Mechanical fans made their first appearance in the 1500s as canvas covered frames called "punkahs" that were hung from ceilings. To create a cooling effect, there were ropes connected to the frame that servants pulled, making the fan move back and forth. Belt driven fans that were powered by factory waterwheels were produced during the 1800s. Electric fans were available to the general public after electric power was introduced. Fans enhanced a home's decor because they were functional and stylish and equipped with brass blades and cages.

Mass production of modern electric fans was made possible by industrialization in the 1920s. Fan sales slowed down when air conditioning was made widely available during the 1960s. Fan popularity has resurged presently and they are still commonly used in many parts of Europe and Asia. They aren't used to enhance home decor as much and feature a more utilitarian design. Electric fans are often used as supplemental cooling devices for spot cooling because they are more energy efficient than the refrigerated cooling provided by air conditioners. Adding ventilation, exhaust or gaseous transport are also functions an electric fan can be used for.

Three types of fan technologies used for air movement are axial, centrifugal and cross flow. The method fans use for climate control and utilized to provide comfort or ventilation is axial flow. Air is forced to move parallel to the shaft by the blades while the blades rotate around it and blow across the axis of the fan. A couple of applications that use axial flows are personal cooling in personal desk fans and giant fans commonly found in wind tunnels. An electric fan's basic components include the base, fan blade, armature and lead wires, motor, blade guard, motor housing, oscillator gearbox and oscillator shaft. The rating of an electric fan is determined by the types, size and number of blades. The materials from which the fan's components are made determine the price. The most common fans have four blades. When providing comfort, fans do not actually lower the temperature. They create a wind chill effect.

There are a wide range of designs and many different kinds of fans. Fans can be built into windows, walls, roofs or chimneys, hung from the ceiling, and can be put on the floor or table. Electric fans are used in electronic systems like computers to cool the circuits inside and in hair dryers and space heaters.

The most popular electric fans are:

Portable Electric Fans- These electric fans are fully portable and can be moved from one room to the next. Many different kinds of fans can fit into this category, such as floor fans, pedestal fans and many types of industrial fans.

Ceiling Fans- These electric fans help cool rooms and complement decor. They employ hub-mounted, rotating paddles constructed of a number of different materials to produce a cooling effect and are suspended from the ceiling of a room. Air is blown or drawn in to create a draft which produces a chill effect. You can air out or freshen a room, lower your household's electric bill, increase the cooling effects of a portable air conditioner or central air conditioner, and increase the efficiency of your heating system when used in reverse during winter.

Exhaust Fans- These fans are mostly used to cool and provide ventilation. Some exhaust fans are installed in a window. These window fans can be used as alternatives to air conditioning. They usually have a 20 inch diameter and require a mounting kit and side panels. Exhaust fans can also be used in attics because they expel the moisture and heat that accumulates before it damages and deteriorate insulation and construction materials.

Industrial Fans- To ensure the health and safety of employees and customers, industrial and commercial settings require proper ventilation and climate and odor control. These settings are usually subject to high heat levels so high volume, low speed industrial fans are crucial when the space cannot accommodate traditional air conditioning systems. These electric fans promote fresh air and circulation so they can regulate odors and gaseous fumes and industrial blowers are particularly useful for cooling or drying applications.

Bathroom Exhaust Fans- These electric fans deal with offensive odors and humidity levels, making them vital components of your home. Excess moisture in bathrooms can lead to paint damage, warping doors, and the eventual accumulation of mold spores. Bathroom exhaust fans can come with built-in heater, lights and timer units. They are designed to be mounted on the ceiling or onto the wall.

Erin Lynn is a marketing writer in Santa Ana, CA, 92705 at Air Conditioner Home with vast knowledge of portable electric fans. For more information about cooling, portable air conditioners, swamp coolers and electric fans, visit http://www.air-conditioner-home.com