live in a 2 bed bungalow the windows were constantly wet with condensation and mold was starting to develop around window and door, fed up with having to put the window on vent in cold weather to try and clear it, so decided to splash out and get the drimaster eco vent, noticed a vast improvement immediately, I was restricted on a suitable location due to the small hall, this has reduced the effect of the unit but on the number 4 speed setting the kitchen and living room are generally free of condensation, still a small amount on the bedroom windows but this is due to the limited option of a suitable fitting location. Worth the cost as without it the mold would have gotten out of hand.