Heat Pump vs Furnace: How They Compare in Cold Climates

Your furnace is 18 years old, it’s making a new noise, and an HVAC contractor just suggested replacing it with a heat pump. Your first thought is probably the same one most people in cold states have: “Do those things even work when it’s 5 degrees outside?”

They do, and much better than they used to. But a heat pump isn’t automatically the right answer for every cold-climate home, and a furnace isn’t automatically the safe one. The decision comes down to your winter lows, your fuel prices, your ductwork and how the system is sized.

This guide explains how each system works, where cold-climate heat pumps fit, when a dual-fuel setup makes sense and how to make sure a contractor sizes it correctly.

How a furnace and a heat pump make heat

A furnace creates heat. Gas, propane and oil furnaces burn fuel and blow the warm air through ducts. Electric furnaces use resistance coils, like a giant toaster. A furnace’s efficiency is rated in AFUE (annual fuel utilization efficiency), the share of fuel energy that becomes heat in your home. A modern condensing gas furnace converts most of its fuel to heat; an older furnace loses more up the flue.

A heat pump moves heat instead of making it. In winter it pulls heat from the outdoor air, even cold air, and pumps it inside. In summer it runs in reverse as an air conditioner. ENERGY STAR says an air-source heat pump can deliver up to 3 times more heat energy to a home than the electrical energy it consumes. That’s why heat pumps can heat a home with far less electricity than resistance heat.

Heat pumps come in 2 main forms:

• Ducted heat pumps replace a central air conditioner and connect to your existing ductwork.
• Ductless mini-splits mount indoor heads on walls or ceilings and connect to an outdoor unit. ENERGY STAR notes they don’t need ductwork, which makes them popular for homes with baseboard or boiler heat, additions and finished attics.

Do heat pumps work in cold climates?

Standard heat pumps lose capacity and efficiency as temperatures fall, which is why older systems in cold states earned a bad reputation. Cold-climate models use variable-speed compressors and refrigerant systems designed to keep producing heat at much lower temperatures.

ENERGY STAR has a Cold Climate designation with specific performance tests at 5°F. To earn it, a heat pump must have:

• a coefficient of performance (COP) of at least 1.75 at 5°F, meaning it delivers at least 1.75 units of heat for each unit of electricity, and
• heating capacity at 5°F of at least 70% of its capacity at 47°F, so it doesn’t lose most of its output when it gets cold.

ENERGY STAR also notes these units keep working below 5°F, though a backup heat source can be the more efficient choice at the lowest temperatures. The Northeast Energy Efficiency Partnerships (NEEP) publishes a widely used list of cold-climate heat pumps with performance data at multiple temperatures, which helps you compare models.

Key takeaway: In a cold climate, don’t ask “heat pump or not?” Ask for a cold-climate-rated heat pump, check its capacity at your area’s design temperature and decide whether you need backup heat.

Heat pump vs furnace: side-by-side

Running costs depend heavily on your local electricity and gas rates. If electricity is expensive and gas is cheap, a furnace or dual-fuel system may cost less to run. If you heat with propane, oil or electric resistance, a heat pump often wins. Our explainer on why electricity bills are rising covers the rate trends to factor in.

When a dual-fuel setup makes sense

A dual-fuel system pairs a heat pump with a gas or propane furnace. The heat pump handles heating for most of the season, and the furnace takes over below a set outdoor temperature, called the switchover or balance point. ENERGY STAR describes adding a heat pump to a newer furnace as a way to create a dual-fuel system for a modest extra cost over an AC system.

Dual fuel fits well when:

• Your furnace still has years of life but your air conditioner needs replacing. Replace the AC with a heat pump and keep the furnace as backup.
• Your winters regularly hit extreme lows and you want strong heat no matter what.
• Your fuel prices swing. A smart thermostat or controller can switch based on outdoor temperature or on which fuel is cheaper.
• You’re nervous about going all-electric and want a gradual transition.

An all-electric heat pump with electric resistance backup strips fits homes without gas service, or homeowners who want to eliminate combustion. In that setup, sizing the heat pump to cover as much of the heating load as possible keeps the expensive resistance strips from running often.

