Lights of the roundtable

Lights of the roundtable
DDI's annual lighting roundtable gets the scoop from industry professionals on the latest technology, trends and applications

By Vilma Barr, New York Editor
May 01, 2008

Peter Aaron/Esto

The lighting industry is in flux. Not only the measurement of luminous flux, which in lighting parlance is a unit measurement of energy of emitted light, but rather, this is the flux of change. The driver of this surge of change is energy use, and how more light from fewer luminaires can help to reduce the worldwide negative climatic changes from CO2 emissions.

Does the threatened ban of the incandescent lamp make sense? LEDs are long-lasting, yes, but how will the heat they generate be effectively dissipated? Has metal halide come of age? Are retailers investing in lighting control systems? Can retailers utilize daylight harvesting? How widespread is the recovery of mercury from used fluorescent lamps, including compact fluorescents? DDI asked designers, lamp and fixture manufacturers, and industry observers around the country for their input.

In early March, the International Association of Lighting Designers (IALD), issued a position paper on the potential banning of the incandescent lamp, under consideration in such countries as Canada and Australia, as well as in California and other U.S. states. IALD urged that incandescent lamps should not be taken off the market until their replacements are proven to be an overall environmental improvement. "The complete environmental impact and lifecycle carbon footprint of each replacement technology must be understood," IALD's statement noted. It urged a grace period to allow the development of light sources that can replace incandescent. "There is presently no lighting technology suitable to be used in place of certain types and uses of incandescent lamps," IALD indicated.

Terry Bell, principal in the Winter Haven, Fla., office of CD+M Lighting Design Group, offered his views on incandescent and tungsten halogen lamps. "Incandescent lamps sometimes are referred to interchangeably as tungsten halogen," Bell points out. "They are not, in fact, the same thing. While both may have a tungsten filament to glow, the halogen version adds a quartz envelope under pressure to allow the filament to burn hotter and longer. A comparable wattage halogen lamp has approximately 50 percent more light output and twice the life of its incandescent version. This would easily fall into the [U.S. Green Building Council] requirement to use energy-efficient light sources, rather than plug a retrofit compact fluorescent lamp into old incandescent cans, which can prove detrimental to the visual quality of a space."

Bell praises the dimming effects of incandescent or halogen. "Dimming can increase the life of the incandescent or halogen lamp well beyond that of fluorescent," he says. "And the quality of dimming, as it warms into the color spectrum—similar to that of a fire down to its last glowing embers, or the setting sun—is something that we inherently have branded into our psychology. Nothing else does that when dimmed. It would be sad to not have that in a built environment."

Use of improved metal halide lamps in retail installations has gained strong support from lighting designers and end-users alike. A member of the HID (high intensity discharge) family, the lamp's envelope contains metal halides, usually iodides, and produces a pleasing, highly efficient white light. "We really like ceramic metal halide (CMH) for retail and hospitality accent," comments Marty Peck, principal at Creative Lighting Design & Engineering, Germantown, Wis. "I'm a big fan of them; they are an ideal combination of color, control and cost." Peck's recommendation to install metal halide illumination at the Metcalfe Sentry Store in Wauwatosa, Wis., had the full support of owner Tim Metcalfe.

Lighting designer and consultant Bernard Bauer, who heads Integrated Lighting Concepts, Westlake Village, Calif., reports an increase in the number of metal halide installations as retailers accept its value-engineered benefits over other lower-priced alternatives. He points out that a metal halide lamp typically uses one-third less power to produce the same amount of light of an incandescent. Bauer cites Neiman Marcus and Costco as representative users of metal halide illumination. He recently visited a Los Angeles Costco store where metal halide was integrated with daylighting. "They had an extremely sophisticated lighting management system, combining a full-grid placement of skylights, and multilevel controlling of luminaires fitted with metal halide lamps," he indicates.

Bauer believes that current LED use is best considered for small-wattage uses rather than as an ambient light source replacement. "By reducing to 3 to 4 watts per linear foot, they are well-suited for point source illumination for china, glass and jewelry, and for undercounter use," Bauer says.

David Apfel, head of New York-based David Apfel Lighting Design, was responsible for the lighting design of the new Lacoste store at Fifth Avenue and 49th Street in Manhattan. Color-changing LEDs are featured in the windows and architecturally within ceiling coves on both floors. Apfel contends that white-light-emitting LEDs work well for close-in lighting, in such areas as shelf lighting and top-lighting for cubby-hole-type display units.

LED users and manufacturers are facing the problem of dissipating the heat that LEDs generate in heated retail interiors. "Heat is the enemy of LEDs," states Brad Koerner, solid-state lighting specialist for Philips Lighting. Siegfried Luger, editor of LED Professional Review, concurs. "Thermal management is a key issue in LED lighting systems because output, light quality and estimated lifetime depend on it. Even with high-efficiency LEDS, about 50 percent of input power needs to be dissipated," Luger wrote in a recent issue.

Architect and store designer Kenne Shepherd, principal of the New York-based firm that shares her name, cites the small profile of LEDs, especially in situations where, she says, "the light source disappears, such as undershelf lighting." Heat dissipation is definitely a factor that has to be considered in the design program, she says. Another factor Shepherd considers is having extra LEDs on hand when ordering the first shipment. "This is insurance that if a partial replacement is needed, the color will be identical because the LED lamps came out of the same manufactured batch," she says.

Safe disposal of fluorescent lamps for mercury extraction and reuse was urged by all interviewees. Apfel and Bauer agree that while many large-scale users of fluorescent lamps have recycling programs in place, small businesses and residences have limited participation. Supermarkets and building supply dealers could set up collection bins for used fluorescent lamps, much like bottle return centers, Apfel suggests.