Double glazing window
A type of window having two layers (panes or glazing) of glass separated by an air space. Each layer of glass and surrounding air space reradiates and traps some of the heat that passes through thereby increasing the window's resistance to heat loss (see R-value). In factory-made double glazing units, the air between the glass sheets is thoroughly dried and the space is sealed airtight, eliminating possible condensation and providing superior insulating properties. Double glazing is the glazing process in which a window is formed by two panes of glass with a space between the panes. The space between the glass is usually several millimeters thick. Air is trapped between the panes of glass and forms a layer of insulation. Before the unit is sealed, a drying agent is added to ensure that no moisture is present inside the finished glass unit. The double glazing unit must be airtight. If condensation appears between the panes, it indicates that the window is not airtight. Do...