Efficiency Rating Converter
Convert between SEER/SEER2, HSPF/HSPF2, and check efficiency tiers. The 2023 rating system change makes old specs confusing; this tool translates them.
SEER Rating Chart
Compare efficiency tiers, former tax credit thresholds, and potential savings
| SEER2 | SEER Equiv | Tier | Tax Credit (Ended) | Savings vs 14 SEER2 |
|---|---|---|---|---|
| 14 | 14.7 | Minimum | No | Baseline |
| 15 | 15.8 | Standard | No | ~7% |
| 16 | 16.8 | Good | Eligible | ~14% |
| 17 | 17.9 | Better | Eligible | ~21% |
| 18 | 18.9 | Better | Eligible | ~29% |
| 19 | 20.0 | Best | Eligible | ~36% |
| 20+ | 21.0+ | Best | Eligible | ~43%+ |
SEER Savings Calculator
Estimate cooling cost savings when upgrading to higher efficiency
How to Calculate Your Savings
Use this formula to estimate annual cooling cost savings when upgrading equipment:
Example Calculation
You have a 10 SEER (9.5 SEER2) system and spend $400/year on cooling. You upgrade to 18 SEER2.
- Savings = $400 × (1 - 9.5 / 18)
- Savings = $400 × 0.472
- Annual savings: $189
- Over 15 years: $2,835 saved
Colorado reality check: Our cooling season runs June-August, so even high-efficiency AC takes 10+ years to pay back through energy savings alone. Heat pump upgrades make more sense because heating costs dominate (8 months of use). Focus SEER decisions on comfort and quietness rather than cooling savings.
For detailed energy analysis including heating costs, use our comprehensive energy calculator, which factors in your actual home size, insulation, and local utility rates.
SEER2 vs SEER: What Changed?
Understanding the 2023 efficiency standard update
The DOE Updated Testing Procedures in 2023
In January 2023, the Department of Energy replaced SEER with SEER2 (and HSPF with HSPF2). The equipment didn’t change. The testing method changed to better reflect real-world installations.
Old SEER Testing
- M0 blower (minimal static pressure)
- Short duct assumptions
- Ideal laboratory conditions
- Higher published ratings
New SEER2 Testing
- M1 blower (realistic static pressure)
- Standard duct lengths
- Reflects typical installations
- More accurate ratings
Quick Conversion Rule
SEER2 ratings are roughly 5% lower than SEER ratings for the same physical equipment:
Important: If you’re comparing equipment specs or checking tax credit eligibility, make sure you’re looking at SEER2/HSPF2 ratings (not old SEER/HSPF). Manufacturers publish both, but only SEER2 matters for equipment sold after January 2023.
Efficiency Ratings Reference
What each rating measures and what qualifies as efficient
| Rating | Measures | Good | Tax Credit (Ended) | Notes |
|---|---|---|---|---|
| SEER2 | Cooling efficiency | 15+ | 16+ | Replaced SEER in 2023. Uses M1 blower testing. |
| HSPF2 | Heating efficiency | 8.5+ | 8.1+ | Replaced HSPF in 2023. Required for heat pumps. |
| EER | Cooling at peak load (95°F) | 12+ | N/A | Snapshot efficiency at specific conditions. |
| COP | Heat output vs energy input | 3.0+ | N/A | COP of 3.0 = 300% efficient (3 units heat per 1 unit electricity). |
Related Tools
Efficiency Rating FAQs
Common questions about SEER2, HSPF2, and efficiency ratings
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