Bell & Gossett introduces formula for smarter hydronic pump selection

Bell & Gossett introduces formula for smarter hydronic pump selection

PLEV calculation gauges true pump performance to maximize efficiency

Morton Grove, Ill. — Bell & Gossett (B&G), 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.

“PLEV is the answer to the industry’s demand for the most efficient pump selection, by taking into account the entire variation profile and flow requirements based on the actual heating or cooling load in a commercial building HVAC system, not just the design model. This formula will enable professionals to more precisely specify the appropriate pump for the application, helping to reduce both energy use and operating costs throughout the lifetime of the product,” said Mark Handzel, Vice President Product Regulatory Affairs and Director, HVAC Commercial Buildings, Americas, Xylem.

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.

“System designers are seeking smarter ways to meet efficiency standards. Our products with extensive Efficiency Island profiles and PLEV selection software are part of our comprehensive portfolio of tools offered to exceed efficiency requirements,” Handzel said.

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 (IPLV) performance calculation developed by the Air-Conditioning, Heating and Refrigeration Institute (AHRI). 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 online through the Xylem software ESP-PLUS. For more information on PLEV, view our industry white paper,, or visit to learn more about our system solutions.

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About Xylem

Xylem (XYL) is a leading global water technology provider, enabling customers to transport, treat, test and efficiently use water in public utility, residential and commercial building services, industrial and agricultural settings. The company does business in more than 150 countries through a number of market-leading product brands, and its people bring broad applications expertise with a strong focus on finding local solutions to the world’s most challenging water and wastewater problems. Xylem is headquartered in Rye Brook, New York, with 2015 revenues of $3.7 billion and approximately 12,500 employees worldwide. Xylem was named to the Dow Jones Sustainability Index for the last four years for advancing sustainable business practices and solutions worldwide and the Company has satisfied the requirements to be a constituent of the FTSE4Good Index Series each year since 2013.

The name Xylem is derived from classical Greek and is the tissue that transports water in plants, highlighting the engineering efficiency of our water-centric business by linking it with the best water transportation of all — that which occurs in nature. For more information, please visit us at