Drafty windows allow moisture to escape, causing condensation. Also, humidity inside the home causes moisture to condense on the window panes. Install ceiling fans to keep the air circulating.
Condensation can form on the ceiling of a home if conditions are very humid and air circulation is poor. Ceiling fans will stop moisture from hanging around on the ceiling and causing mold problems.
Condensation can form on walls as the result of humidity or poor insulation around windows or doors. Ceiling fans will not help with the insulation problem, but can help keep condensation from ruining paint or wallpaper.
Places where food preparation occurs can produce the most humidity, and the most condensation. A ceiling fan near the kitchen and dining room can cut down on damaging condensation.
Most bathrooms have a ventilating fan located on the ceiling to capture and expel damaging moisture from hot showers and the frequent use of water. The bathroom is a common place for mold, and ceiling fan ventilation can help curb it.