The occurrence of condensation on the surface of composite glass units occurs when the surface of the glass exceeds the so-called "dew point.'' Exceeding the dew point is a phenomenon which occurs when very moist air comes into contact with a cold element. This phenomenon is sometimes observed on items taken out of the refrigerator, which moments after removal can be completely covered with dew. A similar phenomenon occurs in the case of composite glazing. On the surface of glass during cold days, fog sometimes appears. This is due to the fact that glass is a room's coolest construction element. Poor air exchange in the room results in moisture condensing on it. In order to prevent this phenomenon, central heating radiators are placed under windows so that the warm air rising from the radiator warms and dries the glass.
What is very important in reducing the phenomenon of moisture condensation on the inside of the room is the insulation coefficient U value used in the composite glass unit.