As manufacturers rush to optimize LED lighting for use in traditional home applications -- recessed downlights, for example, or desk lamps -- it's important to remember that the unique technical properties of LEDs make them immanently well-suited to several specific uses around the house.
At the National Electrical Contractors Association (NECA) annual conference on Oct. 3, Chris Ruud of Racine, WI-based Ruud Lighting hosted an educational session intended to help contractors understand the technology behind LED lighting. At its core, he said, an LED is essentially a computer chip. And as such, development has paralleled the rapid rise of the microchip industry in the 1960s.
Just in the last few years, though, the industry has seen substantial leaps in illumination capability.
"Their performance has escalated pretty dramatically," Ruud explains. "Twenty-four months ago, LEDs were shipping at about 24 lumens per watt. Today that number is about 97 lumens per watt."
During the presentation, Ruud called attention to solid-state lighting’s peculiar technological composition.
LEDs create light by passing an electric current through a semiconductor chip; this process gives off light photons and generates illumination. In their natural state, most LEDs give off a high-color-temperature, blue-white light. The most common way of creating warm, white light involves coating the fixture with yellow phosphor; the right combination of blue and yellow combines to make a warmer color temperature that’s appropriate for a living room or den, for example.
This chemical reaction, however, gives off intense pinpoint heat, requiring a thermal apparatus to channel the heat away and ensure long life for the fixture. There's no danger to residents or installers, but the lamp itself can degrade significantly if not equipped with a heat sink.
"One of the earliest areas that LEDs have started to be adopted in is undercabinet lights," Ruud says, describing how one early installation had been rendered all but useless after just 1,000 hours of use due to ineffective thermal management.
But with proper heat dissipation, residential applications that call for cool, blue-white light can make very effective use of LEDs that are readily available on the market today. In addition to undercabinet illumination, Ruud points to refrigerator/freezer lamps as ideal candidates.
"That's a perfect application for [LEDs]," Ruud says of these applications.
Refrigerator uses have another advantage, he says. LEDs actually function better at colder temperatures -- just like traditional computer chips -- by enjoying a longer life, giving off brighter white light and -- critically -- consuming less power. The technology is tailor-made for other home applications that might operate in the cold, including outdoor lighting in northern climates.
"LEDs don't burn out," he explains. "They just keep getting dimmer and dimmer over time. The higher the temperature that they operate at, [the] faster that they degrade."
Understanding how specific applications might play to the strengths of solid-state lighting technology is key to getting customers to adopt LEDs. Then, when more practical retrofit products hit the market in coming years, customers will be more likely to consider subsequent LED installations.