Consumers are always looking to save money in operating their pools, and one way is to lower energy usage. One of, if not the, biggest energy consumer in a pool is the pump. In an effort to help residential consumers save money and reduce greenhouse gas emissions, the U.S. Environmental Protection Agency (EPA) has updated the requirements for pool pumps under its ENERGY STAR certification program.
This certification is an optional program for manufacturers of residential pool/spa pumps to show their products meet rigorous energy-efficiency requirements. Manufacturers must meet labeling and documentation requirements and have their pumps tested by an EPA-recognized laboratory, such as NSF International, to verify that they meet efficiency requirements.
In May 2017, the U.S. Department of Energy (DOE) updated the energy conservation standards for dedicated-purpose pool pump energy test methods and standards, 10 CFR Part 431, with a compliance date of July 19, 2021. EPA also has noted an ongoing market trend of declining single-speed and two-speed pump sales, while variable speed pump sales are increasing.
The EPA in turn took those updated requirements and market trends as the impetus to draft the new ENERGY STAR Version 2.0 and Version 3.0, which align definitions and test methods with the DOE standard, while capturing additional energy savings by raising efficiency requirements. After several rounds of public comment, both new versions were finalized on April 30, 2018.
Finalizing sequential versions at the same time may seem confusing, but the EPA purposefully took this step-wise approach to reach the desired energy efficiency goal in Version 3.0. While pump efficiencies and market trends have been moving toward more efficient variable-speed pumps, adopting the requirements in Version 3.0 immediately was too large a jump. Version 2.0 bridges the gap between the Version 1.1 requirements and Version 3.0. Besides including energy-efficiency changes, Version 2.0 expands which pumps are included and connectivity requirements.
All three versions of the EPA ENERGY STAR test procedure — 1.1, 2.0 and 3.0 — utilize three plumbing-system pressure-drop curves that represent a typical pool installation: curves A, B and C. These curves are a way to estimate how a pump would operate in a typical pool. Versions 2.0 and 3.0 apply new criteria for efficiency by using the DOE Test Procedure for Dedicated Purpose Pool Pumps to calculate the weighted energy factor (WEF) (kgal/kWh) on curve C. This is different from ENERGY STAR Version 1.1, which required an energy factor (EF) (gal/Wh) calculation on curve A. All three ENERGY STAR versions require reporting values for curves A, B and C.
The equations are similar but with a significant difference: Version 1.1 uses a single data point, where Versions 2.0 and 3.0 utilize multiple data points and take the weighted average.
The DOE test procedure defines the load points (i) and weights (wi) used in calculating the WEF. The points are specific to the pump type (e.g. a self-priming pool filter pump) and number of speeds (e.g. two-speed). As Version 2.0 and Version 3.0 calculate the new weighted energy factor and no longer use the energy factor, the pass/fail requirements have been updated. A direct conversion of a Version 1.1 energy factor to Version 2.0/3.0 weighted energy factor can’t be made; a full set of test data is necessary to determine the new WEF and compliance.
As previously stated, the EPA is taking a step-wise approach to ENERGY STAR efficiency requirements. Version 2.0 and 3.0 were developed concurrently because Version 3.0 was the desired end efficiency level, but an intermediate improvement in efficiency levels was necessary. With the adoption to Version 2.0, overall, the energy efficiency requirement of has gone up in comparison to Version 1.1. Table 1 of the EPA ENERGY STAR Version 2.0 and 3.0 specification shows the changes in efficiency requirements between Version 2.0 and Version 3.0.
ENERGY STAR Version 1.1 certification encompasses a complete pump, motor and wet-end combination. A final difference from Version 1.1 in Versions 2.0 and 3.0 is they include replacement motors in the scope. With the new versions, EPA recognizes that many pumps in the field have replacement motors installed. While these are included in the scope, there currently are no certification requirements or criteria. As test methods to verify replacement motor energy efficiency and data become available, the EPA plans to include those changes as a minor revision.
See the chart above for dates to transition from Version 1.1 to Versions 2.0 and 3.0. Effective immediately, manufacturers may certify products to the Version 2.0 requirements.
