Insulating glass units, or double-glazed units, are one of the
most common types of glass used today for building applications.
Patented as far back as 1865, IG units were implemented in
architectural applications after the World War II. Due to their
excellent thermal and acoustic properties, they have almost
completely replaced basic monolithic windows. Over the decades
IGU?s thermal performance has been upgraded with the
introduction of low-emission coatings and gases with a low
thermal conductivity. Attention was then turned to the edges to
further reduce thermal losses caused by highly conductive
material. Today the most common type of IG unit is composed of
two pieces of glass and a hollow aluminum spacer around the edge
of insulating glass. The hollow spacer contains a moister-
removing desiccant agent. The major benefits of aluminum pacers
are: lightweight, durability and relatively low cost. The dawn
back of this spacer is aluminum conductive properties, which
sometimes cause that the edges of the glas