Here you can find useful information about windows. All of PVC, aluminum and wooden windows, blinds, mosquito nets, etc..
Condensation in the rooms of the house may appear on the surface of the glass and the window frames respectively. Then we say that it`s a process of `wet` or `blurred` windows. This however should not be confused with the formation of condensation on the inside of the glass - when condensation forms between the two panes of the glass, then it`s a defective one. The moisture appears on inside of the glass, when the glazing is fully depressurized or when the whole complex is poorly treated with silica (the silica - hygroscopic granular material). Thus, the glass fails to absorb better the fresh air in the room. The amount of the steam, flowing and entering the room is at it follows:
Condensation starts at the end of the glass as it`s the coldest part of the dwelling. Besides wider sills, the sash frame may hinder the flow of air, so that the moisture on the bottom of the glass may appear earlier than in the middle of the glass.
Condensation could occur in unheated and unventilated rooms. This is a result of the gradual cooling of the room at night, and the saturation of the air with water vapor from the breath at a relatively low temperature.
Condensation can occur not only on the windows, but in the any cold area in the house. It could lead to a formation of mould and mildew stains on the walls of the house.
Subject to certain rules and proper ventilation, the condensation could be reduced or fully disappear.