An air compressor is a pneumatic device that conve...

An air compressor is a pneumatic device that converts power into potential energy stored in pressurized air. Air compressors are machines that convert one form of energy into another form, which can then be stored and used at a later point in time. But neither that brief explanation, nor the more detailed description below, do this invention - and its profound impact on our lives - justice. Compressors supply the air flow for all equipment in a system. Air compressors work in two phases: the compression operation and the release operation. There are two types of compressors, positive displacement and dynamic (also called centrifugal). The rate at which a compressor can deliver a volume of air is noted in cubic feet per minute (cfm). Because atmospheric pressure plays a role in how fast air moves into the cylinder, cfm will vary with atmospheric pressure. It also varies with the temperature and humidity of the air. To set an even playing field, makers calculate standard cubic feet per minute as cfm at sea level with 68° F air at 36% relative humidity. cfm ratings are given at a specific pressure—3.0 cfm at 90 psi, for example. If pressure is reduced, cfm goes up, and vice versa.