Hi all,

We recently purchased high stage screw compressor that has ability to manually change volume ratio while stationary (2.2 to 5.0) Our contractor informed us they will set the volume ration for 5.0. This does not seem right when you run the numbers out for our operating conditions (28 psig suction, 110 to 150 psia discharge depending on season) Based on my calculations the volume ration should be 2.2 to 2.8 depending on season.

With a volume ration is 5.0 I believe we are over compressing with an energy penalty. Please comment or confirm