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How to Identify Failed Double-Pane Window Seals

Insulated windows rely on a set of window seals to ensure minimal thermal transfer and maintain indoor comfort. If the seals fail, it could result in drafts, condensation and higher energy bills. In today’s post, window replacement company Renewal by Andersen® of Long Island takes a look at how to identify failed window seals, and what can be done about them.

Identify Failed Double-Pane Window Seals

What Are Window Seals For?

Insulated windows feature a glass assembly that consists of two panes that are separated by insulated spacers. Separating the interior and exterior surfaces help slow down thermal transfer and function as an insulating layer. The airspace between these glass panels need to be sealed because the gap is a vacuum — the lack of air molecules help slow down the heat that would have been otherwise conducted through the air. This airspace can also be filled with an inert gas for enhanced insulation.

How Can Window Seals Fail?

The seals on insulated windows may fail due to one or more reasons. Some of the most common reasons are wear caused by exposure to the elements, such as extreme heat and vibration caused by wind. Certain types of seals may deteriorate due to age. Some window seals fail when new, which is common with replacement windows that are transported by air over long distances. Extreme changes in atmospheric pressure can loosen the seals during transit. One of the advantages of choosing Renewal by Andersen replacement windows is that our replacement windows are crafted in Minnesota. We ship our replacement windows by land whenever possible, and are only shipped by air for a few hours at most.

What Are the Signs of Failed Window Seals

If you notice any of the following signs, it may indicate failed window seals.

Glass distortion. If the gas fill in an insulated window is leaking, it will have a similar effect as sucking on an almost-empty juice box. The glass panels will be pulled towards each other, resulting in a noticeable distortion in the glass that is more pronounced at the center of the panel.

Condensation between glass panels. Condensation on window glass indicates your window seals are working…unless the condensation is forming between the glass panels. This indicates the window panel has been breached.

Discoloration. Fine particles like dust and smoke may find their way through holes in the window seal. They may be so fine that you won’t notice them, but instead the discoloration that they cause.

Since window seals are applied during manufacture, your replacement window limited warranties may have coverage for premature window seal failure. If not, or if the windows are out of warranty, ask your replacement window contractor if repairs are an option.

Renewal by Andersen® of Long Island is your leading provider of custom specialty windows. Give us a call at (631) 977-7792. You can also fill out our contact form to schedule an appointment. We serve customers in Huntington and the surrounding communities.


"I was very impressed with Renewal by Andersen. They showed up in time and we received several follow up phone calls as the installation was being done as well as the sales representative stopping by to check in on the installation. The delivery/ installer was very professional. I would highly recommend Renewal By Andersen."

February, 18

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