If you are shopping for a new central air conditioner, every quote and brochure will list a SEER2 number. Since January 1, 2023, SEER2 has been the efficiency rating that U.S. Department of Energy (DOE) standards use for central air conditioners and heat pumps. This guide explains what the number measures, what the federal minimum is for a Minnesota home, and how to use the rating to compare equipment.
What SEER2 measures
SEER stands for Seasonal Energy Efficiency Ratio. According to the DOE's FAQ on the 2023 central air conditioner standards, SEER is the total heat a system removes during the cooling season divided by the total electricity it uses in that season. A higher number means the system uses less electricity to remove the same amount of heat.
The "2" marks a change in the test procedure. DOE revised the tests to produce efficiency ratings that better reflect real-world installation and use. Two related ratings changed at the same time:
- EER2 measures cooling efficiency at one set condition: an outdoor temperature of 95°F.
- HSPF2 measures heating efficiency for heat pumps.
SEER vs. SEER2: why the numbers look different
DOE states that the new ratings are similar to the old ones but are not directly comparable. In practice, the same equipment tested under the newer procedure gets a lower number. The Air-Conditioning, Heating, and Refrigeration Institute (AHRI) summary of the residential standards lists the national minimum of 13.4 SEER2 as roughly equal to 14 SEER under the old test.
This matters when you compare equipment. If your current system is labeled with a SEER number and a new quote lists SEER2, you are not comparing like with like. Compare SEER2 to SEER2.
The federal minimum that applies in Minnesota
DOE sets central air conditioner standards by region. The Southeast and Southwest regions are defined by a list of named states, and Minnesota is not on either list. That puts Minnesota in the North region, where the national standards apply.
For split-system central air conditioners in the North, the current minimums are:
- 13.4 SEER2 for all sizes, effective January 1, 2023
- No regional EER2 requirement (EER2 minimums apply only in the Southwest)
In the North, DOE enforces the standard by the date a unit was manufactured, not the date it is installed. A split-system unit built before January 1, 2023 that met the older standard can still be installed legally. A unit built on or after that date must meet the new standard. In the Southeast and Southwest, enforcement is based on installation date instead.
Keep in mind that 13.4 SEER2 is a floor, not a recommendation. Manufacturers sell equipment at many levels above the minimum.
The rating belongs to a matched system
A split air conditioner has two main parts: the outdoor condensing unit and the indoor coil, which usually sits on top of your furnace. The efficiency rating is tied to a specific combination of the two. DOE's FAQ notes that a system not certified as a combination is not compliant for sale in the North.
If a contractor proposes replacing only the outdoor unit and keeping your old indoor coil, ask what rating that exact pairing carries. The SEER2 on a brochure may not apply to your installation.
How much SEER2 makes sense in Minnesota
A higher SEER2 rating lowers electricity use per hour of cooling. How much that matters depends on how many hours your system runs. Minnesota's cooling season is shorter than in southern states, and the heating season is long. That changes the math compared with a home in Texas or Florida.
Weigh these factors instead of chasing the highest number:
- Your cooling hours. A home that runs air conditioning daily from June through August uses more cooling than one that runs it only on the hottest days.
- Humidity control. Ask how each option handles moisture removal during humid summer weather. Two-stage and variable-speed equipment can run at lower output for longer cycles, which is worth discussing with your contractor.
- Your heating plan. If you are considering a heat pump instead of an air conditioner, HSPF2 and cold-weather performance matter as much as SEER2.
- Installation quality. Correct sizing, refrigerant charge and airflow affect real efficiency. A high rating does not make up for a poor installation.
- Ductwork. Leaky or undersized ducts reduce delivered comfort no matter what the equipment is rated.
Practical steps when comparing quotes
- Find your current system's rating on the outdoor unit's data plate or in your original paperwork, and note whether it says SEER or SEER2.
- Ask every contractor for the SEER2 and EER2 of the exact outdoor unit and indoor coil combination they plan to install.
- Ask whether the quote includes a load calculation to size the system for your home.
- Compare quotes at similar SEER2 levels before you compare prices.
- Do not plan on the federal Energy Efficient Home Improvement Credit. The IRS FAQ on changes to the energy credits states it does not apply to equipment placed in service after December 31, 2025. Ask your utility about any current rebates.
When to call a professional
Talk to an HVAC contractor when your current system needs a major repair, is more than 10 years old, or no longer keeps your home comfortable. A contractor can measure your home's cooling load, check your ducts and indoor coil, and show you the rated SEER2 of each option. Our team can help you compare air conditioning installation options with clear ratings on each quote.
Common questions
What is the minimum SEER2 for a new central air conditioner in Minnesota?
Minnesota is in DOE's North region, where split-system central air conditioners must meet 13.4 SEER2. This standard took effect January 1, 2023.
Is 13.4 SEER2 the same as 14 SEER?
AHRI lists 13.4 SEER2 as roughly equal to 14 SEER. The two ratings come from different test procedures, so compare SEER2 only to SEER2.
Can a contractor still install an air conditioner made before 2023 in Minnesota?
Yes, if it met the standard in effect when it was manufactured. In the North region, DOE enforces split-system standards by manufacture date.