According to the literatures, compressed-air systems account for about 10 % of total industrial-energy use for few countries. Compressed air is typically one of the most expensive utilities in an industrial facility. These compressors are ordinarily driven by constant-speed electrical motors supporting varying load conditions; i.e., substantial energy is lost since the loading conditions mismatch the designed optimal energy consumption needs of the desired purpose. In this paper, the electric energy consumption of one-cylinder reciprocating air compressors has been experimentally investigated, once by the use of variable speed drive (VSD) and then by the use of mechanical speed drive. Based on the experiment, the reduction of energy consumption in various compressors' discharge pressures falls between 43.6 % and 60.5 %. The results indicate that the use of a variable speed drive reduces electrical energy consumption and thus reduces greenhouse gas emissions due to the reduction of fossil fuel consumption.
