If you’ve started researching new HVAC equipment recently, you’ve probably noticed a new term showing up everywhere: SEER2. While it looks similar to the old SEER rating, SEER2 represents a major shift in how HVAC efficiency is measured—and how systems perform in real-world conditions.
Here’s a clear, practical breakdown of what SEER2 is, why it exists, and what it means for facility managers and building owners.
SEER stands for Seasonal Energy Efficiency Ratio, a key metric used to measure the cooling efficiency of air conditioning and heat pump systems over a typical cooling season. The updated SEER2 rating improves upon the original SEER by incorporating new testing procedures that better simulate real-world operating conditions, including factors like external static pressure and airflow resistance.
By understanding the difference between SEER and SEER2, HVAC buyers can make informed decisions about efficient systems that deliver energy savings, peak performance, and long-term cost savings across a range of climates and installation scenarios.
What Does SEER2 Mean?
SEER2 stands for Seasonal Energy Efficiency Ratio 2. It is the updated efficiency rating used to measure how efficiently air conditioners and heat pumps operate over an entire cooling season.
The higher the SEER2 rating, the more energy-efficient the system.
SEER2 officially replaced the original SEER rating in January 2023, following new testing requirements set by the U.S. Department of Energy (DOE).
Why Was SEER Replaced with SEER2?
The original SEER testing method measured efficiency under ideal laboratory conditions. While useful for comparison, it didn’t fully represent how HVAC systems actually operate once installed in a building.
SEER2 was created to:
Better reflect real-world airflow resistance
Account for external static pressure from ductwork
Provide more accurate efficiency comparisons
Improve system reliability and performance expectations
In short, SEER2 gives a truer picture of how a system performs after installation—not just how it performs in a test room.
What’s the Difference Between SEER and SEER2?
The biggest change is how systems are tested.
Under SEER2:
Systems are tested with higher static pressure
Airflow restrictions are simulated
Results better match real installations
Because the testing is more demanding, SEER2 ratings are typically lower than SEER ratings for the same equipment—even though the equipment itself hasn’t become less efficient.
Example:
A 16 SEER system may now be rated around 15 SEER2
A 14 SEER system may now rate around 13.4 SEER2
This doesn’t mean efficiency dropped—it means the rating is more realistic.
Minimum SEER2 Requirements
The DOE also updated minimum efficiency requirements at the same time SEER2 was introduced. These minimums vary by region and system type.
For most northern regions:
Split system air conditioners: 13.4 SEER2 minimum
Heat pumps: 14.3 SEER2 minimum
Southern and Southwest regions have higher minimums due to longer cooling seasons.
Any new HVAC system manufactured or installed today must meet these updated SEER2 requirements to be compliant.
How SEER2 Impacts HVAC Buyers
1. Equipment Costs
SEER2-compliant equipment may cost slightly more upfront due to improved design requirements, but it often delivers:
Lower energy usage
Better airflow performance
Improved comfort consistency
2. Energy Savings
Because SEER2 reflects real operating conditions, the projected energy savings are more accurate than older SEER estimates.
3. Installation Quality Matters More
With SEER2 testing factoring in airflow resistance, proper duct design, sizing, and installation play a bigger role in actual system performance than ever before.
SEER2 for Commercial and 
Industrial HVAC Systems
While SEER2 mainly applies to light commercial equipment, the shift reinforces a broader industry trend:
Greater emphasis on system design
Improved focus on airflow and static pressure
Tighter efficiency compliance standards
For facility managers, SEER2 highlights the importance of evaluating HVAC systems as a whole—not just individual pieces of equipment. This comprehensive approach ensures that the entire system, including ductwork and installation quality, contributes to optimal power usage and overall energy savings. Facility managers can select HVAC systems that meet updated efficiency standards and deliver consistent cooling efficiency throughout the typical cooling season.
Is a Higher SEER2 Rating Worth It?
A higher SEER2 rating is usually worth considering if:
Your building operates HVAC systems for long hours
Energy costs are a major concern
Comfort consistency is critical
You plan to stay in the building long-term
That said, the best-performing system is one that’s:
Properly sized for your building and climate
Correctly installed by a professional team
Designed for the building’s actual usage and affected by factors like leaky ducts
Efficiency ratings matter—but execution matters just as much. Choosing a model with the highest efficiency rating can save you money on energy bills by using less energy to deliver total heat removed during the typical cooling season. New testing procedures ensure these ratings are calculated under more realistic temperatures and conditions, reflecting real-world performance rather than ideal conditions. Manufacturers now design equipment to meet new regulations that vary depending on your region and system type, including split system heat pumps and central air conditioners.
Energy Efficient Solutions
SEER2 isn’t just a new number—it’s a more realistic way to measure HVAC efficiency by reflecting real-world conditions like external static pressure and airflow resistance. This updated version of the seasonal energy efficiency ratio helps building owners make smarter decisions about comfort, cooling efficiency, and long-term energy consumption.
If you’re planning an HVAC replacement or upgrade, understanding SEER2 ensures you’re comparing efficient units accurately and investing wisely in systems that deliver cost savings and improved performance throughout a typical cooling season. Choosing a system with a higher SEER2 rating means lower energy bills, better humidity control, and eligibility for energy star rebates and incentives.
By selecting equipment that meets the new efficiency standards and complies with updated testing procedures, you can enjoy the benefits of an efficient system designed for your climate. Proper installation and maintenance also play a crucial role in maximizing your system’s heating efficiency and overall energy savings.
