How to Prevent Condensation and Sweating on Windows

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 ensure 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

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.


  1. 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?

  2. 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!

  3. 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

  4. Hello

    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

  5. 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?

  6. I have the same problem with my windows and I have double panes insulated storm windows.My problems are they have moisture between the panes.The summer time hot outside and air on inside and winter cold outside and heat on inside so how do I handle this.

  7. I live in an apartment with sliding doors. There’s an outside one, then a screen door, then the inside one. The outside door is covered with condensation on its inside. I’ve tried wiping it clear, but it just steams up again. This also happens on some of the windows. Help please.

  8. We purchased the best Andersen windows and now they have condensation on the inside of them each morning. They were not replacement windows new complete windows. It does not matter if we have mini blinds or drapes they still have condensation on top saches. What can we do? Andersen rep has promised us he would be by to check on them for weeks but haven’t seen him and not going to pay all we owe until problem is fixed. We do not have alot of humidity in our home as we are burning wood burning stove and home one level. Any suggestions would be appreciated.

  9. Same problem as Charlotte Rice, new house with with best Andersen windows. Humidity in house 31% and 1to3 inches of Ice & condensation every morning. Contacted lumber yard & Andersen and NO HELP only run around. Anyone with any SUGGESTIONS

  10. We heat our house with a propane fueled heater, supplemented with electric heat. When we have consistent outside temperatures in the teens and lower, we experience a condensation spot in the middle of our 5′ by 6′ picture window. In the past we’ve set up a small fan to blow on it for control. Is there any other window treatment, etc. that we could use? I know that the gas heating is the culprit, just get tired of setting the fan all the time. And we’re currently in the single digits here the last few days. (Texas panhandle area). Thanks for your help.

  11. I have double pane windows (about 8 years old) new metal roof (3 yrs) and only a window in the bathroom. I have electric heat. On the bottom part of my windows which are metal above the caulk my windows sweat..and eventually in the spring when it’s time to clean them there is mold in the little gap where all the water drains..I have a dehumidifier should I use it all winter to keep this moisture from happening?

    • Hi, Mrs. Wildman! If your seal is broken, it may be necessary to replace the windows.
      First, here are articles on this topic:
      Thanks for your question.

  12. Every morning I have sweat or condensation on the outside of my windows in the summertime. My AC vents are on the floor beside all windows but only the front of the house has this problem. Can someone help me determine what to do?

  13. Double pane insulated windows. The older ones sweat in the middle of the glass inside the house(large oval of sweat developes)not inbetween the panes. Newer double pane windows in same areas of home no sweating at all?? We heat mostly with propane gas & some electric base board. If it was the propane heat causing this problem why would only some older windows have this problem. ?? Please help me with a solution to this problem. Thanks

    • Hi, Catherine, hasn’t covered this specific matter, but here’s an excellent article from the New York Times that elaborates on the situation:
      This sounds like what’s happening in your home:
      “There are also some cases in which condensation develops between the two panes of glass – usually on the inner side of the outside storm window. This can happen even if the outside storm window does fit snugly. It usually means that the inside window is allowing warm, moist air from inside the house to leak out into the space between the two panes of glass.”
      The article includes more information and offers solutions.
      Hope this helps!

  14. Your not understanding. There is No Moisture between the panes. They are wet on the glass inside my house. Just such a mess have to put towels on sills to soak up the wet. Someone told me to read an artice they sent printed inNY Times. To small could not enlarge it to read. Help. Thanks

  15. We bought our home new ant. 2 yrs ago. The bottom half of all the windows can fold out for easy cleaning but top half does not. There is condensation in between the top 2 panes. How can get it clean in between the top panes??

  16. Have just bought new triple pane windows for the south side of my house. One window has condensation on the outside every morning. The other window on the same side of the house does not and is clear all the time. They are approximately 12 feet apart. Once again facing the same direction no obstructions in front of either window. Same size windows. Installer says there is nothing wrong windows are fine – THEN WHY CAN I SEE OUT OF ONE AND NOT THE OTHER???? Driving me crazy – I understand about condensation and blah blah blah about how it is a good sign BS one window is transparent the other is not until 10 o’clock in the morning.

  17. I had the same problem with my new house and it turned out that it was very well insulated and really really sealed up so I had to put a heat ventilation Recovery Unit in which brings in outside air exchanges it basically it’s an air Exchange that solve the problem

  18. If you have double pane windows, you should not have condensation on the outside of the windows in any season or temps. I have the same problem with my home. For one thing I do not have a ridge vent in my roof with the proper vents under the overhangs allowing proper air flow through my attic. My problem was not detected to make any recommendations, it’s just my own though. When someone installs attic insulation in your home, they are installing a installation system so it works properly, not some slipshod job. Many contractors just want to make a quick buck and move on to the next job.


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