Heat pumps are the air fryers of the HVAC world. They’re the chic new approach to heating and cooling your home—but at the same time the technology behind them isn’t actually new. You’ve been hearing about them recently because they have plenty of upside: Dollar-for-dollar, a heat pump is the most efficient way to climate-control a home, and, because they can run on electricity, you can add one to virtually any home in the country. These systems can also wean your house off of fossil fuels. Federal and local rebates also sweeten the deal.
While you can walk into a home center, see a heat pump on display, and swipe your card right then and there, there are a few things to consider—and understand—if you’re interested in switching your HVAC to a heat pump.
Big picture, how does a heat pump differ from the heater I already have?
A heat pump is distinct from a conventional heating system in a couple of really important ways. A forced hot air furnace or water boiler uses energy to produce heat through combustion, then those systems need more energy to power fans and pumps to move warmth around a building. A heat pump gets rid of the heat-making element; instead, it moves temperature (that’s heat) from outside to inside, or vice versa. The only energy it needs to do this is what powers a compressor and fans.
This means you get more heat out for the energy that goes in. “For the same energy input you can move two or three units of heat into the house versus, say, one unit of heat from an electric heater,” says Jon Harrod, an HVAC contractor with Housitive, who specializes in heat pumps. A traditional heating system, in theory, maxes out at a 1:1 ratio: one unit of energy into the home for every unit of energy consumed. A heat pump, on the high end, can hit ratios as high as 4:1, which means four units of energy move into the house for every one unit used. The other important difference is that a heat pump is also an air conditioner. It’s one system for all seasons: In the winter, it brings warmth in; in the summer, it shuttles it out.
How does a heat pump work?
If you’ve spent any time searching for heat pump info you’ve probably seen the quip that they “can find heat outdoors on the coldest day” or the summertime version of the phrase. Essentially what that means is that a heat pump is a giant energy exchanger.
Probably the easiest way to explain how a heat pump works is to explain how a conventional air conditioner works—and what distinguishes them from one another. In a window AC unit, a compressor, coils, and a fan circulate a refrigerant that changes from a cold liquid to a hot gas, which provides cooling as it runs in a loop. The cold, liquid refrigerant moves inside the house and into an evaporator coil where it chills conductive metal tubing. A fan pushes warm indoor air across that cold metal surface, which absorbs the room’s ambient heat and moves it into the refrigerant (heat always moves to cold). With the temperature yanked from the air, the fan returns a cold breeze to the room. Meanwhile, the refrigerant moves outside the home where a compressor pressurizes the liquid into a hot gas. Because the vaporized refrigerant is hotter than the ambient temperature outside, even on the hottest summer day—and, again, because heat moves to cold—the environment pulls heat out of the conductive metal condensing coil, lowering the temperature of the refrigerant, which changes back into a liquid. This is what HVAC pros call “dumping the heat outside.” The now cold, liquid refrigerant travels back inside to the evaporator coil to start the process again.
Now picture that same mechanism, but larger and with a valve that seasonally changes the direction of the loop running between an entire home and the condensing unit outside. The heat pump system warms the house with hot air, through ducts, or hot water via piping.
The refrigerant moving through the system can run from 170 to -58 degrees Fahrenheit. When a heat pump “finds heat” outside on the coldest day, that boils down to the difference between the ambient temperature outside and the temperature of the refrigerant. For example, a -8 degree Fahrenheit Minnesota winter is much warmer than the temperature of the liquid refrigerant in the heat pump. So in Minnesota, come January, a heat pump pulls that 50-degree difference in from the outdoors, and the warmer ambient air has no choice but to transfer its temperature to the very cold refrigerant. Inside, that 50 degrees of temperature is put to work warming the house. That’s the efficiency: moving heat from outside to inside, not making it from scratch.
Flip the process in the summer: It might be 100 degrees Fahrenheit outside while the refrigerant is 150 degrees. You can begin to understand how a heat pump can be hotter than August in Death Valley and still find the temperature it can put to use in the house.
What kind of heat pump is right for your home?
There are four main styles of heat pumps: Water to water, water to air, air to air, and air to water. But for most people, an air-to-air or air-to-water heat pump will be the best fit fit. In both of these scenarios, the system gathers heat from the ambient air temperature, and the other side of the equation is how heat moves about inside the house: through forced hot air (air-to-air) or hot water (air-to-water). They both can retrofit onto existing heating systems.
