How to stop lighting dimmer switches from buzzing?

June 24, 2005 3:44 PM

Is there anything I can do about lighting dimmer switches that buzz annoyingly?

I've just renovated a house and the only thing that is annoying me are the dimmer switches. Each bedroom has six halogen downlighters in the (low) ceilings, controlled by a single dimmer switch. I know that most dimmers buzz a little, but usually it is very quiet and it ceases when the lights are turned on full. These switches are quite noisy, and the buzz quietens a little but never stops.

Will I have to hunt out quiet dimmers - and then sacrifice the visual continuity (all the switches and sockets match)? Or, is there anything I can do (or get my electrician to do) to remedy the problem?

posted by Glum to home & garden (6 answers total)

Your dimmers may be running at close to their rated capacity. (To find this out, try removing some of the bulbs and see if the dimmer gets any quieter.) You need a beefier dimmer, probably, or else split up the lights into two or three banks with separate switches.
posted by kindall at 3:55 PM on June 24, 2005

Perhaps the dimmers are the (common) triac-based ones? Are you sure the buzzing is coming from the dimmer, or is it coming from the lights? If it's the lights, then it's the current waveform generated by a triac dimmer. You shuld be able to find autotransformer-based dimmer units, which would be silent.

I think it's more likely what kindall said, though.
posted by 5MeoCMP at 4:07 PM on June 24, 2005

If you take the dimmer out of its wall socket, you should see a heatsink. Dribble some quick-dry epoxy on the places where this thing attaches to the rest of the unit, and that should help dampen the vibrations.

That is, if the sound is indeed coming from the switch, and not the light. If it's the light, you could try replacing the bulb with a flourescent, but I'm not really sure if you can even use a dimmer with those. Hmm.
posted by odinsdream at 4:20 PM on June 24, 2005

We encountered the same problem after installing 12-volt halogen track lighting we bought from Home Depot. They weren't much help, but a specialty lighting store was. Turns out they sell pricier dimmer units for the low-voltage track lighting, which is probably what 5MeCMP is talking about above. We switched them out, and it worked like a charm.
posted by heymarcel at 5:24 PM on June 24, 2005

. . . you could try replacing the bulb with a flourescent, but I'm not really sure if you can even use a dimmer with those.

Mostly, no - you can't.
posted by Kirth Gerson at 3:47 AM on June 25, 2005

Now, my experience comes from running stage lights on dimmers, not house lights, so this might not be exactly on.
With stage lights, they hit their highest hum not when they're being utilized to the utmost, but when they're being used below capacity. About 30% is going to give you the loudest hum. You might, in fact, be under-utilizing your lights. In that case, I'd try to find bulbs that use more power and get used to living in a brighter environment. Or replacing the dimmers.
(Go to your local Sylvania lighting outlet and talk to the people there. They'll be able to tell you what's wrong).
posted by klangklangston at 8:06 AM on June 25, 2005