draughty extractor fan

[mobily]

Hi all,

I have an extractor fan in a downstairs toilet that comes on when you turn the light on and stays on for a few minutes after the light has been turned off.

The problem is that I get a terrible draught coming through the vents. The cowl on the outside is a plastic one with 3 flaps.

I have been thinking if a backdraft damper installed would help the problem but never fitted one and wondered if they are difficult to install. Does anyone have any experience of this?

Thanks!

 

[Burnerman]

Extractor fans that come complete with a backdraught shutter work very well indeed, and close off the back of the fan completely when not in use.
I haven't come across any device that can be retro fitted to the fan duct though so I guess a replacement fan is the thing to go for.
John

 

[foxhole]

You could add a cowl to outside designed with a downward facing opening which help prevent wind entering .

 

[mobily]

Thanks for your replies.

I was thinking of fitting this:

http://www.justfans.co.uk/backdraft-dampers-p-110.html

which would save the cost of a new fan as the fan works fine!

I decided against a new cowl on the outside as the existing one is cemented on and I don't want to chisel away and then fit another one.

Do you guys think this would work?

 

[Burnerman]

It should work ok, but it looks like its only suitable for fitting into flexible ducting - if this is what you have.
You may hear the flaps moving with the wind, whereas on the kosher fans the shutters are usually electrically opened.
John

 

[foxhole]

A cowl can be fitted over the top of existing requires little work.