What is Condensation?

Condensation is moisture in the air that comes into contact with a cold surface and then condenses from water vapour into a liquid again. It points to a problem in humidity levels in the home and a lack of adequate ventilation which in turn can lead to damage and mould growth

Internal Condensation (on the inner pane of a window)

Condensation inside your home points to high moisture levels and a lack of adequate ventilation.  New windows will have been manufactured to achieve a high efficiency and a tight sealed installation, due to this moisture can not escape so it aims for coldest part of the room which is the glass unit. Your old windows may not have produced as much or no condensation at all , this is due to the fact they were less air tight & energy efficient allowing air to pass from the inside to the outside without causing any condensation. Excess moisture can also appear from hot showers, boiling the kettle, cooking and drying wet washing.

What can be done about it?

Condensation can be reduced by allowing adequate ventilation such as opening slot vents and windows. Extractor fans are also  a good way of reducing excess moisture in bathroom and kitchens.

External Condensation (on the outer pane of a window)

Condensation appears externally due to the fact that modern windows are manufactured to be more thermally efficient. As a result, the heat will not be able to escape through the outer pane which then causes condensation to appear on the outer pane. The outer pane of the glass is cooler and when the temperature falls below the dew point, moisture in the air condenses on it. Unfortunately, nothing can be done for condensation on the outer pane. However it usually doesn’t last long and means that your windows are keeping the heat in within your house!

Window condensation can be worse during a Autumn & Spring morning as at these times of the year the temperature of the glass can drop drastically overnight, yet the dew point remains relatively high. Some windows can be affected more than others as slight changes in orientation or shelter can mean that that windows or even panes next to each other can react differently.