Heating · Buying guide
Heat Pump Buying Guide for Heating: Cold-Climate Models, HSPF2, Ducted vs Ductless and Real Costs
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A modern cold-climate heat pump can heat a house through a Minnesota winter; the wrong one leaves you running backup heat every cold night. Here are the standout models, then how to match capacity to your climate zone, ducts and fuel prices.
Buy right once: A heat pump that isn't rated for your coldest nights leaves you running backup heat all winter. Choose by its capacity at your local design temperature, and size for any addition, finished basement or attic conversion you're planning.
Before you buy, check:
- Rated heating capacity at 5°F (or lower) for your climate
- Planned additions or newly finished space that will need heat
- Whether your ducts are usable or you need ductless heads
Top picks
1. Best ductless for cold climates
Mitsubishi MSZ-FS12NA / MUZ-FS12NAH (H2i plus)
Ductless mini-split, cold-climate
- Capacity: 12,000 BTU cooling / 12,300 BTU heating
- Efficiency: 26.3 SEER2 / 11.1 HSPF2
- Power: 208/230V
- Install: Contractor-installed
- Cold-weather heating: 12,300 BTU at -5°F; 11,000 BTU at -13°F
Typical price: Contractor-quoted (equipment plus installation)
See Mitsubishi wall units2. Highest efficiency on paper; heats to -22°F
Fujitsu AIRSTAGE XLTH+ 12K (ASUH12KTAS / AOUH12KTAP1)
Ductless mini-split, cold-climate
- Capacity: 12,000 BTU cooling / 15,300 BTU heating
- Efficiency: 31.5 SEER2 / 13.7 HSPF2
- Power: 208/230V, R-32
- Install: Contractor-installed
- Cold-weather heating: Operates down to -22°F
Typical price: Contractor-quoted (equipment plus installation)
See XLTH+ at Fujitsu3. Best ducted whole-house option
Carrier Infinity 21 Cold Climate (27VNA1)
Ducted central heat pump
- Capacity: Whole-house, sized by your contractor
- Efficiency: Up to 21.2 SEER2 / 12.5 HSPF2
- Power: 208/230V
- Install: Dealer-installed
- Cold-weather heating: Operates down to -23°F; 30–100% variable speed
Typical price: Dealer-quoted (HomeGuide: $10,000–$25,000+ installed for air-source systems)
See 27VNA1 at Carrier4. Best DIY option for mild winters
MrCool DIY 4th Gen E-Star 12K (115V)
Ductless mini-split, DIY
- Capacity: 12,000 BTU (up to ~500 sq ft)
- Efficiency: 22.5 SEER2 / 9.0 HSPF2
- Power: 115V
- Install: Pre-charged 25 ft quick-connect line set
- Cold-weather heating: Not a cold-climate model
Typical price: About $1,100–$1,750
MrCool is replacing 4th Gen with 5th Gen (R-454B) models; check which one is shipping.
See MrCool DIY systemsSpecs from each maker's product page; prices are typical ranges seen in October 2026 and change often.
