The short answer: Warm edge spacer bars are crucial components in modern double glazing units designed to reduce thermal bridging, improve energy efficiency, and minimise condensation.

For IGU fabricators, the benefit goes further: switching from conventional aluminium spacer bars to a flexible foam system like Super Spacer® simultaneously cuts production labour, reduces cycle time, and raises the thermal standard of every unit that leaves the line.

If your operation is still running rigid aluminium, you are competing against fabricators who are already producing more units per shift, with fewer people, and a measurably superior finished product.

superspacer

The spacer bar in traditional double glazing

The spacer bar separates the panes of glass in an IGU and helps create the sealed cavity that provides thermal insulation. Historically, IGUs were made from aluminium. While aluminium is strong and easy to shape, it is also a highly conductive metal. This means it transfers heat quickly.

The physics is damning; 94% of energy loss through a window using an aluminium spacer system occurs at the edge of the glass. This is due to the highly conductive nature of the metal used. Over 950 times less conductive, Edgetech’s warm edge Super Spacer bar is the ideal solution to achieve energy-efficient windows.

When heat flows through a metal spacer bar:

The edge of the sealed unit becomes colder than the centre
Interior heat escapes more easily
The risk of condensation increases
The overall thermal performance of the window drops

This phenomenon is known as thermal bridging.

Understanding thermal bridging at the edge of the glass

Thermal bridging occurs when heat flows through a material with high thermal conductivity. Aluminium spacer bars create a direct thermal bridge between the inside and outside of the building.

In winter conditions, this causes the edge of the glass unit to cool much faster than the centre of the glazing. The consequences are well known to installers and homeowners:

Cold spots around the window reveal
Draughts near the glazing edge
A higher risk of condensation
Greater demand on heating systems

If the glass surface temperature drops below the dew point, moisture in the indoor air forms condensation on the glass. Over time, this can lead to mould growth and damage to frames or surrounding finishes.

What makes a warm edge spacer bar different?

A warm edge spacer bar is designed to interrupt this thermal bridge. Instead of metal, systems like Edgetech’s Super Spacer are made from structural foam and has low thermal conductivity, which means far less heat transfer occurs at the perimeter of the glass unit.

Compared with aluminium spacers, Super Spacer is over 950 times less conductive.

The result is a strong thermal break around the perimeter of the window. This maintains a warmer temperature at the edge of the glass and improves the overall thermal insulation of the window.

Flexible warm edge spacer bars also bring additional benefits:

Better thermal efficiency across the glazing system
Reduced condensation on interior glass surfaces
Improved long-term durability of the edge seal
Greater energy efficiency for the finished building

How warm edge technology improves window thermal performance

The thermal performance of a window is measured by its U-value, which indicates how much heat passes through the structure. In practice, switching from aluminium spacer bars to a warm edge spacer such as Super Spacer can lower window U-values by up to 0.2 W/m²K.

For manufacturers and specifiers, this improvement can be critical when trying to meet demanding energy targets. Lower U-values mean:

Improved energy efficiency
Better high thermal performance windows
Reduced heat loss
Potential lower heating bills for building occupants

This single component change can make the difference between a window meeting minimum regulatory standards and one that exceeds them.

How do warm edge spacer bars improve IGU production efficiency?

The advantages of warm edge spacers are not limited to energy performance. They also change the way insulating glass units are manufactured, and this is where the business case becomes compelling for any IGU fabricator reviewing their line.

There’s no need for Super Spacer to be cut into bar length form, have a PIB primary seal applied or be filled with desiccant, which speeds up insulated glass unit manufacture.

Edgetech’s Super Spacer arrives pre-desiccated and ready to apply directly to the glass. Fabricators do not need to cut, fill or assemble rigid bar frames. Key manufacturing advantages include:

Fewer production steps
Lower labour requirements
Faster cycle times
Reduced material waste
Improved consistency

Automated Super Spacer application also means that there is no wastage, reducing production costs even further.

Edgetech’s warm edge spacer bar product range explained

Edgetech offers a range of Super Spacer warm edge spacer bar products to suit different applications.

Understanding which product matches which application is key to maximising both line efficiency and finished unit quality.

Super Spacer® Premium

The flagship Super Spacer® Premium is widely used across residential glazing production, such as social housing, new-build developments and retrofit projects.

The flexible, silicone foam spacer technology uses a single seal system and a multi-layer moisture vapour barrier. It reduces condensation around the spacer, provides up to two decibels reduction in noise and has a 40-year performance guarantee for long-term durability.

TriSeal and T-Spacer

Large commercial glazing systems present additional challenges for spacer bars. Curtain walling and structural glazing can expose the glass unit to significant pressure changes.

Edgetech addresses these applications with TriSeal™ and T-Spacer™ systems. Super Spacer TriSeal Premium uses a triple-seal design engineered for demanding environments such as silicone structural glazing.

Super Spacer® Heritage

Conservation and refurbishment projects often require slim glazing profiles that replicate traditional windows. Super Spacer® Heritage is a high-performance warm edge spacer system designed especially to meet this sector.

Super Spacer Heritage with a 3mm height allows fabricators to maintain slim sightlines while improving thermal insulation compared with traditional spacer bars.

TruPlas®/Edgetherm RS

Some specifications require a rigid spacer appearance. Edgetech’s TruPlas® / Edgetherm RS system provides an alternative to aluminium spacers while maintaining better thermal performance.

Made from glass-reinforced thermoplastic, TruPlas offers improved energy efficiency and stability. Its design includes eight times more perforations than many rigid spacers, supporting airflow during production and preventing hot melt butyl from blowing out at corners.

Condensation control

Maintaining a warmer glass edge is critical for preventing condensation. By reducing heat transfer at the perimeter of the glazing, warm edge spacers raise the interior surface temperature of the glass near the frame. For building occupants, this means:

Less visible condensation on windows
Reduced risk of mould growth
Greater indoor comfort

For fabricators and installers, it means fewer call backs and longer-lasting glazing systems.

Three application levels: which production setup is right for your operation?

Edgetech supports several production configurations depending on manufacturing scale.

Manual production: Manual systems offer the lowest entry point for fabricators adopting warm edge spacer technology, making it suitable for smaller operations.

Semi-automated lines: Semi-automated solutions bridge the gap between manual and fully automated production.

Fully automated production: High-speed automated lines deliver the greatest efficiency gains. These systems integrate directly into modern glazing lines and maximise the productivity benefits of Super Spacer.

Edgetech’s technical team supports installation, training and ongoing production optimisation.

Ready to upgrade your glazing production?

Warm edge spacer bars are one of the most effective ways to improve both the manufacturing process and the finished performance of insulating glass units. Edgetech has spent decades developing advanced spacer systems that help fabricators produce durable, energy efficient glazing at scale.

To discuss which warm edge spacer bar system is right for your production volume and specification requirements, contact Edgetech now.