Heat Pump vs. Furnace + AC: Lifetime Cost and Comfort
The right choice isn't about which system is "better" in the abstract — it's a math problem set by your local electricity and gas prices, your climate, and whether you're replacing one machine or two. Here's how to run that math for your own house.
The two systems, and why they're not a clean apples-to-apples swap
A gas furnace plus a central air conditioner is two machines doing two jobs. The furnace burns natural gas (or propane) to make heat; the AC uses electricity to move heat out of the house in summer. They share your ductwork and blower but are otherwise independent — you can replace one without the other.
A heat pump is a single machine that does both jobs with electricity. In summer it works exactly like an AC. In winter it runs that same refrigerant cycle in reverse, pulling heat out of the outdoor air and pumping it inside. There's no combustion — it moves heat rather than making it, which is why a good heat pump can deliver two to three units of heat energy for every unit of electricity it draws. That "better than 100% efficient" behavior is the whole reason heat pumps are interesting.
This is the first thing that trips up cost comparisons: a heat pump replaces both the furnace and the AC, so the honest comparison is one heat pump against a furnace-plus-AC pair — not a heat pump against a furnace alone. If you already need to replace your air conditioner anyway (see our central air conditioner cost guide), the incremental cost of stepping up to a heat pump is much smaller than the sticker suggests.
How to read the efficiency ratings
Three numbers govern this decision, and contractors will quote all of them:
- SEER2 — cooling efficiency. Higher is better; current federal minimums are 13.4–14.3 SEER2 depending on region, and mainstream units run 15–18 SEER2. Both a heat pump and a straight AC use this rating for summer cooling.
- HSPF2 — a heat pump's heating efficiency over a season. Higher is better; 7.5–9.5 HSPF2 is the typical range. Roughly, an HSPF2 of 8.5 means the unit delivers about 8.5 BTU of heat per watt-hour of electricity — a seasonal coefficient of performance around 2.5.
- AFUE — a gas furnace's efficiency. It's a straight percentage: an 80% AFUE furnace turns 80% of the gas it burns into usable heat, a 95–98% "condensing" furnace turns nearly all of it. Below 90% is being phased out in much of the country.
These ratings aren't interchangeable, but they're what you plug into an operating-cost estimate, so it's worth knowing which number belongs to which machine.
Upfront cost: what you'll actually pay installed
For a typical whole-home, ducted replacement in 2026:
- Ducted air-source heat pump: roughly $10,000–$25,000 installed, with most straightforward replacements landing around $12,000–$16,000. The spread reflects capacity, brand, and whether you choose a cold-climate inverter model.
- Gas furnace: about $3,500–$7,500 installed with existing ductwork (95%+ AFUE units sit at the top of that range).
- Central AC to pair with it: another $3,000–$5,500 installed.
Add the furnace and AC together and you're at roughly $6,500–$13,000 for the pair — so a heat pump usually costs a few thousand dollars more upfront than furnace-plus-AC, and occasionally the gap closes to nothing. If your ducts need work, add $2,400–$6,600 to either path. For a full breakdown of what drives these numbers, see our HVAC replacement cost guide, and when quotes come in, our walkthrough on how to read a contractor estimate will help you compare like for like.
Operating cost: the part that's decided by your utility bill, not the equipment
Operating cost is where climate and local energy prices take over. Three drivers matter:
- Electricity price. The U.S. residential average is about 18.3 cents per kWh in 2026, but the real range is enormous — roughly 11 cents in parts of the South and Plains to 30+ cents in New England, California, and Hawaii. A heat pump's running cost scales directly with this number.
- Gas price. Residential natural gas averaged around $19.83 per thousand cubic feet in 2026 — about $1.90 per therm — and it, too, varies widely by region and season. Where gas is cheap and plentiful, a furnace is hard to beat on pure fuel cost.
- Climate and efficiency. The colder your winter, the more heating hours you rack up, and the more a heat pump's efficiency at low temperatures matters (more on that below).
The counterintuitive takeaway: at national-average prices, a modern gas furnace and a heat pump often cost about the same to run for heating. Electricity's premium per BTU is roughly offset by the heat pump's 2.5x efficiency. The winner is decided at the margins — your specific rates and your specific climate.
