Avoiding Condensation in Windows

Condensation in windows occurs when the surface temperature of the glass, sash, or frame of a window is lower than the dew point of the humid air in its vicinity. Condensation in windows often occurs at the corners, where the glass and frame touch.

Problems with Condensation

Condensation in windows can obstruct visibility. Moreover, it can cause water damage to the window frame and surrounding area as well as nurture mold growth.

How do window manufacturers control condensation?

Convection-controlling inert gases such as argon, krypton, or a blend of the two, can be used to fill the air space between the insulating chambers of your windows. These gases control convection because they are heavier than air. The movement that often happens with air is suppressed because the gas doesn’t move as readily as air. The gases are also better insulators than air because they have a lower conductivity rate.

Low–E glass coatings help keep the interior glass temperature of your windows warmer in the winter and cooler in the summer. This is important because if the temperature of the glass is kept close to the ambient temperature of a room, the risk of condensation is greatly reduced.

A window’s spacer system is often the weak link in a window, and if improperly designed can facilitate condensation in the corners of a window. Experts estimate that a poorly designed spacer system can reduce the performance of a window by as much as 20%. A well designed spacing system keeps the interior glass at the perimeter of the window at the same temperature as the rest of the window. Smart technology dramatically reduces the probability of condensation and stress on the window.