BU598 Insulating glass units

IGUs are two or more panes of glass spaced apart and sealed together with dry air or argon gas in the cavity. They alter the transfer of heat and light. The lifetime of an IGU is dependent upon the system chosen, manufacturing quality, installation and its treatment in service. 

This bulletin covers the make-up, performance and installation of IGUs and updates and replaces Bulletin 471 of the same name. 

This bulletin covers: 

• IGU function 
• IGU construction
• window frames
• IGU performance.