Window
Condensation

What is window condensation?

Condensation is when humidity or excess moisture in the air forms as water or frost on a surface.

Condensation, or “sweating” on windows, is caused by humidity or excess moisture in the air. When water vapor meets a surface at a temperature below what is called the “dew point,” the vapor condenses on the cooler surface and becomes visible droplets of liquid.

There are multiple reasons condensation can be forming on your windows and doors including but not limited to the following:

• The surface temperature of windows and doors is lower than your home’s dew point temperature

• High indoor humidity levels

• Cold outdoor temperatures

 

Interior Ice Build Up

What if there is ice on the inside of my window?

If there is enough humidity inside the home for window condensation to form, that moisture can freeze if temperatures decrease.

If you have ice or frost on your window, it is most likely in the same areas of your window where condensation has first formed as visible water droplets. Anytime the conditions exist which allow condensation to form, there is the potential for that condensation to freeze if the outside temperature drops. Icing is most likely to occur on operable windows, such as double hung and slider windows, because they tilt, slide and have meeting rails which are the coldest areas on the window, but even a fixed picture window can have interior ice form under the same extreme circumstances.

 

Tips to Reduce & Prevent

How can I reduce or prevent condensation on my windows?

Here are a few things you can do to help control moisture levels in your home

• Use kitchen and bathroom exhaust fans to offset cooking and showering that release moisture in the air.

• Make sure your attic, basement, and crawl spaces are well ventilated and free from obstructions.

• Check your dryer exhaust vent to make sure it is properly working.

• Open curtains and blinds to allow more air circulation around windows.

• Adjust your furnace humidifier based on the outside air temperature to achieve ideal interior humidity levels.

• Run a dehumidifier in rooms experiencing condensation.

• Don’t store firewood inside. Freshly cut wood can consist of up to 45% water, while well-seasoned firewood can have a 20-25% moisture content and naturally release into your home’s warmer temperatures.