What does condensation in double paned windows signify?

Condensation in double-paned windows is a sign that the window has lost its insulation properties. Double-paned windows are designed with two layers of glass that create an insulating space filled with air or inert gas to improve energy efficiency. When the seals around the panes fail, humidity can enter this space and lead to condensation forming between the layers of glass.

This visible moisture indicates a breakdown in the window's ability to insulate, thus compromising its thermal performance and potentially leading to increased energy costs due to heat loss or gain. Recognizing this issue is crucial because it often necessitates repair or replacement to restore optimal energy efficiency and prevent further damage.

The other options do not accurately describe the implications of condensation. For instance, if the window were functioning properly, there would be no condensation, and it certainly would not indicate the window needs cleaning. The size of the window is unrelated to condensation issues.