Induction Technology: A New Generation of Light, Part II

This is the second part of the featured article on Archtectural Lighting. The original post can be found here:

THE FIXTURES

Jacques LeFevre, president of Indy Lighting, remembers the introduction of induction sources in the early '90s. "The first applications were outdoors and the lamps were quite expensive, so we didn't get too excited," said LeFevre. (Indy specializes in specification-grade fixtures for retail and commercial environments.) "But a couple of years ago, our customer base started to show an interest in induction lighting because of the long life, so we began working on fixtures for places like escalator wells and ceilings over open mall areas." Their first product was an induction downlight using the Icetron lamp that was installed above escalators and outside entrances to several Dillard's department stores. Indy now offers standard fixtures using both the 100W Icetron and the 85W QL lamps. Although LeFevre is enthusiastic about induction technology, he wants to be sure that limitations such as temperature control of the generators are addressed. He added, "Premature failures are always bad, but in the places we're putting these fixtures, they would be very costly to replace."

Bob Fiermuga is the owner of Eclipse Lighting, a company that specializes in decorative outdoor luminaires. He said, "We are fascinated by induction technology—we think some of the bigger manufacturers may be overlooking this market." Eclipse offers the 55W and 85W QL lamp in its Galileo outdoor wall sconce, as well as in several institutional and vandal-resistant fixtures. "Induction lighting is a premium system, but the maintenance benefits are worth it," said Fiermuga. "The public sector in particular is always looking for ways to trim their maintenance budgets." He also thinks that induction lighting makes sense for parking garage illumination. Although maintenance access is not difficult for these fixtures, they usually burn 24 hours a day, making the long lifetime an attractive feature. Eclipse offers four different garage fixtures that use either the 165W QL and the 150W Icetron lamp.

Another good place for induction lighting is in bollards. "We've been amazed at the interest in induction-lit bollards," said Kathleen Romfoe, product manager for Phoenix Products Co., an outdoor luminaire OEM. "Owners like the fact that you can put them out there and forget about them. We're selling them to municipal governments." Phoenix offers the 55W and 85W QL lamps in most of their bollards and in some shaded pendants and gooseneck fixtures.

Some of the key applications for induction lighting are roadway environments, particularly in tunnels and underpasses where maintenance is a real challenge. Robert Small, an engineering specialist with the Texas Department of Transportation (TxDOT), says that to change some lamps over roadways requires a small battalion of workers, including bucket trucks equipped with crash cushions, flashing arrow vehicles, cone placement and retrieval, and even police cars. TxDOT is now installing three different types of induction fixtures on a testing basis in the Spring Valley Tunnel in Dallas. "If we get the expected lifetime out of these lamps, we won't be going out there to touch them for 20 years," said Small, noting that test installations are also underway or planned in El Paso, Austin and Ft. Worth.

The Texas installations demonstrate an additional benefit of induction technology: luminaire positioning. Typically, sodium fixtures are mounted to the side of the roadway for maintenance access, so they must throw light across the road. The induction fixtures can be mounted right over the road where they can more effectively and evenly illuminate the road surface.


LINGERING CONCERNS

Induction sources pose technical challenges, most of which have been addressed by vendors now that the technology is nearly a decade old. Early systems faced concerns about electromagnetic interference from the field generators, but today's products meet FCC 47CFR Part 18 Non-Consumer certification, and complaints are just about non-existent.

LeFevre points out that the relatively small lumen package of the induction sources poses a challenge for luminaire designers. He said, "We want to put these things in high-ceiling areas to get the maintenance benefits, but you need a lot of light to reach the floor from up there." The larger 165W Philips QL lamps have helped address this problem. Another consideration is that the induction sources are essentially big blobs of light, so it's more difficult to design an effective reflector for them than the small arc tube of HID sources. Eclipse's Bob Fiermuga notes that the shape of the QL lamp makes it more applicable for refractor-type downlights, while the flat profile of the Icetron makes it more appropriate for cutoff-type floodlights.

A final concern is the temperature sensitivity of the generator, which is a solid-state electronic device that can fail prematurely if it gets too hot. While HID systems can operate at temperatures of 90-105 degrees Celsius, induction systems are limited to the 70-75-degree Celsius range. Danny Lambeth, president of Infinity Lighting, explains that his engineers have been working for the past four years to solve the temperature limitations associated with induction technology. "If you exceed the rated temperature, the warranty is out the window," he said. Still, with careful design and testing, Lambeth thinks induction technology can do the job. He noted, "If you can design an induction fixture that can handle the heat, is watertight and explosion proof, it's a home run."


January/February 2002 Architectural Lighting Magazine