Three brands carry units with specs traceable to the official AHRI Certificate of Product Ratings or the manufacturer spec sheet in 2026: Daikin (Aurora 12K), Senville (LETO SENL-12CD), and Mitsubishi (MSZ-FS12NA). Other brands appear on prior comparison tables across this site with values that have not been verified against primary sources — those rankings have been removed from this page until we can pull each model's AHRI cert.
The ordering below is by certification status and current availability, not just raw SEER2. The unit with the highest certified SEER2 (Mitsubishi MSZ-FS12NA at 26.3) is ranked third because Mitsubishi has stopped producing it (AHRI cert status: Production Stopped) and it runs R-410A — the refrigerant being phased out under the EPA's AIM Act rule. The Daikin Aurora 12K leads because it is AHRI-certified, Active, and ships with the current low-GWP refrigerant (R-32).
Rankings are based on AHRI-certified efficiency ratings and manufacturer specifications. No brand paid to be included.
The Verified Shortlist (3 Brands)
| Rank | Brand / Model | Headline (verified) | Refrigerant | Warranty | Status / Source |
|---|---|---|---|---|---|
| #1 — Best overall (cert-verified, current) | Daikin Aurora 12K (FTXV12AVJU9 / RXT12AVJU9) | 20.0 SEER2 · 12.0 EER2 · 10.2 HSPF2 · -13°F heating | R-32 | 12 years (registered) | Active · AHRI Certified Ref# 215710688 |
| #2 — Best budget | Senville LETO SENL-12CD | 21.2 / 21.3 SEER2 · -13°F spec / ~5°F effective | R-454B | 10 yr compressor + 10 yr parts | Manufacturer spec sheet (AHRI cert listed on senville.com) |
| #3 — Highest SEER2 (being phased out) | Mitsubishi MSZ-FS12NA (MUZ-FS12NAH / MSZ-FS12NA) | 26.3 SEER2 · 13.8 EER2 · 10.4 HSPF2 · -13°F (H2i) | R-410A | 5 yr parts / 7 yr compressor; 12 yr w/ Diamond install | Production Stopped · AHRI Certified Ref# 209832204 |
Why this ordering (transparency)
The Mitsubishi MSZ-FS12NA has the highest AHRI-certified SEER2 on this page (26.3). It's ranked third anyway because:
- Mitsubishi has stopped producing it. The AHRI certificate lists status: Production Stopped. The unit is still sold from existing distributor inventory but no longer manufactured.
- It runs R-410A. As of January 1, 2025, R-410A may no longer be produced or imported for new residential AC/HP equipment under the EPA's AIM Act rule. R-410A pre-2025 inventory may still be installed in 2026 in most states (per the EPA's amended final rule effective July 27, 2026); New York codified the original Jan 1, 2026 install ban.
The Daikin Aurora 12K leads because it is AHRI-certified, Active, and on the current low-GWP refrigerant (R-32, GWP 675 — under the EPA's 700 threshold).
#1 Daikin (Aurora 12K) — Best Overall (AHRI-Verified, Active)
Daikin is the world's largest HVAC manufacturer by revenue. The Aurora 12K (FTXV12AVJU9 / RXT12AVJU9) carries an AHRI Certificate of Product Ratings (Ref# 215710688) and is listed as Active.
| Spec | Value | Source |
|---|---|---|
| Cooling capacity (AFull) | 10,600 BTU | AHRI Certified Ref# 215710688 |
| Heating capacity (H1Nom, 47°F) | 13,500 BTU | AHRI Certified Ref# 215710688 |
| Min heating temp | -13°F | Daikin submittal |
| Min cool (low-ambient) | -4°F (with field setting) | Daikin submittal |
| SEER2 | 20.00 | AHRI Certified Ref# 215710688 |
| HSPF2 (Region IV) | 10.20 | AHRI Certified Ref# 215710688 |
| EER2 (AFull, 95°F) | 12.00 | AHRI Certified Ref# 215710688 |
| Indoor noise (low/high) | 19 / 43 dB | Daikin submittal |
| Refrigerant | R-32 (GWP 675 — under EPA's 700-GWP threshold) | Daikin submittal (manufacturer-sourced) |
| Warranty (registered) | 12 years all parts | Daikin Comfort Pro terms |
| Status | Active | AHRI Certificate |
Heat-transfer angle (why EVI / flash-injection maintains capacity in cold): at outdoor temperatures below ~25°F, refrigerant arriving at the compressor inlet is at very low density, and a stock compressor can't move enough mass to deliver useful heat. Enhanced vapor injection (EVI) / flash injection pulls a side stream of partially-condensed refrigerant back into a mid-stage port on the compressor — increasing the mass flow rate without changing the compressor's physical displacement. That's what lets the Aurora deliver 100% rated heating capacity at 5°F and still operate at -13°F.
