What is a window spacer bar?

A window spacer bar is a small bar that runs along the bottom window rail, separating the panes of glass on double and triple glazed windows.

Having originally done little more than separate the glass panes on double glazed windows in the 1970s, spacer bar technology has really evolved since then.

What materials are window spacer bars built from?

The first spacer bars were built from aluminium because it was a lightweight, durable and relatively cost-effective material. However, it’s also an excellent conductor of heat, so aluminium spacer bars allowed large quantities of heat to escape outside the home. They also made the bottom edge of the window cold, which made them more susceptible to condensation.

Modern spacer bars

However, modern spacer bars are made from a combination of insulating materials, such as thermoplastics and insulating foam. Our flexible warm edge spacer bar range, for example, are built from foam and they are 950% less conductive than aluminium. Therefore, they dramatically reduce heat loss and condensation in the home.

How do spacer bars reduce heat loss?

94% of energy loss occurs at the edge of the window. So, when it is warm inside the home, heat can easily escape outside via aluminium spacer bars. This leaves a cold inside window edge and means more heat is required to keep the home warm.

However, warm edge spacer bars are built from silicone foam, which is far less conductive than aluminium. This means they create a heat barrier at the edge of the window and make it much more difficult for heat to escape.

How do spacer bars reduce condensation?

Condensation forms on the inner windowpanes when humid air in the home meets the cold surface of the glass. However, because warm edge spacer bars reduce heat transfer and make the inner surface of the window warmer, the likelihood of humid air turning into condensation is reduced.

Plus, modern warm edge spacer bars are filled with a desiccant, which is a substance used to sustain a state of dryness. Therefore, this desiccant actively absorbs water, preventing it from forming on the windows as condensation. A good example of a desiccant is silica gel, which is used to keep new shoes dry.

Here at Edgetech, we are market-leaders in double glazing spacer bar technology; our innovative warm edge spacer bar products have helped to set the standards for thermal performance in the glazing industry.

To find out if our products can help you for a project you’re responsible for, give us a call on 02476 639931 or contact us online.