If you’re shopping for a new HVAC system in 2025, chances are you’ve seen SEER2 ratings on equipment labels. Whether you’re comparing ductless mini-splits or traditional central AC systems, SEER2 is now the go-to standard for measuring cooling efficiency.
But here’s the big question: how do SEER2 ratings impact ductless mini-splits versus central systems—and which option delivers better value for your home?
Let’s break down what these ratings mean in practice, how they apply differently to each system type, and what to consider before making a decision.
SEER2 Ratings Recap: Efficiency on Paper vs. Real World
SEER2 stands for Seasonal Energy Efficiency Ratio 2. It’s the updated standard, rolled out in 2023, replacing the older SEER metric. The difference? SEER2 tests reflect real-world static pressure losses in ductwork and account for more realistic operating conditions.
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Higher SEER2 = better efficiency. The rating measures how much cooling a system provides per watt of electricity.
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Minimum requirements: In most U.S. regions, central systems must meet at least 14.3 SEER2.
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Why it matters: SEER2 allows homeowners to compare systems fairly, whether ductless or ducted.
For more context on this shift, check out the AHRI 2023 Energy Efficiency Standards.
How SEER2 Applies to Central Systems
Central air conditioners and heat pumps are still the most common whole-home cooling solution in the U.S. But ducts make all the difference in how SEER2 applies.
Ductwork and Static Pressure
SEER2 is specifically designed to reflect duct-related losses. If ducts are undersized, leaky, or poorly insulated, the real-world efficiency of a central system can fall well below its rating.
According to the U.S. Department of Energy’s duct efficiency guidance, leaky ducts can waste 20–30% of conditioned air. That means a central system rated at 16 SEER2 may perform closer to 13 or 14 in a poorly sealed home.
Sizing and Installation Quality
Even with good ducts, central AC systems depend heavily on proper design. A Manual J load calculation is critical to ensure the system is sized correctly. Oversized systems short cycle, while undersized ones run constantly—both scenarios lower actual efficiency.
Typical SEER2 Ranges for Central AC
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Entry-level: 14.3–15.2 SEER2
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Mid-tier: 16–18 SEER2
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Premium: 19–21+ SEER2
Central systems can absolutely be efficient—but their real-world performance is only as good as the ductwork and installation behind them.
How SEER2 Applies to Ductless Mini-Splits
Ductless mini-splits are growing in popularity, especially for homes without existing ductwork or for add-on spaces like basements and sunrooms. Their design changes how SEER2 plays out.
No Duct Losses
The biggest advantage of ductless is obvious: no ducts, no duct losses. That means mini-splits typically achieve efficiency much closer to their rated SEER2 in real-world use.
The EPA’s ENERGY STAR resources on ductless systems highlight that ductless units can save up to 30% more energy compared to central systems with ducts.
Zoned Comfort and Control
Each indoor unit has its own thermostat, so you only cool the rooms you’re using. This zoned approach aligns well with SEER2 efficiency, since energy isn’t wasted cooling the entire house for just one occupied space.
Typical SEER2 Ranges for Mini-Splits
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Standard: 16–18 SEER2
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High efficiency: 20–25 SEER2
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Ultra-high: 28–30+ SEER2 (especially cold-climate models).
Mini-splits often boast SEER2 ratings far above central systems, making them attractive for energy-conscious homeowners.
Cost, Comfort, and Payback Considerations
Efficiency is only part of the story. Homeowners also need to consider cost, comfort, and long-term ROI.
Upfront Costs
Installing central AC can be less expensive if your home already has ductwork in good condition. But adding ducts to an older home can make central AC far costlier than ductless.
Ductless systems have higher equipment costs per unit, especially for multi-zone setups, but they avoid duct installation altogether. Incentives can also offset upfront costs. According to the Database of State Incentives for Renewables & Efficiency (DSIRE), many states offer rebates for high-SEER2 mini-splits.
Long-Term Savings
Because mini-splits avoid duct losses, their lifetime operating costs are often lower—especially in hot or mixed climates. However, in large homes where multiple heads are required, the savings may narrow compared to a well-installed central system.
Comfort and Control
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Mini-splits: Offer room-by-room temperature control, perfect for families with different preferences.
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Central systems: Provide uniform whole-home coverage and a “cleaner” look without wall units.
Which System Benefits More from SEER2?
The short answer: ductless mini-splits generally benefit more from SEER2 ratings because their performance aligns closely with lab-tested efficiency.
Central systems, while still efficient, depend heavily on duct design, sealing, and installation. SEER2 ratings for central AC highlight the importance of addressing ductwork if you want your system to deliver on its promise.
For a technical perspective, ASHRAE’s duct performance standards emphasize how airflow and static pressure shape efficiency outcomes.
Final Thoughts from Alex Lane
Both ductless mini-splits and central AC systems are impacted by SEER2—but in different ways. Mini-splits typically stay true to their ratings thanks to duct-free design and zoned operation. Central systems, on the other hand, may struggle to hit their rated SEER2 unless ducts and sizing are dialed in.
The best choice comes down to your home’s layout, comfort needs, and budget.
To learn more about the broader impact of SEER2 standards, start with What is SEER2 and Why It Matters.
And for the next step in this series, check out How to Track Your System’s Real-World SEER2 Performance.
Alex Lane
Your Home Comfort Advocate
