Would you believe it if I told you that German windows sweat?

Most likely not, and they really don’t…but, when the cold season starts, you may notice water collecting on the windows inside your home. This condensation can ruin wooden windows, cause mold stains on the silicone seals and even cause mold to grow in your rooms. I will help you out by sharing some easy solutions to prevent that from happening.

German houses are built very differently from the houses back in the States. The newer houses are all about insulation, and even the old houses are fairly airtight. Since our heaters here are mainly radiators and not a central air system, there is not much of an air exchange inside the home. Humidity also collects inside the rooms just from every day things like showering, cooking and even simply breathing. It is quite astonishing how much moisture accumulates in the air inside your home. The humidity in air is calculated in percent per cubic meter of air.  At 100% humidity, the air cannot absorb any more moisture and starts depositing it. That happens by condensation forming; outdoors it would turn into fog, dew or even clouds. The amount of steam air can hold also depends on the temperature of the air.

If you apply that knowledge to your home, you can see how the window regions are some of the coldest areas in the home. The frigid air from outside cools the windows down, and, in turn, the air inside by the windows is much cooler then the rest of the room. Since the warm air holds more moisture than the cold air by the window, the moisture in the air condensates on the cold window. As the warm, humid air circulates inside the room, more condensation is deposited on the window. This is the reason why radiators are often placed under windows, to try to equal out the temperature inside the room.

So… you see why this could turn into an issue, and it would be best to do something about it. One of the easiest things you can do is open up the windows and air out the area a couple times a day. Just a few minutes is enough to enable a good air exchange. It does bring in cooler air, but the relatively oversaturated air is mixed with the new air, and the risk of mold forming sinks drastically. And no worries, the heaters will reheat that cooler air in no time.

Proper heating is also important; it enables the air to keep more moisture. You should also wipe up the excess water with a soft rag, especially if you have wooden windows.

Luckily, condensation is an issue that mainly happens with older windows, but airing out two to three times a day should be enough to keep mold from growing. If you still have issues with mold forming, contact your landlord as soon as possible so that he can take steps to ensure it does not become a problem.