Bathroom fan airflow with exterior vent?

optimystery

Hi, I have a question about airflow with a bathroom fan, in this case a Ventaxia VASF100T with a cover.

It seems quite inefficient at clearing steam, and I am wondering if the exterior vents are just stopping air from moving outside? What I am referring to is called a "gravity grille" I would have expected the flaps to open when the fan is on but I have checked and they do not move at all.
How can air be pulled outside if there is something blocking it? Maybe the air is just recirculating.. There must be some kind of sensible design behind these systems surely!

markin

The flap is to stop drafts and wind, But any fan should be able to make them lift at least 5mm.

They aren't air tight so it may still be some use but Ideally the room should clear of steam within 15min.

The manual says its got 2 Speeds "Low speed setting
(Factory default)" Time to replace it if its no better on top speed.


https://www.vent-axia.com/range/silent-fan

If you rent you should just tell the LL/agency.

andyhop

Axial fans move next to no air , it does not surprise me that it won’t even lift the flap

Change the fan to a centrifugal type fan , DX200 or similar