Abstract: Compared with the traditional energy consumption assessment method based on air flow rate, a new method using air power is presented. The air power is defined as the flux of the available energy of flowing compressed air. The available energy is the work-producing potential of compressed air under a surrounding of the atmospheric pressure and temperature. Air power is a relative potential in the atmospheric environment, because pneumatic systems work in the same environment. With air power, mechanism and factors making energy loss are discussed and some data of energy losses in pneumatic system are shown, which will make objective of energy savings clear.

Key words: Air power, Available energy, Compressed air, Energy loss, Energy saving, Pneumatic system