Article
Correlated color temperature (CCT) has become a hot topic in commercial outdoor lighting, as many have argued LED-based fixtures are just too, well, cool. In part, this is because this newer technology produces a different kind of light than the high-pressure sodium and metal halide fixtures we all became accustomed to during those technologies’ decades of outdoor use.

Don’t Be Blue – Outdoor Lighting Has Warmed Up

Chuck Ross
Correlated color temperature (CCT) has become a hot topic in commercial outdoor lighting, as many have argued LED-based fixtures are just too, well, cool. In part, this is because this newer technology produces a different kind of light than the high-pressure sodium and metal halide fixtures we all became accustomed to during those technologies’ decades of outdoor use. But it’s also because the first generation of LED street and area fixtures produced light that often fell into the bluer, “cooler” end of the CCT spectrum, posing a risk of disrupting sleep patterns. Today, though, specifiers have many more options to choose from that are easier on the eyes.

Understanding color temperature and its effects on the appearance of light can be a little confusing. First of all, we’re talking here of “white” light – that is, the light produced by standard indoor and outdoor lamps and fixtures. But, if you’ve ever shopped for light bulbs (“lamps,” to professional lighting designers), you know that not all white light is alike. Warm white light, with CCTs ranging between the 2000 degrees kelvin (K) to 3500 degrees K has more of a red/yellow/orange appearance. As CCTs rise, light shifts into the cooler, bluer end of the spectrum, with natural daylight falling somewhere above 5000 degrees K. So, unlike the temperatures we’re used to following in the nightly weather report, higher CCTs mean cooler-toned illumination.

Early-generation outdoor fixtures often produced high CCT light, because cool-white lighting also appears brighter to human eyes. Manufacturers were still working to develop the high-output lamps and fixtures this market requires, and that perception of added brightness helped meet outdoor needs. However, these products raised concerns that this more daylight-appearing light also would disturb sleep patterns for both humans and animals. LED technology has developed significantly over the last decade, though, and now there are plenty of high-output options with CCTs between 3000K and 4000K, which is both less disruptive and easier on our eyes.
Photo courtesy of Hubbell Outdoor Lighting
Lutron C·L is now LED+
advertisement
Explore the NEW unvlt.com
advertisement