Pool Pump Energy Efficiency: What to Look For

What efficiency means on a pool pump listing

On a pool pump listing, efficiency is not a single number. It sits behind several stated words: speed type, horsepower, wattage or amps, and sometimes an energy factor figure such as WEF. A listing that states the speed type and the electrical draw gives you the basis for a comparison; a listing that states only a model name gives you fewer clues.

This site compares what the seller states in the listing title and bullet points. It does not measure a pump's energy use and does not calculate operating costs. For questions about what applies in your area, your utility and your local building office can point you to the programs and rules that match your property.

Energy factor (WEF) as a listing term

WEF stands for Weighted Energy Factor. The ENERGY STAR program uses WEF in its certification criteria for pool pumps. The criteria set a minimum WEF level for each pump sub-type: self-priming inground pumps, non-self-priming above ground pumps, and pressure cleaner booster pumps. The thresholds differ by pump size class, and the Version 2.0 criteria took effect January 2, 2019.

A pump listing rarely states WEF, because WEF is a program criterion rather than a sales figure. When a listing does state an energy factor figure, compare it against the ENERGY STAR threshold for the same pump sub-type and size class. The ENERGY STAR pool pump page lists the full criteria.

Wattage, horsepower and amp draw as listing words

Wattage is the rate at which a pump's motor draws electrical power, measured in watts. Horsepower is a unit of mechanical power that the motor delivers to the impeller. The two are related but not identical: the motor converts electrical watts into mechanical horsepower, and some of the input is lost in the conversion. A listing that states both wattage and horsepower gives you more to compare than one that states only horsepower.

Amp draw is another electrical figure on some listings. Like wattage, it describes the motor's electrical side rather than the water-moving output. The article on horsepower and watts explains the terms in more detail.

This site does not convert horsepower to watts or any other unit, and it does not size a pump. The maker's sizing page and the maker's manual state the intended pool volume and plumbing conditions. An installer can confirm what fits a specific pad.

Speed type as the main efficiency signal in a listing

The speed type is the strongest efficiency-related signal a listing carries. A single speed pump has one speed. A dual speed pump offers a low and a high setting. A variable speed pump can be set across a range of speeds. The ENERGY STAR program's criteria for pool pumps describe pumps that allow the owner to vary the pumping speed to match the pool function, such as filtering versus cleaning.

The ENERGY STAR program's pool pump page explains that filtration can run at a lower speed than pool cleaning, and that a pump which can slow down for filtration matches the operation to the need. The program describes single speed pumps as running at the higher speed required for cleaning even during filtration. That is the program's explanation of its approach; this site does not measure or promise any energy outcome.

The article on multispeed versus variable speed and the article on two speed versus variable speed explain how those listing words differ. Motor technology words such as permanent magnet or EC motor describe the motor itself; the EC motor article explains that group of words.

What this site cannot tell you about energy use

This site compares stated details in listings. It does not state how much energy a pump will use, what a pump will cost to run, or what a program in your area offers. Those numbers depend on your pool's plumbing, your run schedule, your climate and your utility rates.

For wiring and electrical service, the maker's manual, a licensed electrician and the local building office are the sources that apply to your property. The Pool & Hot Tub Alliance, an ANSI-accredited standards developer, publishes the American National Standard for residential swimming pool and spa energy efficiency, ANSI/PHTA/ICC-15. This article does not interpret that standard; it explains listing words only.

The U.S. Energy Information Administration publishes general information about residential electricity use, and the ENERGY STAR program publishes its pool pump criteria. Both are listed in the sources below.

How to compare two pump listings

When two pump listings are side by side, compare the stated figures: speed type, horsepower, wattage or amp draw, and any WEF mention. A listing that states speed type and electrical draw supports a comparison; a listing that states only a model name needs more information from the maker's manual.

Points to compare on the listing:

Each of those words is explained in the horsepower, THP versus service factor, flow rate and motor technology articles. The buying guides below compare pumps by speed type, horsepower and price tier.

• Speed type: single, dual or variable
• Stated horsepower, and whether the listing uses total horsepower (THP) or service factor horsepower
• Stated wattage or amp draw
• Any energy factor figure, and the pump sub-type it belongs to
• Motor technology words such as permanent magnet or EC motor
• Pool type: inground or above ground, and whether the listing says so

What to pick for your situation

Questions

Does a higher horsepower pump draw more wattage?

Horsepower is a mechanical output and wattage is an electrical input, with motor efficiency in between. A listing that states both allows a comparison; one that states only horsepower leaves part of the picture unstated. The horsepower and watts article explains the terms.

What is WEF on a pool pump?

WEF stands for Weighted Energy Factor, a figure the ENERGY STAR program uses in its pool pump certification criteria. The criteria set minimum WEF levels that differ by pump sub-type and size class, and most listings do not state WEF. The ENERGY STAR pool pump page lists the criteria.

Is a variable speed pump the most efficient type?

In listing terms, variable speed is the type that can be set to run at lower speeds, and the ENERGY STAR program's criteria for pool pumps are built around pumps that can vary speed. Whether a particular pump is a good fit for your pool depends on the stated details and the maker's sizing guidance. The variable speed guide compares listed models.

Where do you find the efficiency figures for a pump?

Start with the listing title and bullet points for speed type, wattage or amp draw, and any WEF mention. Then check the maker's manual and the maker's sizing page. The ENERGY STAR program publishes its pool pump criteria and a product list in its product finder.

Can the site tell you what a pump will cost to run?

No. This site compares stated details only and does not calculate energy costs. Your utility can answer questions about rates and programs in your area, and the maker's sizing page describes the pump's intended operation.