Fan (mechanical)

A fan is a powered device used to create flow within a gas, usually air.

A fan consists of a rotating arrangement of vanes or blades which act on the air. Usually it is contained within some form of housing or case. This may direct the airflow or increase safety by preventing objects from contacting the fan blades. Most fans are powered by electric motors, but other sources of power may be used, including hydraulic motors and internal combustion engines.

Fans produce air flows with high volume and low pressure, as opposed to compressors which produce high pressures at a comparatively low volume. A fan blade will often rotate when exposed to an air stream, and devices that take advantage of this, such as anemometers and wind turbines, often have designs similar to that of a fan.

Typical applications include climate control, vehicle and machinery cooling systems, personal comfort (e.g., an electric table fan), ventilation, fume extraction, winnowing (e.g., separating chaff of cereal grains), removing dust (e.g. in a vacuum cleaner), drying (usually in combination with heat) and to provide draft for a fire. It is also common to use electric fans as air fresheners, by attaching fabric softener sheets to the protective housing. This causes the fragrance to be carried

Household electric fan

into the surrounding air.

In addition to their utilitarian function, vintage or antique fans, and in particular electric fans manufactured from the late 19th century through the 1950s, have become a recognized collectible category, and in the U.S.A. an active collector club, the Antique Fan Collectors Association, supports the hobby.^[1]

New to the market are sleek portable fans that showcase a modern design sensibility. The New York Times lamented that inexpensive and effective fans abound at drug and discount stores, but they are often eyesores. The writer quoted contemporary ceiling fan designer Ron Rezek as saying: “Portable fans are the ugly ducklings of the fan industry. Not many designers, including myself, have tackled them.”^[2] Rezek praised several appealing contemporary fan designs that have found alternatives to the traditional metal cage and have incorporated innovative approaches to safety, such as the Otto fan by Swiss designer Carlo Borer.