Two Good Reasons You Should Buy Fiber-Optic Lighting
Fiber-optic lighting can save energy and mean the end of hard-to-change light bulbs.
While shopping for interior lighting for the TOH TV project house that the crew worked on in Watertown, Massachusetts, homeowner Susan Denny found herself stumped when it came to how to illuminate the central stairway.
An antique oak beauty, the staircase deserved to be bathed in flattering light, not to mention the fact that this route was now the only access to the second floor and would receive a lot of traffic. She worried that wall sconces might get knocked into as she and her husband, Christian Nolen, lugged furniture up and down.
Recessed lights would solve that problem but create another: "To change a bulb, we'd have to set up a ladder on the stairs," says Denny, "and neither of us was crazy about that."
Their solution came in the form of a thin filament of plastic. For the six ceiling lights, the couple chose ones that use fiber-optic cables, the same cables that carry ultra-clear telephone and computer signals. Yet instead of carrying digital information, these cables transmit light from a single bulb located, in this case, in an attic closet where the bulb can be changed easily whenever it burns out. When a bulb is pointed directly at one end of the cable, composed of a solid core of acrylic in a black plastic jacket, the light reflects internally even if the cable makes a turn — acting like a tube of light. Then it emerges as a single beam of bright light at the other end. "Think of fiber optics as a light 'pump' pushing the light out from one bulb to as many cables as you want," says Doreen Le May Madden. As the owner and principal lighting designer at Lux Lighting Design in Newston, Massachusetts, Madden designed the lighting for the entire Watertown house.
Beyond the techie appeal of fiber-optic lighting, there are some bright advantages to the system. The cables carry no electricity themselves, and they don't heat up. This has made them popular in museums, where artifacts can be damaged by the heat from incandescents. Stringing lights outdoors has always been troublesome because of the threat of electric shock in the rain, but these cables carry no such risk. The bulb can be mounted indoors, and the cables alone can wind their way to light gazebos, patios and gardens. "I'm using these cables underwater to light up a small pond for a client," says This Old House master electrician Allen Gallant. "That way, you'll never have to stand in a puddle to change a bulb — which is okay by me." Fiber-optic lighting in houses is brand new, so new that no one has any idea how fast the market is growing or how popular this innovation will eventually become. "We've just set up a group to study that," says Kyle Pitsor, a spokesman for the National Electrical Manufacturers Association in Rossyln, Virginia. Among other projects, the committee will work to set standards among the different manufacturers, who now make equipment that is by and large incompatible. New advances in technology have made it easier to bunch cables together and couple them to the main light box, or illuminator. "It's pretty easy to install," says Gallant and, because of this, experts foresee the day when an entire house will be lit using fiber-optic cables. "It'd be such an energy saver because you'd be able to use so many fewer bulbs," says Madden. "These will be the lights of the 21st-century." Some glitches have yet to be worked out. Foremost, lights using fiber-optic cables are costly. The lighting box with the coupler for cables big enough to run six lights might run between $500 and $750. Then comes the cost of the cable. Cables made from thousands of strands of glass, rather than plastic, are easier to bend and carry light on longer runs than their acrylic partners. They also hold up longer, because the glass remains stable and will never discolor. But the cables do cost about $10 a foot — making them useful to highlight a few Rembrandts but hardly worth it for some overheads on a staircase. As an alternative, acrylic cables costing half as much are suggested for use at home — even though they may discolor over time, leading to a drop-off in the wattage they pump out at the other end. Glass cables need to be custom-cut so that they have a nice crisp edge that doesn't scatter the light, but their plastic cousins can be trimmed on the jobsite. Still, no ordinary wire cutter will do. They require a special pair of fiber-optic cable cutters that clip the ends at 90-degree angles. "If you mar the edges, you'll get less light flowing through the end," says Gallant. And while computer signals might bounce unimpeded through a cable, light gets weaker as it reflects its way along. Light traveling through a glass cable loses about 1 percent of its intensity over each foot traveled, even more when traveling through bends. But the acrylic cables lose about twice that. "If you go over 50 feet with a cable, then you start having noticeable light loss," says Madden.
The biggest problem with the acrylic cables, unlike the glass ones, is that they might degrade. Heat can cause the plastic sheathing to oxidize and discolor the plastic within. Another problem is dust — of the sort that swirls around tornadolike during most renovations. Dust will not only dim the light transmission if particles work their way into the ends of fiber-optic cables but will also cause deterioration of the plastic cables over time. "They attract a lot of dirt, sort of like a magnet," says Pitsor. He recommends installing the lighting systems "in as clean an environment as you can get." Finding a contractor who can do that might be difficult, he concedes. "I'd say about 80 percent of the electricians out there wouldn't know what to do with this," says Madden. As with anything else, never volunteer to be the guinea pig for your contractor. Instead, Madden suggests looking in the yellow pages for a theatrical lighting installer or supplier, who will be the most likely at this point to have experience with fiber-optic cables. Working in a third-floor closet at the house in Watertown, Gallant installs a light box with a 100-watt halogen bulb. He then attaches a coupler with the six cables to be lit. "To avoid dust contamination, I work on a day when there isn't a lot of construction debris — no Sheetrocking or floor sanding," he says. The cables wind down through the wall studs and emerge in the ceiling of the stairwell. There, they are fitted with a magnifying glass lens that spreads the light over a greater area. When finished, the lights cast a subtle glow over the steps beneath, much softer than the light that ushers from a conventional recessed light. A subtle glow, and convenience, too. "The fact that we don't have to worry about suspending ourselves over the stairway to change light bulbs is a good thing," says home owner Denny.
The dazzling constellation that adorns the ceiling of New York City'sGrand Central Terminal, above, has a ligh-tech glitter to it nowadays. During a recent renovation, the illuminated ceiling was retrofitted with fiber-optic lighting. "The hardest part was getting the intensity of the stars right," says Richard Renfro, a lighting designer who conceived the project. The old constellation was lit by 72 10-watt bulbs. Now, seven fiber-optic illuminators house light bulbs, and each is connected to ten flexible cables that crisscross the ceiling. Each cable terminates in a star, but filters modulate each star's intensity. A hidden plus: the illuminators rest together on a catwalk that runs down the center of the ceiling's apex, so bulb changes are now as simple as a stroll.