Vacuum Pumps Installing a Variable Velocity Drive (VSD), sometimes called a adjustable frequency drive, usually saves between 50 and 65% in electricity costs with the same or better regulation of vacuum. The range of energy savings could be from 30 to 80 percent. They can be adapted to blower or in some cases Energy-Conserving Vacuum Pump rotary vane type vacuum pumps. They function by changing the quickness of the vacuum pump based on the reading from a pressure sensor that’s installed on the vacuum line close to the receiver jar. The VSD is actually a dedicated computer with many adjustments therefore it may be possible to boost vacuum 
regulation over the normal pneumatic vacuum regulator that only includes a vacuum level adjustment. A VSD for a vacuum pump is usually economical for a dairy that milks a total of 8 hours or more each day. Typically a VSD will not be a cost-effective option for little dairies due to less milking period and therefore shorter vacuum pump run times but there are several other options to save lots of energy costs.