The lighting revolution that is now underway is seeing the incandescent bulb slowly go the way of candles and oil lamps. Incandescents' acclaimed heir apparent, the compact fluorescent light bulb (CFL), now accounts for about 25 percent of household bulbs in the United States, according to the National Electrical Manufacturers Association. And there is plenty of reason for its popularity: the bulbs use as little as a fifth of the energy of an incandescent to generate equivalent lighting and have longer lives than incandescents--many CFLs promise up to seven or even nine years of service (assuming 3 hours or so of use per day), adding up to many thousands of hours of lighting. These energy savings help reduce greenhouse gas all temissions from power plants while simultaneously lowering electric bills.
That's not to say this quality light source doesn't come without its own problems. These pricey bulbs occasionally go out with a smoky, smelly bang and, like any other product, they can fail well before their promised lifetime is up.
Unlike incandescent bulbs, which generate light by running a current through a metal filament, CFLs have hundreds of electrical components. The more parts in a system, the greater the opportunities for of one of them to fail, says Conan O'Rourke, technical director at the Lighting Research Center at Rensselaer Polytechnic Institute. In a bulb that burns out early, the electronic components may have been inferior in quality or poorly installed, or the bulbs might have been physically damaged in some way during transport from China, where most are manufactured.
The electrical components also complicate the end of life for the CFL. When dying a timely (or untimely) death, a CFL's components may not get the message that the bulb is no longer working, and it continues to let electricity flow through the plastic base to the nonworking bulb. This creates a puff of smoke and an acrid smell as well as a charred blackening that appears at the bulb's base. This pyrotechnic display may also be spurred by a dried-out electrolytic capacitor--the "weakest link" in a CFL, according to O'Rourke. Still, for a large number of situations, the CFL is the best, brightest, most efficient bulb for the job. You just have to know what that job is, what CFL to look for and a few handy tips to make the most of your bulb.
CFL Solutions: Making the Most of Your Bulbs
Leave Them Running
CFLs do not fare well when flicked on and off repeatedly, so they'll last much longer if turned on for several hours--instead of minutes--at a time. "The more continuous the use of a bulb, the longer it'll burn because the most damage to the components is done during starts," says Russ Leslie, associate director of the Lighting Research Center. Accordingly, CFLs are recommended for use in living rooms and bedrooms where the light will stay on for the evening, rather than in closets, where a quick burst of light is the norm. Choose incandescent bulbs in areas where lights are used for short amounts of time.
Of course, that doesn't mean you should leave CFLs constantly running. Although one could get as many as 18,000 hours out of a CFL by leaving it on for 12 to 24 hours at a time, "You'll pay more in your energy bills overall than you would for periodic bulb replacements," Leslie says.
Pick the Right Bulb for the Right Job
With any light bulb, placement counts, and CFLs are no exception. The typical CFL will work in most of the same fixtures and orientations as an incandescent, though one notable exception is in the overhead, recessed cans often found in foyers. Trapped heat in a recessed lighting fixture can fry a CFL unless it is specifically designed for such a placement.
To find the right bulb, make sure to read labels thoroughly and watch out for "not intended for" warnings. In vibration-intense environments such as a garage door opener, for example, incandescent bulbs are likely to be the best choice, thanks to a CFL's propensity to run interference (especially around 0.45-30 MHz). Also, look for specific advice about bulbs suited for applications such as dimmers, where you will need a specialized CFL bulb.
Prevent a Smoking Bulb
Despite appearances, the rare case of a smoking bulb is not a fire hazard, according to O'Rourke and Terry McGowan, director of engineering with the American Lighting Association. The ballasts are made from flame-retardant material and bulbs for sale must meet safety-code requirements as prescribed by Underwriters Laboratories (the little UL you see on many electronic devices). But to help prevent a smoking bulb, some manufacturers, like TCP, have bulbs that go farther for safety with an "End of Life Logic" system that makes sure they won't end their service lives in such an alarming fashion. Look out for more of these smart bulbs in the near future.
Pay The Price
At $3 to $5 for a quality bulb versus less than a buck for an incandescent, buyers have reason for their annoyance with early failures. Still, as happens with most products, you get what you pay for, says McGowan. While consumers might be loath to pay the higher-end prices for a bulb that is already significantly more expensive than a classic incandescent, buying a CFL in a 99 cent store is not be the best way to reap the bulb's efficiency rewards.