Cold-climate performance, backup heat, and dual-fuel
The old knock on heat pumps — "they don't work when it's really cold" — is outdated but not entirely wrong. As outdoor temperatures fall, a heat pump's capacity and efficiency drop, because there's less heat in the air to harvest. Older units faded badly below freezing and leaned on electric-resistance backup strips, which run at a COP of 1.0 and can spike your bill.
Modern cold-climate heat pumps are a different animal. Under the DOE Cold Climate Heat Pump Challenge and ENERGY STAR's cold-climate spec (v6.2, effective January 2025), qualifying ducted units must hold a COP of at least 1.75 at 5°F and retain about 70% of their rated heating capacity at 5°F versus 47°F. Several challenge models maintain full capacity down to 5°F and keep running below zero. In a cold climate, insist on a cold-climate-rated inverter model — it's the difference between a heat pump that carries the winter and one that hands the job to resistance strips.
Two hedges make cold climates workable:
- Electric backup: resistance strips in the air handler cover the coldest hours. Simple and cheap to install, but expensive to run if they engage often.
- Dual-fuel (hybrid): a heat pump paired with a gas furnace. The heat pump handles mild and moderate weather at high efficiency; the furnace takes over below a set "switchover" temperature where gas becomes cheaper than electricity. This is often the smartest setup in cold regions with reasonable gas prices — you get the heat pump's efficiency most of the year and the furnace's brute force on the worst nights.
Where each system wins
Lean heat pump when: you're in a mild-to-moderate climate (much of the South, Mid-Atlantic, Pacific Northwest, and coastal areas); your electricity is at or below the national average; natural gas isn't available at your address (a heat pump crushes propane and electric-resistance furnaces on operating cost); you're replacing a dying AC anyway; or you want one system, one outdoor unit, and no combustion or gas line in the house.
Lean gas furnace + AC when: you're in a genuinely cold climate (Upper Midwest, Northern Plains, interior Northeast) with a long, deep heating season; natural gas is cheap in your area while electricity is expensive; or you value the higher, faster supply-air temperature a furnace produces on the coldest days. In these conditions the furnace's low fuel cost over many heating hours can outrun the heat pump's efficiency — and a dual-fuel system is often the best of both.
A 15-year total-cost example
Let's put numbers to it. Consider a 2,000-square-foot home in a mixed climate (think St. Louis or Kansas City), with an annual heating load of about 50 million BTU delivered and a cooling load of roughly 2,500 kWh, priced at 2026 national averages (electricity $0.183/kWh, gas $1.90/therm). We compare a ducted heat pump (SEER2 16 / HSPF2 8.5) against a 95% AFUE gas furnace paired with a SEER2 15 AC.
| Line item (15-year horizon) | Heat pump (SEER2 16 / HSPF2 8.5) | Gas furnace (95% AFUE) + AC (SEER2 15) |
|---|---|---|
| Upfront installed cost | $14,000 | $11,500 (furnace $6,000 + AC $5,500) |
| Annual heating energy | ~$1,075 (≈5,880 kWh) | ~$1,005 (≈526 therms) |
| Annual cooling energy | ~$455 (≈2,500 kWh) | ~$455 (≈2,500 kWh) |
| Annual maintenance | ~$150 (one system) | ~$200 (two systems) |
| 15-year energy total | ~$22,950 | ~$21,900 |
| 15-year maintenance total | ~$2,250 | ~$3,000 |
| 15-year total cost of ownership | ~$39,200 | ~$36,400 |
In this mixed-climate, average-price base case, the gas furnace + AC comes out about $2,800 cheaper over 15 years — roughly $187 a year. That's a real but modest gap, and it's small enough that it flips easily:
- Cheaper electricity ($0.13/kWh): the heat pump's heating cost falls to about $765/year, saving roughly $240/year versus gas — the heat pump now wins the lifetime comparison outright.
- No gas at the address: the alternative to a heat pump is an electric-resistance or propane furnace, both far more expensive to run. The heat pump dominates by thousands of dollars.
