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Shedding light on the controversy over fluorescent bulbs

Compact fluorescent light bulbs are a revolution in the lighting technology industry, which improved and miniaturized fluorescent technology so that bulbs could fit into regular light-bulb sockets. They last 10 years and use about a quarter of the energy of traditional light bulbs. The technological revolution happened 20 years ago - but the consumer revolution never arrived. The compact fluorescent light bulb (CFL) is found in less than 6 percent of U.S. households.

Then came Wal-Mart. The retailer recently announced its intention to put compact fluorescent light bulbs into 100 million homes. Media controversy has been rising ever since. Neighbor against neighbor, it seems everyone has a rabid opinion about the bulbs. How could light bulbs create such controversy? There appear to be more opinions than bulbs.

Each CFL saves $30-$40 in energy, which translates to nearly 1,300 pounds of carbon dioxide and 20 pounds of sulfur from coal-fired power plants over each bulb's lifespan. What's not to like?

Plenty, say many consumers, who complain about fluorescent bulbs' headache-inducing flicker, unflattering color and annoying buzz. We've all experienced the horrors of a buzzing, flickering, ghostly fluorescent light that makes you feel like you're trapped in a Frankenstein movie. Who would ever voluntarily introduce the torturous devices into the tranquility of the home?

Experts counter that the stereotypes associated with fluorescents are outdated and mere ignorance keeps the stigma alive. Who's right?

The renewed controversy sparked my attention. I admit that before writing this article I thought I knew all that needed to be known about fluorescents. I found the topic has more twists than a mountain road. Let's see if we can shed some light on the topic.

Most fluorescents sold today for residential applications are called compact fluorescent bulbs, which resemble traditional incandescent light bulbs in shape and size and can be screwed into the same sockets. CFLs were made possible by the development of electronic ballasts, which have largely replaced the old magnetic ballasts, and many incremental improvements in fluorescent technology, including cost reduction, better gases and improved manufacturing techniques.

Color and heat

Incandescent bulbs have been known to create warm, comfortable color that is pleasing to the eye. It is no wonder. Incandescent bulbs burn very hot, in many ways emulating our most ancient artificial light source: fire. Unfortunately, the warm glow from incandescent bulbs, their best quality, is also the biggest problem. When you burn power in any light bulb, the electricity is transformed into either heat or light. The more heat you have, the less light you have - simple physics. Incandescent bulbs produce a lot of heat and only a little light, making them the "gas guzzlers" of the lighting world.

Because lighting represents 15 percent to 25 percent of a typical household's electric bill, it really adds up. The heat produced by incandescent bulbs increases cooling bills in the summer. That same heat is what makes them burn out so fast that the average bulb lasts 750-1,000 hours, compared with fluorescent's 10,000-hour usage.

Compact fluorescent color

What about fluorescent bulbs? Most of the electricity is translated into light with very little loss in heat, but the light is bluish and ghostly, right? Yes and no. Fluorescents use phosphor instead of a burning filament to create light. Back in the day, the phosphor used for fluorescent bulbs was very white and of limited spectrum. Compared to incandescent, the light seemed bluish. Now, quality residential fluorescent bulbs contain a number of different phosphor gases with a range of colors that increase the spectrum of color available.

CFLs are now available in an assortment of color ranges. The cooler, whiter shades are more energy efficient and provide better contrast for reading and other tasks, so they work best in reading lamps, kitchens, garages and offices. Warmer-color bulbs are more important in bathrooms, where makeup is applied, and where softer ambient light is desired, such as family and dining rooms.

The best way to evaluate color is based on the temperature of the light, which is done on the Kelvin scale. Unfortunately, many manufacturers do not provide this information on the consumer packaging, preferring a shorthand that varies among brands.

In side-by-side tests, consumers cannot distinguish the differences in fluorescent versus incandescent light unless they see the bulb. However, when evaluated on a spectrograph, the range of colors varies between fluorescents and incandescents, with fluorescents tending to peak sharply.

Forrest Linebarger is CEO and chief designer at VOX Design Group Inc. He lives in Los Altos and has been designing and building sustainable homes for more than a decade. For more information, e-mail This email address is being protected from spambots. You need JavaScript enabled to view it. or call 694-6200.

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