Bathroom Extractor Fan Backdraught

[swanny65]

I have a bathroom extractor fan fitted on a SW facing wall which is letting a backdraught. Searching on here i need to fit an in line shutter.

Straightforward not quite? The fan ducts through a length of 4inch Osma. Can anyone recommend a suitable shutter or do in need replace the Osma with a length of flexible ducting?

Thanks

 

[HERTS P&D]

Are these any good?

http://www.ebay.co.uk/bhp/extractor-fan-cowl

http://www.ebay.co.uk/itm/100mm-in-...-Draught-Ducting-Shutter-4-Inch-/251193552865

http://www.fastlec.co.uk/vortice-100mm-inline-backdraught-shutter-p-2747.html#.UsA4TPRdVv0

Andy

 

[foxhole]

The outlet usually incorporates a backdraft shutter.
Where does yours exit?

 

[swanny65]

It exits through the external brickwork where there is a louvre vent cover like this

http://www.screwfix.com/p/manrose-louvre-vent-brown-125mm-x-160mm/40945

Thanks, I had seen this but wasn't sure it would fit inside the Osma

http://www.ebay.co.uk/itm/100mm-in-...-Draught-Ducting-Shutter-4-Inch-/251193552865

 

[foxhole]

Should have this fitted,
http://www.screwfix.com/p/manrose-square-brown-100mm-flap-vent/13161

has the wrong vent outlet.

 

[swanny65]

Foxhole - thanks will get the ladder out and replace!!