.....Therefore, the weight of more than three blades would use more electricity, as well as put more stress on the motor, causing it to burn out more quickly. Unlike residential fans, decoration is not a concern. They are usually produced only in the colors black, white, or gray. As you can see in the photograph, it is simplified to the bare necessities: a long down-rod, 3 large blades, and an electric motor.

All fans are made up of the same basic parts:

A. electric motor~  in the center of the fan; the control center for all of the other parts.  Gets its energy source from a few different alternatives, differ in noise levels, and vary in sizes and strength (see motor size).

B.  motor housing~  mainly used on residential fans, it is a decorative covering to conceal the motor.  In association with the motor housing, the switch housing is also used to hide the inner-workings of the fan.  Also known as a “switch cup,” the switch housing is metal cylinder installed underneath and in the center of the motor.  Its purpose is to hide and protect wires, switches, capacitors, etc. 

C.  blades~  the paddles positioned around the fan that force the air to circulate.  Are attached to motor by blade irons⒟ and a flywheel⒠, or rotor.  They vary in material, size, and amount.  As mentioned above, residential fans generally have four to five blades, while commercial fans generally use three. 
             ♦ blade materials ~  wood, metal, plastic, and MDF*.  Most popular residentially, are wood blades.  Many kinds of wood can be used, such as cherry, oak, walnut, maple, teak, etc.  Though the weights can slightly vary from one another, the consumer usually decides the kind of wood by its color, since it’s being used in a home.  Plastic blades (typically made of fiberglass) and the metal blades are used industrially and commercially.
 
It wasn't until the late 1970's until people began noticing that these energy-efficient ceiling fans were a much cheaper alternative to air-conditioning.  And as we all know today, not only cheaper but more eco-friendly.  In the present day, we now have several types of ceiling fans, which vary in shape, size, and devices.  They are used residentially, commercially, and industrially and will continue to grow and change for years to come.
 

D.  blade irons~  also known as “blade brackets,” “blade arms,” “blade holders,” or “flanges.”  These are the metal supports that hold the blades to the motor. 

E.  flywheel~  a metal or a tough rubber ring that attaches the blade irons to the shaft of the motor.  The inside of the ring fastens to the shaft with a lock screw, while the outside of the ring connects to the blade irons with bolts.  A substitution for the flywheel is a “dropped flywheel,” which is mounted below the fan’s motor housing, as opposed to level with the motor housing.

F.  downrod~  the pipe used to hang the fan from the ceiling.  They come in all different lengths, depending on whether the fans are for residential or industrial use, or simply the height of the room. 

G.  canopy~  the piece that is mounted onto the ceiling, and connects with the downrod. 

rotor~  an alternative part of the fan; can be used instead of the blade irons.  As opposed to attaching the blades to the blade irons, the blade irons to the flywheel, and the flywheel to the motor, the rotor connects the blades right into the motor.  This method decreases balance problems and more efficiently hides fasteners. 

* “MDF” stands for “Medium Density Fiberboard.”  This is an engineered wood, that’s produced by breaking down the wood and combining it with wax and resin.  Recently, more eco-friendly materials have been used such as, recycled paper, straw, bamboo, steel, and glass.  Most popularly the straw and bamboo are used, due to their fast growth.  Some of these blades are manufactured to be moisture-resistant or flame-retardant.  Definitely recommended given that they can be less expensive than most woods, they’re earth-friendly, reliable in strength yet flexible, and have a lesser chance of splitting. 
Mounting Mechanisms 
ball-and-socket system~  a good mechanism for vaulted ceilings since the piece that connects to the downrod, moves freely which enables it to be placed on a slanted ceiling. 

close-to-ceiling mount~  similar to the ball-and-socket system.  The difference is that it connects from the canopy straight to the motor housing, so that the whole fan can be attached to the mounting bracket. 

J-hook system~  also known as the claw-hook system.  A metal hook is mounted to the ceiling with a metal bolt and then the fan is attached to the hook.  Usually a rubber bushing is placed in between the hook and the bolt to minimize noise. 

low ceiling adapter * ~  This is a must for rooms with low ceilings since there is no need for a downrod.  However, this adapter must be purchased separate from the fan.
 

pull chain~  the original control for fans.  It’s very basic, controlling both the fan speed and the light fixtures.  Usually a bead chain or a cloth cord, the pull chain generally turns on the fan and goes directly to the “high” position.  After another pull, the fan slows down.  It continues this process until the fan turns back off.  It usually cycles through three speeds - high, medium, and low; but sometimes it can have from one to four speed(s). 
 
wall-mounted~  2 different types:  ס digital control » used for all of the fan’s functions; a computerized wall control that needs no special wiring and has anywhere from three to six speeds.   ס choke »  comes in different forms.  It establishes how much power is being sent to the fan, controlling how fast it spins. 

variable-speed control~  a dial is mounted on the fan.  Similar to a dimmer switch, this dial can be rotated and the blades speed up or slow down depending on which way you turn the dial, as opposed to having set speeds (high, medium, low…).  This can be installed in 3 different ways:   ס the dial can power the entire fan »  speed, off/on, and light fixtures.   ס the dial is accompanied by a pull chain »   pull chain controls whether it’s off or on while the dial controls the speed.  Light fixtures can be controlled by either of them.   ס dial and pull chain; pull chain has two modes » ¹ "high power,” ² “variable.”  When the fan is in the “variable” mode, the dial can then control the range of speed.

wireless remote control~  included with new luxury fans.  Like any other remote control, it sends frequencies that the fan recognizes and it operates accordingly.  This can also be purchased separately and installed into your current fan.

Ceiling Fans are well-known for their Cooling Abilities but few know about their Heating Abilities...
Fans have assorted switches, which have many controls, such as turning the fan on or off, adjusting the speed, changing the blades’ direction, and operating light fixtures that may be on the fan.
HEATING (winter) →
direction set clockwise, pulls air upward; takes advantage of hot air rising and cold air sinking; pulls the cold air up from the floor to mix with the warm air from the ceiling

COOLING (summer) →
direction set counter-clockwise, air is blown downward; doesn’t actually lower the temperature of the room, but it has a cooling effect because the breeze helps evaporate sweat and keeps the air from feeling thick.
Usually the blades spin counter-clock wise.  This enables air to be propelled downward.  This is how it keeps us cool in the summer since it causes airflow in the room.  Contrary to this “cooling effect,” when the blades spin clock wise, it pulls the air up.  This is essential in the winter since cold air sinks and hot air rises.  This way, the fan pulls the cold air up from the floor and combines it with the hot air from the ceiling.

EXCEPTION:  with ceilings that are two or more stories high the directions would be reversed (counter-clock wise → winter; clock-wise → summer).  This is because the ceiling would be too far above the ground for the cooling effect, therefore hot air must be pushed down in the winter and hot air pulled up in the summer. 

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