Window Condensation: Should You Be Worried?

Many people regard condensation on patio doors and windows a bad sign, but you might be surprised to learn that in most cases, this isn’t true. Renewal by Andersen® of Sacramento shares an in-depth look at window condensation, its causes, and what you should do if it starts forming on your doors and windows.

Causes of Window Condensation

Condensation forms when warm and moist air comes in contact with a cool surface. Condensation would form on a cold glass of water because its outer surface is colder than its surroundings; the moisture doesn’t come from the drink in the glass but from the surrounding air. Another example is when eyeglasses turn foggy when you come in from the cold or when you leave a room with the air conditioning turned up.

The same thing happens with the glass panels on your windows and hinged French doors. When it’s cold outside, moisture from indoors will form on the cooler glass panel. The glass surface doesn’t have to be cold for condensation to happen; it just has to be relatively cooler than the air. Condensation forming on the glass does not indicate inefficient windows. Rather, it indicates high humidity levels. It also indicates your window seals are perfectly functional.

There is one exception that you should be aware of, however. If your windows are equipped with double-pane glass and you see condensation between them, it means the glass seals have failed.

Controlling Indoor Humidity

If condensation frequently obscures your view, you should look into sources of moisture that may be raising your home’s humidity levels. Daily activities such as cooking, bathing and washing the laundry release moisture into the air.

The simplest way to balance indoor humidity levels is through proper ventilation, which can be accomplished with two openings, such as windows, in the same room. One window vents moisture (along with indoor air pollutants like VOCs), while the difference in air pressure pulls fresh from another window. Certain window styles like double-hung and bay windows can be opened to create two openings. Mechanical ventilation such as range hoods, exhaust fans, and dehumidifiers can also help.

Renewal by Andersen of Sacramento is your leading provider of energy-efficient replacement windows and sliding French doors. Give us a call at (916) 226-3359 or fill out our contact form. We serve customers in Roseville, CA, and the surrounding areas.