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How to Prevent Condensation and Sweating on Windows

By: Danny Lipford

Condensation or sweating on the inside of windows during cold weather is caused by high humidity inside your home and single pane windows that allow cold outside air to come into contact with heated air inside your home.

To prevent condensation on windows:

  • Run vent fans in bathrooms when showering or bathing.
  • Turn on vent fans in the kitchen when cooking.
  • Have your heating and cooling system inspected to make sure it’s running properly.
  • Install storm windows or replace single pane windows with insulated glass windows.
  • In extreme situations you also may need to install a dehumidifier in your home.

Watch this video to find out more.

Further Information

Print   Video Transcript

Melissa asks: What causes my windows to sweat?

Danny Lipford: Now, that is probably the most common question I’ve heard over the last couple of years, and it is quite a problem for a lot of homeowners regardless of the type of windows that you have. Now, condensation on the inside of windows is simply a result of excessive moisture in your home. And that emphasizes the need to use, on a regular basis, your kitchen and bath exhaust fans.

Also, you want to make sure your heating and cooling system is working properly to keep your humidity in your house under control. Now, to see if you have any kind of a problem like that you can pick up one of these. It’s a very simple hydrometer, only costs about $20, and it’ll tell you exactly the percentage of relative humidity you have in your home.

Ideally, you need it to be below 40% to control condensation on your windows. And in more severe situations you may have to install a de-humidifier.


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5 Comments on “How to Prevent Condensation and Sweating on Windows”

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  • Carol Says:
    January 17th, 2017 at 12:48 pm

    3 Windows on the back of my house get condensation in the winter which is right now. The odd thing is the MBR has 2 Windows but only the one on the back side sweats. All 3 of these windows were replaced 15 plus yrs ago. All of the others were replaced at the same time maybe 10 yrs ago. None of the other Windows sweat. The house temp is typically set at 64-66 degrees. It is usually on the cooler side unless weather is very cold out. Bathroom is vented. Strangely the front Bedrooms/front of the Ranch house tends to be warmer than the back half. Any ideas on why some sweat and not others?

  • Belinda McNair Says:
    December 19th, 2016 at 1:06 pm


    I have a Mobile Home and the back door glass is my issue. Back door is located in a hallway facing the North side with a long rectangle single pane window that I keep covered for privacy. How do I prevent the condensation which starts a mold build-up?

    Thank you

  • Timothy Lynch Says:
    May 30th, 2016 at 7:14 am

    Hi Could you tell me why i am getting condersation on my and ceiling after putting in insulation batts under a tin roof.

    Regards Tim

  • Tianna Says:
    November 8th, 2014 at 4:15 pm

    A very easy and inexpensive way to deal with window condensation is to use a simple tool called a ‘Scoopy’ window condensation squeegee. Until recently they were only available in New Zealand, but they are now available in Canada as well. They will also be available in the US within the next month or so, I believe. A great investment!

  • Deborah Says:
    July 16th, 2014 at 1:22 pm

    My question I was seeking an answer to was about condensation on the outside of windows. We keep our house pretty cool and every morning the outside of our glass is cover in condensation so much that I can’t see outside. I tried Rainx, but it’s is not working. I raise the temperature inside but it takes a long time to clear. Mainly I like to watch the birds outside my bedroom window. Are there any products that will repeal the moisture?

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How to Prevent Condensation and Sweating on Windows