Why Are My Home's Windows Fogging?

While the foggy windows in your home can be fun for your children to draw their names or pictures in the condensation on the panes, they're a common household issue. And while some fogging on your window panes is harmless, this issue may call for new window installations. Learn more about foggy windows here and what you can do about them. 

A Guide to Your Home's Foggy Windows

Why Windows Fog

Fog is actually condensation, which occurs when warm, moisture-rich air makes contact with a cold surface, and water vapor condenses on that surface as a result. Exterior windows usually fog because it's colder inside than outside. For example, when humid, outdoor air hits the cool glass, condensation forms on the exterior of your window panes. Condensation on interior window glass occurs when the outside temperature is cooler than the inside temperature, causing warm air within the home to condense on the interior of your chilled windows. 



Sometimes condensation occurs between interior and exterior glass panes. Such condensation indicates air leaks from damaged window seals that allow warm air to collect between the glass. Unlike the other two forms of condensation, this type cannot be wiped away with your hands or a clean rag, and is a common issue with older windows. 

Fogging Window Solutions 

Exterior window pane fog is normal and does not signify a problem, while interior fogging can indicate a high humidity level that needs correcting. The ideal humidity level is between 30 and 50 percent, as levels that are 60 percent or above promote mold growth in addition to causing foggy windows. 

For condensation in between interior and exterior panes, request professional assistance. Resealing deteriorating caulk might be enough to solve the problem if the windows are only a few years old. However, if the windows are the house’s original panes or are several decades old, it's best to schedule new window installations. New windows relieve condensation problems, as well as heat cooling losses that spike utility bills, increase your carbon footprint, and affect interior comfort. Window installation services also improve your home’s resale value, since most home buyers willingly pay more for real estate with new features they do not have to replace. 

For superior window installations, rely on East Tennessee Continuous Guttering, Siding & Windows. The home improvement company serves residents throughout Knox, Blount, Sevier, Anderson, Loudon, Jefferson, and Union counties in Tennessee, and is fully licensed and insured. All services include five-year workmanship guarantees. Call (865) 687-0170 today for an estimate or request one online.