Session 11 –“Vertical Pumps (VS1, VS2, VS3)” Session 12 –“Vertical Pumps (VS4, VS6, VS7)”

What Is a Pump? A pump is a machine or device for raising, transferring, or compressing fluids. Pumps represent the largest single use of power in the industry (31%) by motor-driven equipment. Process variables, including pressure and flow of gases and liquids, have long been regulated using mechanical clutches, throttles, and adjustable inlet guide vanes. Pumps often operate as a variable torque load, a load that increases as the speed increases. These mechanisms waste energy, require frequent maintenance, and provide inaccurate control.

Summary Centrifugal pumps perform many important functions to control the built environment. The physics and basic mechanics of pumps have not changed substantially in the last century. However, the state of the art in the application of pumps has improved dramatically in recent years. Even so, pumps are still often not well applied, and become common targets in retrocommissioning projects where field assessment and testing can reveal significant energy savings potential from optimizing pump performance. Typically, retrocommissioning finds that pump flow rates do not match their design intent and that reducing flow rates to match load requirements or eliminating unnecessary pressure drops can save energy. As the example below illustrates, decisions made during the design phase have implications throughout the operating life of the building. Although fully optimizing any design will require some effort after installation, the prevalence and magnitude of the savings that are commonly found in retrocommissioning and ongoing commissioning begs the larger question: How much greater would the savings be if pumps were selected and applied optimally during the design phase?