Extractor fan not powerful enough

[Python]

Hi

My small bathroom has a 100mm 12V extractor fan located above the bath, on a timer which runs for about 3 minutes after the light is switched off.

Still, after a bath or shower the whole room is covered in a film of water, and I have to open the window.

It looks to me like the fan isn't powerful enough to open the flap vent on the other side of the wall (which is about 40cm thick because of extra boxing-in in the room).

I wondered if I should try a more powerful fan - any recommendations?
As an alternative, could I install a fan with automatic shutters, and replace the flap vent with something that presents less of an obstance to air flow (louvre or cowl vent)?

thanks

[collectors]

Hi, i would replace the outside flap with just a grill, the flap ones are used more for tumble dryers. . See if you can get one with a wire mesh to stop the bugs getting in. Would also turn the timer up to 5 minutes. Sounds like you might have a north facing bathroom? which is always a bit worse for condensation if an older house.

[Python]

Hi

Thanks for the advice

[quote="collectors"]See if you can get one with a wire mesh to stop the bugs getting in.[/quote]

I'd worry then about draughts. It's already very cold in winter - that's why I was thinking of a fan with automatic shutters. I've read about inline backdraught shutters, but they sound like they're difficult to fit.

[quote="collectors"]Sounds like you might have a north facing bathroom? which is always a bit worse for condensation if an older house.[/quote]

It's actually East facing. It's a ground floor converted flat (part of a Victorian terrace). The bathroom is at the side of the house, only a couple of meters from the boundary fence.