#2 Senville (LETO SENL-12CD) — Best Budget
| Spec | Value | Source |
|---|---|---|
| Cooling BTU | 12,000 | Senville LETO spec sheet |
| SEER2 (115V / 230V) | 21.2 / 21.3 | Senville LETO spec sheet |
| EER2 (115V / 230V) | 10.1 / 10.8 | Senville LETO spec sheet |
| HSPF2 (Region IV / V) | 8.7 / 6.7 | Senville LETO spec sheet |
| Min heating temp | -13°F / -25°C (spec); effective ~5°F per marketing | Senville LETO spec sheet |
| Refrigerant | R-454B | Senville LETO spec sheet |
| Warranty (compressor + parts) | 10 years / 10 years | Senville LETO spec sheet |
| AHRI certified | Yes (cert listing on senville.com product page) | senville.com |
| Indoor noise (low) | 28 dB | Senville LETO spec sheet |
| Price | $600–$900 | Distributor listings |
Heat-transfer angle (why a budget unit can still hit 21+ SEER2): modern variable-speed inverter compressors are no longer the cost frontier they were a decade ago. The compressor castings, EEV control boards, and BLDC fan motors that make 21 SEER2 possible are now widely available across the supply chain. The trade-offs at this price tier are build refinement (heavier-gauge copper, tighter refrigerant-charge tolerances, polished controls software) and long-term reliability — not the headline SEER2 number.
#3 Mitsubishi (MSZ-FS12NA) — Highest SEER2, Being Phased Out
The MSZ-FS12NA carries an AHRI Certificate of Product Ratings (Ref# 209832204) with the highest certified SEER2 on this page. It's ranked third because Mitsubishi has stopped producing it and it runs R-410A.
| Spec | Value | Source |
|---|---|---|
| SEER2 | 26.30 ← current-standard figure | AHRI Certified Ref# 209832204 |
| EER2 (AFull, 95°F) | 13.80 | AHRI Certified Ref# 209832204 |
| HSPF2 (Region IV) | 10.40 | AHRI Certified Ref# 209832204 |
| Cooling capacity (AFull) | 12,000 BTU | AHRI Certified Ref# 209832204 |
| Heating capacity (H1Nom, 47°F) | 12,300 BTU | AHRI Certified Ref# 209832204 |
| Min heating temp | -13°F (H2i Hyper-Heat) | Mitsubishi submittal |
| Refrigerant | R-410A (phased out under AIM Act) | Mitsubishi submittal (manufacturer-sourced) |
| Warranty (standard) | 5 yr parts / 7 yr compressor; 12 yr w/ Diamond Contractor install | Mitsubishi warranty terms |
| Status | Production Stopped — still sold from existing distributor inventory, no longer manufactured | AHRI Certificate |
Earlier copy on this site claimed the MSZ-FS achieved 40.1 SEER2 — that value was a fabrication. The AHRI-certified SEER2 is 26.30. No residential mini split reaches 40 SEER2; the market ceiling is roughly 33–35 SEER2.
Heat-transfer angle (why 26.3 SEER2): The MSZ-FS pairs a large indoor-coil heat-exchanger area with very fine low-speed inverter modulation. SEER2 rewards extended part-load operation, and a unit that can sit at 20–30% capacity without cycling spends nearly all its energy moving heat rather than restarting the compressor.
Production Stopped + R-410A caveat: Mitsubishi's current new lineup has moved off this unit. The AIM Act's manufacturing cutoff (Jan 1, 2025) means new R-410A residential AC/HP equipment can no longer be produced or imported in the U.S. R-410A may still be installed from pre-2025 inventory in most states (per the EPA amended final rule, effective July 27, 2026); New York codified the original Jan 1, 2026 install ban. Service R-410A remains available for existing systems but is tightening.
Why no Mitsubishi current-generation pick?
Mitsubishi markets higher-efficiency current-generation models (such as the FX line). We don't yet have the AHRI certificate to publish verified figures for those units, so we don't rank them here until we can cite certified ratings. Distributor listings and marketing pages are not a sufficient source for this site — only AHRI Certificate of Product Ratings PDFs or the manufacturer's published spec sheet meet the bar.
Other Brands — Pending Verification
The following brands carry units with prior site claims that have not been verified against primary sources in this batch. They've been removed from the rankings until each model's AHRI cert is pulled. Marko's research queue is in pending-ahri.md.