Comparison table
| Model | Type | Capacity | Efficiency | Power | Install | Cold-weather heating | Typical price |
|---|---|---|---|---|---|---|---|
| Mitsubishi MSZ-FS12NA / MUZ-FS12NAH (H2i plus) | Ductless mini-split, cold-climate | 12,000 BTU cooling / 12,300 BTU heating | 26.3 SEER2 / 11.1 HSPF2 | 208/230V | Contractor-installed | 12,300 BTU at -5°F; 11,000 BTU at -13°F | Contractor-quoted (equipment plus installation) |
| Fujitsu AIRSTAGE XLTH+ 12K (ASUH12KTAS / AOUH12KTAP1) | Ductless mini-split, cold-climate | 12,000 BTU cooling / 15,300 BTU heating | 31.5 SEER2 / 13.7 HSPF2 | 208/230V, R-32 | Contractor-installed | Operates down to -22°F | Contractor-quoted (equipment plus installation) |
| Carrier Infinity 21 Cold Climate (27VNA1) | Ducted central heat pump | Whole-house, sized by your contractor | Up to 21.2 SEER2 / 12.5 HSPF2 | 208/230V | Dealer-installed | Operates down to -23°F; 30–100% variable speed | Dealer-quoted (HomeGuide: $10,000–$25,000+ installed for air-source systems) |
| MrCool DIY 4th Gen E-Star 12K (115V) | Ductless mini-split, DIY | 12,000 BTU (up to ~500 sq ft) | 22.5 SEER2 / 9.0 HSPF2 | 115V | Pre-charged 25 ft quick-connect line set | Not a cold-climate model | About $1,100–$1,750 |
- Which type for your winters
- Find your climate zone
- HSPF2, SEER2 and the cold-climate label
- Cold-climate vs standard heat pumps
- Ducted vs ductless mini-split
- Sizing for heating
- Backup heat and dual fuel
- Running costs vs a furnace (estimates)
- More cold-climate lines
- Buying and installation
- Sources
- FAQ
Which type for your winters
| Where you live (2021 IECC zone) | What to look for | Backup heat |
|---|---|---|
| Zones 1–3 (Hot-Humid, Hot-Dry, warm Mixed) | Any efficient variable-speed heat pump; cooling usually sets the size | Usually small or none |
| Zone 4 (Mixed-Humid, Mixed-Dry, Marine) | Variable-speed model; check capacity at 17°F and 5°F against your heating load | Small electric strip or existing furnace |
| Zones 5–6 (Cold) | ENERGY STAR cold-climate or NEEP-listed model sized to your heating load | Plan for it; size depends on design temperature |
| Zones 7–8 (Very Cold, Subarctic) | Cold-climate model rated to well below 0°F | Yes: electric, or a furnace or boiler in a dual-fuel setup |
This mapping is a rule of thumb, not an official standard. Use it to decide which models to shortlist, then get a room-by-room load calculation from an installer.
Find your climate zone
Look up your county: pick your state and county to see its 2021 IECC climate zone and DOE Building America region[11], with what that usually means for heat pump heating (our guidance).
Climate zones are broad. Within one zone, a mountain town is much colder than a valley city, so your installer should use your local heating design temperature (the outdoor temperature your home is only colder than about 1% of the hours each year). NEEP's cold-climate sizing tool, for example, uses the location's 99% heating design temperature from ASHRAE data[6]. Need cooling sizing too? Our mini-split BTU calculator uses the same county lookup.
HSPF2, SEER2 and the cold-climate label
- HSPF2 (Heating Seasonal Performance Factor) is heating efficiency over a season, in BTUs of heat per watt-hour of electricity. Higher is better. The national minimum for split-system heat pumps made since January 1, 2023 is 7.5 HSPF2[1].
- SEER2 is the cooling equivalent. The national minimum for split heat pumps is 14.3 SEER2[1].
- ENERGY STAR cold climate is the label that matters most for heating in the north. Under Version 6.1, a cold-climate heat pump must have a COP of at least 1.75 at 5°F, keep at least 70% of its rated 47°F heating capacity at 5°F, and meet HSPF2 of 8.5 (ductless) or 8.1 (ducted) and SEER2 of 15.2[2].
- NEEP's cold-climate list publishes each model's tested capacity and COP at 5°F, and some at -5°F or lower. It's the best place to compare how two models really behave in the cold[6].
A useful conversion: divide HSPF2 by 3.412 to get an approximate average COP (heat out per unit of electricity in). An 8.5 HSPF2 model averages about COP 2.5 and a 10 HSPF2 model about 2.9. HSPF2 is calculated for a moderate climate, so in colder climates the real seasonal average is usually lower. That's why capacity and COP at 5°F matter more than HSPF2 if you live in zones 5–8.
Cold-climate vs standard heat pumps
Every air-source heat pump loses heating capacity as it gets colder outside, just as the house needs more heat. A standard single-stage heat pump might deliver well under its rated output on a 5°F night, which is when backup heat kicks in. Cold-climate models use variable-speed (inverter) compressors and refrigeration cycles designed to hold their output in the cold. Several now publish full rated capacity at 5°F or below:
- Mitsubishi says its deluxe wall-mounted H2i plus system (MSZ/MUZ-FS) delivers 100% capacity down to -5°F[7].
