Ceiling fans are becoming more popular these days as they can save homeowners money by reducing the electric bills. But despite this advantage, it can be annoying when a ceiling fan hums whether due to low voltage or other problem affecting the fan's operation. In most cases, the humming sound is actually some part of the fan vibrating while the motor is running. Even though certain model fans are quieter than others, there are things that you can do to try to silence the noise.
Purchase a quality product. Ceiling fans are available in a wide range of prices; however, the cheaper models are often constructed from lower quality materials, including parts made from thin metal, which can cause a fan to vibrate or make a humming sound. Poorly assembled motor casings, in particular, can cause a ceiling fan to hum when operating.
Look for a ceiling fan with a motor large enough to operate that size fan. Some manufacturers use motors which are too small, and this can lead to humming. A ceiling fan must have a motor powerful enough to operate efficiently; however, a manufacturer might use smaller motors in larger fans either to cut costs or promote a product advertised as using less energy. Consumers should look for a ceiling fan that comes with a lifetime warranty on the motor, which usually means that it is a better product.
Change a light dimmer switch to a regular on-off switch. Most ceiling fans are not designed to work with a dimmer. Unless a dimmer switch is a better quality dimmer, or is specifically designed for use with a ceiling fan, the fan will probably hum when running. Installing the proper electric switch should make the fan motor less noisy. You also have the option of not using the wall switch to operate the ceiling fan or light. You can always use the pull chains to work the fan and light both. Screw wire nuts onto the wires disconnected from the wall switch, and then cover the electrical box and hole in the wall with a blank switch plate.
Check to see if your ceiling fan has a rubber spacer between the ceiling and the mounting bracket. Hugger style ceiling fans should have rubber washers between the motor flange and mounting bracket to help cushion the vibration. If your fan did not come equipped with these accessories, you can purchase them at a local home improvement or hardware store
Test the fan's different speeds. You may find that one speed produces less noise than another. A humming noise is frequently common when running a ceiling fan on low speed. Sometimes turning the fan up to a higher speed for few minutes and then setting it back down to a lower speed will help to quiet the humming.
Tighten the screws fastening the fan blades to the motor using a large flathead screwdriver. Check to make certain that the screws in the motor casing and mounting plate assembly are tight enough as well, and adjust if necessary. Oftentimes, loose screws can cause humming. You might also want to take a look at the light bulbs and screws securing the lighting fixture and glass light shades.