Energy Savings by Variable-Speed Control of Commercial Pumps

Somchart Chantasiriwan


variable-speed, energy efficiency, affinity laws


For an oversized pump operating at a reduced load, variable-speed control is a good energy-conserving method. It is popular among pump users to estimate energy saving by using the affinity laws, which imply that power input varies with the cube of flow rate. However, this estimation is erroneous if the pump must deliver the fluid against not only frictional resistance in the piping system but also static head or differential pressure. This paper presents a method for deriving a formula that provides a better estimate of energy saving of a variable-speed pump. This method is applied to 4 commercial pumps manufactured by Apex Pumps.

Important Links:

Go Back