What is a Spacer Bar?

Spacer bars are an integral and critical feature of a sealed unit – the glazed element of the window that sits within the frame. Spacer bars are used to separate the panes of glass to form a cavity that enables thermal insulation.

How does a spacer bar work?

Spacer bars are constructed into a frame that is smaller than the glass. This enables sealant to be applied flush to the edge of the glass, to achieve an airtight seal and maximise insulation.

The bars are cut to size, and then connected using corner keys that are inserted and invisibly concealed within the tube endings.

Spacer bars hold a desiccant – an absorbent substance such as silica pellets. Small holes in their surface allow the desiccant to adsorb moisture from within the sealed unit during its lifetime.

What are spacer bars made from?

Traditionally, spacer bars have been made from aluminium due to its lightweight and structurally strong properties and the fact that it is one of the most abundant metals available.

However, as it is such a highly conductive metal, it is not the most efficient material. Aluminium conducts heat at the edge of the sealed unit, which reduces the insulating effect.

Hence the introduction of ‘warm edge’ spacer bars, which are made from an insulating plastic composite.

What is a warm edge spacer bar?

The function of a warm edge spacer bar is to keep the edge of the sealed unit warm; this is where most heat is lost.

They are often referred to as a ‘thermal break’ as they become a barrier to heat loss and help to minimise condensation.

Warm edge spacer bars lower the U-values of windows, and are therefore becoming an industry standard.

Is there a choice of colour?

We offer a choice of either black or silver warm edge spacer bars.

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