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Latest LED lighting facts

The DOE's Lighting Facts program recently updated its Product Snapshot, which tracks the changes in the LED lighting market. DOE personnel familiar with the program commented that the latest results seem to show that SSL is still far from being a "no-brainer" choice, but say LED luminaires are competing with their traditional counterparts in many applications, at least in the highest-performing products.

The latest Snapshot focused on LED luminaires, and the DOE says several performance trends are worth noting. Commercial outdoor luminaires -- including area and roadway, parking garage, and wall pack -- are getting more efficient. And it looks as though the municipalities, utilities, and retailers that typically use these devices are willing to pay up for them because these applications have high baseline wattages and long hours of daily use. Thus even incremental improvements in efficacy can save them a lot of money.

The efficacy of LED indoor luminaires is improving at varying rates, says DOE. For example, the efficacy of downlights and undercabinet lights is improving at a slower rate than those in other categories. The reasons aren't entirely clear, says DOE, but one possible reason might be that the warmer color temperatures typically specified for residential indoor applications generally aren't as efficient as other types, because of losses that arise in creating warmer color temperatures.

The latest report also finds that some LED outdoor area and roadway luminaires put out more than 10,000 lumens – equivalent to or exceeding those of typical metal halide (MH) and high-pressure sodium (HPS) systems with 150-W lamps. Some LED parking garage and wall pack luminaires have light outputs exceeding 7,000 lumens, equivalent to or exceeding MH and HPS systems with 100-W lamps, DOE says.

The efficacy of LED outdoor luminaires varies considerably, but many of them surpass the efficacy of MH and HPS systems (which can range from 45 to 75 lm/W), with the highest LED efficacy levels approaching 100 lm/W.

In terms of color quality, DOE says most LED outdoor luminaires have CRIs that exceed those of MH (CRI typically 65) and HPS (CRI typically 20) systems and range in CCT from 4,000 K to 7,000 K, which is cooler white light than traditional fixtures (2,000 K to 6,000 K).

And there is good news for those who aren't fans of CFLs: DOE says the majority of LED recessed downlights meet or exceed the light output levels of their incumbent CFL counterparts. The efficacy of LED downlights varies a great deal (from 11 to 80 lm/W), but the average (45 lm/W) exceeds average CFL benchmark levels (35 lm/W). But LED undercabinet/shelf-mounted lights and troffers also vary considerably in output, says DOE, with only the higher-performing products matching the most common benchmark performances.

Finally, most LED undercabinet lights and troffers are more efficacious than the fluorescent benchmark products, with the highest LED troffer efficacy levels exceeding 90 lm/W. LED troffers generally have higher CCTs (~4,500K, on average) than LED downlights and undercabinet lights (~3,300K and ~3,100K, respectively), as well as lower CRIs. DOE says this is unsurprising given that troffers are used primarily in commercial spaces, while the other two types of lights are used in a mix of residential, commercial, and architectural spaces, which tend to have more demanding color requirements.

The Product Snapshot can be found here: http://www.lightingfacts.com/default.aspx?productsnapshot

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