Whole-home solutions: Air-to-air and air-to-water heat pumps
Air-to-air heat pumps are a good retrofit in most American homes, particularly the 60% that use furnaces to generate hot air that circulates through ductwork.1 In these instances, a heat pump can replace the furnace, and the existing ductwork can stay in place. Air-to-water systems, meanwhile, are best in homes that rely on radiator heating systems, in which hot water flows from a boiler to baseboard radiators or heavy, cast-iron heaters—around 8% of U.S. homes.2 In these cases, a heat pump replaces the fossil fuel–burning boiler and the existing piping stays put.
Small space solution: Ductless heat pumps
Ductless heat pumps, in contrast, are not a whole-home solution. Also referred to as mini split systems, these air-to-air heat pumps are a means to deliver climate control to a new addition, newly converted attic, or another area that’s not on your home’s centralized HVAC. A mini split consists of a wide air handler mounted on the inside of an exterior wall paired with a condenser on the outside. As the name implies, you don’t have to rip open walls and ceilings to run ductwork.
Sales of single-zone ductless mini splits—meaning one unit to condition the air in a room—have grown in the last three years. In 2032 the market is expected to reach 1.5 billion in the U.S., up from about 900 million in 2023, according to Global Market Insights.3 About 87% of those ductless mini splits were installed on the wall as opposed to a more elaborate ceiling mounted option. These appliances have been popular elsewhere in the world for years, and globally account for about 61% percent of the air conditioning market, according to AstuteAnalytica India.4
Are there other things I need to improve in the home first?
Even the most cutting-edge HVAC system won’t live up to its efficiency promises or make you more comfortable if your home (what folks in the biz call the “building envelope”) isn’t sealed up tight. Before you think about upgrading to a heat pump, you’ll want to have an energy efficiency audit done. That report will pinpoint areas where air is leaking from the home and where the building’s shell could benefit from added insulation.
How much does a heat pump cost?
In 2023 the median cost to install a whole-house heat pump and ductless mini-split systems was just over $16,000 after incentives, according to EnergySage. Most of the installation quotes for heat pumps fall between $7,100 and $36,000, and, generally you’ll pay more in colder climates where heat pumps are working all year. The median price for a heat pump in Massachusetts was nearly $16,000, compared to Florida where one might cost less than $9,000.
Are there tax incentives available for heat pumps?
Through 2022’s Inflation Reduction Act’s Energy Efficient Home Improvement Credit, if you install a heat pump between 2023 and 2032 you can qualify for a federal tax credit of 30%, up to a maximum of $2,000. Additionally, the High-Efficiency Electric Home Rebate Act allows states to provide point-of-sale rebates to low- and moderate-income households, which can cover $840 to $8,000 towards upgrades like a heat pump water heater, clothes dryer, or HVAC system. That program, though, is still rolling out.
How much can a heat pump lower energy costs? What’s that mean for emissions?
Rewiring America, a nonprofit that focuses on electrifying homes, found that the average homeowner can save $370 annually on heating costs—though the savings vary based on the HVAC setup they’re replacing. Those who currently heat with delivered fuels, like oil or propane, can save about $840 per year; folks who heat via electricity save around $780; while homeowners who use gas will pocket an extra $60. At these rates, you can expect the initial cost of a heat pump to pay for itself after about 15 years.
According to a report from Carbon Switch, heat pumps could save up to 7.6 tons of carbon emissions annually if you use baseboard heaters, about 5.1 tons if you’re converting over from an electric furnace, and 4 tons if you currently have an oil burning boiler.5 Heating buildings accounts for about 10% of the global emissions, according to the International Energy Agency, and the demand for cooling could triple by 2050. Switching to heat pumps can help reduce global CO2 emissions by half a gigatonne by 2030, the IEA found. But refrigerant leaks, which contribute to greenhouse gas pollution, can eat into the positive impacts.
What should you look for in a heat pump installer?
For starters, you’ll want to work with an HVAC contractor who is licensed and insured (which goes for anyone who works on your house). It’s also a good idea to look for a provider with nationally recognized training through organizations like the North American Trade Excellent (NATE) and the EPA’s 608 certification, which means they’ve been trained to deal with refrigerants that might leak into the atmosphere. A good contractor will also be familiar with the rebate process and consider the big picture of your home’s climate control system. Part of an HVAC meeting with you should also take into account how well sealed and insulated the home is, along with basics like square footage, how many floors, and how many zones.
- Residential Energy Consumption Survey (RECS), U.S. Energy Information Administration ↩︎
- Ibid ↩︎
- U.S. Mini Split Air Conditioning System Market, Global Market Insights, Jun. 2024 ↩︎
- Air Conditioning Market – Industry Dynamics, Market Size, and Opportunity Forecast to 2032, Astute Analytica, Feb. 2024 ↩︎
- How Much Money Do Heat Pumps Save?, Carbon Switch ↩︎