Everything you ever wanted to know about CFLs but were afraid to ask

OK, maybe not everything, but we're here to point you to many experts around the Web who have the hard facts about compact fluorescent light bulbs.

Maybe you've heard some troubling things about them (Oh no, mercury!). Maybe you think you already know it all. Or maybe you're totally new to the swirly bulbs.

No matter where you stand, you and I can always learn a few more things. So here goes. 

Why CFLs?

Simply put, these bulbs use less energy than regular old incandescent lights. Energy Star-qualified CFLs use 75% less energy.

In addition, Consumer Reports found that CFLs last 3,000 hours before wearing out, compared to only 1,000 hours for a standard bulb.

Since the bulbs draw less power, each one you install will save you $30 or more in electricity costs over its lifetime, according to Energy Star.

Bottom line: CFLs cost a bit more than incandescents in the first place, but you save in the long run because you won't spend as much on your utility bill each month or buy as many replacement bulbs.

One last bonus: CFLs create 75% less heat, so they're safer and don't heat up your house.

Where can I use CFLs?

Most lighting fixtures that accept standard incandescent bulbs will also take CFLs. Just look for the right size and similar wattage, which will be noted on the CFL package.

Lights with dimmer switches or three-way switches need CFLs specifically designed for dimmers. Read the label for this info too.

CFLs are not well-suited for recessed lights, and you may want to get a specially rated CFL for a ceiling fan fixture because of the extra vibrations. Otherwise, most places work.

GE Lighting has a comprehensive list of frequently asked questions about using CFLs, and while it recommends GE products, the info. is still useful. 

Don't CFLs give off a nasty, harsh light?

People have their own tastes and perceptions of light, so ultimately, you'll have to test out different CFLs to see what works best for you. Broadly speaking, the early CFLs were harsher and the cheapest ones still are. Avoid the bargain bin for better quality light.

Popular Mechanics has a detailed comparison of eight commonly available brands. The reviewers gave high marks to several bulbs, but the N:Vision Soft White CFL got the highest grade for "reading and illuminating faces."

Grist also reviewed several CFLs and found the Philips Soft-White was the best of the bunch, providing a " nice warm glow." In general, Grist says to pick bulbs described as "soft white" instead of ones labeled "daylight or bright white."

A friend said his CFLs burned out fast...

Every new technology has horror stories and "I got a bum deal" tales. Sometimes, this is frankly due to user-error, but it can also be that the product simply wasn't suited to the application.

CFLs work better in lamps and fixtures with a bit of space around them, as opposed to recessed lighting, which can trap heat and cause premature burn-out according to National Geographic's Green Guide.

Also, don't flick the switch! Turning a CFL fixture on and off quickly also can shorten the bulb's life. Energy Star recommends using CFLs in fixtures that are generally left on for at least 15 minutes each use.

Using regular CFLs in light fixtures with a dimmer switch will shorten their life dramatically. Use only CFLs clearly labeled as "dimmable" for this purpose.

Energy Star-qualified CFLs automatically come with a two-year warranty, so you should be able to get a replacement or refund from the manufacturer if this kind of bulb burns out unexpectedly.

How can I dispose of CFLs? What about the mercury?

Yes, there is a trace amount of mercury in CFLs. But it averages only 5 milligrams — for comparison, a home thermometer has 500 milligrams. So you'd have to break 100 CFLs to expose yourself to the same mercury as in one thermometer, according to the Energy Star fact sheet (PDF).

Still, light bulbs do break. The EPA has detailed instructions on how to clean it up, and the method isn't hard. Open a window, and much of the potential harm will dissipate in about an hour.

You shouldn't toss old, unbroken CFLs in the trash because of that tiny bit of mercury. Instead, look for a recycling center in your area:

• EPA's CFL recycling programs by state


• Earth911's CFL recycling database -- click "More" next to the search box, enter your ZIP code, and then click "Go" to get a personalized list.


• IKEA — every store has a free "Take Back" CFL recycle bin.


• Hardware stores — chains like Ace and True Value are starting to collect CFLs.

Is there a connection between CFLs and migraines?

This question began popping up in early 2008 after an item in U.K Daily Mail presented questions asked by the Migraine Action Association as a statement of fact. No science has been offered to substantiate the suggestion that CFLs cause migraines.

The flip side of the same coin is that there are relatively few online resources refuting the claim.

EcoGeek came down hard on the subject, calling it a "crazy wildfire" of a rumor. TheDailyGreen.com also weighed in, quoting a representative from the migraine association as describing the connection between CFLs and migraines as "anecdotal." To date, no substantial research has been done on the subject that anyone's aware — or at least, that anyone has published online.

So there you have it. Compact fluorescent light bulbs save energy and money. Not great for dimmer switches and recessed lights, but the mercury won't kill you either. And you can try taking CFLs to the hardware store to recycle when they finally burn out after a long, bright life in your living room.