- Daikin says its Aurora multi-zone line provides up to 100% of rated heating capacity at 5°F and operates down to -13°F[8].
- Fujitsu's XLTH series is engineered to operate down to -15°F[8].
Two cautions. First, "operates to -15°F" isn't the same as "full capacity at -15°F". Look for the capacity at your design temperature, not just the lowest operating temperature. Second, capacity at a given temperature varies by size within a model line, so compare the exact outdoor unit on NEEP's list[6].
Cold-climate installation details matter too. NEEP's installation guide calls for mounting the outdoor unit on a stand above the expected snow line, including drifts, away from roof drip lines, with room for defrost meltwater to drain without refreezing on paths[9]. Some models include a base-pan heater for this reason; Fujitsu lists one on XLTH units[8].
Ducted vs ductless mini-split
| Ducted (central) heat pump | Ductless mini-split | |
|---|---|---|
| Best for | Homes with sound, well-sized ducts | Homes without ducts, additions, problem rooms, zoning |
| Comfort | Whole-house, one or a few zones | Room-by-room control; open plans heat well, closed rooms may need their own head |
| Efficiency | Duct losses in attics or crawlspaces reduce real performance | No duct losses; often the highest HSPF2 |
| Installed cost (HomeGuide) | Air-source $10,000–$25,000+[10] | $2,000–$17,000+, mainly by number of zones[10] |
Mixed systems are common: a ducted unit for the main floor and a ductless head for a cold bonus room, or ducted mini-split air handlers that serve a few rooms each. If your existing ducts run through an unconditioned attic, have them tested and sealed before you size a new ducted system. Leaky ducts can cost more than the efficiency difference between two heat pumps.
Sizing for heating
In cooling climates, oversizing makes a home clammy. In heating climates, undersizing leaves you on backup heat. The professional sequence is the same either way: an ACCA Manual J heating and cooling load calculation, then equipment selection. DOE's Building America guidance recommends sizing a cold-climate heat pump that's meant to cover nearly all heating to the home's design heating load at the design temperature, using the heat pump's capacity at that temperature. With backup heat available, you can target a lower fraction and a higher balance point[5].
What that means in practice:
- Get a real load number. Ask for the Manual J heating load in BTU/h at your design temperature. Rules like "one ton per 500 square feet" ignore insulation, windows and air leakage.
- Compare capacity at the design temperature. If your load is 30,000 BTU/h at 0°F, the heat pump needs about that capacity at 0°F, not at the 47°F rating.
- Check the minimum output too. Variable-speed units run most efficiently when they can turn down low in mild weather. A heat pump far larger than the cooling load may short-cycle in spring and fall.
- Fix the house first if you can. Air sealing and attic insulation can shrink the heating load enough to drop a size, which saves money upfront and every year.
Backup heat and dual fuel
Below the balance point, the outdoor temperature where the home's heat loss is greater than the heat pump's capacity, something else has to make up the difference[4]. The options:
- Electric resistance strips in the air handler. Cheap to install, but each unit of electricity gives only one unit of heat (COP 1), so they're expensive to run. DOE guidance says auxiliary resistance heat should be minimized and locked out whenever the compressor can carry the load, except for defrost or emergencies[3]. Ask your installer to set an outdoor lockout temperature.
- Dual fuel: a heat pump paired with a gas or propane furnace that takes over below a set outdoor temperature. The switchover can be based on capacity (when the heat pump can't keep up) or on cost (when fuel is cheaper per unit of heat at that temperature)[4]. This is a common way to keep an existing, newer furnace.
- Existing boiler or wood or pellet stove as backup for ductless systems. A boiler keeps the pipes and baseboard in service for the coldest days.
- Room heaters for a single cold room. These are fine as a stopgap but not as a plan.
In an outage, a heat pump needs electricity like any furnace blower does. See the generator size calculator if you want backup power for heating.
