// interesting facts

Condensation on the outside panes of the window

Especially in the autumn it is possible to observe this phenomenon, which can be confusing for some homeowners, who wonder about external condensation after fitting new windows. Die windows panes steamed up on the outside!

Why does condensation form on the window?

The outside panes of the windows steam up because the high atmospheric humidity on autumn, especially in foggy days, drawn to the coolest surfaces, such as your windows.
Now it is possible to visualize the effect of highly insulating glass units, which would only happen in case of excellent glass insulation effect, so that his exterior surface does not warm up, although the temperature of the internal surface is almost as high as the temperature inside the room.
Glass is doing its job well and reflecting heat back into the room. We can speak rightly of a “thermally insulated glass”. Use condensation to your advantage: If you open the windows for a short time, the thermally insulated glass and the outside temperatures below 5°C will steam up the outside panes of the windows, if you swing the window and inside the room there is a high relative humidity. As long as moisture remains in the glasses, humid air inside your house will be replaced with dry air from outside. The humid air is completely renovated only when the moisture disappeared. Now you can close the window again and you can be sure you have done optimal ventilation.

In short the “problem” is not a problem anyway. It is a “Quality Seal”, a purely physical effect caused by the fact that the glass is doing its job well.

Definition: Condensation
If warm humid air reaches a cooler surface (window panes), will the air condense into vapor (water drops).

The ambient air contains always some water vapor. Cool air cannot hold as much moisture as warm air, so windows and doors often collect this moisture and make it visible as condensation water. This means, as soon as the relative air humidity has reached almost 100%. It is possible to find condensations groups in the sky as clouds, closer to the ground as fog, in the grass as dew and in the windows panes as condensation water.

to your advantage...