has been a point of contention, especially for the DOE and its supporters. The cover letter from EPA’s Baker says that the “two specifications complement each other” and both have “robust requirements.”
Also, Baker’s letter says that, “for the few fixture types where both specifications apply, partners can consider the requirements of each program and decide which approach best suits their needs for a given product.”