- Milder climate: fewer heating hours shrink the fuel-cost gap and favor the single-system heat pump.
- Colder climate / more heating hours: gas pulls further ahead, especially if resistance backup engages — which is where dual-fuel earns its keep.
The lesson isn't a universal winner. It's that this is a close race at average prices, and your local electricity-to-gas price ratio and climate decide it. Run your own numbers with our HVAC cost calculator using your actual utility rates.
Comfort, noise, and dehumidification
Cost isn't the only axis. A gas furnace delivers hot supply air — typically 120–140°F — so it warms a room fast and feels toasty at the vents. A heat pump delivers cooler supply air, often 90–105°F, which is above body temperature but can feel like a "cool draft" to people used to a furnace. Inverter-driven heat pumps mitigate this by running longer at lower speeds, which actually improves comfort: steadier temperatures, fewer swings, and quieter operation than a furnace that cycles hard on and off.
On dehumidification, the long, low-and-slow cooling cycles of a variable-speed heat pump generally pull more moisture out of the air than a single-stage AC's short bursts — a real comfort advantage in humid summers. Noise favors modern inverter heat pumps too; many outdoor units run in the mid-50s dBA range, quieter than older single-stage condensers. The trade-off homeowners most often notice is that winter supply air feels less hot — a matter of expectation more than actual comfort, but worth knowing before you switch.
One 2026 caveat on incentives
Be careful with any advice that assumes a federal tax credit. The 25C Energy Efficient Home Improvement Credit — which offered up to $2,000 toward a qualifying heat pump — expired on December 31, 2025 under the 2025 budget law (the "One Big Beautiful Bill"). Installations completed in 2026 and later do not qualify for that federal credit. What may still help: state energy-office rebates, local utility rebates and rebated financing, and electrification programs that vary widely by ZIP code. Check your utility and state energy office directly before assuming any dollar figure, and don't let a contractor quote you a "credit" that no longer exists.
Frequently asked questions
Do heat pumps really work in freezing weather?
Yes — modern cold-climate models are rated to keep heating below 0°F and hold roughly 70% of capacity at 5°F. The caveat is that capacity and efficiency drop as it gets colder, so in a cold climate you should specify a cold-climate-rated inverter unit and plan for backup heat (resistance strips or a dual-fuel furnace) for the coldest snaps.
Is a heat pump cheaper to run than a gas furnace?
It depends on your local prices. At national-average rates the two are close for heating, with gas often slightly cheaper per BTU. Where electricity is below average or gas is unavailable, the heat pump wins. Where gas is cheap and winters are long, the furnace wins. Your electricity-to-gas price ratio is the deciding factor.
What's a dual-fuel system, and should I get one?
Dual-fuel (hybrid) pairs a heat pump with a gas furnace. The heat pump handles most of the season efficiently; the furnace takes over below a set switchover temperature. It's often the smartest choice in cold climates with reasonable gas prices, because you get the heat pump's efficiency most of the year and the furnace's power on the worst nights — at the cost of a higher upfront price for two heating sources.
If I only need to replace my AC, should I switch to a heat pump?
It's the best moment to consider it. Because a heat pump also cools, you're only paying the incremental cost above a new AC to add efficient heating — often a much smaller premium than a from-scratch comparison suggests, and it can let you retire or downgrade your reliance on the furnace.
Sources
- U.S. Energy Information Administration — Electricity data and average residential prices: https://www.eia.gov/electricity/
- U.S. Energy Information Administration — Price of natural gas delivered to residential consumers: https://www.eia.gov/dnav/ng/hist/n3010us3a.htm
- ENERGY STAR / U.S. Department of Energy — Cold Climate Heat Pump Challenge and specifications: https://www.energystar.gov/products/heating_cooling/heat_pumps_air_source
- Rewiring America — 25C Energy Efficient Home Improvement Credit status (expired Dec. 31, 2025): https://homes.rewiringamerica.org/federal-incentives/25c-heat-pump-tax-credits
- HomeGuide — Heat pump vs. furnace installed cost data (2026): https://homeguide.com/costs/heat-pump-vs-furnace-cost