Extractor vent noise

[Nick1c]

We have three extractor vents in our current house. With the 65mph gusts we have been getting recently the vanes which are there to reduce back flow have been making a fair old noise. Does anyone know if it possible to buy an external fitting with an electronic actuator which releases the vanes from a closed position (or forces sprung loaded vanes open) when the fan is turned on?

[PeterW]

I fitted a backflap into one and it virtually stopped it overnight. Replaced the vanes on the outside with just angled vent with mesh so no clattering. 

[Nick1c]

Thanks Peter,

The angled vent is easy, but where does the backflap go [and where do you get them]? Two of the ducts are horizontal through walls, the fan for the third one is celling mounted.

[PeterW]

You can get them on eBay

 

Manrose Back Flap

[Nick1c]

Thank you.