It cleared condensation overnight. I have a 3 bed bungalow with no fans etc. Started at fan level 3 overnight with mid point heat and down to constant fan level 2 after one night. Hardly audible and so effective that I don't need any windows open now or even the trickle vents. Easy to fit as long as you realise that the ceiling template is within the packaging that I had thrown in the bin! As the hole is elliptical, I had to empty the bin! Even the cord and hook for hanging from purlins etc, is included. Fantastic product.