Published on March 4th, 2013 | by Henri0
Attic fan causes moisture on basement ceiling
Q. My neighbor has an attic fan with the thermostat set at 85 degrees F. He was forced to shut the fan off because it created a great deal of moisture on the ceiling in the basement of his house. What is the problem?
A. It sounds as if there is a louver in the ceiling of the top floor of the house. The attic fan sucks air from the house and depressurizes it. Outside air is sucked in through whatever avenues it can find and, if there is not enough supply air through openings on the lived-in floors because windows are kept closed, outside air may be drawn through openings in the basement. Warm, moist air will condense on any cooler surfaces.by