Ceiling fans are designed to run in two directions to save on energy costs in the summer and winter by shifting air to different positions in a room. They run clockwise in the winter and counterclockwise in the summer.
Fans are controlled by a switch that move it from circling one way to circling the other. The fan blade direction controls the flow of air in the room. In the summer, the fan sends air down into the room to create a breeze, making the room seem cooler. In the winter, the fan moves the air upward. Because heat rises, it collects near the ceiling. The upward movement of air causes the warm air near the ceiling to drift back down into the room. Changing the direction of a fan for summer and winter helps the room feel the right temperature, so the thermostat can be left alone.