What Causes Window Condensation?

In winter especially, people notice moisture on their windows. It can be just a little bit or enough to obscure the glass completely. Some choose to ignore it, and for others it causes great concern. People may blame it on new windows or claim that it’s supposed to happen. What’s the truth about condensation on your glass?

It’s Not Always BadCondensation Face

The simple answer is always the same. Humidity causes condensation. Warm moist air is meeting a cool and dry surface. The vapor is forced to condense because of the temperature change, and suddenly there’s a fog on your glass. It’s the same principle as steaming up a mirror while you’re in the shower – it just doesn’t tend to dissipate as quickly.

Many times, your condensation issues are not the fault of your windows. In truth, it’s likely because of your home, appliances, and habits. It’s likely that all the moisture in your home is simply building up with no way to escape. Every time you cook, shower, do laundry, etc., you’re adding more water to the air. Since drafty windows and doors are a thing of the past, the liquid simply accumulates. If you never noticed the problem before, but it’s become evident with new windows, you can safely assume that the new draft-free setup is the cause.

The Cause of CondensationHow Do I Fix It?

It’s not very hard to control the humidity in your home. Always use exhaust fans in the kitchen and bathroom, and you may notice a significant difference. You can also open a window if it’s close to the same temperature outside. Unless it’s raining or has been recently, the outside air will probably be drier than what you have indoors. They’ll equalize and help reduce condensation. When it gets cold, turn on the heat and the warm air will no doubt be significantly drier and fight the humidity for you.

If none of these is enough, you may want to invest in a dehumidifier. Condensation collecting on your windows means enough moisture is in the air to damage other aspects of your home. Excessive humidity can cause expensive damage to paint and wallpaper.

Warning Signs

Humidity Causes CondensationIf your windows are new, condensation is not a sign that they are faulty. If they’re old, it could be a cause for concern. Chances are that older windows are letting in some amount of air. This means that in order for the humidity to form condensation, the windows would have to be losing a lot more heat than modern windows.

A good way to check the amount of heat transfer is to put your hand against the glass on a cold day. The closer the window is to the outside temperature, the poorer job it’s doing holding in your precious heat. In extreme cases, the moisture on the glass may freeze completely and leave a layer of troublesome frost.

Another problem is if the moisture is between the panes of glass. In new windows, this can signify a leak or breakage, which is never good. It may be covered by warranty or insurance, so it’s not the worst-case scenario. Windows that are a bit older and have interior condensation probably need window replacement.

Part of the reason double-pane windows are so effective is the space between the pieces of glass. Older versions included a vacuum and newer ones are filled with gas. The purpose is to prevent heat transfer as much as possible, and in doing so make the windows more energy efficient.

If you’re noticing moisture and streaking, those are telltale signs that the gas has leaked. The insulating abilities of your window will be very severely impacted. This kind of malfunction is a good indicator that it’s time for total replacement.

If the issue has existed for some time, you may be surprised to see how much new windows can impact your energy bill. There have been incredible advances in insulation and UV blocking technology. Plus, a new set of windows will offer a nice boost in value and curb appeal when professionally installed.

Recognize the different kinds of condensation and use common sense. If you’re noticing more and more problems (such as streaking inside and drafts), a window overhaul could save you lots of money in the long run.

Mr. Roof

Exterior renovation contractors providing roofing, siding, windows, gutters, masonry and insulation. Get a free estimate today!

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