How to size a heat pump correctly

Sizing is where cold-climate installs succeed or fail. ENERGY STAR says your contractor should verify the right size using Manual J, a standard calculation from the Air Conditioning Contractors of America that estimates your home’s heating and cooling needs room by room. Rules of thumb like “1 ton per 500 square feet” ignore insulation, windows, air leaks and climate.

What good sizing looks like:

1. A Manual J load calculation using your home’s actual insulation, windows, orientation and air tightness.
2. Your area’s heating design temperature, the cold outdoor temperature used for sizing in your location.
3. Equipment capacity at that temperature, not just the rated capacity at 47°F. Cold-climate data sheets and the NEEP list show output at 17°F and 5°F.
4. A plan for the coldest hours. Decide whether the heat pump covers the full load or a share of it, with a furnace or backup strips covering the rest. DOE’s Building Science Education Center publishes NEEP’s guide on sizing and selecting cold-climate heat pumps, which walks through both approaches.
5. Ductwork checks. Heat pumps often deliver air at lower temperatures than furnaces and may need adequate airflow. Leaky or undersized ducts can undercut performance.

Before sizing, consider cheaper fixes. Air sealing and insulation reduce the heating load, which can mean a smaller, less expensive heat pump.

Costs and incentives in 2026

Installed costs for heat pumps and furnaces vary widely by home, region, equipment and whether you need duct or electrical work. Get at least 3 written quotes that list equipment model numbers, the Manual J result and any electrical upgrades.

One big change: the federal energy efficient home improvement credit (Section 25C), which covered heat pumps and efficient furnaces, ended for property placed in service after December 31, 2025, according to the IRS. Many websites, including some government product pages, still mention the old credit, so don’t count on it. This is not tax advice.

Incentives that may still be available:

• Utility rebates for heat pumps, smart thermostats and weatherization.
• State programs, including some funded through federal home energy rebate allocations, that vary by state and income.
• Special electric rates some utilities offer for homes with heat pumps.

Check your utility’s rebate page and your state energy office before choosing equipment, because many rebates require specific models or approved contractors. Our guide to how technology is changing plumbing, HVAC and electrical businesses explains what good contractors now use for quoting and load calculations.

Where to start: a 6-step plan

1. Note your system’s age and condition. Replacing before failure gives you time to compare options instead of taking whatever is in stock in January.
2. Gather 12 months of utility bills for gas, propane or oil and electricity so you can compare operating costs.
3. Get a home energy audit and fix major air leaks and insulation gaps first.
4. Request quotes for 2 options: a cold-climate heat pump, all-electric or dual-fuel, and a high-efficiency furnace with AC. Ask each contractor for a Manual J calculation.
5. Compare equipment data at low temperatures using manufacturer sheets or the NEEP list.
6. Pair the system with good controls. A compatible smart thermostat helps manage dual-fuel switchover and schedules. See our smart home setup guide if you’re adding connected devices.

If you’re also considering solar or a home battery, plan them together. A heat pump increases electricity use, which changes the math in is solar worth it after the tax credit changes and in sizing home battery backup.

The bottom line

Cold-climate heat pumps now heat homes reliably in places that would have been out of reach 15 years ago, and they add air conditioning in the same box. A furnace still makes sense where gas is cheap and winters are brutal, and dual-fuel systems give you the best of both. Insist on a Manual J calculation, compare low-temperature performance and check local rebates before you sign.

Sources

• ENERGY STAR: Air-source heat pumps — how heat pumps work, ductless options, dual-fuel systems and Manual J sizing
• ENERGY STAR: Air-source heat pump key product criteria — Cold Climate COP and capacity requirements at 5°F
• DOE Building Science Education Center: Guide to sizing and selecting air-source heat pumps in cold climates — NEEP sizing approaches for full or partial heating loads
• IRS: FAQs on sections 25C, 25D and others under Public Law 119-21 — end of the energy efficient home improvement credit after 2025