Think of SEER like a vehicle’s MPG rating. Just as MPG measures a vehicle’s efficiency, the AC ratings known as SEER, or “Seasonal Energy Efficiency Ratio” and EER “Energy Efficiency Ratio,” will be higher the better the efficiency.
The DOE introduced the SEER testing procedure in 1987 to assess the average operating time and energy efficiency over the entire summer season.
The testing conditions have now been adjusted starting in 2023 and the new minimum standards have been moved up. Prior to 2023, the minimum SEER in Minnesota was 13, in 2023 this number was raised to 14 SEER. Another set of numbers was introduced as a part of this new testing procedure: SEER2 and EER2. In short, SEER2 is calculated in the same exact way as SEER, but measured under more stringent test conditions. Specifically, there is a 5-times increase in external static pressure. The resulting SEER2 rating is thus lower than the SEER rating because the blower motor has to work harder to push the air against the higher external pressure, consuming more watts.
Basically, equipment is currently tested to more closely match the ductwork, filters, and general setup in the average home.« Back to Glossary Index