Editing Ceiling fan (section)

{{short description|Type of fan mounted to a ceiling horizontally}}

{{Use mdy dates|date=August 2014}}
[[File:Ventilatore a soffitto (3).png|right|thumb|300px|A modern ceiling fan]]
[[File:Spinning ceiling fan.jpg|thumb|A ceiling fan mid-spin]]
A '''ceiling fan''' is a [[mechanical fan|fan]] mounted on the [[ceiling]] of a room or space, usually [[electric power|electrically powered]], that uses hub-mounted [[rotation|rotating]] blades to [[wikt:circulation|circulate]] air. They cool people effectively by increasing air speed. Fans do not reduce air temperature or relative humidity, unlike air-conditioning equipment, but create a [[Thermal comfort#Cooling Effect|cooling]] effect by helping to evaporate sweat and increase heat exchange via [[forced convection|convection]]. Fans add a small amount of heat to the room mainly due to waste heat from the motor, and partially due to friction. Fans use significantly less power than air conditioning as cooling air is [[Thermodynamics|thermodynamically]] expensive. In the winter, fans move warmer air, which naturally rises, back down to occupants. This can affect both thermostat readings and occupants' comfort, thereby improving the [[Efficient energy use|energy efficiency]] of [[climate control]]. Many ceiling fan units also double as [[light fixture]]s, eliminating the need for separate overhead lights in a room.