Can You Put a Dimmer on a Halogen Bulb?
Halogen bulbs can be dimmed in lamps with standard incandescent bulb dimmers, up to a point. Incandescent halogen bulbs produce a bright, white, long-lasting light that shows colors to their best advantage. They last two to five times longer than standard incandescent bulbs. The bulbs make use of the atomic properties of gaseous iodine and bromine, members of a group of highly reactive chemical elements called halogens.
How They Work
The halogen gas in the bulb basically recycles tungsten atoms that boil off the white-hot, tungsten metal filament. This process gives halogen bulbs their long life -- but it only works at extremely high temperatures. If a 120-volt halogen bulb is dimmed by more than 40 percent, to less than 72 volts, the process stops and the wayward tungsten atoms instead stick to the glass walls of the bulb. In a relatively short time, the filament weakens and breaks.
Some halogen bulb makers say you can minimize adverse effects on halogen bulb life caused by dimming. They recommend keeping the light level above 60 percent of full brightness, and returning the bulb to full brightness for at least one minute before turning it off. Halogen bulbs may be of higher wattage than standard incandescent bulbs, so your dimmer should be rated for the wattage of the halogen bulbs it controls.