Heat pumps are more efficient than gas furnaces at converting energy into usable heat, but the real savings depend on your climate and electricity rates

A heat pump moves heat from outside air (or ground) into your home using electricity. A gas furnace burns fuel to create heat. Heat pumps deliver more heat per unit of energy consumed — typically 2 to 3 times as much useful warmth per kilowatt-hour of electricity as a gas furnace produces per therm of gas. This is measured as coefficient of performance, or COP. A heat pump with a COP of 3 means you get 3 units of heat for every 1 unit of electrical energy you put in. A gas furnace cannot exceed a COP of about 0.95 because some heat always escapes up the flue.

That efficiency advantage shrinks in very cold climates. Below freezing, most air-source heat pumps lose effectiveness and switch to electric resistance heating, which is less efficient than the heat pump mode. Ground-source heat pumps stay efficient in cold weather but cost $15,000 to $30,000 to install. In regions where winter temperatures rarely drop below 35°F, an air-source heat pump will outperform gas year-round. In regions where temperatures regularly fall below 0°F, a heat pump may need backup heating or a hybrid system that switches to gas when outdoor air is too cold.

Key Takeaways

  • Heat pumps convert energy more efficiently than gas furnaces in most climates, delivering 2 to 3 times as much heat per unit of energy consumed.
  • Your actual savings depend on local electricity rates versus gas rates — in areas where gas is cheap and electricity is expensive, the payback period stretches longer.
  • In climates colder than 0°F regularly, air-source heat pumps lose efficiency and may need a backup heating source or a hybrid system.
  • Heat pump installation costs $4,000 to $8,000 for air-source models, while gas furnaces typically cost $3,000 to $6,000, but heat pumps also cool your home in summer.

How the efficiency numbers actually work

Efficiency is measured differently for each system. Gas furnaces are rated by AFUE (Annual Fuel Utilization Efficiency), which shows what percentage of the fuel burned becomes heat in your home. A modern gas furnace has an AFUE of 90 to 98 percent, meaning 2 to 10 percent of the gas energy escapes as exhaust. Heat pumps are rated by HSPF (Heating Seasonal Performance Factor) for heating and SEER for cooling. HSPF measures how many BTUs of heat you get per watt-hour of electricity over a full heating season, accounting for temperature swings.

A heat pump with an HSPF of 10 delivers 10 BTUs of heat for every watt-hour of electricity used. The same energy in a gas furnace at 95 percent AFUE produces roughly 3.4 BTUs of heat per watt-hour equivalent. This is why heat pumps appear so much more efficient on paper — they move existing heat rather than creating it from combustion. The trade-off is that they work best when the temperature difference between inside and outside is small.

Real-world performance also depends on installation quality. A heat pump installed with poor ductwork, inadequate insulation, or incorrect refrigerant charge will underperform its rating. A gas furnace is more forgiving of installation mistakes because it straightforward burns fuel to reach a set temperature.

When electricity cost matters more than efficiency

A heat pump that is twice as efficient as a gas furnace will not save you money if electricity in your area costs three times as much per unit as gas. You need to compare the cost per BTU, not just the efficiency rating. If your local electricity rate is $0.14 per kilowatt-hour and natural gas is $1.20 per therm, a heat pump delivering 10 BTUs per watt-hour costs about $0.014 per BTU. A gas furnace at 95 percent AFUE delivering 95,000 BTUs per therm costs about $0.013 per BTU. In this scenario, gas is slightly cheaper to operate, even though the heat pump is more efficient.

Rates vary widely by region and change over time. The Northeast and California typically have higher electricity rates and lower gas rates, which favors gas. The Pacific Northwest and parts of the South have lower electricity rates and higher gas rates, which favors heat pumps. Your utility bill shows your exact rates — use those numbers, not regional averages, to calculate your own payback period.

A heat pump also cools your home in summer, while a gas furnace does not. If you currently use a separate air conditioner, replacing both systems with a heat pump may lower your total annual energy cost even if heating alone would not pay back the installation cost.

Performance in cold climates

Air-source heat pumps lose capacity as outdoor temperature drops. At 47°F, a typical air-source heat pump operates at full capacity. At 32°F, it may deliver 70 to 80 percent of rated capacity. At 0°F, it may deliver 40 to 50 percent of rated capacity. Below about -13°F, most air-source heat pumps switch to electric resistance heating, which uses as much electricity as a space heater and costs more to operate than gas.

