Are You Ready for Load-Based Performance Testing?

With increasing concern over global warming and rising energy costs, consumer products’ energy efficiency is becoming a critical consideration. As residential air conditioner and heat pump product technology improves, it’s essential to update testing methods and standards, as well. Load-based testing represents a novel way to better characterize new products’ energy efficiency performance. The recently published Canadian Standards Association (CSA) SPE-07-2023 load-based test procedure relies in part on load-based testing conducted by UL Solutions.

The Energy Policy and Conservation Act has authorized the U.S. Department of Energy to regulate the minimum energy efficiency values of consumer air conditioners and heat pumps sold and purchased in the United States. Those minimum energy efficiency requirements have steadily risen over the years, along with the energy costs of using those products in our households.

Innovative developments in air conditioning and heat pump technology, such as control algorithms, variable-speed compressors and variable-speed fan motors, can potentially increase and optimize those products’ energy efficiency performance over an increasing range of operating conditions. However, traditional energy efficiency performance testing standards and their associated testing methods do not characterize the variable-speed equipment’s performance, as it operates using its own control algorithms across a wide range of operating conditions. Traditional test methods utilize static performance testing conditions while locking the compressors and fan motors in fixed, non-representative conditions, while not using the control algorithms designed for the equipment.

Published in 2019, CSA EXP07:19, Load-Based and Climate-Specific Testing and Rating Procedures for Heat Pumps and Air Conditioners, introduced an innovative, dynamic, load-based performance testing method and represented years of effort by a working group of industry individuals and organizations across North America. The working group recognized that the performance ratings that result from using the current, static-based performance testing standards in North America do not adequately represent climates that differ substantially from the assumed ratings. Further, in-field monitoring of the equipment suggested significant shortcomings in the ability of the ratings to predict installed performance.

The UL Solutions HVACR (heating, ventilation, air conditioning and refrigeration) Energy Efficiency and Performance Testing Laboratory in Plano, Texas, began testing based on an early draft of EXP07 in 2018. The results and lessons learned from that load-based testing supported the development and release of EXP07:19. Since then, our laboratory in Plano has conducted over $1 million (USD) in value-engineering and research and development (R&D) projects for various industry groups across North America. The projects comprised more than 21 ductless and ducted products, ranging from 0.9 tons to 4.6 tons, from eight different manufacturers. The projects focused primarily on examining the repeatability and reproducibility of the EXP07:19 load-based test methods. The results from those projects supported the publication of various papers and, more significantly, the development of SPE-07-2023.

SPE-07-2023 represents the work of approximately 20 industry subject matter experts, manufacturers, regulators, program developers, utilities and test laboratories, including UL Solutions. The Canadian Standards Association (CSA) has also initiated the C700 project to take the SPE-07-2023 testing and rating procedure through an accreditation process prescribed by the Standards Council of Canada (SCC). The purpose of the project is to take SPE-07-2023 from a voluntary standard to a nationally accredited standard that regulatory agencies and utility programs can use to support their energy efficiency programs for residential air conditioners and heat pumps.

Currently, several stakeholders of SPE-07-2023 load-based testing have initiated projects that are focused on examining the representativeness of the SPE-07-2023 energy efficiency metrics. The representativeness projects will study how the load-based energy efficiency metrics compare to the measured, in-field performance of residential heat pump systems. The projects’ laboratory testing portion is currently being conducted at UL Solutions’ Plano laboratory.

At UL Solutions, we are dedicated to bringing science and research to bear on the HVACR industry today and tomorrow. To learn more about our work, visit our HVACR page.