Monday, March 15, 2010

"The buzz on dimmable CFL light bulb"

More and more consumers will discover that CFL bulbs are not going to be a viable solution in applications where dimming is desired.

Even CFL bulbs that are "dimmable" are:
  1. Only partial dimmable - usually they cut off once they reach 70-80% dimmed.
  2. They "cool" instead of "warm" when dimmed.  This means their color temperature moves to a blue/white light versus the orange/red shifts that we get (and expect) from an incandescent bulb
  3. Only dim once fully up to brightness - often taking up to two minutes.  
  4. Will not come back on at the pre-dimmed level once they have been turned off.  You have to start the entire process -  turn on, warm up, dim down process - each time you use the bulb
  5. Require that all bulbs on the circuit be identical (dimmable, same wattage, same manufacturer).
  6. Often cause the dimmer to buzz

From the Seattle Times:

"We have looked at around 20 different brands and although some of them get close, the science is not yet there," McLellan said. "We do hear of some success, however, usually with high-quality, brand-name bulbs and dimmer switches." Sometimes it's a matter of finding which brand of bulbs works with specific dimmer switches. You may need to change the dimmer."