This article was published in the Fall 2013 issue of Illumination in Focus.
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While LED-based solid-state lighting (SSL) is about one-third more energy efficient than compact fluorescent lighting (CFL), its traditional drawbacks have included glare, the inability to provide useful and functional light, and difficulty achieving the warmth needed for interiors. New white LED fixtures now exist that create non-glare, useful light and produce significant energy savings over CFLs. These new fixtures produce as much light as a 450W incandescent source while using less energy than a 60W bulb. This now makes LEDs a viable useful light source for surface-mounted architectural applications such as offices, lobbies, libraries, museums, and conference rooms.
"What we're seeing is a change from LEDs as a colored light source for special effects to a white light source for general lighting," says David Malman, a lighting designer and owner of San Francisco-based Architectural Lighting Design. "They're becoming a part of virtually every project I do."
According to Malman, the problem of LED glare when viewed directly is essentially solved by a new class of indirect LED lighting. Among other manufacturers, Borden Lighting offers such products in its line of decorative architectural lighting fixtures and glare control products. "The company is successfully pursuing the use of LEDs as an indirect, ambient light source in a variety of fixture shapes, materials, and finishes," says Malman.
Borden, for instance, has developed an LED pendant fixture with three 17W LED arrays pointed up to the ceiling for indirect light and one 4W LED pointed down for a little downlight. This provides a layered light, which is an aesthetic way to light a space as the indirect light is broad and smooth with no glare.
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Since the fixture uses 55W — yet sheds the equivalent light of four 42W CFL lamps, which consume 168W total — it provides the same level of light at less than one-third the energy. With a target reduction by 2020 of 60–80% percent of statewide electrical lighting energy consumption by the California Public Utilities Commission Lighting Action Plan and a push toward zero net energy structures, such LED fixtures provide architects and designers with new warm interior lighting alternatives to CFL.
Although early generation LED lights lacked the color warmth that people enjoy and traditionally associate with incandescent lamps, technological advances have narrowed the gap to virtually nil. The first LEDs tended to be a cool, blue-white color in the 5000ᰫ6000K CCT range, but some of the latest LED fixtures offer warm, white light at 2700K with a 90 CRI (color rendering index), which is almost equivalent to sunlight or halogen incandescent lighting.
Art-gallery quality light
Michael Souter, a design principal and owner of Luminae Souter Associates, a San Francisco-based lighting design firm, has found that the new class of indirect, white-light LED fixtures provides quality light good enough for art galleries, with dimming control that makes the lighting flexible enough for a variety of uses. "We developed an all-LED pendant luminaire with Borden that will be installed at a Santa Clara University art gallery," says Souter. "It provides ambient lighting with the aesthetics required to view the artwork properly. Since it is totally dimmable, when they have parties or receptions, they can increase the lighting level or dim it as needed."
According to Souter, dimmability for lighting designers and clients is often vital to provide flexible use of a space. While CFLs are dimmable, they typically require costly extra equipment to achieve the necessary dimming capability. "Since LED lighting is usually designed to be dimmable, it doesn't require extra equipment for dimmability," says Souter. "When you compare the cost of a dimmable CFL with a dimmable LED, the cost is similar but the LED is more aesthetically compact and space efficient."
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Because of a host of LED advantages over CFLs, Souter is also in the process of using all LED lighting to illuminate a zero net energy building in Silicon Valley that is aiming for a LEED Platinum sustainability rating. "When it comes to sustainability, CFLs have another issue: mercury content," says Souter. "When CFLs need to be disposed of, do you want to tell people that you're dumping their toxic mercury content into a landfill? LEDs don't have that problem because they're mercury-free, and last at least as long, if not longer."
Aesthetic design flexibility
As LED lighting increasingly takes the place of CFL, the way CFL took the place of incandescents in the 1990s, one thing that architects, lighting designers, interior designers, and electrical engineers appreciate is a lighting manufacturing partner willing to work with them to deliver the aesthetic design, sustainability, and value required of them. Orlando Diaz-Azcuy, a member of the Interior Design Hall of Fame and owner of Orlando Diaz-Azcuy Design Associates, an interior design firm that does commercial and residential design nationwide, recently commissioned Borden to do two customized versions of a chandelier using LEDs.
According to Diaz-Azcuy, the LED chandelier light is primarily ambient, reflected from the ceiling, though the bulb is visible. One chandelier version in New York is about 8 ft in diameter. It has LEDs at the ends of a series of metal bars about 1/2-in. in diameter that vary in length from 3–5 ft, and go in all sorts of directions. "When you view the chandelier in the evening, you literally see stars over your dining room," says Diaz-Azcuy. "Today, LEDs are more available than ever for useful light. I'm a strong supporter of LEDs, and with energy and environmental sustainability becoming critical, they are absolutely the way to go."