42,000 Btu/h mini- and multi-splits
Rated products: 43 · model numbers: 108 · certified cooling 39,500–44,999 Btu/h
Of the 12 mini- and multi-split size classes on this site, the 42,000 Btu/h class has the second-highest share with the EPA cold-climate designation and the second-lowest top HSPF2. The MDV M5OG-42HFN1-M keeps the largest share of its 47°F capacity at 5°F. The Toshiba Carrier RAV-BP421AT2P-UL lists the top HSPF2 and the AUX AM5-H42/2DR3B the top SEER2.
What the class is made of
Compressor staging
- variable-speed
- 43
Refrigerant
- R-454B
- 14
- R-32
- 20
- R-410A
- 9
Most listed brands: Mitsubishi Electric (7), Fujitsu (4), LG (4), TCL (3), Della (2), Gree (2), Hitachi (2), and Trane / Mitsubishi Electric (2).
Highest in the class, rating by rating
| Rating | Highest | Value | Next value down |
|---|---|---|---|
| Kept at 5°F | MDV M5OG-42HFN1-M | 102% | Fujitsu AOUH42KUAH1, 102% |
| Output at 5°F | Fujitsu AOUH42KUAH1 (joint, with 4 more) | 48,000 Btu/h | LG KUMXA421A, 44,000 Btu/h |
| COP at 5°F | Mitsubishi Electric PUZ-AK42NL (joint, with 1 more) | 2.70 | Fujitsu AOUH42KUAS1, 2.36 |
| HSPF2 | Toshiba Carrier RAV-BP421AT2P-UL | 11.2 | Mitsubishi Electric MXZ-SM42NAMHZ2 (SEER2 21.5), 11.1 |
| SEER2 | AUX AM5-H42/2DR3B (joint, with 3 more) | 24 | Hitachi RAM-G42N5HAA, 23 |
| EER2 | LG KUMXA421A | 13.8 | LG KUSXA421A, 13.5 |
Most heat kept at 5°F
EPA cold-climate designation only.
| Product | Kept at 5°F | Output at 5°F | COP at 5°F | Model numbers |
|---|---|---|---|---|
| MDV M5OG-42HFN1-M | 102% | 44,000 Btu/h | 2.00 | 1 |
| Fujitsu AOUH42KUAH1 | 102% | 48,000 Btu/h | 2.02 | 1 |
| Mitsubishi Electric MXZ-SM42NLHZ | 100% | 48,000 Btu/h | 2.00 | 3 |
| Daikin 5MXT40AVJU | 95% | 38,000 Btu/h | 1.90 | 2 |
| LG KUMXA421A | 92% | 44,000 Btu/h | 2.00 | 1 |
| Mitsubishi Electric MXZ-SM42NAMHZ2 (SEER2 21.5) | 92% | 44,000 Btu/h | 2.00 | 2 |
| Mitsubishi Electric MXZ-SM42NAMHZ2 (SEER2 19.75) | 92% | 44,000 Btu/h | 1.92 | 2 |
| LG KUSXA421A | 91% | 43,500 Btu/h | 2.20 | 1 |
| Boreal MUL42HPJ132OA | 90% | 37,800 Btu/h | 2.10 | 17 |
| TOSOT GWHD21-42H5D | 90% | 37,800 Btu/h | 2.10 | 4 |
Next to the other mini-split sizes
Share of 47°F capacity kept at 5°F: dot = class median, ring = 90th percentile.
At the low end of the class
- Boreal EMUL42HPJ132OA: the lowest HSPF2, one of the 3 lowest COP at 5°F figures, and one of the 4 lowest SEER2 figures.
- Trane 4TXM2336A15NU: one of the 2 lowest HSPF2 figures, one of the 2 lowest SEER2 figures, and one of the 4 lowest COP at 5°F figures.
Certified as of October 27, 2026.