The U.S. Department of Energy (DOE) has issued the 2023 requirements. It reviews efficiency standards for HVAC products every six years. EER, SEER, and HSPF are no longer used. The new terms are EER2, SEER2, and HSPF2. New DOE testing procedures required the use of higher external airflow pressures to simulate real-world conditions. The new metrics are EER2, SEER2, and HSPF2. Equipment that has been tested using the new procedures is distinguished from equipment that was tested using the old ones by the new names.