What is Thermal Glass?

A house without windows might feel more like a prison than a home. Windows let in natural light, give us the views we enjoy, and allow us to quickly circulate fresh air from outdoors throughout our living space. It’s undisputed that windows are among the most important aspects of our homes, so it’s important that we understand as much about them as possible.

When considering a major home upgrade like solar window film, it’s a good idea to back up a step an do some research on the windows that we are to go about modifying. At Sun Shade, we have received questions about how window films interact with thermal glass (also known as double or triple paned windows, insulated glass, thermal pane, and many other terms).

Here’s a description of what thermal glass is, and a follow-up on how to correctly use window film on thermal glass windows.

What is Thermal Glass?

When some people hear the term “thermal glass” for the first time, they might make the assumption that the glass itself has special properties that changes its insulate properties. This is an understandable assumption, but is incorrect. Thermal glass refers to how a window pane is constructed, not to the glass itself. Put plainly, thermal glass refers to a window that is composed of two (occasionally three) sheets of normal glass separated by a dead space.

Think of thermal glass as a sandwich. Glass is the bread, and the middle of the sandwich is composed of 2 things: an inert gas such as Argon or Krypton, and a desiccant (a material that absorbs water vapour). The purpose of the gas filling is to reduce the conduction of heat from one side of the window to the other, thus improving insulation.

These units are sealed to prevent regular air from getting in-between the two panes, which would cause two problems. Regular air would reduce the effectiveness of the insulation, but more importantly, regular air contains water vapour which could condense on the inside of the panes. The desiccant helps to absorb any water vapour that finds its way into the airspace between the two panes, but the seal is crucial for the performance of thermal glass.

Can Window Film Cause Seal Failure?

Yes, and no. The answer to this is more simple than many people make it sound. If the right type of window film is used, it will not cause seal failure on your windows. If the wrong type of film is used, you are at serious risk of seal failure.

How do you know which film is safe to use? Consult an expert!