Air-source heat pump systems deliver 1.5 to 3 times more heating or cooling energy than the electricity they consume. When paired with a gas (or propane) furnace in a dual fuel configuration and installed in a properly sealed, well insulated home, a heat pump system can quickly show energy bill savings while also helping to mitigate winter heating demand. 

WHAT IS AN DUAL FUEL AIR-SOURCE HEAT PUMP?

Dual fuel air-source heat pump (ASHP) systems—sometimes called hybrid or dual fuel heat pumps—use refrigeration technology to both heat and cool your home, just like a standard ASHP, but add a high efficiency gas or propane furnace for backup heat instead of electric resistance strips. 

How it works: The heat pump extracts heat from outdoor air down to about 25–35 °F. Below this “balance point” temperature, an integrated control automatically switches to the gas furnace, delivering dependable heat without large spikes in electric demand. In summer, the heat pump reverses the refrigeration cycle to air-condition your home. 


Components: A compressor, outdoor coil, indoor coil (evaporator), and a matched gas furnace or dual fuel air handler controlled by a dual fuel thermostat. 

For more detailed heat pump information, visit the Department of Energy’s website in the air-source heat pump section.

HOW MUCH DO DUEL FUEL AIR-SOURCE HEAT PUMPS COST?

Installed cost typically falls between $7,000 and $12,000 for a complete dual fuel system (heat pump condenser, compatible indoor coil, and gas furnace), depending on efficiency, capacity, and installation complexity. Five key cost drivers remain the same: 

  1. Unit size: Larger homes or multiple zones require higher capacity systems (more BTUs), increasing equipment and installation cost. 

  1. Equipment: Brand, efficiency ratings (SEER2 / HSPF2), and cold climate features influence price. 

  1. Installation costs: Labor generally ranges from $70 – $150 per hour and goes up with system complexity (gas line modifications, venting, controls). 

  1. Type of equipment: Air-source heat pump cost can vary depending on whether you’re installing a ducted or ductless system. If your home already has a duct system installed, the cost is relatively standard. If your local installer needs to install a complete duct system in your home, the price will substantially increase ($15,000 to $30,000). However, you could install a ductless heat pump system to avoid the added cost of installing ductwork in your home. 

  1. Extras & upgrades: Advanced filtration, smart thermostats, humidifiers, and zoning dampers can add to project cost. 

WHAT SIZE AIR-SOURCE HEAT PUMP DO I NEED?

Your new heat pump should be properly sized to fit your home. Oversized equipment can cause reduced comfort and excessive noise and will shorten the life of the equipment by causing it to cycle on and off more frequently than a properly sized unit. Undersized equipment with airflow that is too low can reduce the efficiency of the air distribution and accelerate wear on system components, leading to early failure. Equipment should be sized by a heating and cooling professional. See more about sizing below.

AIR-SOURCE HEAT PUMP SIZING CALCULATOR

Sizing can be calculated by a heating and cooling contractor, who will complete a load calculation by taking measurements of your home and asking you some questions. The calculation is usually done using software and should be based on professional guidelines.

A good contractor will not size your equipment solely on the square footage of your house or assume that your existing equipment was sized properly in the first place. Proper equipment sizing is based on your home’s heat loss during cold weather and heat gains during warm weather.

Your contractor will specify the recommended system capacity in either Btu/h (British thermal units of heat removed per hour) or refrigeration tons (one ton being equal to 12,000 Btu/h). As a general rule, for every 500 to 600 square feet of space, you should have 12,000 Btu/h in heating and air conditioning capacity.

Listed below are six questions you should consider when determining what size air source heat pump you should purchase for your home:

1. How well is your house insulated?
2. How well are air leaks sealed?
3. How well are your ducts sealed and insulated?
4. What are the size, type, and number of windows and the direction they face?
5. Is there shade from overhangs and landscaping?
6. What is the size, layout, and orientation of your house?

PROS AND CONS OF AIR-SOURCE HEAT PUMPS

PROS

Air-source heat pumps offer various benefits to those looking to add them to their homes. Below, you can find the most noteworthy advantages air-source heat pumps have when compared to other options.

• Energy efficient: Delivers 1.5 – 3 times more heating energy than the electricity it consumes; gas furnace takes over only when outdoor temperatures drop below the balance point. 
• All year service: Heats in winter and cools in summer with a single outdoor unit. 
• Lower winter energy use: Switching to gas backup at colder temps avoids high use of electric strip heat.

CONS

Just as there are benefits to installing an air-source heat pump in your home, there are also disadvantages you must consider before installation.

• Higher upfront cost: Dual fuel systems cost more than heat pump plus strip heat systems due to the furnace and controls. 
• Gas infrastructure required: Home must have a natural gas or propane line, venting, and combustion air. 
• System complexity: Two heat sources mean more components and potential maintenance. 
• Fuel price volatility: Savings depend on the relative cost of electricity vs. gas or propane. 
• Noise: Outdoor compressors can be audible, though newer models are quieter. 

• Home insulation: Your home must be well insulated for ASHPs to save you money on energy costs. 

TERMINOLOGY EXPLAINED

 • Air handler / furnace: Indoor unit that circulates conditioned air; in dual fuel setups this is a gas or propane furnace with an added evaporator coil. 
• Compressor: Pumps refrigerant to meet heating or cooling demand. 
• Heating Seasonal Performance Factor (HSPF2): Measures heat pump efficiency over an entire heating season (higher = better). 
• Seasonal Energy Efficiency Ratio (SEER2): Measures cooling efficiency over the cooling season (higher = better). 
• Balance point: Outdoor temperature at which the system switches from heat pump mode to gas furnace mode. 
• System capacity: Total heat or cooling produced in one hour, expressed in Btu/h or tons (1 ton = 12,000 Btu/h). 

CALCULATING THE SIZE OF EQUIPMENT

Sizing can be calculated by a heating and cooling contractor, who will complete a load calculation by taking measurements of your home and asking you some questions. The calculation is usually done using software and should be based on professional guidelines. A good contractor will not size your equipment solely on the square footage of your house or assume that your existing equipment was sized properly in the first place.

Proper equipment sizing is based on your home’s heat loss during cold weather and heat gains during warm weather. Your contractor will specify the recommended system capacity in either Btu/h (British thermal units of heat removed per hour) or refrigeration tons (one ton being equal to 12,000 Btu/h).

*This temperature will vary based on your heat pump model and desired comfort level in your home.