Leading lamps: The lighting market embraces electrodeless technology

Mar 1, 2000 12:00 PM, William L. Maiman
The original post can be found here

"Look, no wires"--a familiar exclamation, one much in use by fans of induction lighting technology. Call it what you will (every manufacturer has a different name for it; designers know its chief product as the electrodeless lamp), its strongest features are a 100,000-hour life, low energy consumption, and a selection of very pleasing color temperatures.

The electrodeless lamp uses magnetic induction, instead of an electrode at each end of the fluorescent tube, to produce illumination. The absence of electrodes (or filaments/wires) is a significant factor behind the much longer lamp life. A conventional fluorescent lamp has an average life of 20,000 hours, with higher operating costs for its associated ballast.

The comparison to a fluorescent system is appropriate, since the operating theories of the induction system and fluorescent lighting are similar. The conventional fluorescent system, with its internal electrodes, utilizes the UV radiation generated by the internal discharge. The radiation is converted to visible light by the phosphor coating on the inner wall of the glass tube. Different phosphors provide for different color temperatures and corresponding CRIs.

Osram Sylvania's Icetron system incorporates an electrodeless fluorescent lamp that is excited by a radio frequency (RF) magnetic field. The two large ferromagnetic (metal) cores create a magnetic field around the glass tube, using the high frequency generated by the RF power converter (ballast). The discharge path, induced by the ferrite cores, forms a closed loop--it is this inductively coupled field that initiates, excites, and maintains the interaction between the electrons and the phosphor within the tube, converting the UV light to visible light. Under the leadership of Valery Godyak, the Osram Sylvania Icetron was developed as the firm's entrant into the induction technology field.

The Icetron lamp has an unusual shape, guided, says Bob Horner, marketing manager for fluorescent products at Osram Sylvania, "by physics, and the need to maximize the efficiency of the system." The choice of phosphors is directly related to the need to be consistent with conventionally used lamps, as well as to ensure the longevity of the 100,000-hour product and to decrease the amount of lumen fall-off that can occur over time. Its frequency is 250kHz, which is considered very safe, and meets the more stringent European standards besides all applicable Federal Communications Commission EMI (electromagnetic interference) regulations.

The Icetron is available in 3500K and 4100K color temperature versions, and in three model types: the 100/QT100 at 100W, with 8,000 lumens; a 100/QT150 at 150W, with 11,000 lumens, and the 150/QT150 at 150W, with 12,000 lumens. There are now over two dozen fixture manufacturers certified by Osram Sylvania to offer complete lighting systems based on Icetron technology (see chart, facing page), which outside North America is marketed as Endura.

Horner says the technology allows for installations in industrial environments; interior settings like atria and entryways; exterior applications such as landscape, under-canopy, and pole-mounted street lighting; and even backlit signage applications. With this technology, aesthetics aren't skimped on, either.

In an era of tighter budgets and more restrictive building codes, many LDs and specifiers are compelled to do more with less. Demanding clients want creative approaches and specialized lighting for their installations. For existing buildings, for example, the textbook approach has been to replace incandescents with compact fluorescents, then to replace inefficient linear fluorescents with metal-halide sources. The inductively coupled electrodeless lamp, with its choice of color temperatures and other features (see chart, page 85), allows for use in many venues that have been hard to light with conventionally equipped lighting fixtures.

Icetron's crisp white light, combined with its very long life, suit it for outdoor applications like parks and public plazas. New York City's Union Square Park, a turn-of-the-last-century park that was the first in the US to have electric light, was recently restored and renovated with assistance from Icetron. "The challenges for the new lighting in Union Square Park were to increase the quantity and quality of light, and reduce maintenance and energy consumption versus the existing high-pressure sodium (100W) system. The new technology achieved all these goals, and demonstrates that there should be no compromising design and maintenance issues for lighting application," says Peter Jacobson, lighting specialist for Con Edison in New York.

Sentry Electric developed the historically appropriate lighting fixtures that accommodate the 100W, 3500K, 8,000-lumen Icetron system. "Using this technology in a post-top fixture required a specially engineered reflector to be developed to allow for good light dispersion and to dissipate the heat associated with the Icetron. However, careful engineering has solved these challenges, and we have seen an increase in sales of Icetron-equipped systems," says Shepard Kay, Sentry Electric's vice president of engineering.

Sentry supplied 60 Union Square ball globe fixtures, which were installed atop poles cast from original 19th-century molds, and 121 Riverside fixtures (a tulip-contoured luminaire with a top decoration and finial), equipped with Icetrons. All units operate on 120VAC, a city standard. The system was formally switched on last spring, and was completely operational by fall. Public (and bureaucratic) reaction has been very favorable, and plans are to expand induction lighting technology in a retrofit of existing roadway fixtures along nearby 14th Street, and possibly bring it to New York's Madison Square and Battery parks. (Currently, Sentry Electric has installed six 100W 3500K Icetron systems for testing and evaluation purposes.) Osram Sylvania's parent company, Siemens, has produced a videotape outlining the Union Square application.

