SEER2 Explained for Indiana Homeowners

What changed in 2023 · What rating you actually need · No marketing math

SEER2 ratings replaced SEER ratings for all new residential AC equipment in January 2023. If you're quoting AC installation in 2026 you're going to see SEER2 numbers, and they look lower than the old SEER ratings you remember. Here's what changed and what it means for your install decision.

What SEER and SEER2 measure

Both measure seasonal cooling efficiency — how much cooling output (BTU) you get per unit of electricity input (watt-hours), averaged across a simulated cooling season. Higher number = more efficient = lower electric bills.

The difference is the test conditions. The old SEER standard used an idealized test that didn't account for real-world ductwork pressure drop. SEER2's M1 test standard simulates 0.5 inches of water column external static pressure — closer to what equipment actually experiences in a real home. Result: same equipment scores lower under SEER2 than SEER, by roughly 4-5%.

Conversion table — old SEER vs new SEER2

The equipment didn't get worse — the test got more realistic. Don't let a contractor quote you "we'll install an 18 SEER" and bill you for it when the SEER2 sticker says 17.2. The terminology must match the test.

Federal minimums (Indiana — North region)

• Residential central AC: 13.4 SEER2 minimum (effective Jan 2023)
• Residential air-source heat pump: 14.3 SEER2 / 7.5 HSPF2 minimum
• South region (Indiana not in South): 14.3 SEER2 minimum — doesn't apply to Indiana

Note: federal minimums are floors, not recommendations. Almost no one installs minimum-rated equipment anymore because the next-tier-up units have better long-term economics.

What rating to actually pick for Lebanon

The 15-17 SEER2 sweet spot

For most Boone County homes, 15-17 SEER2 (equivalent to ~16-18 SEER under old terminology) is where price and efficiency curves meet best. Going from minimum 13.4 to 16 SEER2 saves real money on summer cooling bills. The cost premium is reasonable — typically $400-$800 for the next tier up.

When 18-20+ SEER2 makes sense

• Large home (3,500+ sq ft) with high cooling load
• Western or southern sun exposure with limited shading
• Owner-occupied for 12+ years
• High electric rates (Indiana average is moderate but specific tariffs vary)
• You want quieter operation and better humidity control (variable-speed compressors at higher SEER2 tiers excel here)

When 13.4-14 SEER2 minimum makes sense

• Rental property — tenant pays the cooling bill
• Vacation home with limited use
• Short-term occupancy (selling in 1-3 years)
• Tight replacement budget
• Backup system (window units or partial cooling, not primary)

Real bill impact in Lebanon

Typical 1,900 sq ft Lebanon home, central AC running June-September, electric rates around $0.13/kWh. Estimated annual cooling cost by SEER2:

Payback periods on typical install premiums:

• 13.4 → 15.2 SEER2: ~$500 premium → 8 years
• 15.2 → 17.2 SEER2: ~$1,200 additional → 22 years (diminishing returns hard)
• 17.2 → 19.1 SEER2: ~$1,500 additional → 38 years (specialty cases only)
• 19.1 → 23.8 SEER2: ~$3,000 additional → 43 years (almost never makes financial sense)

This is why we typically recommend 15-17 SEER2 to most Lebanon customers. Beyond that, the math gets brutal unless you're in the specialty cases above.

Variable-speed vs single-stage at the same SEER2 rating

SEER2 only measures cooling efficiency. It doesn't capture two factors that matter for Indiana climate:

• Humidity control. Variable-speed compressors run longer at low load, removing more moisture. Single-stage cycles on/off and leaves humidity higher. For Indiana summers, this matters.
• Noise level. Variable-speed at partial load is dramatically quieter than single-stage. If your outdoor unit is near a patio or window, this matters.

Two units at the same 17 SEER2 rating can feel completely different in practice. A 17 SEER2 single-stage works on bill savings. A 17 SEER2 two-stage or variable-speed works on bill savings AND comfort. Pricing differs by $1,000-$2,500. Worth it for many homeowners; not for all.

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