Whole-house fans operate in a fairly simple manner. The system pulls hot air out of a house and vents it through the attic. Cooler air moves in through the windows to replace the hot air, and the house cools. The fans were the main source of cooling in the first half of the 20th century, before residential air conditioning became common. In the right conditions, they still provide a good option to homeowners who want to avoid running their air conditioning all the time. But homeowner interest remains limited, and many HVAC contractors avoid the market.
The main reasons for limited homeowner interest in whole-house fans is they require one key element — cooler outside air. Paul Scelsi, marketing communications manager at Air Vent Inc., said his company’s fans work best in climates like the Northeast. In Dallas, where he lives, the outside air rarely meets the right conditions during the summer.