The U.S. Department of Energy has instituted the Pump Efficiency Index (PEI). Its goal is to improve the overall efficiency of pumps sold in the U.S.
Clean water pumps designed for 25 gpm or more at best efficiency and are 1 HP or greater, qualify under the new regulations. Qualifying pumps used for clean water must display the PEI starting January 27, 2020.
The PEI number is expressed as a decimal and must be 1.00 or less to be marketed as a clean water pump. The lower the PEI number, the more efficient the pump is in relation to the minimum standard of 1.00.
There are two types of PEI numbers. The first is the PEIcl which is a fixed speed constant load pump, and the second is PEIvl or variable speed load. Normally PEIvl numbers are much lower, but the pump must be packaged and sold with that specified control. The same efficiency can most often be obtained by adding a drive to constant load pump.
This stands for Impeller Diameter and is the diameter of the full impeller. The impeller diameter is displayed on the pump label as Imp. Dia. Some pumps have the impeller diameter reduced to make a smaller pump and the reduced diameter is displayed on the pump label.
Locating the PEI and Imp. Dia.
Both numbers will now appear on our labels along with the serial number for each pump that qualifies under DOE regulations. The serial number also contains the date code for customer reference in that the first two digits refer to the month and the second refer to the last two digits of the year of manufacture.
While you can find a full explanation of the PEI on the government’s website, the Water Well Journal does a great job of presenting the information in an easy to read article Eight Things to Know About Pump Efficiency Standards.
Return to Blog Page