Vane motors can run at much higher speeds (2000 rpm and up), but piston motors tend to turn much slower – less than 1000 rpm. For slower speed applications, vane motors are mated with a gear reducer and called a gearmotor. The gearmotor can produce the higher torque and slower speed needed for some applications, but the gear reducer can add some drivetrain loss. While a piston air motor may not be able to replace a vane motor where high speed is needed, it can be a good choice for high torque/low speed applications.
The intent of this article is to provide readers with simple examples of calculations one can perform to evaluate two sample energy efficiency projects for compressed air systems; pressure sensing vortex vacuum generators and outside air intake (for air compressors).
Figuring out the energy savings for the switch from pneumatic to electric tools requires an estimate of energy use for each case. The effect of replacing a few tools in a large compressed air system may be too small to detect using power monitoring on the air compressors. However, it is still a good practice, and when part of a larger program to reduce air consumption, the combined efforts will amount to something measurable. Another positive aspect may be that reduced compressed air use frees up needed air compressor capacity.