Swap your boiler for a money-saving heat pump
Colder weather is quickly approaching, which means it’s time for many folks to start cranking up the heat in their homes and apartments. But for many Americans, heating up their homes is a costly affair–and it’s only getting more expensive. New research from the National Energy Assistance Directors Association (NEADA) estimates that prices for heating a home will increase by about 7.6 percent from last year’s winter heating average.
One often-touted way to slim down your energy usage is switching to a heat pump instead of using an old fashioned furnace or boiler. This swap can be very cost effective, saving about $370 per year. Air-to-air heat pumps can also be cost effective even without subsidies in 59 percent of households, and energy and money saving benefits are amplified when using high-efficiency equipment and insulation. A 2021 paper found that 32 percent of US houses would benefit economically from installing a heat pump and 70 percent of United States homes would see emissions reductions. The average savings for an American home that makes the switch are nothing to scoff at, with even bigger savings when making the swap from fuel oil, propane, or traditional electric heating.
While heat pumps in the US have traditionally been associated with warmer locations, they are starting to become more feasible for colder climes. “You can pretty much buy a heat pump for most climates in the US and it can lower your energy bills,” Allison Mahvi, a professor of mechanical engineering at the University of Wisconsin-Madison, tells Popular Science. Some of Mahvi’s research focuses on how to make more efficient heat pump systems for cold climates.
Here’s how a heat pump works, and why this is a technology to keep an eye on even if your HVAC is in pristine shape.
How heat pumps work
The heat pump itself isn’t a new invention–its roots go all the way back to the 1850’s. You probably already have one in your home–inside your fridge, says Ian Shapiro, a professor at Syracuse University who specializes in heat pump research. A refrigerator works by taking heat out of last night’s chilli and a half-finished basket of berries and moving it into your kitchen, he adds. This then keeps your leftovers at a cool, bacteria-resistent temperature. This process works via a very simple law of nature–heat will always travel from a high temperature to a low temperature, even if both of the temperatures in question are quite low.
In terms of a heat pump that warms up a house, it requires a super cold refrigerant that typically sits about 30 degrees colder than the outside air, Shapiro adds. Even when the outside temperature is a blustery 30 degrees Fahrenheit, heat still moves into a refrigerant that sits at 0 degrees Fahrenheit. When that happens, the refrigerant evaporates and gets compressed at a very high pressure–typically several hundred pounds per square inch.
“And what happens when a gas gets compressed? It gets hot,” he adds.
That hot air then gets dispelled into the house. Heat pumps can also work in reverse, by taking hot air from inside the home and sending it back outside–just like a traditional air conditioner.
What are the types of heat pumps?
These air-to-air heat pumps are the most common type. They work by pulling heat from the air inside or outside the home and then depositing that heat in the opposite direction, depending on the season.
Air-to-water heat pumps still take heat from outside air, but instead of heating the air in a home, it’s fed into a wet central heating system which works kind of like gas central heating.
Ground-source heat pumps or geothermal heat pumps extract heat from underground to heat a home during cold seasons and reverse when it gets warm out. There are even some systems, dubbed hybrid heat pumps, which work the same as traditional heat pumps, but stay connected to a furnace system just in case of extremely cold weather
The benefits of a heat pump
Energy efficiency is the main benefit of a heat pump, since it takes heat and moves it around instead of generating it from scratch the way that a boiler or furnace does. According to the International Energy Agency, the coefficient of performance (the ratio of electricity in to heat energy out) is about four, making current models 3 to 5 times more energy efficient than gas boilers.
The most exciting thing about heat pumps is that there is still significant room for improvement, whereas we’ve pretty much maxed out on how to make combustion heating systems more efficient.
“We’ve done everything we’re going to do with fossil fuel, and that’s not the case with heat pumps,” Shapiro says.
One major development we’ve already seen in the past few decades is the development of a variable speed heat pump. These help amplify the effects of a heat pump in extra-cold weather without having to run it on high speed year round, Shapiro adds. But there’s still a lot to make heat pumps better–closing up leaks in heat exchangers, controlling the speed of compressors, setting up defrosters to only defrost when needed, and even testing out how placing thermostats and other equipment in the home can impact a heat pump’s efficiency.
“We’re looking for all these little savings, and I think they are going to add up,” he adds.
Until recently, there were significant federal tax credits to help ordinary Americans get heat pumps, and other energy efficiency upgrades, in their homes. Due policy changes those benefits are now limited until the end of 2025. Some states, including California, New York, Maine, Georgia, and New Mexico, still have benefits that locals can take advantage of as well. While losing the federal tax credits is not great, Mahvi says that these policy changes are more of a speed bump than a car crash.
Installation costs are also still a high barrier to entry, as it costs an average of $10,750. But the word about this technology is continuing to spread. Americans bought 32 percent more air-source heat pumps than gas furnaces in 2024, according to data from the Air-Conditioning, Heating, and Refrigeration Institute. Mahvi says that the costs continue to drop over time, but the key is to start thinking about how realistic it is to get a heat pump in your home now, even if your HVAC is in perfect shape.
“If your heating system dies in the middle of the winter, you’re not going to spend three weeks getting the right contractors,” Mahvi says. “I would recommend that people spend a little bit of time thinking of what they want to do in the future with their home.
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