Noted for their efficiency and flexibility, light-emitting diodes (LEDs) are often billed as the second coming in the evolution of lighting. An exciting work-in-progress may be a better descriptor. Solid-state lighting (SSL) for commercial, industrial and municipal applications is rapidly advancing as product costs come down and research and development (R&D) efforts pay off. For electrical contractors (ECs) and their customers, LEDs are adding choice and paying dividends.
Kevin L. Willmorth, MIES, is a strong proponent of LED lighting. His Milwaukee-area firm, Lumenique LLC, is a four-year-old product design company for lighting manufacturers. Willmorth started as a lighting consultant and later became a product designer.
“LED technology is developing and evolving at such a rapid pace,” he said. “The speed may level off in a few years, but advancements will continue into the next decade. The years 2008–2009 were breakthrough in terms of LED color and performance, consistency and light output. All those gains have just solidified in 2010.”
Willmorth added that LEDs have some obstacles to overcome in areas of efficiency droop, power management and cost in some markets. “But the R&D is so robust I have no doubt these challenges will be met,” he said.
The advancements in commercially acceptable white light have been a key victory for LEDs. Warm-light LEDs in the 2,600K to 3,500K range have improved significantly and are approaching the efficacy of compact fluorescents, reports the U.S. Department of Energy (DOE) at www.doe.us.gov.
“Fluorescent phosphor for broad spectrum light is very limited,” Willmorth said. “In contrast, the garnet phosphor in LED creates smooth waveform without the spikes, a better conversion and a better light.” In this approach, white LED light is created by combining a blue LED with phosphor.
Grasping the technology
Willmorth feels, in only a matter of years, compact fluorescent lamps (CFLs) may no longer be a specifier’s top choice.
“Europe and Asia have already walked away,” he said. “CFL puts out an unattractive yellow-green hue. Today’s LED light for a commercial space is much more attractive. I think we’ll wean ourselves from 2,700K. The efficacy gains in 3,000K have been very dramatic.”
“CFL is not a good substitution in a reflector lamp,” he said. “It’s too big and hard to focus. A LED can drive a flood to a pinpoint focus. LED lights are also instant on/off and do not pose a switching problem.”
Avraham “Avi” Mor, IALD, LEED AP, MIES, is a lighting design consultant and partner of Lightswitch Architectural, based in Chicago. He doesn’t see commercial CFLs disappearing, though he predicts the residential CFL replacement lamp may be resigned to a short-lived history. Above all else, Mor believes education is the key in considering LED lighting.
“It’s a complicated technology,” he said. “You have to understand the LED itself, the luminaire and issues like performance and warranty. I am always trying to use LED products, but I do my research, verify products’ UL listing, LM [light microscopy] test reports, and read the fine print in warranties. I encountered one LED product listed as ‘built’ to UL standards, but in reality, it hadn’t gone through UL testing. I asked one sales rep if his replacement bulb product was UL listed and he replied, ‘What’s that?’”
For Mor, the free New Generation Luminaries (NGL) annual catalog is a helpful LED product guide. It features the winners in an annual SSL competition sponsored by the NGL (www.nglbc.org). The NGL’s mission is to “recognize and promote excellence in the design of energy-efficient LED commercial lighting luminaires.”
“All submissions in the competition have to be commercially available,” Mor said.
Kevin Gauna is the owner of Sun Brothers Studio in Richmond, Calif., which provides lighting and energy consulting. Gauna worked in lighting research for Lawrence Berkeley National Laboratories and later at the California Lighting Technology Center. He believes LEDs have the potential to be viable in just about every lighting application. He added, however, that today’s products can widely vary in performance and quality.
“Price pressure can allow lower quality LED products to steal the markets and not make the best case for LED,” Gauna said. “Know your manufacturer, develop a relationship or, at least, research the manufacturer. Make sure they have the infrastructure to produce their product. Recognize the name brands and ask the distributor if the company has done the research and product engineering to meet minimum standards. Retain the critical eye, even if it’s a big-name manufacturer. Get real product and evaluate it before it goes into a big installation.”
Where LEDs compete today
The market for LEDs continues to be established as green building practices grow.
“LED is best served and offers the best payback in long-lived commercial projects,” Willmorth said. “I see the market for hospitality business emerging in maybe three years. Residential is still way off, I think. It is more price sensitive. One exception may be in high-end residential where homeowner wants the aesthetic quality of the LED lighting and sees that as a value in itself.”
