Hi Has anybody come across humidity operated bathroom vents before, they are a d*m nuisance.
They consist of a 4 inch duct leading from a vent tile on the roof to a moisture operated device in the bathroom ceiling. They are supposed to open when the humidity in the bathroom has reached a certain level then open whereby the air passing over the roof sucks out the stale air.
However what they actually seem to do is react to the humidity of the external air and blow this into the bathroom. During the past few days the vents on the two bathrooms facing the prevaling winds have been wide open ( relative humidity was measured as 42 - 45% in each bathroom) while the bathroom in the lee of the wind has remained fully closed.
I am about to stuff the things with rockwool and use the window as a vent.
Paul