Much like in the summer, when condensation beads up on an ice cold refreshment, windows will fog, steam or freeze solid in the winter due to moisture in the air. Warm air with water particles come in contact with a cold surface and the invisible water particles condense on to the glass. This can occur a few different ways. You can get moisture on the interior of the home, inside of the window, or on the storm window, which typically freezes and becomes a wild frozen piece of art. It may look neat, but you can’t see out the windows and that’s no fun.
Some homes have it good. In the winter, once they’re shut in and the furnace runs, the interior air dries and condensation stops. Homes that don’t have it so sound have a constant battle. If condensation continues, it can easily become a serious problem. Not only can it obstruct your view by fogging up or freezing, but the condensation can collect, drip and pool. If/when that happens, it will rot wood, encourage mildew growth, damage the framing around your windows and costs a pretty penny to fix.
What are some of the options to stop this nuisance of foggy, steamy or frozen windows? Reducing moisture and increasing ventilation. Windows are rarely the problem in these situations. Typically, they’re just the cold surface that the warm moist air is condensing to, showing you that the moisture level is high in your home.
The American Society Of Home Inspectors have a great article on how to reduce moisture and increasing ventilation, “Fogged Up? Clearing the Air About Window Condensation”.