Research is underway to develop a 20,000-lumen system which could provide designers with a comparable light to replace 250W metal-halide lamps. Dimming capability is also being actively explored by Osram Sylvania. Based on the level of activity surrounding it, the Icetron would appear to have a hot future.

Another entrant into this technology, from Philips, is the QL Induction Lamp. Its features include a white light with high CRI values, a 100,000-hour life, and high energy-efficiency, all enclosed in a glass envelope in the familiar bulb shape, similar to an A-lamp.

Operation is similar to other induction-type products, and the QL has three major components--the high frequency ballast (generator), power coupler, and bulb. The ballast contains an oscillator that introduces a high-frequency current (2.65MHz) into the power coupler, located inside the bulb. The power coupler consists of an inductive coil wound around a ferrite core, and is the only metal object within the bulb. Consistent with the term "induction," filaments (electrodes) are not used, providing long life. Completing the system is a coaxial cable connecting the ballast to the power coupler.

Philips says the principle is similar to a transformer. The core-and-coil power coupler produces a magnetic field, which then induces a secondary electrical current in the mercury vapor in the bulb. Similar to fluorescent lamps, the excited mercury ions produce UV radiation that strikes the phosphor coating lining the bulb, and emits the visible white light.

Philips uses two different phosphor coatings (the same as those used in its TL80 T-8 series) that allow the QL to be offered in color temperatures of 3000K and 4000K. Three styles are available: the 55W QL, at 3,500 lumens; the 85W QL at 6,000 lumens; and the recently developed 165W system, capable of producing 12,000 lumens.

This range of lumen packages has been incorporated into outdoor post-top luminaires, downlights, bollards, and other fixtures. The versatility of the QL shape easily allows for incorporation into lighting retrofits, especially for clients with demanding design requirements. The Comfort Inn in midtown Manhattan has numerous fiberglass bowl-type fixtures suspended 20' (6m) above its cozy lobby. "The hotel management wanted to retain its beloved fixtures, and not replace them, and still achieve the benefits of conversion to QL. They were primarily interested in the long life characteristic, which would eliminate the frequent (almost every three months) cycle of lamp changing. We designed a replacement of the three-lamp (100W) incandescent electrical component with one 85W QL at the 3000K temperature," says Judi Nadel, president of Energy & Lighting Systems.

The lighting retrofit (conducted under the Shared Energy Savings Program, administered by Con Edison) retained the muted look of the fixtures and was consistent with their originally measured lumen output, while generating substantial energy savings for the hotel. Nadel says that while saving energy was the impetus behind the introduction of induction lamp technology, an equally important consideration was the time saved on changing the lamps, a process that inevitably discomfited the Comfort Inn with scaffolding, ladders, and floor protection.

The QL's versatility will further increase as more manufacturers release fixtures based on this technology. So far, the QL has also been used on exterior lighting projects within numerous historic districts throughout North America, lanterns in the Museum of the City of New York, downlights over escalators at JC Penney stores, and a test installation of QL-equipped "jelly jars" on the George Washington Bridge in New York City.

Long 100,000-hour life High lumen output Instant on (regardless of temperature) Cold-weather starting, as low as -40 degrees F Instant restrike Wide operating temperature range 80-85 CRI provides excellent color rendition Consistent color over system life Two color temperatures available High system efficacy Flicker-free illumination Electrodeless design Universal operating position Low EMI, compliance with applicable regulations

Compact Fluorescent Systems (CFS), Marlboro, NJ Cooper Lighting, Chicago, IL Esco Lighting, Chicago, IL 1st Source Lighting, Auburn, CA Hadco, Littlestown, PA H.E. Williams, Carthage, MO Hi-Tek, Conyers, GA Holophane, Newark, OH Incon Industries, Sanford, FL Infinity, Carthage, MO Intrepid, Ronkonkoma, NY Kim Lighting, City of Industry, CA Louis Poulsen, Miami, FL Nu-Art, North Salt Lake, UT Pacific Lighting and Standards, Lynwood, CA Paramount Industries, Crosswell, MI Phoenix Lighting, Milwaukee, WI Quality Lighting, Franklin Park, IL Robert Lighting & Energy, Fairfield, NJ SPI Lighting, Mequon, WI Sentry Lighting, Freeport, NY Spring City Electrical, Spring City, PA Sterner, Winstead, MN Tri-Star Lighting, Huntington Valley, PA Widelite Outdoor, San Marcos, TX Winona, Winona, MN Zumtobel, Highland, NY

General Electric Osram Sylvania Philips Lighting