Why is there fog on my windows?

Should you be worried if your windows are foggy or have condensation? Andersen Windows has the answer to these frequently asked questions:

Why does condensation form on the inside of my windows?

The reason condensation forms inside the window is because the humidity level is too high indoors, not because there is something wrong with the window.
Humidity is the moisture in the air. It forms when we breathe, when we cook, when we shower, when we do laundry, and other everyday activities. It’s always present in air, and it’s not an inherently bad thing.

Condensation on the outside of your windows

When condensation forms on the outside of your windows, it’s really just dew — just like wet grass on a summer morning. Dew forms on windows when the glass is cooler than the dew point (the point when water vapor turns into liquid water droplets.)
It’s most common to see condensation outside your windows on spring and fall mornings when humidity levels are higher and cool nights are followed by warm days. You may only notice this a few times a year. When you do, rest assured, it’s the result of conditions outside — not a sign your windows are failing.

Condensation between the glass.

Most windows these days are dual pane, which means there are two panes of glass with an air space in between. If you ever notice condensation in between the two panes of glass, it’s a sign that the seal on your window has failed. Unfortunately, this is an indication that your window needs to be replaced. Older windows can lose their seal over time, making them less energy efficient.

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