Introducing a New Era of Heat Pump Testing Accuracy

After noticing a discrepancy between heat pump efficiency ratings and real-world performance, NEEA collaborated with partners from across North America to develop an improved energy rating and test procedure. These changes will benefit Northwest consumers in a variety of ways, such as empowering HVAC contractors to make more informed decisions when choosing heat pumps to match the needs of a particular home.

NEEA’s field and lab testing revealed that standard HVAC testing procedures did not accurately capture heat pump performance under real-world conditions. Because the standard procedures measured at a static fixed speed, the testing overestimated heat pump performance compared to field conditions when the heat pumps operate under their own controls.

The alliance recognized this as a potentially industry-changing opportunity to develop a load-based test procedure that provides a more accurate evaluation of heat pump performance. By bringing together a coalition of industry and government partners, NEEA helped to develop a controls-verification procedure (CVP) that has been incorporated into the latest North American test procedures from the Air-Conditioning, Heating and Refrigeration Institute (AHRI), while also influencing Canadian, European and Japanese testing standards. These updates are especially important for modern variable-speed heat pumps, as the performance of this technology is heavily dependent on how well their controls modulate the speed of the compressor and fans under real-world conditions.

By reflecting the actual performance of modern equipment, the updated test procedures empower HVAC designers and contractors to make more precise product selections, equip utilities with more accurate savings claims, and motivate manufacturers to create better-performing products.

Convening a Continent-Wide Coalition

NEEA has long explored ways to cost-effectively enhance the energy efficiency of the region’s new homes. During the alliance’s Market Transformation efforts on new residential construction, NEEA’s detailed performance monitoring of heating systems revealed the shortcomings of the standard test procedure for heat pumps. This finding motivated NEEA to help the market move beyond static testing at fixed-compressor speeds by convening a collaborative to develop a new load-based test procedure. Initial partners included Natural Resources Canada (NRCan), BC Hydro, Purdue University and Pacific Gas and Electric (PG&E) and BC Hydro.

Once the load-based test was developed and initially tested, NEEA helped build a broader coalition to confirm whether the load-based test procedure improved upon the current testing method. These efforts were administered by Northeast Energy Efficiency Partnerships (NEEP) and included more than a dozen funders and five heat pump manufacturers. After measuring the performance of six machines in the field under identical conditions, the group collected performance data and conducted laboratory tests to compare the results to a variety of energy ratings. With findings released as Phase 1 and Phase 2, the project confirmed the significant gains in accuracy provided by load-based testing.

Passing the Test for Consumers Across the Northwest, Nation and World

In addition to being incorporated into the latest version of the AHRI test procedure 210/240, the new load-based test procedure is making international waves as well. The CVP has been integrated into the Canadian national standard, and it has influenced changes to HVAC test methods used in Europe and Japan.