Condensation Control

Condensation forms when the surface of the glass or frame drops below dew point, the temperature where the airborne moisture condenses.

For a double-IG unit, there are four surfaces, surface 1, 2, 3, 4, from exterior to interior. As long as the insulating glass unit (IGU) is well sealed, condensation should not happen on surfaces 2 and 3.

Generally speaking, low-E coatings on insulation glass unit can help reduce condensation on surface 4, or the interior surface because the insulation capability retards the flow of building heat through the glass and helps prevent the cooling of the interior glass below the dew point.