Hello, just a quick question about bathroom fans. Bathrooms fans are for pulling the warm and humid air out of bathrooms and moving it outside, right? I have noticed that a certain sector in our bathroom fan round intake, about 1/6 of the intake, actually blows air inside the bathroom, the rest 5/6 of the intake sucking the air in the vents, as expected. Is this by design? If yes, where does this air come from?

Is a fraction of the bathroom air normally directed back to the bathroom to create some turbulence for faster drying?

Where does the cool and dry replacement air come from?

So much for thinking that bathroom ventilation isn't rocket science! Is rocket science a prerequisite for bathroom ventilation?

Would greatly appreciate your sharing your knowledge on this and any feedback.

Best wishes,
h.

Could you show a picture of your fan. I have never seen a bath exhaust fan that had any recirculating capabilities to it.

There is some turbulence and back pressure when going from a blade fan into a duct. That is normal but not sure it is as much as you think. Make up air comes from the house.

Attachment 46829

Thanks for the responses! I am trying to find out if this fan is working properly or it's time to replace it. When looking on the photo, the sector from 12 to 2 o'clock is blowing air inside the bathroom from somewhere, the rest sucks the air away from the bathroom. A strip of paper on the second photo sort of demonstrates it.

Attachment 46830

Remove the cover and vacuum away the dust so we can see the inside structure.