SEER2 Explained: What the New Rating Means for Your Next AC

What Changed in 2023

The Department of Energy introduced SEER2, a new efficiency rating standard that replaced the old SEER rating. If you're shopping for a new air conditioner, you'll see both numbers — and understanding the difference matters.

SEER vs SEER2

SEER (Seasonal Energy Efficiency Ratio) measured cooling output divided by energy input under ideal conditions. SEER2 uses tougher, more realistic testing conditions — higher external static pressure that mimics real-world ductwork.

The result: SEER2 ratings are about 4–5% lower than the old SEER for the same equipment. A 14 SEER unit under the old test becomes roughly 13.4 SEER2.

New Minimums

• Northern states: 13.4 SEER2 (was 13 SEER)
• Southern states: 14.3 SEER2 (was 14 SEER)
• Southwest: 14.3 SEER2 with additional EER requirements

What This Means for You

Don't compare old SEER to new SEER2. A 16 SEER2 system is more efficient than a 16 SEER system from 2022. When comparing quotes, make sure both contractors are quoting in SEER2.

Higher SEER2 = bigger savings, but diminishing returns. The jump from 14 to 16 SEER2 saves about 15% on cooling. The jump from 16 to 18 saves another 10%. Beyond 18 SEER2, you're paying a premium for marginal gains.

Proper installation matters more than the rating. A 16 SEER2 system installed with leaky ducts and wrong charge will perform like a 13. We verify our installs with commissioning tests.

Bottom Line

If your system is 10+ years old, any new SEER2-rated unit will cut your cooling bills significantly. The question isn't whether to upgrade — it's which tier fits your home and budget.