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Indoor LED Luminaires: State of the Art

Indoor LED Luminaires: State of the Art

By Craig DiLouie

A 2013 report by the DOE provided insight into the current state and trajectory of LED luminaires designed and marketed for indoor applications. The DOE recently followed up with another snapshot of the state of the art for indoor luminaires. This new report, based on Lighting Facts data through the first quarter of 2014, focuses on five types of indoor luminaires: downlights, industrial ambient luminaires, track heads, troffers (e.g., 2×2´, 2×4´, etc.), and linear luminaires such as linear pendants and striplights. Some 15,000 products are now listed with Lighting Facts, providing a large pool of data with which to compare them.

Lighting Facts is the product of the Quality Advocates Initiative founded by the DOE and the Next Generation Lighting Industry Alliance. The program encourages LED product manufacturers to voluntarily follow certain guidelines and labeling to report performance claims so as to eliminate confusion and allow apples-to-apples comparisons among consumers.

Products are tested using the IES-LM79 standard, and the data is then verified during registration. The label summarizes light output, input watts, efficacy, color appearance, and color rendering.

Indoor LED luminaires listed in Q12014 had a mean efficacy of 86lm/W, with a maximum efficiency of 139lm/W. This reflects a 16% increase over the previous year and marks the 11th consecutive quarter efficacy has gone up. When combined with older products active in the database, mean efficacy is 75lm/W.

The troffer, industrial, and linear luminaires listed by Lighting Facts have a mean efficacy of about 90lm/W, while track heads and downlights have a lower mean efficacy of 52lm/W and 57lm/W, respectively. In all five categories of indoor LED luminaires, more than 70% of the products met relevant efficacy qualification criteria for energy-efficiency programs. At least half of the products emitted light output within a range considered typical for a con-ventionally lamped luminaire. For ex­ample, many of the LED troffers in the Lighting Facts database are generally comparable to two-lamp fluorescent troffers.

Aside from industrial luminaires, a majority of which have a CRI in the 70s (suitable for most industrial applications), the large majority of the indoor LED products have a CRI in the 80s. This is considered good for most commercial lighting applications. A choice of color temperatures is offered, with prevailing color temperatures in each category being ap­propriate for their intended applications. Power factor is generally very good, with 90% of the products having a power factor greater than .90.

In short, in terms of efficacy, light output, color, and power factor, indoor LED products are competitive with many conventional luminaires—and getting better.

To learn more, download the free report at www1.eere.energy.gov/buildings/ssl/caliper-snapshot.html.

Craig DiLouie, LC, principal of Zing Communications (zinginc.com), is a lighting industry journalist and analyst. Reach him at cdilouie@zinginc.com.

Caption: The latest snapshot of indoor LED luminaires listed in the Lighting Facts database shows continuing improvement in efficacy, with the products listed in the first quarter of 2014 having a mean efficacy of 86lm/W. Image courtesy of the DOE.

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