Two pieces of glass that have been sealed together with a vacuum created in the center for insulation purposes. This glass rejects heat and doesn't affect the viewing quality of the window.

unit Two or more pieces of glass spaced apart and hermetically sealed to form a single-glazed unit with an air space between the glass. (Commonly called IG units.)

Two pieces of glass spaced apart by a metal strip and sealed with rubber to create a more weatherproofed joint.

Window or door in which two panes of glass are sealed with air space between. Also referred to as Double glass or Thermal Pane.

A glass unit using more than one piece, i.e. “double pane” or “double glazed”, “triple pane” or “triple glazed”.

Two pieces of glass spaced apart (with intercept spacer) and hermetically sealed to form a single glazed unit with an air space between.

(I.G.) A panel of glass comprising of at least two pieces of glass separated by a hermitically sealed air space. The most common method of achieving the hermetic air space is to prepare a spacer system of hollow aluminum bars that are filled with desiccant and placed between the pieces of glass, a sealant is then applied to the perimeter which will prevent moisture penetration and bond the unit together structurally. Also frequently called "double pane" glass.