What is SEER2?
SEER2 is the revised federal efficiency rating standard for air conditioning and heat pump systems, introduced in 2023, that uses updated testing conditions to better reflect real-world performance than the older SEER metric.
The Department of Energy replaced the SEER rating with SEER2 starting January 2023. SEER2 stands for Seasonal Energy Efficiency Ratio and measures how much cooling an air conditioner or heat pump produces per unit of electricity consumed over a typical cooling season. The change reflects updated testing protocols that account for higher outdoor temperatures and more realistic operating conditions.
SEER2 ratings are numerically lower than their SEER equivalents because the new standard tests at 95 degrees Fahrenheit outdoor temperature, versus the old SEER's 82-degree baseline. A unit rated 16 SEER might earn only 13 SEER2, for example. This shift does not mean systems got less efficient; instead, the metric now provides a more accurate picture of performance.
In Phoenix's heat, where summer temperatures regularly exceed 110 degrees and cooling runs continuously from May through September, SEER2 ratings carry real weight on your energy bill. Higher SEER2 numbers mean lower cooling costs over the unit's 15 to 20-year lifespan. Federal minimums now start at 14 SEER2 for most air conditioners in Arizona, but units rated 16 SEER2 and above will reduce strain on equipment during peak heat and lower monthly utility expenses. When selecting a new system or replacement from AC contractors, SEER2 is the current standard to compare across products.