What Are the Causes of Steam and Frost Inside Thermal Windows?

Condensation

• Condensation occurs on window surfaces and, over time, can cause damage to the window's integrity and seal. Moisture is present in the air at all times. This humidity is greater during some seasons than others, but it is always present. Condensation forms when the window surface is cooler than the surrounding air. Humidity collects on the cool surface and appears as minute droplets. You will notice that condensation tends to collect in the corners of windows or at their edges. This is because heat is usually lost through these areas, making them more favorable for condensation buildup.

Care and Maintenance

• Condensation buildup at the outside edges of windows has the potential to damage paint and the window's framing material. Wood framing materials can warp. Metallic frames can rust or corrode. Condensation buildup within sealed glass impairs visibility and is a sign of a poor seal. If replacing the window is not an option, then ensure that the weatherstripping, caulk or other window seal material is not impaired. Reseal with more material. Once moisture is trapped within the thermal glass, however, it is not possible to effectively remove all of the condensation. Resealing windows is only a temporary solution to a potentially greater problem. The windows will eventually need to be replaced.

Prevention

• Prevent condensation buildup by inspecting the thermal seal between panes prior to and during the installation process. Energy-efficient windows, those with inert gases between window layers or those with low-emissivity coatings, are able to withstand humid conditions better than other types of thermal windows. Overall, the less indoor humidity, the less likely moisture will penetrate the thermal seal. Keep indoor humidity low through good ventilation, venting clothes dryers to the outside, using dehumidifiers and taking shorter showers.

Considerations

• Condensation buildup within thermal windows may be cause for concern, because this may indicate condensation buildup in other household areas. Condensation buildup near electrical outlets poses an electrical risk during usage. Buildup within walls is a contributing factor for mold and mildew damage.