Energy Ratings Program Now
ECM Circulator pumps are now part of Hydraulic Institute’s nearly 10,000-pump-strong Energy Rating Program.
The Hydraulic Institute’s Energy Rating Program has expanded to include efficient circulator pumps. These ratings provide test data from third party audited labs that make pump energy cost savings credible and easier to assess. The program has the support from the largest circulator pump manufacturers in the world, representing more than 90% of the energy efficiency circulator pumps sold in North America.
Circulator pumps have advanced in efficiency over the years through the use of variable speed electrically commutated motors (ECM) that typically use integrated controls to adjust their speed to meet system demand. Like many advances, market adoption has been slow because of both comfort with the status quo and up-front cost considerations. The Circulator Pump Energy Rating Program will help move the market past the status quo toward significant national energy savings.
Circulator pumps are used primarily to recirculate hot water for hydronic heating and HVAC systems in residential and commercial buildings. By adjusting their speed to water demand (or other factors), ECM pumps can slash energy use by up to 80 percent when compared with traditional, full-speed circulator pumps. They also improve comfort, optimize water system performance, and enhance reliability, said Hydraulic Institute technical program manager Edgar Suarez.
Since the primary increase in efficiency is due to the motor and controls, more efficient ECM circulators are simple drop-in upgrades for conventional pumps and may qualify for utility energy rebates.
Understanding the Label
“Our goal is to support the switch to more efficient products by providing a label that makes it easy for customers to differentiate between pumps based on energy performance,” Saurez said.
The information needed to assess pump performance is found on the energy rating label. It is divided into five categories:
Basic Information. This includes the pump brand, model number, and weighted average input power (in horsepower) for the baseline ECM circulator.
Circulator Energy Index (CEI). The CEI compares ECM energy consumption to a traditional circulator. The lower the value, the less power it consumes and the greater the savings. CEI is calculated using the ECM pump’s most energy-efficient control mode.
Energy Rating. The energy rating is derived from comparing the rated CEI for the efficient circulator compared to the CEI of a typical (baseline) circulator pump. With respect to energy rating, larger is better, meaning a larger number will consume less power for a comparable circulator with a lower number. The energy rating can then be used to calculate savings over a traditional circulator or another comparable circulator with a lower energy rating. The circulator pump label always express this figure as a range of numbers that includes its least energy-efficient and most energy-efficient control modes.
Control Modes. ECM pumps may operate under a variety of control methods to best meet the needs of the application, such as full-speed, pressure and temperature controls. For example, when a building needs less heating, the pump automatically adjusts its speed to operate at a lower pressure or maintain a constant differential temperature. Many circulator pumps use local controls to accomplish this, but they can also accept control inputs from a larger building operating system or another external system.
Estimated Savings. This section shows how to use the Energy Rating to calculate estimated savings over the traditional baseline circulator pump. This is done by multiplying the Energy Rating by the weighted average input power, then multiplying the product by 7.46 to change it from horsepower to kilowatts. Multiplying kilowatts by operating hours and the cost of electrical energy yields the cost savings. Additionally, when comparing two energy ratings, the same formula can be used, except use the difference in Energy Rating.
Next Steps
While data for Energy Ratings comes from manufacturers, the Hydraulic Institute has set guidelines for this process and audits the labs that do the actual testing. All requirements for rating ECM pumps are set out in HI 41.5 Program Guideline for Circulator Pump Energy Rating Program.
Labs are audited annually to ensure they comply with all test standards, employ properly trained personnel, and have the right equipment and quality management systems. If a lab achieves zero non-conformances for two consecutive years, it moves to a two-year audit schedule. For each newly tested pump, the Hydraulic Institute double-checks all calculations before the information is entered in the database.
Manufacturers’ participating in the program have completed most of their testing. Starting in June, 2021, a majority of the energy efficient circulator pumps can be found at er.pumps.org. This preparation positioned the industry to have labeled products on the shelf for the 2021 fall heating season, which will be a new step toward communicating the value of energy efficiency.
In addition to Circulator pumps, the Hydraulic Institute’s Energy Rating Program currently covers nearly 10,000 commercial and industrial pumps in five categories: end-suction frame mount (ESFM), end-suction close coupled (ESCC), in-line, radially split multi-stage vertical inline diffuser casing (RSV), and submersible turbines.
The Hydraulic Institute also provides a variety of pump savings calculators for these pumps. They are essentially Excel spreadsheet templates linked to the Energy Rating database. This simplifies the process of pump comparisons based on estimated costs. These calculators are accessible at www.pumps.org/freetools” www.pumps.org/freetools. The Circulator Pump Calculator is nearing completion and is scheduled to be available soon.
“Our goal is to make it easier for everyone—owners, operators, contractors, and distributors—to make the transition to more efficient pumps,” Suarez said. “The addition of a rating system that helps show the benefits of ECM circulators is a step on the road to making that happen.”