The most important information is that CFs shouldn't be used in places where you turn the lights on and off a lot--like a bathroom. They pull a lot of power to turn on, so if they're not on for at least 15 minutes, you're losing money. Also, they wear out a lot faster.

Most people know they can't be used with dimmers, but in addition to not dimming, dimmer switches also greatly reduce the life of the bulb.

Finally, there are CFs designed for outside use, but the ballasts are good only to about 5 degrees. So they're not practical for cold winters. And if you turn your outside lights on and off like I do, they're not practical, period.

I wish this info was on the packaging.

Kevin

Some CFs are rated for colder than 5F, the coldest I've seen was -10F. They'll usually start that cold but they'll be dim for quite awhile until they warm up. My parents have used a CF in an outside fixture for years now, its dim for the first hour or so but once it warms up internally its fine even at -20F.

Also, I have been a utility energy engineer and have done quite a bit of energy metering using ameters, handheld watt meters, and have a permanent energy data logging system in my house where I'm measuring the refrigerator, the lighting, dishwasher, clothes dryer, stove, microwave, washing machine, etc.

I've also individually measured current, watts, volts, power factor, on lighting. I've seen amperage surges on electric motors, especially when powering large centrifugal loads, but no such surge on lighting.

A month ago I retrofitted all two and four foot fluorescent lamps from older T-12 (1 1/2 inch diameter tubes) to T-8 (1 inch diameter) with electronic ballasts. There was a reduction in wattage from two 2 foot lamps from 44 watts to 30 watts for both 2 ft lamps.

In using a handheld Fluke power meter as well as my data logger, both showed no surge when turning the lamps on. Perhaps there is a surge of such short duration that it can't be seen. It certainly won't effect your utility bill. I also plugged in lamps w conpact fluorecents. No apparent surge, it was drawing 20 watts, .559 power factor, 35.8 volt amops (meaning the power company has to generate more power than necessary at their transmiion point) one second after I turned on the light fixture. There was very little variation in wattage after the light was on for several minutes.

Some compact fluorescents are designed with a high power factor and in the future it will probably be required. In any case the power company does'nt charge extra for this for residential customers, charging only for watts. To get a high power factor the manufactrer of the Compact fluorescent simply has to install an appropriatly sized capacitor.

A company called Lutron (Lutron.com) makes fluorescent ballasts that can dim standard lamps with their ballast and control. Then you can dim ballasts from full light to 1/100 light or better. And when you do so, energy is saved, not wasted. I plan to try one on my four foot fixture soon.

One last thing. LED's are being used more but until the Lumens per watt greatly exceeds that of the best fluorescnts (100 lumens per watt) they won't replace them unless its in an enviroment where labor to replace lamps is important (TV towers, etc.) I also use a high pressure sodium light fixture outdoors, which is more energy efficient per lumen than the fuorescent.

Julio

If any fluorescent lamp is broken there are small amounts of mercury inside. That's the oly thing I've heard. You can carry worry to an extreme, believin that electricity is harmful and refusing to use it. If CFL's are harmeful, what about TV's.

I think its likely cell phones can cause tumors but the cell phone industry aggresively defends their product. I think if CFL's were kept adjacent to someone's head that could also be dangerous, but they're not.