Running costs vs a furnace (estimates)
The fair comparison is the cost of one million BTUs of heat actually delivered to the house. Using EIA's 2026 U.S. average residential prices (about 18.2¢ per kWh and $16.09 per thousand cubic feet of natural gas) and the 2025–26 winter average for propane ($2.55 per gallon)[12], here's what that works out to. These are our estimates from national averages, and local prices vary widely.
| System (assumed efficiency) | Cost per million BTU delivered (estimate) | Example: 50 million BTU per winter (estimate) |
|---|---|---|
| Natural gas furnace, 95% AFUE | About $16 | About $820 |
| Natural gas furnace, 80% AFUE | About $19 | About $970 |
| Heat pump, seasonal COP 3.0 | About $18 | About $890 |
| Heat pump, seasonal COP 2.5 | About $21 | About $1,070 |
| Heat pump, seasonal COP 2.0 | About $27 | About $1,330 |
| Propane furnace, 95% AFUE | About $29 | About $1,470 |
| Electric resistance (baseboard, strips) | About $53 | About $2,670 |
How it's calculated: one million BTU equals about 293 kWh, about 9.6 hundred cubic feet of natural gas, or about 10.9 gallons of propane. Divide by each system's efficiency and multiply by price. The 50 million BTU example is roughly a moderate-size home in a cold climate, chosen only to show scale.
What the numbers show:
- Against propane, oil or electric resistance, a heat pump usually wins clearly. That's where heat pumps tend to pay off fastest.
- Against cheap natural gas, it's close. At average prices, a high-efficiency gas furnace and a good heat pump cost about the same to run. Where electricity is expensive and gas is cheap, gas can be cheaper; where electricity is cheap, the heat pump wins. A heat pump also replaces your air conditioner, which changes the upfront math.
- To redo this with your own bills, take your price per kWh × 293 ÷ COP for the heat pump, and your price per therm × 10 ÷ AFUE for gas. Many utilities also offer heat pump rates or rebates.
More cold-climate lines
| Brand / line | Type | What the maker publishes |
|---|---|---|
| Mitsubishi Electric Hyper-Heat (H2i plus) | Ductless and ducted | Deluxe wall-mounted MSZ/MUZ-FS: 100% capacity down to -5°F[7] |
| Fujitsu AIRSTAGE XLTH | Ductless (wall, floor, multi-zone) | Line operates down to -15°F (the 12K XLTH+ model is rated to -22°F); metal fan guard and base heater on outdoor units[8] |
| Daikin Aurora | Ductless, multi-zone | Up to 100% rated heating capacity at 5°F; operation to -13°F (multi-zone MXT)[8] |
| MrCool DIY (4th gen) | Ductless, DIY install | Pre-charged quick-connect line set designed for homeowner installation; heating down to -13°F[14] |
| Gree Sapphire (R-32) | Ductless | Up to 30.0 SEER2 and 11.2 HSPF2; heating range -22°F to 86°F[14] |
| Carrier Infinity 21 cold climate (27VNA1) | Ducted | Heating operation down to -23°F; up to 21.2 SEER2 and 12.5 HSPF2; variable speed 30–100%[14] |
Each of these lines covers several sizes and indoor units with different ratings, so check the NEEP list or AHRI certificate for the exact matched system you're quoted[6].
Buying and installation
- Installer-sold vs online. Mitsubishi, Daikin, Fujitsu and Carrier systems are mostly sold and installed through contractors. Online HVAC retailers also sell equipment directly, including DIY lines like MrCool. Buying online can save money, but check whether a local contractor will install customer-supplied equipment, and whether the warranty requires licensed installation and registration. Many brands shorten or void the warranty otherwise.
- DIY mini-splits. Pre-charged quick-connect systems avoid refrigerant handling, but the 240V circuit and disconnect still need to meet code. Many areas require a permit and an electrician for that part.
- Get three quotes with load calculations. Ask each installer for the Manual J heating load, the model's capacity at your design temperature, the backup plan and the lockout settings. If a quote doesn't include them, ask why.
- Permits. Heat pump installs usually need mechanical and electrical permits. DOE publishes a permitting and inspection checklist for heat pump heating[3].
- Controls. Use the thermostat the maker recommends. Third-party thermostats on variable-speed systems can disable modulation or bring on backup heat too early.
FAQ
Do heat pumps work in very cold climates?
Cold-climate models do. Several now publish full rated heating capacity at 5°F or lower and keep running to -13°F to -23°F. ENERGY STAR's cold-climate label requires a COP of at least 1.75 and at least 70% of rated capacity at 5°F. Most homes in very cold climates still keep some backup heat for the coldest nights.
