Conventional wisdom says that using ceiling fans will reduce energy use, because occupants can raise the thermostat setting point two or three degrees. A field study by the Florida Solar Energy Center (FSEC) says that this bit of conventional wisdom is just hot air. FSEC researchers monitored energy use and surveyed the occupants of 400 new homes in central Florida. They also collected indoor temperature readings for 63 homes. The average home had four or five ceiling fans that operated 13 to 14 hours per day.

Surprisingly, the survey and monitoring revealed no correlation between using ceiling fans and saving energy. Instead, a computer simulation showed a potential energy use increase of 10 percent. It seems that the energy to run all those fans exceeds the potential savings from reducing the thermostat setting. Waste heat from the motors also added to the building's cooling load. There was no indication that occupants of the homes were operating the fans in a way that would save energy. The report, titled Are Energy Savings Due to Ceiling Fans Just Hot Air?, is available from FSEC 904-487-1824.