In the worst case, the condensation can cause mold, since the water film is an ideal breeding ground for the spores. The corners of the rooms, niches and the area around the window are particularly susceptible to this, but it can also happen behind pieces of furniture directly on the outer wall.
Mold can be avoided by heating and regular airing – the latter preferably several times a day with the windows fully open.
If you like it precise: the humidity in the room should not rise above 60 percent, advises the Bremen consumer advice center. In addition, all living rooms and bedrooms in the house should be heated to at least 16 degrees, even if they are not used in winter.
In this way, on the one hand, you regularly ventilate the excessive humidity, and on the other hand, you prevent it from settling on the cold walls as condensation. In addition, large furniture can be moved away from the outer wall, at least in the cold months.