- The Washington Times - Thursday, November 1, 2001

Buying a light bulb these days is no easy matter. The number of styles and designs is bewildering enough, but the modern consumer also is up against the claims of competing manufacturers asserting the different advantages of each of their products, many of which look remarkably similar.
Equally important is the design of the lighting fixture, to be sure the bulb works in a particular fitting. Sizes and widths vary. The bulb obviously must be compatible with the base of the fixture.
Most bulbs which professionals prefer to call lamps are categorized as either filament or discharge types. According to General Electric's Lighting Institute, incandescent and halogen bulbs, by definition, are both filament lamps because nearly all styles contain a wire (the filament).
In a filament lamp, Lighting Institute materials say, light is emitted by a tungsten wire that gets hot from having electricity pass through it. Thomas Edison used a vacuum in the bulb; today these bulbs are filled with an inert gas, such as argon, that lengthens the life of the filament. An electrical voltage similar to water pressure pushes a current through the filament, causing friction, which heats up the wire. Fluorescent bulbs use a different kind of gas.
Typically, the hot filament converts only about 6 percent of the electricity to light; 94 percent is wasted as heat. (Edison's original carbon filament lamp converted only 2 percent of the electricity into light.). Halogen bulbs are filled with a halogen gas that keeps the filament intact while it burns hotter. These bulbs last longer than regular incandescent versions and are more efficient, converting as much as 12 percent of the electrical charge into light.
Types of incandescent bulbs sold commercially keep multiplying, and as technology develops, the bulbs become more aesthetic as well as more efficient. A new halogen design has a heat-reflective coating that redirects radiated heat back to the filament, helping reduce losses, GE's Lighting Institute says.
Fluorescent and high-intensity lamps are gas-discharge lamps. High-intensity lamps include the mercury-vapor and high-pressure sodium lamps most frequently found in street lighting. Gas-discharge lamps, while generally more efficient and expensive, need a ballast to connect the lamp with an electric outlet. The ballast regulates the discharge and ensures that the current does not stop after the gas is set off by an electric "spark."
Fluorescent lamps are labeled as low-intensity discharge lamps and typically are linear in shape. Today's models, however, can be found in U shapes, in circles or twisted into compact shapes to fit household screw sockets normally used for incandescent lamps.

The key question for many homeowners is what is the most economical and energy-efficient method of lighting a house cheap incandescent light bulbs, more expensive incandescent brands or the costly but longer-lasting compact fluorescents and whether the trade-off in light quality vs. lower cost is worthwhile. Manufacturers may keep refining the technology to produce better-quality light at less cost, but trade-offs still matter. Economy in some respects (as well as what is meant by quality of light) still is in the eye, and pocketbook, of the beholder.
A person might choose a more expensive incandescent bulb that gives off a more flattering light and vow to save money by restricting use of the bulb. Or someone may prefer the whiter, brighter light of the traditional halogen bulb even though most halogen bulbs, though less expensive to buy, are not always energy savers.
Energy scares of late have made people more aware of the choice, helped along by federal rules in the mid-90s requiring a bulb's lumens, or light output, to be displayed prominently. Every bulb now must show the light output (lumens), energy used (watts) and average life (in hours) of the product next to this common-sense message: "To save energy costs, find the bulbs with the light output you need, then choose the one with the lowest watts."
One of the newest incandescent (filament) products on the market is a bulb that produces a light said to closely resemble natural daylight and therefore billed as "full spectrum light" or "natural spectrum light." The Real Goods catalog out of California, which gives advice in generic terms without mentioning manufacturer names, says that because "humankind evolved with full-spectrum light, it's only natural that bulbs approximating the sun's spectrum would be beneficial for us. Natural-spectrum bulbs permit you to read for long periods of time with less eyestrain. Also, they render colors more exactly: artists and craftspeople insist on them."
Reed Electric Co. in Georgetown sells a model by Verilux that costs $9.95 each but is claimed to last up to 5,000 hours.
The compact fluorescent bulb, known as CFB for short, is a relatively new gas-discharge item on the market. Consumer Reports in July 1996 called it the most economical bulb over time, even though its initial cost was high. (A 15-watt CFB is the equivalent of a conventional 60-watt bulb, which accounts for the savings.) The Real Goods catalog says the bulb lasts eight to 10 times longer than conventional incandescents and saves up to $80 in electricity per bulb because it uses less power. It may cost 10 times more, but at least the consumer is spared the trouble of replacing it very often. At Reed, a CFB costs $29.95 for any of three sizes.
Halogen still is popular in spite of its incendiary reputation, says Mike McReynolds, sales associate at Reed, which stocks "at least 50 or 60 different kinds of halogen lights" among a total of nearly 10,000 bulbs of all types. One $7.95 halogen model looks like a standard incandescent model and is said to last at least one-third longer. Mr. McReynolds maintains that a 300-watt halogen lamp is equal to 500 degrees of heat, or hot enough to use for cooking.
"But I don't recommend it," he jokes. "The eggs don't come out right."
Mr. McReynolds says both Georgetown and American universities have banned the use of halogen lamps in campus dormitories because many students were drying clothes on top of them and causing fires.
While recommending that all outdoor bulbs be halogen because they are better sealed than incandescent bulbs of a similar design, Mr. McReynolds warns halogen bulb buyers not to touch the bulbs with their hands "because the oil on your skin will reduce the light from the bulb."
Another drawback is putting halogen lights in cabinets near food and even canned goods that can be affected by heat. "The food can spoil, and the cans explode."


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