Windows

Spacers

Spacers are the material that separate the sheets of glazing in a window.

Spacers are usually 12.7mm (1/2 inch) wide although narrower spacing may be used if the space between the glazing is filled will argon or krypton gas.

The spacers and layers of glazing they separate are coated around the perimeter with special sealants. This assembly is often called a “sealed unit”.

Gas fills

In the past, the space between the layers of glazing was always filled just with ordinary air. Now, this space is often filled will an inert gas, usually argon, to further reduce heat loss through the glazing.

Frames and sashes

A window consists of a frame, sash and glazing. The glazing is fit into the sash and the frame holds the sash.

Both the frame and sash can be a major source of heat loss and condensation problems. This heat loss is a result of conduction through the material. If highly conductive materials (e.g. aluminum) are used for the frame and sash, they must have thermal breaks in order to reduce heat loss.

Heat loss also results from air leakage. Poor window design can lead to excessive expansion and contraction or warpage of a window’s frame or sashes resulting in a dramatic increase in air leakage.