WINDOW CONDENSATION: WHAT DOES IT MEAN AND HOW TO PREVENT IT
When winter comes—so does window condensation. Condensation occurs when moist, or humid air comes in contact with a colder surface. The build-up of condensation on the inside of a glass window can sometimes occur, although this happens less frequently with modern glazing than older windows. Condensation found on glass windows can be broken into three categories: exterior condensation, interior condensation and between-the-glass condensation.
ROOMSIDE (OR INTERIOR) CONDENSATION
Condensation forming on the interior of windows and doors is the result of high humidity levels in your home combined with cold temperatures outside. This occurence is called roomside condensation. Roomside condensation occurs when high humidity within your home interacts with cold external temperatures. Air carrying elevated humidity retains water vapor until it encounters a surface temperature equal to or less than the dew point, leading to the appearance of condensation, typically in the form of water droplets or frost on the inner side of windows. As indoor air becomes drier or the glass surface warms, the condensation gradually diminishes.
Roomside condensation can be managed by upgrading to energy-efficient windows and doors or implementing changes like a new roof or siding can diminish air infiltration.
EXTERIOR CONDENSATION
Exterior condensation is a phenomenon predominantly observed in summer. It is caused by specific atmospheric conditions: heightened outdoor humidity, minimal wind, and clear night skies. Similar to roomside condensation, it forms when glass temperature drops below the dew point of the external air.
To address exterior condensation, open window coverings at night, trim shrubbery for better air circulation, and consider a slight air conditioner adjustment. Redirect air vents blowing cool air directly at windows to mitigate condensation.
BETWEEN-THE-GLASS CONDENSATION
One of the biggest red flags is condensation between multiple panes of glass. This occurrence is an indication of window sealing failure. Prolonged affects of leaving this untreated include growth of mould and rot between your windows.
To remedy this between-the-glass condensation, consult an expert to inspect the window and either seal or replace if necessary.
HOW TO PREVENT CONDENSATION ON WINDOW
For new construction homes, there are multiple reasons why minor condensation build-up may occur—ventilation, humidity, and more. Download our Condensation Guide for details on how to identify and prevent condensation on glass windows and doors.