What Does It Mean If You Have Condensation On Your Windows

You might be cleaning your windows, or pulling back the curtains and suddenly see moisture on the windows. Your initial reaction may be to panic and leave you wondering,

What does it mean if you have condensation on your windows?

Does this mean the windows need to be replaced immediately? Is the condensation doing damage to the windows or the frames? Should this condensation be cause for concern?

The short answer is, no, you shouldn’t be too concerned about having condensation on your windows. Condensation on household windows is a relatively common occurrence. Generally speaking, if condensation has formed on the inside of your window that means the interior surface temperature of your windows is at or below the dew-point temperature of the surrounding air in your house. 

Think of the air in your home like a sponge holding water. When the temperature drops, the sponge is squeezed and the water comes out onto the interior surfaces of your windows. 

The difference in interior surface temperature and the dew-point temperature can be affected by the inside and outside temperatures, the overall humidity, and an increase in the humidity inside your house. In other words, there are a number of factors that can cause the sponge to take in more water which means when it is squeezed there will be more water to come out onto the interior surfaces of your windows. This process can be caused by showers, plants, pets, or a large group of people.

While it is generally not a cause for concern if you notice condensation on the inside of your windows, if you notice that the condensation is occurring between your window panes, this is often a sign that it is time to replace the windows. Additionally, allowing the condensation to occur regularly or to never be cleared up can lead to rot, mold, and mildew. If there is enough condensation it can even lift up paint and damage the frame or surrounding plaster.

To avoid this damage you’ll want to be mindful of reducing the condensation on windows. This can be accomplished by adding window inserts, simply opening the windows for 20-30 minutes each day, using a dehumidifier, drying clothes in a ventilated area or using an extractor fan when cooking, showering or bathing. Depending on if damage has already been caused to the current window and/or frame you will also want to consider replacing the windows.