Dimmer switches work by chopping up the AC current flowing between the switch and the light. Rather than literally “dimming” the light itself, these switches actually cause the current to undulate or flicker extremely rapidly, so that to our human eyes, it appears that there is less light. The interrupted current can produce a vibration in the electromagnetic field within the light bulb filament or within the switch itself, which can cause a humming or buzzing noise.
Here are some steps you can take to reduce or eliminate the annoying sound:
1.Change Light Bulbs: If the sound is coming from the light fixture itself, you might try a different type of bulb. Decorative bulbs, with their long, delicate filaments, are more susceptible to the changes in magnetic field. Standard and rough service bulbs, such as those used in workshops and appliances, have tougher filaments that might stand up better to the choppy current.
2.Upgrade Dimmer Rating: If the sound is coming from the dimmer switch, you may be overloading the switch’s capacity. Dimmer switches are rated according to the maximum wattage they can handle. If you’ve installed high wattage bulbs in your chandelier, the switch may be over capacity. You can check this by removing a few bulbs and seeing if the buzzing gets better. Or by checking the wattage rating on the switch against the sum of the wattage of all the bulbs. If so, reduce your overall wattage, or look for a dimmer switch with a higher wattage rating.
3.Upgrade Dimmer Switch: With dimmer switches, you get what you pay for. Buzzing is more common with cheaper triac-based switches (a triac is the gizmo inside the switch that chops up the current). Better quality triac dimmers have an internal choke or filter that evens out the current and can reduce buzzing. Or, you can go for an even higher quality dimmer that uses an autotransformer, rather than a triac, which causes much less interruption to the current.
4.Consider Lighting Usage: If you always use the lights on a dimmed setting, consider installing lower wattage bulbs so the dimmer doesn’t have to work as hard.