Architectural Glass
Vacuum Insulating Glass Explained
Vacuum insulating glass takes the cavity of a conventional insulating unit and evacuates it, removing the air that conducts and convects heat across the gap.
How VIG is built
Two panes are separated by a narrow evacuated cavity, held apart by an array of micro-supports and closed with an edge seal that maintains the vacuum.
Because the cavity carries almost no gas, heat transfer across it is reduced without the cavity depth a conventional unit needs.
Why thickness matters
Conventional insulating units improve by adding panes and cavities: more thickness, more weight, deeper frames.
VIG improves envelope performance where thickness and weight are constrained — heritage sashes, slim sightlines, retrofit work.
Specification considerations
VIG is a glazing build-up like any other and has to be coordinated with the frame that holds it.
- —Rebate depth and edge seal detailing
- —Support-pillar visibility under some lighting conditions
- —Size limits and handling
- —Whether solar control is also required, which may point to a hybrid unit
Performance data
Thermal, acoustic and safety figures are specific to the manufacturer and the configuration. Reliance supplies the manufacturer's technical data for the unit being specified rather than generic values.