When the weather turns cold, many of us wake up to foggy, dripping windows. A little is normal. A lot, every morning, can peel paint and grow mold on the sills.
The fix is usually not a new window. It is a few small changes in how the house breathes.
Why It Happens
Warm air holds moisture. When that warm, damp air touches cold glass, the water turns back into droplets. Cooking, showers, drying laundry indoors and even breathing all add moisture to the air.
What Helps
- Run the bathroom fan during a shower and for 20 minutes after.
- Use the range hood when you boil or simmer, and put lids on pots.
- Open the curtains in the morning so air can reach the glass.
- Move plants off the windowsill. They give off moisture.
- Crack a window for ten minutes in the morning, even in winter. It swaps damp air for dry.
- Keep the house at an even temperature. Big swings make it worse.
- Dry laundry outside or in a vented dryer when you can.
A Dehumidifier or Moisture Absorber
A small dehumidifier in the dampest room makes a clear difference. For a single window or a closet, a tub of moisture-absorbing crystals from the hardware store is a low-cost help.
Wipe It Up
Until the air is drier, wipe the glass and sill each morning with a dry cloth or a window squeegee. Standing water is what causes mold and damage.
When It’s the Window
If the fog is between the two panes of a double-pane window, the seal has failed. That can’t be wiped away, and the glass unit needs replacing.
Frequently Asked Questions
Is condensation on the outside a problem?
No. That means the window is insulating well.
Does a bowl of salt on the sill help?
A little, for a small space. A dehumidifier does far more.
What should the humidity be?
Many home guides suggest about 30 to 50 percent indoors in winter. An inexpensive humidity gauge will tell you.
Dry air and a little airflow are all most windows need.
