Condensation forms when an object is cooler than the surrounding air and water droplets accumulate on the surface of the cooler object. It can form on the inside or outside of a window, and also in between the panes of glass. In some cases, condensation is completely normal and nothing to worry about, but in other instances, it’s a sign that your windows need to be replaced.
Condensation Inside Your Home
When the interior of your house is warm, the windows are usually colder than other parts of a room because the windows come into direct contact with cold outside air. If moisture inside your house comes into contact with cool windows, condensation can form on the interior surfaces of windows.
Using a dehumidifier can lower the humidity level inside your house, which may reduce or eliminate condensation on the windows. If condensation is only forming on the inside of some windows, that may be a sign that your home has drafts. In that case, using weather stripping to seal the areas around windows with condensation may take care of the problem.
Condensation on the inside surfaces of several windows can also be a sign that your home has inadequate ventilation. If you don’t address the issue, high levels of humidity inside your house can lead to mold and mildew, which can endanger your family’s health and can cause physical damage to your home.
Condensation Outside Your House
Condensation can form on the outside surfaces of windows when there is moisture in the air outdoors and the windows are slightly cooler than the outside temperature. When condensation forms on the outside of windows under those conditions, it means that the windows are doing their job and providing good insulation, which isn’t allowing heat transfer to occur.
Condensation Inside Windows
Double- and triple-pane windows have multiple panes of glass that can provide better insulation than single-paned windows. The space between the glass panes is filled with a gas, such as argon, that provides insulation.
If the seals break and the gas escapes, the windows can no longer provide adequate insulation. The loss of the insulating gas can allow hot air to enter your house in the summer and warmed air to escape in the winter. That can lead to high utility bills.
If you see condensation that you can’t wipe away because it’s not on the surfaces of the windows, but rather located between the panes of glass, that means that the windows are failing. The solution is to install new windows.