On January 1, 2023, the Department of Energy (DOE) will require new testing procedures for developing efficiency ratings on split system heat pumps. Products that have gone through these updated testing procedures will display SEER2, EER2 and HSPF2 ratings, in addition to the older SEER/EER/HSPF ratings. The 2023 testing procedures are more stringent and will result in lower efficiency ratings compared to the older ratings. As we transition all our products to these new testing procedures, we'll publish both ratings on our heat pumps category page for better comparison.