September 20, 2025
Insulated Glazing Units
In this video, Francesco Fiorito explains the importance and construction of Insulated Glazing Units (IGUs), which are fundamental to energy efficiency in modern buildings. Windows are a significant source of heat loss, accounting for a large portion of a building's energy transfer. An IGU combats this by consisting of two or more glass panes separated by a spacer and sealed to create a single unit with an insulating cavity filled with dry air or inert gas. The key components that define an IGU's performance are the glass panes, which can be laminated, tinted, or coated for specific performance needs; the spacer, which maintains the gap between panes; the primary and secondary sealants, which hold the unit together and protect it from moisture; and the cavity filling, where gases like argon significantly improve insulation over dry air. IGUs are primarily classified by their number of cavities: double glazing (DGU) and more insulating triple glazing (TGU). A newer development is Vacuum Insulated Glazing (VIG), which offers superior thermal performance in a very slim profile but faces challenges with durability. The video concludes that by combining these different components and technologies, a wide variety of IGUs can be created to meet specific aesthetic and energy performance requirements for buildings. The video was produced by the Open GLASSroom project. Special thanks to Francesco Fiorito for contributing to the Open GLASSroom OER collection. The creation of these resources has been (partially) funded by the ERASMUS+ grant program of the European Union under grant no. 2022-1-DE01-KA220-HED-000089750. Neither the European Commission nor the project's national funding agency DAAD are responsible for the content or liable for any losses or damage resulting of the use of these resources.