How to Fix Condensation on Inside of Windows

    Window condensation could become a bigger problem than it shows on the surface. The excess moisture could lead to further damage to your home, so it is essential to find the root of the problem and to quickly address it. Read on to learn what could be causing condensation to build on your windows and how to fix it!

    Causes of Window Condensation

    The main culprit of window condensation is excess humidity. Condensation forms when the warm air inside of your home comes into contact with the cold surface of your window. Because the indoor air has a higher humidity level, meaning its holding more moisture, the water vapor condenses into a liquid on your window pane. When the outside temperature drops, you can expect to see condensation on the inside surface of your windows. Your indoor air is usually more humid because of your everyday living. As you go about your day, you are adding more indoor humidity, increasing the inside temperature.  This could be addressed by using a dehumidifier but sometimes this solution cannot fix every condensation problem.

    Most experts agree that condensation or "fogging" inside a double-pane window technically is not a fixable problem ... at least not in the sense that your window can be restored to its original level of performance. Presently, there are two different ways to deal with window condensation: 1) either replace the window -- you can usually replace only the glass unit and not the whole window -- or 2) hire a local company to drill holes in the outer pane, clean the windows from the inside, and install one-way air vents to help prevent future condensation. 

    The Problem with Tempered Glass

    If your condensation problems are in a sliding glass door or a window that is likely to have tempered glass (for example, if the window has more than 9 sq. ft. of glass area and is less than 18 inches above the floor), your only option is replacement. This is because it’s essentially impossible to drill tempered glass without breaking it. You should assume that all doors with double-pane glass areas large enough to fit a 3-inch sphere through them are made with tempered glass (or in some cases, laminated safety glass). 

    Replacing a Double Pane Window

    Double pane windows, also called “insulated” or “thermal” windows, are made with two panels of glass sandwiched over a spacer and sealant, creating a space between the panes that is filled with air or with a gas, usually argon or krypton. It is this sealed space that gives the window most of its thermal performance. The spacer may also contain a desiccant material to help absorb any excessive moisture in the air within the sealed space. Interior condensation in a thermal window typically indicates a failure of the seal between the glass panels and/or saturation of the desiccant.

    Because a breached seal allows fresh air and water vapor to enter the window space, a condensation problem simply becomes a function of nature. Condensation is also a sure sign that gas-filled windows are no longer so. And since there’s no way to re-seal an insulated window, replacement of the glass is the only option for restoring maximum thermal performance, in addition to solving the problem of condensation on your windows. As mentioned, most glazing on insulated windows can be replaced as a unit, which saves you the expense and remodeling work of replacing the entire window, frame and all.

    If your windows are still under warranty, the first step is to contact the supplier or manufacturer, since replacement may be free. If the warranty has expired, it’s a good idea to consult with the manufacturer to discuss the recommended replacement options. Many local glass companies can also fabricate new window units in any size. 

    Restoring Insulated Windows

    The only way to rid a thermal window of condensation is removing the moist air between the panes and replacing it with dry air. And there’s a professional service based on this very technique. Thermal window restoration or repair companies will come to your house and drill a small hole (3/8-inch or so) at one top and bottom corner of the affected window. They spray various liquid solutions onto the inside faces of the panes through the top hole and suck them out through the bottom hole. Once the window is clean and dry, the holes are sealed with little vent plugs that allow air and water vapor to escape the window cavity but don’t let them back in. 

    Will this process work for your windows? It might. Or it might not. There are numerous consumer accounts in both directions. In any case, restoration companies commonly claim that their process costs 1/3 to 1/2 as much as glass replacement. And don’t even consider a service that doesn’t offer a money-back guarantee.

    Deciding Which Way to Go

    This can be a tough call, and you should examine your options carefully. If you decide to try restoration and it doesn't work, you won't really devalue the window further, since it has already failed. On the other hand, if the restoration isn't satisfactory and the company doesn't make good, you'll be out the cost of restoration and will still be faced with paying for a new window glass. Of course, if thermal performance is a high priority, replacement is clearly the best option.

    To hire a local window replacement professional in your area, visit our handyman services near me page.


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