construction element consisting of at least two glass plates for windows and other glazing
Insulated glazing, otherwise known as double glazing or triple glazing, refers to the layers of glass in a window. A double glazed window is two panes of glass (also called a lite) with a sealed air (or gas) space in the middle. The edges are sealed together with an air-tight spacer. This is used so that heat cannot escape through the air space by conduction or convection. Heat radiation is not affected as it can travel through a vacuum space. To increase the R-value of insulated windows are sealed with argon gas.