Droplets on your windows every morning? Condensation on the inside of glass is one of the most visible signs that the air in your home is too humid. Below you can read where it comes from, when you should be concerned, and what you can actually do about it.
What causes condensation on windows?
Air can only hold a limited amount of water vapor, and the colder the air, the less moisture it can hold. The air inside your home is usually warm and humid, partly due to showering, cooking, drying laundry, and simply breathing. As soon as that warm, humid air comes into contact with a cold surface like a window pane, the air there cools down rapidly. The moisture that the air can no longer hold settles as droplets. This process is called condensation.
When is condensation most noticeable?
Condensation on windows is most noticeable in the early morning, after sleeping, after showering or cooking, and on cold days when the difference between the indoor and outdoor temperature is large. Single glazing and older window frames are more sensitive than well-insulated double or triple glazing, simply because the glass surface remains colder in those cases.
Is condensation on windows a problem?
A little condensation now and then is not cause for panic in itself. It is primarily a signal that the humidity at that moment is too high for the temperature of the glass. If water remains on window frames and sills for weeks, an environment is created in which mold feels right at home. Wooden frames can start to rot and paint can peel. Structurally wet edges around the window are therefore a sign that you need to adjust something.
How do you prevent condensation on windows?
- Ventilate daily. Open windows or ventilation grilles regularly, even in winter, to discharge humid air.
- Keep doors closed while showering and cooking and turn on the extractor fan so that moisture does not travel throughout the house.
- Do not unnecessarily dry laundry indoors without extra ventilation or dehumidification.
- Heat evenly. A constant temperature keeps the glass less cold than a room that repeatedly cools down and warms up again.
- Lower the overall humidity when ventilation alone proves insufficient.
The role of a dehumidifier
Ventilation remains the foundation, but in some homes (think of well-insulated houses where moisture does not escape as easily, or bedrooms that are poorly ventilated at night) the humidity remains on the high side. In those cases, a dehumidifier can help to structurally remove moisture from the air, rather than just wiping away the fogged glass. Our advice is the Dynter AirPure DH251 dehumidifier, which removes excess water vapor from the air before it has the chance to settle on your windows. In our experience, the combination of regular ventilation and, where necessary, dehumidification is the most sustainable approach to persistent condensation.
If you still have wet window frames despite ventilating, try measuring the humidity with a hygrometer. If you are structurally above 60 percent, then that is a good moment to consider dehumidification in addition to ventilation.