If you see condensation on your windows, it means the panes are not efficient enough to keep the cold air out.
Same goes in the summer: Single-pane windows are not high-quality enough to keep your cool, air-conditioned air indoors.
Those foggy windows are trying to tell you something: Replace them.
Moisture in the air condenses when it touches a cold surface, causing the glass to “sweat” like a cold glass of iced tea on a hot day. Condensation can form on the glass and even pool on the window sill. And like any excess moisture, it can eventually lead to mold and mildew. It also can damage your windows over time.
One solution: Replace drafty, single-pane windows with double-pane versions that are more energy efficient. Here are four other ways to cut down on condensation:
1. Install ventilating fans in every bathroom, and turn them on before every shower. Let
the fan run until the “fog” clears out of the bathroom, but no longer.
2. Use the hood fan over your stove when you cook. Cooking sends moisture into the air—along with lingering odors. The fan will rid your home of those smells and humidity.
3. Vent your clothes dryer to the outside.
4. Limit your use of humidifiers indoors. It’s possible to add too much moisture to indoor air.