The steadfast rotating fan has been employed to keep people cool since the eighteenth century, and it remains highly effective, requiring much less energy and providing more comfort than air-conditioning. Cooling people by increasing local airflow is at least ten times more energy efficient than refrigerating the air in a given space, and it also adds the benefit of a personally controlled thermal environment.
If used in combination with air-conditioning, fans could lower energy use by 30-70%, even in incredibly hot climates or during heat waves. Circulating fans, which have become very energy efficient in their design, can be readily and cheaply applied in both new and existing buildings. Recent changes in international comfort standards have paved the way for their comeback.