Uses

Unlike air conditioners, fans only move air—they do not directly change its temperature. Therefore ceiling fans that have a mechanism for reversing the direction in which the blades rotate (most commonly an electrical switch on the side of the unit) can help in both heating and cooling.
Some ceiling fans have adjustable blade pitch instead of reversible motor. In this case, the blade should be pitched to the right (or left if the motor spins clockwise) for downdraft, and left (or right if the motor spins clockwise) for updraft. Hunter Hotel Original is one example.
In summer, the fan's direction of rotation should be set so that air is blown downward (Usually counter-clockwise from beneath). The blades should lead with the upturned side as they spin. The breeze created by a ceiling fan speeds the evaporation of perspiration on human skin, which makes the body's natural cooling mechanism much more efficient. Since the fan works directly on the body, rather than by changing the temperature of the air, during the summer it is a waste of electricity to leave a ceiling fan on when no one is in a room.^[3]
In winter, ceiling fans should be set to turn the opposite direction (usually clockwise; the blades should spin with the downward turned side leading) and on a low speed (or the lowest speed the fan is able to circulate the air down to the floor). Air naturally stratifies — that is, warmer air rises to the ceiling while cooler air sinks. Unfortunately, this means it is colder on or near the floor where human beings spend most of their time. A ceiling fan, with its direction of rotation set so that air is drawn upward, pulls up the colder air below, forcing the warmer air nearer the ceiling to move down to take its place, without blowing a stream of air directly at the occupants of the room. This action works to even out the temperature in the room, making it cooler nearer the ceiling, but warmer nearer the floor. Thus the thermostat in the area can be set a few degrees lower to save energy, while maintaining the same level of comfort. It is important to run the fan at a low speed (or a lowest speed the fan is able to circulate the air down to the floor) to minimize the wind chill effect described above.
An additional use of ceiling fans is coupling them with an air conditioning unit. Through-the-wall/through-the-window air conditioning units typically found in rented properties in North America usually have both the tasks of cooling the air inside the room and circulating it. Provided the ceiling fan is properly sized for the room in which it is operating, its efficiency of moving air far exceeds that of an air conditioning unit, therefore, for peak efficiency, the air conditioner should be set to a low fan setting and the ceiling fan should be used to circulate the air.

Exception

There is an exception to the standard rule of blowing air down in the summer and pulling it up in the winter. When a ceiling fan is mounted in a room with very high ceilings (two stories/levels high or higher),or at the head of a tall set of stairs, the mode of operation is reversed. In this scenario the fan is mounted so high up that there is no significant "wind chill effect". The purpose then becomes to move hot air down in the winter and pull cold air up in the summer.^[4]

History

Collage of three photos of an extraordinarily rare Panasonic-brand ceiling fan from the early 1980s; model unknown, believed to be F5210WH. Example of an early high-quality imported ceiling fan.^{[citation needed]}

The first ceiling fans appeared in the early 1860s and 1870s, in the United States. At that time, they were not powered by any form of electric motor. Instead, a stream of running water was used, in conjunction with a turbine, to drive a system of belts which would turn the blades of two-blade fan units. These systems could accommodate several fan units, and so became popular in stores, restaurants, and offices. Some of these systems still survive today, and can be seen in parts of the southern United States where they originally proved useful. The electrically powered ceiling fan was invented in 1882 by Philip Diehl; he had engineered the electric motor used in the first electrically powered Singer sewing machines, and in 1882 adapted that motor for use in a ceiling-mounted fan. Each fan had its own self-contained motor unit, with no need for belt drive.^[1] He was almost immediately up against fierce competition due to the commercial success of the ceiling fan. He continued to make improvements to his invention; by creating a light kit fitted to the ceiling fan to combine both functions in one unit. By World War I most ceiling fans were made with four blades instead of the original two, which made fans quieter and allowed them to circulate more air.
By the 1920s ceiling fans had become commonplace in the United States, and had started to take hold internationally. From the Great Depression of the 1930s until the introduction of electric air conditioning in the 1950s ceiling fans slowly faded out of vogue in the U.S.,^[1] almost falling into total disuse in the U.S.; those which remained were considered items of nostalgia.
Meanwhile, they had become very popular in other countries, particularly those with hot climates such as India but without the infrastructure or financial resources for high-energy-consuming and complex freon induced air conditioning equipment. In 1973, Texas entrepreneur H.W. (Hub) Markwardt began importing highly efficient ceiling fans to the United States that were manufactured in India by Crompton-Greaves, Ltd. Crompton-Greaves had been manufacturing ceiling fans since 1937 through a joint venture formed by Greaves Cotton of India and Crompton-Parkinson of England, and had perfected the world's most energy efficient ceiling fans thanks to its patented 20 pole induction motor with highly efficient heat-dissipating cast aluminum rotor shell. These Indian manufactured ceiling fans caught on slowly at first, but Markwardt's Encon Industries branded ceiling fans (ENergy CONservation) eventually found great success during the energy crisis of the late 1970s and early 1980's, since they consumed far less energy (under 70 watts of electricity) than the antiquated shaded pole motors used in most other American made fans, and far more efficient than using expensive air conditioning units.
Due to this renewed commercial success using ceiling fans effectively as an energy conservation application, many American manufacturers also started to produce, or significantly increase production of, ceiling fans. In addition to the imported Encon ceiling fans, the Casablanca Fan Company was founded in 1977. Other American manufacturers of the time included the Hunter Fan Co. (which was then a division of Robbins & Myers, Inc), FASCO (F. A. Smith Co.), Emerson Electric, and Lasko; the latter two were often branded as Sears-Roebuck.
Through the 1980s and 1990s, ceiling fans remained popular in the United States. Many small American importers, most of them rather short-lived, started importing ceiling fans. Throughout the 1980s the balance of sales between American-made ceiling fans and those imported from manufacturers in India, Taiwan, Hong Kong and eventually China changed dramatically with imported fans taking the lion's share of the market by the late 1980's. Even the most basic U.S-made fans sold at $200 to $500, while the most expensive imported fans rarely exceeded $150.
Since 2000 important inroads have been made by companies offering higher price ceiling fans with more decorative value. In 2001, Washington Post writer Patricia Dane Rogers^[2] wrote, “Like so many other mundane household objects, these old standbys are going high-style and high-tech.” Newer companies such as Monte Carlo, Ellington, Quorum, Craftmade, Minka, Fanimation, The Modern Fan Co. and Big-Ass Fans brought well-built fans with distinctive design to the market.