Insulation pane

An insulation pane is a windowpane made up of two or more layers glass glued together and hermetically sealed along the edges. In the earliest insulation panes, there was dry air between the glass layers to minimize condensation. Modern insulation panes use inactive gasses such as argon, krypton, or xenon.

Insulation panes were first patented by American engineer and inventor Thomas D. Stetson in 1865, but were not put into production until the 1930’s.