Window Condensation: Causes and Prevention

Are you having issues with your windows “sweating” or fogging up on the inside as soon as the temperature changes? If you are, be rest assured that you’re not the only one. This phenomenon is called condensation and it occurs more often than you would think. Window condensation can be downright irritating and it’s easy to blame your windows for the issue, but in actuality, your windows are not the problem. Learn more about what causes condensation, steps to take to reduce it and when it might be a bigger problem.

Window Condensation

Causes of Window Condensation

Condensation is caused by an excessive amount of humidity in your home. As the temperature outside drops so does the temperature of your window glass. As a result of this, when moist inside air comes in contact with the cold glass pane, condensation forms. The tight seal of your window is actually resulting in a higher relative humidity in your home because air can’t circulate in and out. It’s normal to experience condensation once you have replaced old, drafty windows since the humid air can’t escape and cold, drier air cannot enter.

Window Condensation 101: What Homeowners Need to Know

Solutions to Combat Window Condensation

Just because condensation is a normal issue doesn’t mean you have to deal with it all winter long. To reduce this problem you need to lower the amount of moisture in the air inside your home and prevent it from coming into contact with cold window surfaces. Here are some steps you can take that might help:

1. Open Curtains and Blinds

It’s important to note that windows covered by blinds and curtains are more likely to experience condensation. This is because there is reduced airflow getting to the surface of your window, trapping the humid air between the window treatment and the glass. Tie back your curtains and raise your blinds to avoid this problem.

2. Air it Out

Now that we know condensation is caused by the amount of humidity in your home, there is a simple solution to get rid of it. Air out your home for a few minutes each day. If it’s snowy or rainy outside and weather doesn’t permit opening your windows, use a fan inside the home for a similar effect.

Window Condensation

3. Use Ventilation Fans

When you’re cooking or showering, a lot of humidity is released into the home from the hot water. Run a vent fan in the bathroom or kitchen and leave it on for anywhere from 10-15 minutes after you’re done. Make sure the fan is vented to the outside to let the warm, humid air out. This also goes for your clothes dryer.

4. Turn Down the Thermostat

As air warms, it expands, allowing more moisture to be trapped in the molecules. Therefore the warmer the air in your home, the more moisture you will have to deal with. Turn down your thermostat slightly to reduce the amount of humidity in your home.

Window Condensation

5. Lower Your Humidifier

If you use a humidifier in any part of your home or if it’s included with your furnace, you can try turning it down to a recommended level. As a result, the humidifier will release less moisture into the air, which will reduce condensation.

7. Buy a Dehumidifier

If the other steps don’t help relieve some condensation build up, using a dehumidifier is an easy but pricey way to remove excess moisture in your home. Some dehumidifiers need to be turned on and off, while others work automatically when the humidity in your home reaches a certain level.

Window Condensation

Moisture Between Window Panes

If you’ve tried to wipe condensation away and it doesn’t wipe off, you may have a bigger problem at hand. Unfortunately, if the water is between the windows panes, your window may have seal failure. Seal failure can happen due to many reasons from extreme weather conditions to every day wear and tear. Having a window with seal failure can affect the overall energy efficiency of your home and it’s important to get the issue fixed as quickly as possible.

Depending on the condition of your window, the most common solution to seal failure is to just replace the glass units. However, if your window is older and is experiencing additional problems, you may want to consider replacing the whole window.

Helpful Resources

Here are some helpful resources for window condensation that can help you further:

The Bottom Line

As mentioned, drafty windows allow moisture to escape through seals and cracks and that’s why older homes may not experience as much condensation.

With today’s window technology, your home becomes more energy efficient and tightly sealed. This is great for keeping your home more comfortable and quiet year round, but it also traps the moisture in, causing condensation when the temperatures change.

Now that you have learned what window condensation is and how to reduce it, you’ll be able to enjoy your existing or new windows to their full extent regardless of what time of year!

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