Huge wrote:

On 2006-08-27, john2 wrote:

There should be a air-pressure operated flap installed on the outside to
prevent wind blowing in when the fan is off, otherwise the bathroom will
be permanently cold.

IME these are completely useless, and on windy days a freezing draught
will howl through the fan. Get one with positive operation on the
shutters.

That's my experience as well. They also make a terrible racket on
windy days.

Much better to get a fan with integral shutters and have a plain vent
on the outside.

John
--
John White,
Electrical Contractor