drafty coming through extractor fan

[seneca]

I have an extractor fan facing out of the side wall of the house I recently moved into. It's postioned above a kitchen cabinet and has a switch that is built into the wall like a light switch. I have recently noticed that when the fan is not switched on there is a huge draft coming through it. Is there anything I can do about this? some sort of outside cover, or a different kind of fan? My old house used to have a fan with a pull cord that would open a vent on the fan. I can't install one here because the hole is above a kitchen cabinet and I would like to use the switch built into the wall.

any advice would be appreciated.

 

[Lectrician]

A back draft shutter? They have 3 veins which fall shut when the fan stops blowing. They do chatter a bit in the wind though.

 

[RF Lighting]

What size is the fan?

Vent axia fans have a solonoid built in which opens a shutter when the fan is switched on, and shuts it when the fan is off.

 

[seneca]

sorry about the late reply, vent was demoted on list of priorities.

I have come across 2 alternatives

a vent with flaps that open when the fan is on and something called a cowl (basically it looks like a hodd with a gap at the bottom).

which do you guys thin would be better?

 

[JohnD]

The ones with little flaps like a venetian blind are terrible. The flaps rattle annoyingly in the wind, and break off in bad weather.

Go for the cowl. It will probably have one single large flap inside to prevent backdraughts (all mine do).

 

[seneca]

seen the cowl on screwfix, but it doesn't mention a flap inside. Anywhere on the interent which sells the kind you mention? Otherwise I'll have to go to b&q and have a look. Seen plenty of the flap variety, but i agree, they look flimsy. Where my fan is postioned is directly in the line of oncoming winds, hence the need to stop the huge draught coming through.

thanks.