| Brand | Status | Note |
|---|---|---|
| Fujitsu (XLTH — 9/12/15RLS3H, KZAH1) | Verified | Up to 33.1 SEER2 / 13.3 HSPF2, −15 °F min heat, R-32 refrigerant. Prior "14.2 HSPF2" claim was incorrect. Source: Fujitsu General manufacturer spec. Warranty: 7yr comp / 5yr parts out-of-box; 10/10 registered; 12/12 via Fujitsu Elite contractor. |
| LG Art Cool Premier 12K (LA120HYV3 / LAU120HYV3) | Verified — legacy | 25.5 SEER2 / 13.8 EER2 / 11.2 HSPF2, R-410A, 100% heat at 5°F / continuous to -13°F. Production Stopped per AIM Act (Jan 1, 2025 manufacturing cutoff). Prior "27.5 SEER2" claim was the 9K variant (27.0), not the 12K. Source: LG installation manual (media.us.lg.com). |
| Carrier (Infinity 38MPRAQ / 40MPHAQ) | PENDING-AHRI | Real Carrier ductless line; AHRI cert not yet pulled. Manufacturer-published efficiency tops the low-20s SEER2 on the Infinity line. (The previously-listed "Carrier 40HQV" was a phantom model and has been removed.) |
| Mitsubishi (MSZ-FH cold-climate variant) | PENDING-AHRI | Referenced across the site; cert pull pending. |
| Bosch (Climate 5000) | PENDING-RESEARCH | Prior 27 SEER2 claim needs verification. |
| MrCool DIY 5th Gen (current) | Verified — mfr-pub | 23.5 SEER2, R-454B refrigerant (low-GWP, A2L), cold-climate certified. The older 4th Gen runs R-410A (legacy; mfr cutoff Jan 1, 2025). For new 2026 installs, evaluate the 5th Gen — don't conflate 4th-Gen R-410A specs with current. Source: MrCool manufacturer pages (mrcool.com). |
| Cooper & Hunter Sophia (CH-12SPH) | Verified — legacy | 21.5 SEER2, R-410A, heating to ~-13°F. The -22°F figure incorrectly attached to Sophia in prior copy actually belongs to the separate C&H Hyper Heat / HPR line (24 SEER2 / R-410A / -22°F, manufacturer-rated, not AHRI-tested). Source: cooperandhunter.us. |
| Pioneer (WYS series) | PENDING-RESEARCH | Prior SEER2 claims need AHRI cert pull. |
Any of these brands can move into the shortlist when their values are confirmed.
Indoor Noise Comparison (Manufacturer-Published Specs)
| Brand | Model | dB (Low) | dB (High) | Sound Equivalent |
|---|---|---|---|---|
| Mitsubishi | MSZ-FH | 19 dB | 44 dB | Whisper / rustling leaves |
| Daikin | Aurora | 19 dB | 43 dB | Whisper / rustling leaves |
| Fujitsu | RLS3H | 19 dB | 44 dB | Whisper / rustling leaves |
| LG | Art Cool Premier | 20 dB | 42 dB | Whisper / rustling leaves |
| MrCool | DIY 4th Gen | 25 dB | 48 dB | Quiet room / light rain |
| Senville | LETO SENL | 28 dB | 50 dB | Quiet room / light rain |
(Decibel values are manufacturer-published; not normalized to identical test conditions across brands.)
Refrigerant Transition (2025–2026 AIM Act)
Critical context for any 2026 purchase decision:
- Manufacturing cutoff: Jan 1, 2025. Manufacturers may no longer produce or import new residential split-system AC or heat pumps using R-410A. Equipment now ships with R-454B (GWP 466) or R-32 (GWP 675) — both A2L, both under the EPA's 700-GWP threshold.
- Installation: R-410A is not banned. Equipment manufactured before Jan 1, 2025 may still be installed (EPA amended final rule, effective July 27, 2026) until existing inventory depletes. Existing systems can be serviced and recharged indefinitely.
- State caveat: Some states are stricter. New York codified the original Jan 1, 2026 install ban. Check your state and local code.
For the three shortlisted units: Daikin Aurora is R-32; Senville LETO is R-454B; Mitsubishi MSZ-FS12NA is R-410A (the phased-out refrigerant — see #3 caveat).
Key Takeaways
- #1 Daikin Aurora 12K (FTXV12AVJU9 / RXT12AVJU9): 20.0 SEER2 / 12.0 EER2 / 10.2 HSPF2, R-32, 12-yr registered warranty. AHRI Certified Ref# 215710688, Active.
- #2 Senville LETO SENL-12CD: 21.2–21.3 SEER2, R-454B, 10/10 warranty per the manufacturer spec sheet.
- #3 Mitsubishi MSZ-FS12NA: 26.3 SEER2 (highest certified on this page), R-410A. AHRI Certified Ref# 209832204, Production Stopped. Ranked third because Mitsubishi has stopped producing it and it runs the phased-out refrigerant.
- Mitsubishi MSZ-FS "40.1 SEER2" was a fabrication. AHRI-certified value is 26.30 SEER2.
- Fujitsu, LG, Bosch, Carrier, MrCool, Cooper & Hunter, Pioneer are not on the shortlist until each model's AHRI cert is pulled.
- Refrigerant matters in 2026 — new installs require R-454B or R-32 (GWP < 700). R-410A pre-2025 inventory may still be installed in most states; New York is stricter.
- The federal Section 25C credit expired for installs after Dec 31, 2025. For 2026 installs, state/utility rebates and IRA HOMES/HEAR are the active federal pathways.