12 volt air compressors are comparatively small mechanisms that are used most often in industrial settings. 12 volt air compressors can be charged by being plugged in to a standard 120 volt AC electrical outlet, 12 volt DC batteries or cigarette lighters in vehicles. Cordless compressors have rechargeable batteries that allow them to be extra-portable. 12 volt air compressors are small, usually weighing less than 10 pounds.
They have a motor and a small air tank along with various valves and tubes. To keep them lightweight, the enclosures and motors are made from plastic or a less dense metal such as aluminum or steel. Most compressors come with an air hose, a power cord, appropriate fittings and a gauge that displays the pressure. Mounting and anti-vibration kits are available as well.
The low voltage compressors are typically portable and are used in situations where there is no external power source or where a large machine wouldn’t fit. 12 volt air compressors are effective for inflating flat tires, sports balls, inner tubes, and craft tools such as airbrushes.
Air compressors are similar to pumps because both machines increase the pressure for a gas or liquid. Gases can be condensed whereas liquids cannot, so a compressor works with gases while a pump transports liquids under pressure. Air compressors are able to convert the mechanical energy of the motor into pneumatic energy because of the pressure that occurs when air is condensed. Air molecules move faster when they are compressed into small spaces, and when a valve opens, the molecules try to escape and flow out with great energy.
There are two main ways of condensing air that compressors use: positive displacement and dynamic compressors. Positive displacement compressors work by filling and emptying an air chamber while dynamic compressors use a rotating component to speed and slow air movement. Within these two categories are many other styles of compressors, including reciprocating, centrifugal, screw, diaphragm and axial-flow compressors.
Another way of identifying air compressors is whether or not they require oil to operate. Oilless compressors are used in applications that need completely clean air; even a tiny amount of oil in the air is unacceptable. Oilless air compressors have half the moving parts of regular compressors and therefore are more reliable and require less maintenance.