If you hear noise from the bathroom fan when it's windy, there's an easy explanation. It's because the wind is picking up the vent flapper and dropping it down repeatedly. You can resolve the issue by adding sound absorption, weight the damper, or replace it with a spring.
I have a two-year-old home which has vent fans in the two bathroom ceilings. We live in a windy area, and the flabber doors on the fans are often banging open and shut. The noise is annoying, but I'm also concerned about the heat loss in the winter.
Bathroom Exhaust Vent with Flapper & Attached Collar - Canplas
The fans are vented out the roof through a. The vent exits to the roof which has the standard Home Depot purchased style damper with built in flapper style damper. What is happening is that slight air pressure changes in the roof are causing the fan's built in plastic damper to ever so slightly lift and then drop.
It would be easy to test with the bath fan turned off. Take an incense stick or cigarette and let it smoke near your bath vent. If the smoke blows toward you, the system is leaking outside air into your house.
Bathroom vent flapper noise from wind | Terry Love Plumbing Advice ...
Ok, I removed the bathroom vent fan from the ceiling, but I left the plastic damper duct connector with the flapper door assembly to remain in place on the vent tubing that runs up through the attic. Bathroom Vent Flapper Noise from Wind guide. Your bathroom fan makes noise when it's windy because its flapper gets raised by the wind, then drops down, producing the banging noise.
Wind on the outside causes the air pressure to drop, sucking out the high. 3. Clean the vent regularly: Keeping your bathroom vent clean will help reduce dust and dirt buildup, reducing noise from the air vents.
Roof Dryer & Bathroom Exhaust Vent with Flapper & Attached Collar - Canplas
4. Eliminate noise sources: If you can hear your bathroom fan vents running, it's time to clean them out! The flapper is a small, flexible piece of material located in the exhaust vent of your bathroom fan. It opens and closes to allow air to flow out, but sometimes it can become loose or damaged, causing it to flap and rattle.
The exhaust port flapper is a circular piece of plastic that opens when the bath fan is turned on. And when the fan turns off, this damper closes by gravity (or a small metal spring) in order to prevent air infiltration.
