This condition is called stratification. Destratification is the process of mixing the air with ceiling fans to evenly distribute heat. Destratifying room air brings heat down to floor level where it is needed to keep people comfortable. Mixing the air also reduces ceiling temperatures, which in turn reduces energy losses through the roof and saves money. Destratification can be done with paddle or ducted ceiling fans.
Paddle fans work well in most applications, mixing the air throughout the room.
Ducted ceiling fans blow warm air through a flexible duct to a spot at floor level. The ducted fans can supply heat to specific locations such as work stations. Both types of fans are rated in square feet of floor space covered. For example, a gymnasium has a 25 foot high ceiling and a thermostat mounted at 5 feet. The thermostat is set at 68 .