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What causes condensation on windows?

Each morning, the interior side (as in the glass facing the room) of some of our windows is covered with thick condensation. Our house was built in the 1950's, but replacement windows were installed about 10 years ago. The outside temperature is about 55, and the inside temperature is about 75 when this happens. What causes this? What can I do to fix it? Thanks. I should add that the windows are double-pane, and in case it wasn't clear in my description, the condensation is NOT between the panes. It is on the room-side of the window such that I can wipe it off. Thanks.

Public Comments

1. its caused by the temperature difference. getting double paned windows should help if they are double paned already, then they are broken and they need to be resealed.


2. poor ventilation mixed with humidty, caused by dishwasher, washer,showers/baths....all that moisture is trapped.

   It is also possible that you have double paned windows with a gas filled gap between the 2 panes of glass. If this failed you are losing a vapour barrier and would cause fogging or condensation



3. Differences in temperature from inside to outside.


4. The gasket that sealed the windows have failed. The only way to fix it that I know of is to replace it.


5. i dont no


6. its caused by the temperature difference. the outside of the glass as well as the glass is much colder than the inside. on the inside of the glass there is moisture in the air at a quanitiy that is in vapor form at 75 degrees but condenses into dew at 55. its the same thing that happens to a cold drink can on a hot day. the can is about 40 degrees but the air is 90, so the moisture that comes in contact with the can condenses into liquid. to fix it get a dehumidifier.


7. I would guess strongly that the windows(double pane I suppose) has a leak in one of them or all of them if all the windows are frosted(condensed) over... Do you have a warranty on the windows? I am having some put in here and they have a lifetime warranty


8. Humidity of the air inside the window.

   And difference in temperature.



9. The humidity in the air in your house condenses on the window due to the difference in temperature from outside to inside. You could try a de-humidifier and see if that takes care of the problem.

   I've actually had ice form on some windows in a house I was working on during the winter months. It wasn't that it was that cold in the house, it was that there was just that much condensation on the windows and they were that cold that it froze.



10. Why not try a barometer to see what the temperature is on the inside of the house.