Using about a third as much energy as a comparable incandescent bulb, and lasting as much as 25 times longer, the latest-generation LEDs are finding applications almost everywhere.
By: Janice Cha
If LED lights aren't currently part of your restaurant-lighting toolbox, they will be soon. Light-emitting diodes—small, glowing silicon chips harnessed together to form a lamp—produce light using a fraction of the electricity required by traditional incandescent bulbs, and they can last up to 50 times longer.
"LEDs are really poised to change the world. We're right on the cusp," says Richard Young, senior engineer and director of education at Pacific Gas & Electric Co.'s Food Service Technology Center in San Ramon, Calif. Speaking to an audience of operators and suppliers at FER's Multiunit Foodservice Equipment Symposium, Young quickly sketched in LEDs' history, then delved into their design, practical applications and considerations.
"LED lighting is like the PC in 1995," Young says. "The light output is going to rise dramatically and the price is going to fall dramatically."
LEDs Vs. CFLs And Incandescents
For anyone wondering how LED lamps stack up against compact fluorescents and incandescents in terms of longevity and energy-use, a detailed life-cycle assessment of the three types provides answers. A study conducted in 2009 by OSRAM, a German semiconductor manufacturer, found that LEDs and CFLs are just about equal in efficiency and power use, while incandescents lag far behind.
According to the study, one LED 8W bulb, lasting 25,000 hours, is the equivalent of two and a half CFL 8W bulbs lasting 10,000 hours each, or 25 incandescent 40W bulbs lasting 1,000 hours each. In other words, over a nearly three-year span, you'd be paying cost and maintenance only once for an LED, nearly three times for CFLs, and an eye-popping 25 times for incandescent bulbs.
LEDs In Action
LED lights are already being used in exit signs, signage backlighting, spotlights, pendant lights and case and undercounter lighting, to name a few applications.
A Leadership in Energy and Environmental Design-certified Taco Bell/KFC restaurant in Massachusetts is using LEDs extensively with excellent results. The store's front-of-house section relies on 6" down-lights throughout, for an elegant yet simple appearance. The menu boards are lit by LED light bars.
The kitchen and bathrooms rely on a combination of LEDs and light pipes. "The nice thing about the kitchen is the evenness of the light," Young notes. "There's no glare, even with all the stainless steel."
Outside, LED area-lights illuminate the parking lot more evenly than conventional lights while using fewer fixtures. The building signage and menu board are backlit with LEDs, and the building trim is highlighted with a flexible red LED strip that replaces traditional neon.
Points To Ponder
Young gave the audience plenty of technical considerations for anyone considering LEDs:
- Heat sinks are crucial. Heat lowers LED performance, and too much heat will destroy an LED lamp. On the flip side, LEDs shine even in sub-zero temperatures, making them a natural for outdoor signage and lighting.
- Steady power supplies are key. If you don't have a constant voltage and current, the lamps will die prematurely.
- If an LED fixture is installed and wired at the wrong voltage, its electronics will quickly self-destruct—a costly mistake. Look for lamps (new to the market in 2010) with auto-switch capability that can handle 100/120-, 220/240- and 277-volt applications as needed.
- White LED lamps tend to slightly color-shift over time toward blue. If light color is important, look for newer lamps with automatic color-correction.
- The lumens-per-Watt-measurement is sometimes overemphasized when it comes to comparing LEDs. Manufacturers may tout the highest "lumen-per-Watt" lamp, but ratings may not reflect the actual performance in the field. "What really matters is how well the fixture performs—in other words, not just how many lumens (total), but how many lumens are you actually getting on your table where you need them? That's what's important," Young said.
- A good lighting designer is critical when you're switching over to LED because the technology is so different. "You can end up with too many fixtures, too much light and an unacceptable cost model." Young says. "When you're buying expensive components like LED fixtures, you want to get it right the first time."
- With LEDs, as with anything else, you get what you pay for. "Anyone can buy a chip and stick it into a lamp," Young notes, "and scores of small companies are doing just that." Poorly made LED lamps tend to have more drop-off in light output and fail more easily than lamps from reputable companies.
The bottom line is that it's important to do a life-cycle cost analysis that includes lamp purchase, maintenance and energy cost when considering LEDs. "A $90 LED will save you a couple hundred dollars compared to a $7 halogen if you look at the big picture," Young says. "If you're going to be around for a while, or you're a chain that's growing, and you can afford the up-front capital cost, then LED has excellent ROI."
Click Here For LED Innovation
To find some of the latest innovations in LED lamps, start with winners of the 2009 Lighting For Tomorrow Competition, sponsored by the American Lighting Association. These cutting-edge LED winners feature high-output and high-efficacy lamps, with multiple beam angles, deep dimming (down to 1%), auto-switching (to adjust for different electric outputs) and automatic color correction.