All about CFLs
Compact fluorescent light bulbs (CFLs) use up to 75 percent less energy than traditional incandescent bulbs and last about six times longer. Over the years, users have criticized these energy-saving bulbs for a host of reasons – from harsh light to humming noises to health concerns. But the CFL has come a long way since it first hit the market, and one of the hundreds of Energy Star qualified models available may be a good fit for you. Keep the following considerations in mind as you make your choice, and find a new-to-you way to shrink those energy bills.
How CFLs work
CFLs produce light by driving electric current through a tube containing argon and a small amount of mercury vapor. This generates invisible ultraviolet light that excites a fluorescent coating (called phosphor) on the inside of the tube, which then emits visible light.
CFLs require a bit more energy when they are first turned on, but once the electricity starts moving, are far more efficient than their incandescent counterparts. A CFL’s ballast helps “kick start” the bulb and regulates the current once the electricity starts flowing. This process typically takes 30 seconds to three minutes to complete, which is why CFLs take longer than other lights to become fully lit.
One of the most common complaints with early CFLs is that the light they provide is harsher than that of traditional incandescents. But the wide profile of choices on the market have made this issue a thing of the past.
“All of the light bulbs now have a label on them called the Lighting Facts label, and it will tell you whether that product is going to put off a warm light or a cool light,” Jantz-Sell told Earth911.
Before purchasing a CFL bulb, check out the Lighting Facts label on the packaging. Bulbs labeled with a warmer color, typically in the 2,700 to 3,000 Kelvin range, will give off a warm yellow light, while bulbs labeled with cool colors (between 5,000 and 6,500K) will give off a bright blue that mimics natural daylight.
Humming and flickering
Problems with humming noises and flickering light have largely been addressed by improvements in CFL technology. Magnetic ballasts run fluorescent lamps at about 60 cycles per second, which causes the lamps to flicker noticeably. The new generation of energy-efficient fluorescent lamps, including Energy Star qualified CFLs, use electronic ballasts, which operate at a minimum of 40,000 cycles per second – eliminating perceptible flickering, according to Energy Star.
That said, if you notice humming noises or flickering light, this is likely a sign of loose parts in the ballast. Contact the manufacturer or return the bulb to the store where you bought for a replacement, Energy Star advises.
CFLs require a small amount of mercury (about 4 milligrams per bulb on average) to produce light. To put that figure in perspective, the mercury content of a CFL is less than 1 percent of the amount present in the mercury thermometers of years passed. That said, many users still express concern about trace levels of mercury, which may lead them away from purchasing CFLs.
If you’re concerned about mercury content, consider a shatter-resistant CFL, like these options from Philips, which have a coating on the outside that greatly reduces the risk of breakage, Jantz-Sell said. LEDs are extremely durable and do not contain mercury, so you can also go with those for fixtures in precarious locations to reduce your risk of mercury exposure.
If you’d rather not use CFLs at all due to mercury content, this may be a factor in your decision to go with LEDs instead. But keep price differences in mind when making your choice. Click here for more information about mercury in CFLs and what do if you happen to break a bulb at home.
Hesitant about how an exposed spiral bulb will match your lovely home decor? You’re not alone. Due to customer concerns about aesthetics, CFL manufacturers have debuted bulbs in a wide variety of shapes and sizes to mimic the appearance of incandescent bulbs, from rounded globes to pretty candles. They may be easier on the eyes, but these alternative shapes do have their drawbacks.
“With that aesthetic benefit there are some trade-offs,” Jantz-Sell says. “So, it’s important for people to realize that if you put a cover over a CFL it’s going to take longer to reach its full brightness.”
If you have the patience to wait a minute or two for your bulb to brighten up, go for it. But keep this fact in mind when purchasing your CFL to ensure you have the best experience, she suggests.
For best results, leave your CFL bulbs on for at least 15 minutes at a time. Flipping your bulbs on and off frequently can shorten the bulb’s lifespan, Jantz-Sell says.
“CFLs don’t like to be switched on and off a lot,” she told Earth911. “For Energy Star we have testing to make sure they can withstand a lot of switching, but it’s one of those things that will inevitably cause early failures.”
Choose the right bulb for your fixture
Different fixtures often require different light bulbs. Energy Star qualified CFLs are available with special features, such as dimming capability and three-way lighting, to accommodate most fixtures. Special considerations should also be made when using your bulbs outdoors or in the bathroom. Keep in mind that the bulb you choose must be compatible with your light fixture.
“It’s very important to read the packaging on all of these products to make sure you know that they’re going to work in your particular application,” Jantz-Sell says. “So, unfortunately it takes a little bit more effort nowadays to choose a light bulb.”
Read the packaging carefully to be sure you’re selecting a compatible bulb. For more guidance on how to choose and where to use your bulbs, check out the Energy Star Choose a Light Guide – which allows you to browse a virtual home and learn about the bulbs that are best suited for different fixtures.