SEER2 Explained: What HVAC Contractors Need to Know About the New Efficiency Standard
SEER2 replaced SEER in 2023 as the efficiency standard for HVAC equipment. Here is what contractors need to know about the new ratings and minimum requirements.
What is SEER2?
SEER2 (Seasonal Energy Efficiency Ratio 2) is the updated efficiency rating standard that replaced SEER in January 2023. The Department of Energy (DOE) introduced SEER2 to better reflect real-world operating conditions for air conditioning equipment.
Technical Difference: SEER vs SEER2
The key difference is the external static pressure used during testing:
- SEER: Tested at 0.1 inches of water column (WC) external static pressure
- SEER2: Tested at 0.5 inches WC external static pressure
The higher static pressure in SEER2 testing more accurately represents typical ductwork conditions in real installations. As a result, SEER2 ratings are approximately 5% lower than comparable SEER ratings for the same equipment.
DOE Minimum SEER2 Requirements
Minimum efficiency requirements vary by equipment type and climate region:
- Commercial packaged units (national): 13.4 SEER2
- Residential/light commercial — North region: 13.4 SEER2
- Residential/light commercial — South region: 14.3 SEER2 (single-phase)
Converting SEER to SEER2
When comparing older SEER-rated equipment to new SEER2-rated equipment, a rough conversion is: SEER2 is approximately 95% of SEER. So a unit previously rated at 14 SEER would be approximately 13.3 SEER2. This is useful when evaluating replacement equipment against existing specifications.
Energy Code Compliance
Building energy codes reference SEER2 ratings for new construction and equipment replacement. When submitting mechanical permit applications, ensure your equipment specifications include the SEER2 rating from the current AHRI certificate — not the older SEER rating.
AHRI Certificate Ratings
All equipment sold through ClimateProDirect includes AHRI certificates with current SEER2 ratings. These certificates are suitable for permit applications, energy code compliance documentation, and mechanical engineering submittals.
Practical Implications for Contractors
For replacement projects, be aware that new equipment with a lower SEER2 number may actually be equivalent to or more efficient than the unit being replaced, when comparing against the older SEER standard. Always compare like-for-like using the same rating standard.
Browse our AIM Act compliant catalog with current SEER2 ratings at ClimateProDirect.com.
