Sealing over an Extractor Fan Vent Causing Interior Drafts

Hi all.

I'm not sure if this is a good idea at all, however what are the methods of sealing over an external wall extractor fan vent which is possibly causing interior drafts.

Ideally the plan would be to try something temporary, but effective, to see if the vent is the cause of a major draft, but which can also be reversed easily enough. ie don't want to brick it over at this stage.

A few years ago I had an external extractor fan installed in the kitchen. Previously it had been a char coal unit extractor unit which had no external vent.

Thanks.

cnocbui

Gaffer tape, or similar, but only as a temporary measure for diagnosis. Do you not have an exterior vent cowling with louvres that closes and seals when the fan isn't on? If not, you could get one.

Thanks cnocbui.

Yes we have an external vent with louvres that close when fan not working, but I don't think its very effective. When the van vent is closed over, you can still feel a draft on your hand.

I haven't seen any that I would think are 100% effective?

cnocbui

My extractor has an effective internal back draught flap that opens and closes. Perhaps you could retrofit something?

https://duckduckgo.com/?q=extractor+fan+back+draught+&t=ffnt&iar=images&iax=images&ia=images

Thanks cnocbui. I'l try a temporary fix to see if it is the cause of a major draft, and then I'll retrofit as best I can. The vents that were available in local stores at the time were pretty poor.

But at this stage, being able to feel the air coming in, I'd think it needs attention to some degree?

PS: I probably should have mentioned, the current interior extractor fan is installed as part of the cooker hood.