What is the cause of window condensation?

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Posted by: from Ajax
10/15/2015 at 9:54:23 AM

I noticed a lot of condensation on the windows. House is only 5 years old. Is there any solution to this? Do I need to replace the windows?

Looking forward to hearing from you guys.


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Date/Time10/15/2015 at 11:24:54 AM

Hi Olivia,

The condensation is either due to the moisture content in your house or inadequate ventilation around your window.start by checking to see if you have a humidifier on your furnace and turn it down and keep the windows free of drapes or blinds that can hamper ventilation.

Good luck.

Ben Ozorak

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Date/Time10/15/2015 at 11:32:30 AM

Hi Olivia,

The condensation on the windows can be caused by a shortage of air flow in front of the windows.

If you look you will find most of the air vents right under the windows and that is so that air will come up and replace the standing air in front of the windows, if the air just stand there it will get colder and will deposit humidity on the glass and it will transfer to water from the colder glass.

one quick solution is to change the fan thermostat from auto to on,

This will make sure to move the air all the time whether the heat is on or not.

Another thing that can help create the water is putting furniture on top of the vent, this will block direct access of air to the window,

To be more spesific I will need to come and see the issue.

Hope this is helpful. Thanks,

Harry C.

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Date/Time10/15/2015 at 11:33:13 AM

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.

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Date/Time10/15/2015 at 11:46:57 AM

Hi Olivia,

There are numerous reason for condensation build up on Windows. Since your house is only 5 years old there should be no reason to change out the windows. Some of the causes could that could contribute to condensation build up are, the size of family, the use of showers,laundry facilities or cooking just to mention a few. The one I would look into first is to have a certified heating and venting technician come and test the air and moisture content of your home, to ensure that your heating and cooling system is functioning properly.

Hope this helps, if you have any other questions please don't hesitate to ask.

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Date/Time10/21/2015 at 8:42:20 AM


Condensation on the interior of the glass is typically homeowner maintenance.

ie. lack of air flow (blinds covering the windows, furniture covering supply air vents, etc.)

Any fog/condensation within the window panes will mean the seal has broken to allow air inside.

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Date/Time10/28/2015 at 5:00:54 PM


I can almost guarantee that your windows are completely fine, considering they are 5 years old. I will assume the are double paned, argon filled and covered with Low E film so they would be quite efficient (even if an inexpensive brand). I would say you have an airflow problem. I would suggest starting with an HVAC contractor and having the air tested. This will give you a very good inclination of the issue and would be anywhere from $80.00 to $120.00 on average. You can also check if your furnace has a dehumidifier and adjust it accordingly. As well ensure you are using bathroom fans during showering. Good Luck and keep us posted of what you find out!

Kindest Regards,

Don Engler

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Olivia from JDesigners in Ajax
Date/Time10/29/2015 at 9:37:31 PM

Thank you everyone for advice. Problem is fixed now. Apparently, there was lot of standing air. :)

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