How to Spot Seal Failure on Old Windows

Older windows only had one pane of glass protecting the inside of a home from the outside. Fortunately, modern windows and replacement windows in Portland, OR have double or even triple panes for better insulation. But there are more to these insulated glazing units (IGUs) than just a couple extra panes of glass. Here is what you should know about IGUs and how to spot seal failure.

What is the Construction of an IGU?

There was nothing to seal on old, single pane windows. It was simply one pane of glass fitted into the frame. If the glass got loose homeowners could secure it with glazing putty. But windows with two or three panes of glass are sealed as a single unit.

A spacer keeps the glass separated and the space between the panes of glass was sometimes a partial vacuum. More often now the space is filled with inert gasses. The most common in use are argon, krypton, and xenon. While colorless and odorless, these gasses have more density than air and improve the insulating properties of IGUs. But it isn’t foolproof. Over time the seals weaken and fail, and the inert gas leaks out.

How Seals Fail

Even under the best circumstances, IGUs will not last forever. On average about 1% of the gas leaks out per year. This is because of the pressure differential between outside air and the inert gas. But different conditions can mean faster seal failure. Things like transportation through different elevations, temperature fluctuations, and poor manufacturing all have a bearing on how much gas leaks out.

How to Tell if Your Windows Have Seal Failure

It isn’t always easy to tell if the seals on windows have failed. Here are a few steps you can follow

1. Clean Your Windows

The first thing you can do is thoroughly clean the glass, both inside and out. That way you know you are not looking at external smudges and grime.

2. Check for Distortions

Next, you want to examine the glass for any distortions. Stand at a distance outside and look at the reflections. When inert gas begins to leak out the window panes will bow, collapsing slightly in the center. This will distort the reflections.

3. Watch for Condensation

Hazing, fogging or moisture caught between the panes is a clearer sign of seal failure. It doesn’t always happen to windows with broken seals, but it is common to see. This happens because normal air has replaced the inert gas. And normal air contains moisture. The fogging will probably come and go with different temperature conditions. But the moment you notice it you know you need replacement windows.

Seal failure is not something you can easily repair. You can try filing a warranty claim and hope your window is still covered. Or you can try having the window defogged with varying results. But ultimately the best option is getting a new IGU or replacement windows in Portland, OR. For more information on these options contact EnergyGuard Windows & Doors. Call us at (503) 554-5500 or stop by 516 E. 2nd St., Newberg, OR 97132.