Window condensation 411

You’ve tried cleaning your windows, but you can still see a film on your window panes. It’s probably not dirt or grease, but condensation between the panes of glass.

Energy efficient windows have two panes of glass—one on the outside and one on the inside. High quality windows have argon and nitrogen gas sealed between the panes, which creates better insulation.

With double pane windows, condensation can get between the individual panes of glass. This happens because the airtight seal that holds the gas in has broken. This often requires the entire window to be replaced.

Condensation on the inside

Condensation can also be weather-related. As the weather gets cooler, more condensation may be noticeable on your windows. No need to worry, this isn’t caused by faulty windows or bad insulation. It’s generally caused by excess humidity inside your house.

Window condensation happens when warm, moist air contacts cooler surface air. When this occurs, the inside or outside of your windows can sweat or fog because of the temperature difference.

You might see more condensation in your house because of modern energy efficient sealing and insulating methods used by homebuilders or products you may have in your house. The insulation and construction materials used today are specifically designed to keep cold air out and warm air in. Older windows and insulation, which are less efficient, allow moisture to escape rather than collect on the window glass.

If you recently replaced your windows and see more condensation on your new glass than on your old windows, it’s probably because they were drafty, and the new windows and insulation are creating a barrier to the air exchange. When you add in additional water vapor, such as steam from cooking, dryers that aren’t vented outside, and steam from showers, the result is excess moisture and a relatively high indoor humidity level.

How to control condensation

To help control the amount of condensation in your home, you can:

• Tie back your curtains and open the blinds. This will expose the surface of your windows to circulating air, and help regulate the temperature of the window glass.
• Open your windows for a while each day to help circulate the air inside of your home. If it’s too cold outside, turning on your ceiling fans will have the same effect.
• Place a dehumidifier close to the windows with the most condensation. Dehumidifiers help remove the airborne moisture that contributes to condensation buildup.
• Run vents or exhaust fans for about 15 minutes after cooking or showering. This will help remove the added moisture from the air.
• Make sure your dryer is vented outside. If your dryer is vented inside, all of the steam created during its cycles is released back into your home, adding even more moisture to the air.
• Although small contributors, cracks in your walls and basement floors can add to the humidity level. Filling them in can help reduce humidity.
• Check around your windows to ensure they are caulked correctly. If you find the caulking is weakened, reinforce it to prevent additional outside air from entering your house.
• Check your vents for blockages, and remove them if needed.
• Replace single pane windows with more energy efficient, wood composite, double pane windows.

If you suspect that there is condensation between the panes of glass of your windows, consult a professional. It may be time to replace and upgrade your windows.