Foggy windows are annoying. You can’t see well out of them, they make your house look bad cosmetically and you can’t get in there to wipe it off. It’s

enough to make a homeowner fume.But, why are you the only one on the block with foggy windows?

Foggy Windows Are Not from a Broken Seal

Most people believe that a broken seal in their window is what causes it to fog up. In reality, moisture and air are always going in and out of a window. If a window was ever sealed airtight it would actually explode.

Solar Pumping Leads to Foggy Windows

Solar pumping is something that happens just about every day to your windows. When the sun comes out and heats the airspace between the two panes, it causes the window to pressurize. This pressurization pushes out air in small amounts through the window’s semi-permeable seal.When the sun goes down and the temperature decreases, the air that was heated up during the day is now cooled. The cooler air decreases the pressurization between the panes and allows small amounts of air to be pulled back in through the same semi-permeable seal.This new air that is drawn back in contains little water molecules that get trapped in the window; which is what causes the foggy windows.

Why Don’t I have Foggy Windows Every Day?

There is a material inside the window known as a desiccant that soaks up the moisture that gets inside the windows. A desiccant is simply a drying agent and it is what prevents you from having foggy windows every day.Over the years this desiccant becomes saturated from all of the moisture that is has absorbed. When it can no longer absorb any more moisture, the water molecules collect inside the window and create fog.

How to Repair Foggy Window

There are two options in dealing with a foggy window. First, you can hire a company to come in and defog it. They will bore little, tiny holes in your windows and install vents in these holes to return your window back to its proper solar pumping capability.Second, if you have allowed the fogging to go on for too long, the windows could be damaged. If this is the case, the windows will need to be replaced. Even having them defogged at this point won’t restore them back to their original condition.Call our showroom today or schedule a free consultation to learn more about your replacement window optionsLouisville: (502) 716-7264 | Lexington: (859) 629-4649

Recent Blogs

Southern Indiana & Louisville's Heat Dome Is Here: How Renewal by Andersen Replacement Windows & Doors Keep Your Home Cooler This Summer

Beat Louisville's heat dome with Renewal by Andersen replacement windows and doors. Discover how Fibrex® frames block heat and humidity, lower AC strain, and cut energy bills—plus quick tips to cool your home now.

Renewal by Andersen's Window Cleaning Tips

Keeping your Renewal by Andersen windows clean is essential for maintaining their beauty, energy efficiency, and long-term performance for Louisville homeowners. Using gentle solutions like mild soap and water or diluted vinegar, paired with soft microfiber cloths and a squeegee, will protect the exclusive Fibrex® composite finish and keep glass streak-free. Follow these expert tips to extend the life of your windows and safeguard your investment for years to come.

How to Tell If Your Patio Door Is Costing You Money (And What to Do About It)

This blog outlines common warning signs that a patio door is hurting a home's energy efficiency- Such as drafts, foggy glass, and warped frames. As well as explains how these issues lead to higher energy bills and home damage.