Bell & Gossett Introduces Formula for Smarter Hydronic Pump Selection

MORTON Grove, Ill. – Bell & Gossett, a Xylem Inc. brand, has released its PLEV pump selection criteria, a new standard for the industry to provide the most accurate and efficient specification of a centrifugal pump at partial flow rates, designed to save energy and reduce costs. PLEV, which stands for Part Load Efficiency Value, helps HVAC system designers select pumps based on real-world system demands to ensure the most efficient hydronic system performance.

Until now, a system designer specified a pump at maximum capacity or flow at all times during pump operation, even though a pump operates at 100 percent flow just 1 percent of the time. PLEV is calculated based on the partial load that a pump will experience throughout its operation. B&G’s ESP-PLUS pump selection and system design software has been updated with the PLEV selection criteria to assist specifying engineers.

When PLEV is used in the specification process with newer pump designs that use computational fluid dynamics technology to increase efficiency over a wider range on the performance curve — a range B&G terms efficiency islands — system designers can maximize overall system performance.

The operating cost analysis section of ESP-PLUS has been revised to default to PLEV as the standard load profile, giving specifiers instant operational efficiencies.

PLEV is derived from the successful Integrated Part Load Value performance calculation developed by the Air-Conditioning, Heating and Refrigeration Institute. It is used to calculate equipment efficiency while operating at various capacities in a chiller system, leading to energy and cost savings.

The free PLEV application is available from the iTunes App Store for iPad, iPhone and through Google Play for Android, in addition to being available online through the Xylem software ESP-PLUS.

For more information on PLEV, view B&G’s industry white paper at:, or visit