Newer cold-climate heat pumps are designed to maintain higher capacity at low temperatures — some models deliver 50 to 60 percent capacity at 0°F instead of 40 to 50 percent. These models cost $1,000 to $3,000 more than standard air-source heat pumps. In climates where winter temperatures regularly fall below 0°F, a hybrid system that switches to gas when outdoor temperature drops below a set point (usually 35°F to 40°F) can reduce operating costs compared to a heat pump alone. The gas furnace runs only during the coldest weeks, while the heat pump handles the rest of the season.

Ground-source heat pumps maintain efficiency even at -20°F because the ground stays above freezing year-round. They cost $15,000 to $30,000 to install and require significant excavation, but they deliver consistent efficiency in any climate. They are most practical for new construction or when you are already doing major landscaping work.

Installation cost and payback period

An air-source heat pump costs $4,000 to $8,000 installed, depending on your home size and ductwork condition. A gas furnace costs $3,000 to $6,000. If you are replacing both heating and cooling, a heat pump system costs $8,000 to $15,000, while a furnace plus air conditioner costs $8,000 to $14,000 — roughly the same. If you already have air conditioning, adding a heat pump may cost $2,000 to $4,000 more than replacing the furnace alone.

Payback period depends on your climate, energy rates, and how much you heat. In a mild climate with low electricity rates, a heat pump may pay for itself in 5 to 8 years through lower heating and cooling costs. In a cold climate with high electricity rates and low gas rates, payback may take 12 to 20 years or longer. Some states and utilities offer rebates of $500 to $2,000 for heat pump installation, which shortens payback by 1 to 3 years. Check your local utility's website for current incentives.

Maintenance and durability

Heat pumps have moving parts (compressor, fan, refrigerant lines) that require regular maintenance. Annual service costs $150 to $300. Gas furnaces also need annual maintenance at similar cost. Both systems last 15 to 20 years with proper care. Heat pumps may need refrigerant recharge if a line develops a leak, which costs $300 to $800. Gas furnaces may need a new heat exchanger or blower motor, which costs $400 to $1,200.

Heat pumps are quieter than gas furnaces during operation because they do not have a combustion flame or exhaust fan. They are also safer because they do not produce carbon monoxide. Gas furnaces require annual inspection to may support the heat exchanger is not cracked, which could allow carbon monoxide to enter your home.

Hybrid systems: gas plus heat pump

A hybrid heating system runs a heat pump as the primary heater and switches to gas when outdoor temperature drops below a set threshold, usually 35°F to 40°F. The heat pump handles mild weather, when it is most efficient. The gas furnace handles extreme cold, when the heat pump loses capacity. This approach costs $1,000 to $3,000 more than a heat pump alone but can reduce operating costs in cold climates by 20 to 40 percent compared to a heat pump without backup.

Hybrid systems work best in climates where winter temperatures drop below freezing for weeks at a time but rarely stay below 0°F for extended periods. If your area has only a few days per year below 0°F, a heat pump alone is usually more cost-effective. If your area has months below 0°F, a ground-source heat pump or a furnace-only system may be more practical.

Frequently Asked Questions

Will a heat pump work in my climate?

Air-source heat pumps work in any climate but lose efficiency below freezing. In regions where winter temperatures rarely drop below 35°F, a heat pump will outperform gas year-round. In regions where temperatures regularly fall below 0°F, you may need a hybrid system or backup heating. Check your local average winter low temperature and compare it to your heat pump model's rated capacity at that temperature.

How much can I save by switching from gas to a heat pump?

Savings depend on your local electricity and gas rates, your climate, and how much you heat. In mild climates with low electricity rates, annual savings may be $500 to $1,500. In cold climates with high electricity rates, savings may be $200 to $500 or even negative. Calculate your own payback by comparing your current gas bill to estimated heat pump operating costs using your local utility rates.

Can a heat pump replace my gas furnace and air conditioner?

Yes. A heat pump heats in winter and cools in summer, so it can replace both systems. Installation cost is similar to replacing a furnace and air conditioner separately. You will need ductwork inspection to may support it is adequate for heat pump airflow, which is different from furnace airflow.

Do heat pumps work if the power goes out?

No. Heat pumps require electricity to operate. Gas furnaces also require electricity for the blower and controls, so both systems fail during a power outage. A backup generator can power either system. If backup heating is a priority, a gas furnace with a battery-backed blower is more practical than a heat pump.

What is the difference between air-source and ground-source heat pumps?

Air-source heat pumps pull heat from outdoor air and cost $4,000 to $8,000 installed. They lose efficiency in extreme cold. Ground-source heat pumps pull heat from underground and cost $15,000 to $30,000 installed. They maintain efficiency in any climate because ground temperature stays above freezing. Ground-source is practical only for new construction or major renovation.