Can dimmer switches be use on lights that use CFL bulbs? -Glenn
While there are special dimmable CFLs available, most CFLs cannot be used with a dimmer. Unless the CFL bulb specifically says on the box that it is dimmable, don’t use it with a dimmer switch. Even dimmable CFLs may not have as great a dimming range as regular incandescent bulbs.
The ballast on standard CFL bulbs requires 110 volts to work properly, and a dimmer switch works by lowering the voltage to the lighting fixture. Dimming a CFL that is made to operate at 110 volts will cause it to not light at lower voltages, and it may shorten the life of the bulb.
More information on dimmable CFLs can be found on the Energy Star website at their CFL Frequently Asked Questions page.
You can find a list of dimmable CFL bulbs at Energy Star Advanced CFL Search. Check the “dimmable CFL” box then click on “Find CFLs” at the bottom of the page for a list of manufacturers and dimmable bulb model numbers.
For more information on CFLs, check out our article CFL: A Bright Idea for Going Green.