An air compressor increases the amount of air in a separate space. The original air compressor is the lung. Men are increasing the pressure of the air in his lungs and than use the force of this air to blow out the flame of a candle, for example. Ultimately, man-made air compressors were created. The air compressors wildly known by the public are used for the following purposes:
- To supply a high-pressure clean air to full breathing apparatus cylinders
- To supply a moderate-pressure clean air to supply air to a submerged surface supplied diver
- To supply a large amount of moderate-pressure air to power pneumatic tools
- To filling pneumatic tyres
However, the increased air pressure which creates a force is useful for a variety of purposes, from industrial and manufacturing to commercial and personal .Compressed air can be used to maintain industrial plants or to change chemical composition as in the case of producing fertilizer. One the most well known use of the air compressor is in the case of pneumatic tools like spray guns, ratchet wrenches or air powered nail guns.
Air compressors are of two types: positive displacement or dynamic, defined by its mode of operation. A positive displacement air compressor works by filling and then emptying an air chamber. Three common types of positive displacement air compressors are: rotary screw, rotary sliding vane and reciprocating. A dynamic air compressor, uses a a rotating device to accelerate and then decelerate air. Centrifugal air compressors are dynamic air compressors.
Another way to group air compressor types is by the number of stages it has. For example, a two-stage air compressor is often used for heavy works. This type of unit offers a higher level of compression than smaller, single stage air compressors.
There are a few ratings of air compressors. CFM is the rating that is very important and one that most reputable. For example,for home use 6 CFM is a good compromise for an entry level compressor. It is large enough to power most smaller air tools, but most can still be used on a 15 amp 120 volt circuit. HP rating is stamped on most consumer type compressors and is absolutely meaningless. Commercial motor manufacturers have firm requirements when marking their motors with a HP rating. When shopping for a compressor you will probably see the HP rating or "SPL", which means a non standard rating.