42,000 BTU heat pumps
3.5 ton heat pumps — every certified unit at this capacity, ranked.
Data current as of July 12, 2026 · 236 certified units · source AHRI + ENERGY STAR
The two numbers that decide a heat pump at this size
What it costs to deliver heat. Across these 236 certified units the computed cost runs $16.81 to $26.15 per MMBtu — the least efficient costs 56% more to run than the most, for the same heat. Over a 40 MMBtu heating season — the moderate-climate default our operating-cost calculator uses, and where you can put your own load in — that is $672 against $1,046, a gap of $374 a year.
Whether it still delivers when it is cold. COP at 5°F runs 1.80 to 2.70 here. A COP of 1.0 is a plain electric heater, so a unit near 1.80 has almost stopped being a heat pump on the coldest night — exactly when the bill is largest. 164 of these (69%) carry the cold-climate designation. This is the number to sort on if your winters bite, and it is not the same ranking as HSPF2.
A 3.5-ton ducted heat pump installs for $10,000 to $18,000, so the premium tier costs about $8,000 more. Against a $374 a year saving that is a 21-year payback — longer than the equipment lasts on energy alone, so justify the upgrade on cold-climate output or comfort rather than on the bill.
$/MMBtu is computed from certified HSPF2 and EIA average electricity prices; the formula is in our methodology. Install ranges are US national typical for a like-for-like ducted swap, compiled 2026-07-16, and exclude ductwork, electrical upgrades and backup heat.
Highest HSPF2 in this group
TOSHIBA CARRIER RAV-BP421AT2P-UL
HSPF2 11.2 · still delivers 33,400 BTU at 5°F · $16.81 per MMBtu to run.
See installed costs →HSPF2 is the seasonal heating efficiency rating — heat delivered per unit of electricity across a whole season. Higher is cheaper to run.
The 20 highest-HSPF2 of 236 certified units · 2 with a verified place to buy
| Brand & model | HSPF2 | Capacity | Heat at 5°F | $/MMBtu | Buy | |
|---|---|---|---|---|---|---|
| TOSHIBA CARRIER RAV-BP421AT2P-UL | 11.2 | 3.5 ton | 33,400 BTU | $16.81 | Get quotes | |
| Mitsubishi Electric MXZ-SM42NLHZ-** | 11.1 | 3.5 ton | 48,000 BTU | $16.96 | Get quotes | |
| Mitsubishi Electric PUMY-HL42NKMU*** | 11.1 | 3.5 ton | 48,000 BTU | $16.96 | Get quotes | |
| MDV MOE30U-48HFN1-M[X] | 11.0 | 3.5 ton | 56,500 BTU | $17.12 | Buy | |
| LG KUMXA421A | 11.0 | 3.5 ton | 44,000 BTU | $17.12 | Get quotes | |
| LG LMU421HHV | 11.0 | 3.5 ton | 44,000 BTU | $17.12 | Get quotes | |
| LG KUSXA421A | 10.8 | 3.5 ton | 43,500 BTU | $17.44 | Get quotes | |
| LG KUSXB421A | 10.8 | 3.5 ton | 40,000 BTU | $17.44 | Get quotes | |
| Hitachi PAS-48BUFASDQ1 | 10.8 | 3.5 ton | 36,600 BTU | $17.44 | Get quotes | |
| LG LUU420HHV | 10.8 | 3.5 ton | 40,000 BTU | $17.52 | Get quotes | |
| Fujitsu AOUH42KUAH1 | 10.6 | 3.5 ton | 48,000 BTU | $17.76 | Get quotes | |
| Mitsubishi Electric MXZ-SM42NAMHZ2 | 10.6 | 3.5 ton | 44,000 BTU | $17.85 | Get quotes | |
| Mitsubishi Electric PUMY-HP42NKMU2 | 10.6 | 3.5 ton | 44,000 BTU | $17.85 | Get quotes | |
| Trane / Mitsubishi Electric NTXMSH42A152B* | 10.6 | 3.5 ton | 44,000 BTU | $17.85 | Get quotes | |
| 1HVAC EZ-48Z-M5B | 10.5 | 3.5 ton | 37,000 BTU | $17.93 | Get quotes | |
| ACIQ ACIQ-42Z-E-HH-M5 | 10.5 | 3.5 ton | 34,000 BTU | $17.93 | Buy | |
| AUX AM5-H42/2DR3B | 10.5 | 3.5 ton | 34,000 BTU | $17.93 | Get quotes | |
| AUX ASUM42HPMULO | 10.5 | 3.5 ton | 34,000 BTU | $17.93 | Get quotes | |
| Armbridge AB-GTMH42-230VO | 10.5 | 3.5 ton | 34,000 BTU | $17.93 | Get quotes | |
| Armbridge AB-GTMR42-230VO | 10.5 | 3.5 ton | 34,000 BTU | $17.93 | Get quotes |
Showing the top 20 by HSPF2. All 236 certified units in this group are filterable in the full database — we rank here rather than dump, because a table nobody can read is not a resource.
Capacity and efficiency are AHRI-certified values; $/MMBtu is computed by us from EIA energy prices — see methodology. Heat at 5°F is the number that decides whether a heat pump keeps up in real cold, and most listings omit it.