Compressor Efficiency Definitions

There are many different compressor efficiency definitions in use by the compressor industry, which can cause confusion when comparing compressors. For positive displacement compressors (non-dynamic), there are two major types of efficiency. One characterizes flow (mass flow or volume flow) and is called volumetric efficiency. The other characterizes power, and comes in a wide variety of forms: adiabatic, isothermal, mechanical, overall, and system, to name a few.

Vairex has adopted definitions to satisfy industry convention and theoretical standards. Below are brief descriptions of the volumetric efficiency, specific overall adiabatic efficiency, and system efficiency, which Vairex currently uses in specifications. For a more complete explanation of these efficiencies and their derivation, please download the attached white paper on the subject.