What does condensation between glass layers of thermal pane windows suggest?

When condensation forms between the layers of glass in thermal pane windows, it typically indicates that the sealant that helps maintain the integrity of the insulated glass unit has failed. This failure allows moisture-laden air to enter the space between the glass layers, leading to condensation.

While cleaning breather holes and checking sealant are important aspects of window maintenance, they are not the primary causes of internal condensation. The presence of condensation signifies that the insulating properties of the window have been compromised, which can significantly reduce energy efficiency and may lead to further issues if not addressed promptly.

Replacing the glazing, sash, or entire window is a common recommendation in such cases because it not only resolves the issue of condensation but also restores the thermal performance of the window, ultimately enhancing the comfort and energy efficiency of the home.