Most ceiling fans can shift between forward and reverse rotations by a simple flick of a switch located on the motor housing of the fan. Fan blades are set at an angle so that one edge sits higher than the other edge.  If you’re not sure which direction the fan should go, here’s a helpful memory device: The leading edge of the fan blades should correlate with the outdoor temperature. Depending on which direction the fan is spinning, either the high edge or the low edge will be the leading edge. In winter, when the temperature outside is low, the leading edge should be the one that sits lower. This will pull the warm air up where it will move along the ceiling and move down the walls for an insulating effect. In summer, when the temperature is high, the leading edge should be the higher edge, which blows a cool breeze.