Warping or Distortion
When the inert gas between the windowpanes begins to leak, the panes may start to bend and collapse a bit in the center. This can cause the glass to look distorted, or sometimes even break. By looking at the reflection from a distance, you can see if the glass is more distorted than other windows nearby. If it is, seal failure may have occurred.
To confirm, clean the surface completely with a clean, non-abrasive cloth. Check that the distortion is not caused by any dirt on the surface. If the distortion remains, you’ll need to consult with a window contractor about replacing the unit.
Dual-pane replacement windows have a thin layer of gas sandwiched between two panes. This space is often filled with an inert gas such as argon or krypton, which are set in place by a special seal around the glass panels. This seal usually lasts up to 25 years, the typical lifespan of a window. When this seal breaks, the gas escapes and the insulation and thus energy efficiency of the window will be severely compromised.
Fogging, hazing, or visible moisture between the panes may signal window seal failure, though these issues can also be caused by other factors. If you notice condensation in your window and can’t determine the cause, contact your window contractor for an inspection.