In general, ceiling fans are cost efficient when properly installed in your home, as dictated by your ceiling fan's installation instruction manual. By using ceiling fans in combination with your air conditioner or heater, you will save money on your monthly energy consumption.
Fans are an energy efficient option year-round because most new models have a feature that allows you to change the direction of the fan blade. One direction pushes cool air down into the room, while the opposite direction pulls cool air up and out of the room.
To get the maximum energy savings for your home, purchase fans that are Energy Star-qualified. Energy Star's strict specifications, as stipulated by its website, include an airflow efficiency of 1,250 CFN and an efficiency of 155 CFM/watt for low speeds, 5,000 CFN and an efficiency of 75 CM/watt for high speeds; a 30-year motor warranty; a one-year component warranty; a two-year light kit warranty; and light kits that meet RLF specifications.