Re: Noisy bathroom fan
Depends on the noise.
If it's a fairly smooth RRRRRRRR then it's probably air turbulence due to the impeller and housing design. There isn't much you can do to quiet this short of replacing the entire unit: housing, motor, impeller, and all. Completely cleaning the dust can help quiet it down a little bit. Sometimes you can put some rubber tape between parts of the housing to reduce vibration noise.
If it's a rattle or a rumble, the bearings in the motor are shot. Replace the motor. Inspect the impeller, and if there is any cracking or broken fins replace it, too.
Bathroom fans shouldn't be too quiet. Sometimes you want to mask other noises. While you're at it, replace the switch with a countdown timer. Then you can leave the fan on for a few minutes clear the air when you're done, and it will automatically shut off.
The "Senior Member" designation under my name doesn't mean I know a lot, it just means I talk a lot.I've been a DIYer since I was 12 (thanks, Dad!). I have read several books on various home improvement topics. I do not have any current code books I can refer to. I was an apprentice plumber for two years.