Air movement increases the effectiveness of the body's own evaporative cooling system.
A slight breeze in conjunction with perspiring can have the cooling effect of a ten-degree drop in temperature. Most ceiling fans are capable of moving either counterclockwise, blowing air downward or clockwise, pulling air upward. If the fan is used to create a cooling breeze inside the house it is best to have the air blow downward. If the fan is used in conjunction with a heat pump or other heating and cooling device, it is more effective to have the warm air pulled upward towards the ceiling. This shortens the time required to circulate air through the building interior and can increase heating and cooling efficiency.