SEER2 (Seasonal Energy Efficiency Ratio 2) measures the cooling efficiency of an AC unit over a typical cooling season under new testing standards. Higher SEER2 ratings, like those found in the Cooper & Hunter Olivia Series, indicate better efficiency. Looking through our Wall Mounts 2 Zones selection will reveal several high-SEER options. These ratings help consumers understand the long-term cost of operating their mini-split. Efficient units often qualify for federal tax credits or local utility rebates. Choosing a high SEER2 unit is an investment in both comfort and environmental sustainability.