We have tried everything possible to clear up our condensation over the years. De humidifiers, window vents, larger extractor fans in kitchen and bathroom, soffit vents, roof vents you name it and we have tried it. Talking to our new neighbour who told me that he fitted one of these in his previous property and he never had condensation problems. Well we took his advice and bought one. The morning after fitting this we couldn't believe our eyes. All three bedroom windows, bathroom window, kitchen window and doors and conservatory were all condensation free, unbelievable. If you have any condensation problems fit one of these. You won't regret it.