Vacuum insulated glass

Vacuum insulated glass gives high thermal performance in a very slim unit. A vacuum between the panes replaces the wider gas filled cavity of standard double glazing, so the pane stays thin. ArxBridge supplies and installs vacuum insulated glass across the UK, including in heritage and security window projects.

• Slim profileThin unit, strong insulation
• Heritage fitSuits shallow sash frames
• Laminated optionsSecurity build ups available
• UK wideSurvey, supply and installation

About vacuum insulated glass

Vacuum insulated glass is a sealed unit in which the space between the panes is evacuated. With almost no gas between the panes, heat has little medium to travel through, so the unit insulates far better than its thickness suggests. A vacuum unit can be a fraction of the depth of a standard double glazed unit while losing less heat.

The panes are held apart by a grid of tiny spacers that stop the vacuum pulling the glass together, and the edge is hermetically sealed. The result is a rigid, thin pane that handles like a single sheet of glass in the frame, which is exactly what makes it useful where frame depth is limited.

For security work, vacuum insulated glass can be supplied in laminated build ups. The vacuum pane is bonded with laminated security glass, so the unit keeps its slim profile while the laminate provides the attack resistance the specification calls for.

Picking the rating for vacuum insulated glass

Vacuum insulated glass is chosen for thermal performance and slim section first; the security rating comes from the laminated build up and the window system around it.

Where a forced entry rating is required, the window is specified as a tested assembly to LPS 1175, with the laminated vacuum unit forming part of the proven build up. The rating belongs to the assembly, never to the glass alone.

Specifier note. Vacuum glass is thinner and lighter than the double glazed unit it replaces, which can actually help: existing sash weights and balances sized for single glass often suit the vacuum unit without alteration.

The build behind vacuum insulated glass

Two panes of glass are sealed at the edge and the cavity between them is evacuated. Microscopic spacers in a regular grid keep the panes apart against atmospheric pressure. The edge seal must hold the vacuum for the life of the unit, so edge quality is the defining factor in manufacture.

For security applications the vacuum pane is laminated with additional glass layers and interlayers. The laminate sits on the protected side of the unit, so an attacker meets the security glass first. The interlayers hold the pane together under attack, exactly as in any laminated security glass.

The unit is then glazed into the frame like any sealed unit: bedded on setting blocks, retained by beads, and sealed against weather. In security sash windows the slim unit drops into the original sash section, which is why conservation officers accept it where standard double glazing would force a deeper, non historic frame.

Combining vacuum insulated glass with other ratings

Vacuum insulated glass pairs naturally with thermally driven products. Thermally broken doors on the same project address heat loss at the entrances while the vacuum units handle the windows, giving the envelope a consistent thermal story.

On the security side, the laminated vacuum unit sits inside security window systems where the specification calls for a rating. The Security range covers those window systems alongside the doors and glazing for the rest of the facade. Where the original windows must be kept untouched, blast protection window film is a reversible alternative that holds fragments together, though it carries no forced entry rating.

Where to use vacuum insulated glass

Residential and housing is the largest market: period homes whose sash frames cannot take standard double glazing, and conservation areas where the window design is fixed. Education estates use it in historic school and college buildings where listed status rules out deeper frames.

Hotels, offices and civic buildings in converted historic stock use vacuum glass to cut heat loss without touching the facade design. New build projects with slim steel windows use it to keep sightlines minimal while meeting thermal targets.

What affects the cost and lead time of vacuum insulated glass

Pane size and shape drive the cost: the vacuum process and the edge seal are more demanding than standard sealed unit manufacture. Laminated security build ups add glass, interlayer and weight on top of the vacuum pane. Curved or shaped units extend lead times further.

Because the technology is specialist, the supplier base is narrower than for standard double glazing, and unusual sizes need early ordering. The frame must be surveyed for depth and condition before the unit size is fixed, since the whole advantage of vacuum glass is its fit into shallow sections. A schedule of pane sizes and the target performance are the basis for a quotation.

How to specify vacuum insulated glass

1. Measure the frame depth. Confirm the rebate can take the vacuum unit and its beads.
2. Set the thermal target. State the heat retention the project needs from the glazing.
3. Decide on security. Choose plain or laminated build ups, and name any rating required.
4. List every pane. Sizes, shapes and any bars or applied glazing details.
5. Confirm the edge guarantee. Check the sealed unit guarantee terms for the vacuum edge.
6. Get a detailed quotation. Supply the glazing schedule and drawings for a fixed quote.

Frequently asked questions