Now I know that one of the benefits of double glazing is that it removes that problem that folks used to have with single-glazed windows – the horror of condensation during cold weather when it was like a fog looking out of your windows and your mother put towels on the window sill to dry up the water running down. But there can be a problem with double glazing as I found out from my hairdresser who told me that both herself and her mother who had had new double glazing units fitted in their homes and had terrible problems in their conservatories with pouring condensation.
My hairdresser was talking about getting a large dehumidifier, though I did think that this was rather extreme for a situation that seemed to be caused by the fitting of the sealed units themselves. It appears that the issue for internal condensation is all about ventilation – you need to have an airflow in a room in which you are heating – warm air holds moisture which will condense upon colder windows. Opening windows will defeat the point if this lets in the cold air you want to keep out. We have an airbrick fitted in one room and a fan in the kitchen – but one of the ways that ventilation can be ensured in rooms without ventilation is to have “trickle vents” fitted in your replacement windows which lets in small amounts of air. Sounds like a good idea but why didn’t her supplier suggest it? Paying for a humidifier is going to be cheaper than having new windows, but it is better to think of things before you have stuff fitted. You obviously need a top-class supplier for your double glazing to thoroughly advise you.