In the cold season, many tenants and homeowners are faced with a problem: In the morning, the windows are fogged up from the inside and condensation collects in the corners of the frame. But what is the reason for this and how to avoid it? This article explains why windows fog up and how to prevent the problem.

Why do condensation form on the inside of windows?

It is caused by the strong combination of high humidity and different temperatures in the room. This humidity comes from various sources, such as breathing, sweating, washing machines, hot showers or plants. In total, the amount of water released at the end of the day is about 10-15 liters.

If you turn on your heating in the winter, moisture may condense on your windows. This is especially the case if the windows are old and leaky. The reason for this is that the cold air from outside can enter the apartment and mix with the warm, moist air inside. The result is condensation at the coldest point in the apartment – often at the window or mirror. This is completely normal and can usually be eliminated by airing. However, if this happens more often or even diminishes, you should have your windows checked.

Condensation on the window: What are the possible consequences?

Condensation on the window can have negative consequences for your health under certain conditions. This is because where it is damp and warm, mold feels particularly at home. However, this is even more dangerous because mold is usually only detected when it has already spread and grown larger. In addition, the mold may form not only on or around the window, but also on the walls of the apartment. Living in a moldy apartment can lead to asthma, coughing, respiratory problems or skin rashes – even in dogs or cats.

What can be done to prevent windows from misting up from the inside?

To prevent the unwanted leakage of condensation on the inside of the windows, it is advisable to dry them thoroughly on a regular basis. However, one should make sure that no heat sources such as hair dryers are used, as this promotes the formation of the condensation water. Furthermore, regular airing of the living rooms is recommended in order to replace the damp, warm air with cold, dry air. The heating should be switched off during this process.