An attic fan is meant to reduce the temperature in the attic by sucking out hot air. Most attic fans are controlled by thermostats that turn them on or off according to the temperature in the attic. They are most useful during summers, when the attic temperature can reach upwards of 120ºF.
Occasionally, these fans start making annoying noises. If the attic fan eventually gets too loud, look it over for any obvious components that could be working poorly, and then run through the following tasks.
1. Balance the Blades
If the fan makes a constant metal clanking noise, in all probability the fan blades are imbalanced. This is something that can occur even in regular ceiling fans as a consequence of regular use. In such cases, either balance them out or replace the blades entirely.
2. Replace the Bearings
Attic fans also have small ball bearings that help lubricate the fan's movement. Due to regular wear and tear, these bearings can become worn out or lose their lubrication ability. This can cause the fan to start making constant noise and, in some cases, even a loud squealing sound. Remove the current worn out bearings and replace them. Just be sure that the new bearings you're installing are for the same make and model.
3. Tighten the Screws
Occasionally, screws used to fix the fan to the gables or roof become loose. This causes the entire assembly to vibrate and make noise. This problem can be solved by tightening the screws.
4. Replace the Fan Itself
If you have been using the same fan for at least a couple of years, its life is probably close to over, and it most likely requires replacement. A rusted motor is difficult to repair and easier to replace. Just order a new set of fan motors and enjoy your silent nights.