Extractor fan question

[mikeymikec]

I've never lived in a house that had an extractor fan that exhausts air to the outside of a house before (or at least, I wasn't of an age to pay any attention to it), and I'm a bit surprised by the two we have in the house we've bought. One is in the bathroom and the other is in the kitchen. The kitchen one has flaps over the intaket area (in the kitchen), but even when it's off, if I put my hand in front of the intake area, I can feel a fair breeze coming through. The bathroom one is a different design and without those flaps, and I get a fairly similar breeze coming through that as well when it's off.

Are modern extractor fans (I have no idea how old these are) any better? Is there something in particular I need to look for if I sought to replace the fans with something that isn't like leaving a window open all day? While a nice breeze coming in would be appreciated in the height of summer, in winter it's just throwing money out of the window.

 

[Greenman]

Bath fan should have a check valve at the fan body, it's a simple spring loaded flap. The kitchen fan should have the same thing or a butterfly valve.

 

[mikeymikec]

Bath fan should have a check valve at the fan body, it's a simple spring loaded flap. The kitchen fan should have the same thing or a butterfly valve.

And would that completely stop (or at least make it not perceivable) airflow coming in from outside while the fan is off?

 

[Greenman]

It should. There is often a tiny amount of leakage, but you shouldn't be able to feel a breeze.

 

[snoopy7548]

It's possible there isn't any sealing around the fan unit. There are likely gaps between where the fan housing meets the drywall. Before sealing around my bathroom fan with foil tape, I could feel a pretty good breeze. After, absolutely nothing.

 

[Paperdoc]

People often lose track of a routine maintenance requirement of such fan systems - cleaning. The system we have that allows the clothes dryer to exhaust warm wet air to the outside is the most obvious case. Lint builds up in the vent ductwork and flex hose to some extent, but especially around the flap valve at the end of the pipe, just outside the house. This can prevent that valve from closing. Periodic inspection and cleaning solves that. The same principle applies to the flap valves in any air exhaust system. They need to be inspected and cleaned occaisionaly, and MAYBE even lubricated lightly to ensure they move freely.

 

[boomerang]

If it's older construction they didn't typically didn't worry too much about keeping drafts out. In other words the only recourse may be replacement.