Gauna thinks LED recessed-can downlighting can be a competitive option today for residential markets on account of the technology’s performance.
“I’ll venture that, in two years, the use of CFL in downlights will be toast. LEDs will outperform at every level. CFLs cannot overcome their physical size,” Gauna said.
Another growth market for LED is outdoor lighting.
“LED is a powerful player in this market,” Gauna said. “LED wasn’t matching the source efficiencies for street and parking lot lighting a few years ago. Metal halide and sodium bulbs were offering at least 100 lumens per watt. What wasn’t taken into account were fixture luminary efficiency. LED’s multiple emitters and design optics have better light distribution uniformity, so you don’t need as many lumens. The color rendering beats sodium as well. It picks up reds and other colors. Bulb replacement is greatly diminished too. These factors are now being recognized.”
The promise of LED has pushed improvements in competing lighting technologies, as well.
“T8 fluorescent is one example,” Gauna said. “Costs are way down, providing thousands of lumens. They are inexpensive and high performance. That will be huge for LEDs to displace. But there is a fair amount of penetration in downlights, task lights and streetlights. Solid state is where the R&D is going, and we’re seeing quantum gains.”
Working toward standardization
The need for standardizing LED lighting is a hot topic. More LED field performance data is available, which will help. Dimming and drivers are a big focus.
“LEDs and dimmers need to be figured out,” Gauna said. “A distribution list of compatible systems is offered by manufacturers, but those systems need to be tested by the specifier somewhere in the chain.”
A key component, the LED driver, remains an evolving, complex technology.
“You want [the driver] to handle the various upstream power sources like wall-switch dimming,” Mor said. “Driver designs can be vast and varied and sometimes unpredictable. Right now, LED manufacturers either over- or under-drive their product. Drivers remain a huge R&D endeavor.”
So, are LEDs standard-less? Not quite, Mor said.
“There are standards for testing when you consider light output (IES LM 79), color or board testing (IES LM 80). Those are just a few existing standards of many. A driver standard from ANSI is in development. Lamp-life determinations are also in the works as is a residential dimmer standard (ANSI). Hopefully, some of this will be completed sooner than later,” Mor said.
A contractor’s experience
Mor has collaborated with a number of ECs in his lighting design work including Chicago-area based Block Electric Co. Inc. and JMS Electric Inc. Projects have typically been design/build emphasizing energy efficiency and aesthetics. Showcase work has included Millennium Park, the Shedd Aquarium and the latest Wit Hotel, all in Chicago.
“ECs who get involved in LED lighting do so because they realize it has become relevant to their business,” Mor said. “They quickly discover LEDs are simply another light source, albeit with a different dynamic.”
Jack Nelson, senior design and estimating project manager for JMS Electric Inc. in Schaumberg, Ill., is an LED fan and has observed how fast the lighting had advanced.
“We did the design work for the historic Blackstone Hotel in Chicago back in 2006,” Nelson said. “The developer liked LED but wanted to use it selectively due to cost and limited application. Our next big hotel project was a new Wit Hotel. In this case, the design emphasized cutting-edge, gravitating toward more LED lighting. In the two years that passed between these two projects, LED technology had really advanced. Its costs had come down, its white light balance properties had improved and its applications increased.”
Nelson also learned a few things that helped when he estimated subsequent LED projects.
“Our initial Wit designs focused on load. We projected a $10,000 monthly electrical bill, predicated on past projects of similar type and finish and on the criteria established by the hotel operator’s design standard modules, which had not been updated with the new technologies in mind. Costs ended up much lower, closer to $4,000 monthly. We hadn’t anticipated how the branch loads really dropped using LED. If we knew of this efficiency beforehand, the construction budget could have been reduced in terms of distribution and service-equipment sizing.”
For the Wit developer, the more expensive LED lighting wasn’t a deterrent. In fact, it was viewed as the lower cost choice over the life of the hotel.
“We’re now advocates of LED when we discuss lighting options with clients,” Nelson said.
Any current limitations aside, all interviewees see great advances and improved economics for LED lighting.
“If used properly, LED is a very flexible and powerful in terms of lifetime, efficiency and its ability to deliver light and control color,” Gauna said. “I think LED is the true reinvention of the light bulb.”
GAVIN is the owner of Gavo Communications, a marketing services firm serving the construction, landscaping and related design industries. He can be reached at firstname.lastname@example.org.