* S&P 250 m3/h quiet fan mounted above the ceiling * humidistat + timer control on the wall close to the ceiling * flexible ducting from a grate close to the centre of the ceiling to the fan, & from the fan to the grate in the outside end wall (above the ceiling)
The fan is audible, but by no means noisy. I am amazed by how effectively it removes condensation in the bathroom (I was going to try this & then consider an illicit dehumidifier arrangement) --- within 24 hours of firing it up, even with showers in that time, all the condensation cleared off the ceramic toilet tank, & it has stayed clear.
The window is still locked "vented" (about 10 mm open) for the summer, so the fan is mostly replacing bathroom air with outside air. Can I expect such good results during the winter too, when it's sucking "indoor" air under the door?
(It's a small bathroom with a radiator. The door has a spring-closer. The ceiling is now insulated.)