I had a problem with a bungalow we had just purchased last year. We had mould and condensation running down the windows every morning. I got a dehumidifier this didn’t solve the problems.I found envirovent online got a rep out and was in two mind if their system would do what it said on the can as I was an engineer. System was fitted after Christmas this year best thing I have done condensation gone within a day of it being fitted mould gone over the next few weeks. I would recommend this system made a great difference to our bungalow. Many Thanks Dave Morris