Condensation and frost on the inside of windows are common problems.
It could be slight condensation on some windows or persistent frost covering the entire glass. Many homeowners buy new windows and realize that the problem has only worsened because the old leaky window was actually helping to reduce humidity. The new windows make the house more airtight, which increases the humidity level. One solution to this problem is to reduce the humidity level in the house.
Figure 8-2 Cross-sectional view of a double-hung window showing the parts and locations where air leaks occur.
You can also increase the surface temperature of the window and frame by installing an additional layer of glazing. Energy-efficient windows are the best solution.
When condensation forms between the panes of unsealed windows, it means that humid air from the house has escaped around the inner pane and condensed on the outer pane. Even drier homes can experience this kind of issue, which often occurs on the second floor, where more air exits through the window due to the chimney effect. Therefore, you need to install weather stripping on the interior frame to prevent air leaks, but make sure that the weep holes on the outer window, which allow water to drain, are open to the outside.
If condensation occurs inside a sealed double-glazed window, the issue can only be corrected by replacing the glazing. While some specialized companies offer the service of refurbishing poorly sealed glazing, this repair is temporary and will not match the initial level of energy efficiency. Check if the window is still covered by the warranty.