What HSPF2 rating should I look for?
The national minimum for split heat pumps is 7.5 HSPF2. ENERGY STAR's cold-climate criteria require 8.5 for ductless and 8.1 for ducted systems. In cold climates, compare capacity and COP at 5°F as well, because HSPF2 is calculated for a moderate climate.
Is a heat pump cheaper to run than a gas furnace?
It depends on local prices. At 2026 U.S. average prices, the estimates above put a good heat pump and a 95% gas furnace at about the same cost per unit of heat, while a heat pump is much cheaper than propane, oil or electric resistance heat. Use your own electricity and gas rates to check.
Should I get a ducted heat pump or a ductless mini-split?
If you have sound, properly sized ducts, a ducted heat pump is usually simplest. Without ducts, or for additions and problem rooms, ductless mini-splits avoid duct losses and allow room-by-room control. Many homes combine both.
Do I still need backup heat with a cold-climate heat pump?
Often, yes, in zones 6–8, though it may rarely run. Options are electric strips with an outdoor lockout, a gas or propane furnace in a dual-fuel setup, or an existing boiler or stove. Size it with your installer based on your design temperature.
Is there still a federal tax credit for heat pumps?
No. According to the IRS, the Section 25C credit isn't allowed for property placed in service after December 31, 2025. State and utility rebates may still be available.
Sources
- U.S. DOE, 2023 central air conditioner and heat pump standards FAQ (14.3 SEER2 / 7.5 HSPF2 for split heat pumps): energy.gov (PDF)
- ENERGY STAR, Version 6.1 Central Air Conditioner and Heat Pump final specification and key product criteria (cold climate): energystar.gov (PDF) · key criteria
- U.S. DOE Building Energy Codes, Heat Pump Space Heating Permitting & Inspection Checklist; DOE FEMP, Purchasing energy-efficient residential air-source heat pumps: bsesc.energy.gov (PDF) · energy.gov
- CEE / DOE, Controls for a heat pump with secondary heating (for contractors): bsesc.energy.gov (PDF)
- DOE Building America Solution Center, Cold climate heat pump sizing and selection: basc.pnnl.gov
- NEEP, Cold Climate Air Source Heat Pump specification and product list, and product-list user guide: neep.org · user guide (PDF)
- Mitsubishi Electric Trane HVAC US, "Introducing the Deluxe Wall-mounted H2i plus System!" (May 2024): mitsubishicomfort.com
- Fujitsu AIRSTAGE, XLTH Low Temp Heating; Daikin, Aurora MXT multi-zone catalog: airstagehvac.com · daikincomfort.com (PDF)
- NEEP, Guide to installing air-source heat pumps in cold climates: neep.org (PDF)
- HomeGuide, "How Much Does a Heat Pump Cost? (2026)": homeguide.com
- Pacific Northwest National Laboratory for DOE, Guide to Determining Climate Zone by County: Building America and IECC 2021 Updates (PNNL-33270): doi.org/10.2172/1893981 · county lookup
- U.S. EIA, Short-Term Energy Outlook (2026 residential electricity and natural gas prices); Heating Oil and Propane Update (2025–26 residential propane): eia.gov · eia.gov
- IRS, FAQs on modification of sections 25C, 25D and others under Public Law 119-21: irs.gov
- Manufacturer pages: MrCool DIY 18k 4th Gen E-Star; Gree Sapphire R32; Carrier Infinity 21 Cold Climate Heat Pump (27VNA1): mrcool.com · greecomfort.com · carrier.com
- Mitsubishi Electric, MSZ-FS12NA / MUZ-FS12NAH submittal; Mitsubishi H2i plus announcement (May 2024): mitsubishicomfort.com
- Fujitsu General, AIRSTAGE Orion XLTH+ wall-mounted page and 12KTAP1 submittal: fujitsugeneral.com
- Carrier, Infinity 21 Cold Climate Heat Pump (27VNA1) product page: carrier.com
- MrCool, DIY 12k 4th Gen E-Star (115V) support page and DIY E Star brochure: mrcool.com