SEER vs SEER2: Complete Efficiency Guide
Understanding the new 2025 HVAC efficiency standards
2025 Update
All new HVAC equipment sold in the US must now meet SEER2 minimum standards. SEER ratings are being phased out in favor of the more accurate SEER2 testing method.
What is SEER2?
SEER2 (Seasonal Energy Efficiency Ratio 2) is the updated efficiency rating standard introduced by the U.S. Department of Energy in January 2023. It replaces the original SEER rating to provide more accurate real-world efficiency measurements.
Key Difference: Testing Conditions
SEER2 testing uses 0.5 inches of water column external static pressure—five times higher than the 0.1 inches used in traditional SEER testing. This better simulates real-world conditions when HVAC systems are connected to ductwork, filters, and registers.
The result: SEER2 ratings are typically 4-5% lower than equivalent SEER ratings for the same equipment. This doesn't mean the equipment is less efficient—it means the testing is more realistic.
SEER to SEER2 Conversion Chart
Use this chart to compare old SEER ratings with the new SEER2 equivalents:
| SEER (Old) | SEER2 (New) | Efficiency Level | Tax Credit Eligible |
|---|---|---|---|
| 13 | 12.5 | Below Minimum | No |
| 14 | 13.4 | Minimum (North) | No |
| 15 | 14.3 | Minimum (South) | No |
| 16 | 15.2 | Standard | No |
| 17 | 16.0 | High Efficiency | Yes - $600 |
| 18 | 17.1 | High Efficiency | Yes - $600 |
| 20 | 19.0 | Premium | Yes - $600 |
| 21+ | 20.0+ | Ultra Premium | Yes - $600 |
* Conversion formula: SEER2 ≈ SEER × 0.95 (approximate)
2025 Federal Minimum Requirements
The DOE has established different minimum SEER2 requirements based on geographic region:
Northern Region
States with cooler climates
Southern Region
States with warmer climates
Southern Region States: Alabama, Arizona, Arkansas, California, Delaware, Florida, Georgia, Hawaii, Kentucky, Louisiana, Maryland, Mississippi, Nevada, New Mexico, North Carolina, Oklahoma, South Carolina, Tennessee, Texas, Virginia
SEER2 Energy Savings Calculator
Estimate your annual energy savings by upgrading to a higher SEER2 rated system:
2025 Federal Tax Credits
Energy Efficient Home Improvement Credit
Through the Inflation Reduction Act, homeowners can claim up to $600 for qualifying central AC systems and up to $2,000 for qualifying heat pumps.
Qualifying Requirements:
Central Air Conditioner: SEER2 ≥ 16.0
Tax credit: 30% of cost, up to $600
Heat Pump: SEER2 ≥ 16.0 and HSPF2 ≥ 8.1
Tax credit: 30% of cost, up to $2,000
Must be ENERGY STAR certified
Look for the ENERGY STAR "Most Efficient" designation for best savings
Quick Reference
What's a Good SEER2 Rating?
14-15 SEER2
Entry level, meets minimum
16-17 SEER2
Good balance of cost & efficiency
18-20 SEER2
High efficiency, great for hot climates
21+ SEER2
Premium, maximum savings
Other Efficiency Ratings
EER2 (Energy Efficiency Ratio 2)
Measures cooling efficiency at a specific outdoor temperature (95°F). Important for peak demand conditions.
HSPF2 (Heating Seasonal Performance Factor 2)
Measures heat pump heating efficiency over a typical heating season. Higher is better. Minimum: 7.5 HSPF2.
Related Resources
Frequently Asked Questions
Is a higher SEER2 always better?
Not necessarily. While higher SEER2 systems are more efficient, they also cost more upfront. The best value depends on your climate, usage patterns, and electricity costs. In hot climates with high cooling hours, a higher SEER2 pays off faster. In cooler climates, a mid-range SEER2 may provide better value.
Can I still buy SEER-rated equipment?
No, as of 2023, all new residential HVAC equipment must display SEER2 ratings. However, equipment manufactured before 2023 with only SEER ratings can still be sold until inventory is depleted. All new production uses SEER2.
Why did the DOE switch to SEER2?
The original SEER testing used unrealistically low static pressure (0.1" w.c.), which didn't reflect real-world conditions. SEER2 uses 0.5" w.c., better simulating actual ductwork, filters, and registers. This gives consumers more accurate efficiency expectations.
How much can I save with a higher SEER2 system?
A 20 SEER2 system is approximately 43% more efficient than a 14 SEER2 system. For a typical 3-ton system in the South running 2,000 hours annually at $0.15/kWh, upgrading from 14 to 20 SEER2 could save approximately $300-400 per year on cooling costs.