5 Stats That Show Heat Pumps Work In Cold Climates

Modern heat pumps absolutely work well in cold temperatures. In fact, most ducted heat pumps on the market today that replace central heating and air conditioning units work great down to sub-zero temperatures that are colder than it ever gets in the vast majority of cities in the United States, even major cities in Alaska, Minnesota, and Maine. 

The myth that heat pumps don’t work well at cold temperatures is outdated and, frankly, wrong. 

To convince you of this, we’ve collected the four most important stats that show you heat pumps can be a great heat source in cold climates.

-55.3 F: The Boiling Point of Heat Pump Refrigerants

The easiest way to understand why heat pumps work well in cold climates is to understand how heat pumps work. They work almost identically to air conditioners: a fluid, called a “refrigerant” is cycled through pipes inside and outside your home and it picks up heat from one side and dumps it off on the other. 

The only difference between a heat pump and an air conditioner is that heat pumps work in both directions: they can grab heat out from your room and dump it outside (cooling mode, just like an A/C) or grab heat from outside and dump it into your room (heating mode, like a reverse A/C). 

This mechanism is why people falsely think heat pumps don’t work well in cold temperatures. If it’s really cold outside, how can the refrigerant grab heat from the cold outside air and bring it into your home? 

Because heat pump refrigerants can get extremely cold – way colder than the outside air in almost any place where people live. And because heat always moves from warm to cold, as long as the refrigerant is colder than the outside air, it’ll suck heat out of the outside air.

Now, for some detail: most heat pumps “capture” this heat from the outside not by just getting a little bit hotter but by boiling from a liquid to a gas. The hot, gaseous refrigerant can later be turned back into a liquid by adjusting the pressure in the pipes, which releases this heat (which eventually makes its way to your home, heating it).  The most common heat pump refrigerant is called R-410A and its natural boiling point is -55.3 degrees Fahrenheit. Now the actual boiling point will depend on the amount of pressure it’s under, but the point is, it picks up heat by boiling from a liquid to a gas, and it does that an extremely low temperature. So, if the ambient temperature outside is higher than -55.3 F, say -10 F, this refrigerant can still capture heat from it, which it can later dump off into your home, heating it up. 

This, fundamentally, is why heat pumps can work in cold temperatures. Their refrigerants stay ridiculously cold, so even what we consider cold outdoor temperatures are hotter than the refrigerant, so the refrigerant can capture heat from them. 

-10 F: What Many Modern Heat Pumps Are Rated Down To

Now just because the refrigerant boils at such a low temperature, it doesn’t mean heat pumps work perfectly down to -55 F. There are other factors that affect performance. But if you’re looking for a heat pump to run in cold climates, you simply have to look at their specs to see what temperatures they can handle. 

In our research we found that many on-the-market heat pumps today are rated for use down to -10 F. Negative ten degrees Fahrenheit is, as we’ll explain in the next section, far colder than almost all populous cities in the U.S. ever get down to. 

Here are some examples: 

• The Mr. Cool Universal series keeps 100% heating efficiency down to -5 F and retains 78% heating efficiency even at -22 F.
• Carrier, another popular heat pump and air conditioner manufacturer boasts operation of many of its heat pumps down to -15F.
• The website Carbon Switch likes the Mitsubishi H2i series, which is rated down to -13 F and the Fujitsu AOU series which works well down to -10F. 

That’s three options we found quickly. There are likely many more.

Now: Are heat pumps that heat well down to -10F or even -22F good enough for you? 

Let’s explore that in our next stat. 

0 F: A Temperature That Very Few U.S. Cities Get Below

The vast majority of cities in the U.S. rarely get below zero degrees F, much less -10 F, which means that the heat pumps above, and many others like them, can work at or near full efficiency year round in most cities. 

For example, here are the average low temperatures of the most populous “cold” cities in the U.S. 

In fact, even if you look at the lowest temperatures recorded in Anchorage, Alaska by year for the past decade, it’s only -15F, right in the range of what the Mr. Cool and Carrier heat pumps can operate down to. Again, that is the coldest temperature recorded in the past decade in Anchorage Alaska! And the Mr. Cool heat pump above works just fine at that temperature. 

Minneapolis has gotten colder, reaching -28F in January 2018. But that is one day in the past decade and even the Mr. Cool heat pump listed above will retain decent efficiency down to the negative twenties Fahrenheit. 

If you then look at high-population cities in the U.S. that are often considered to have “cold” winters, like New York City, Chicago or Detroit, you see that they don’t get anywhere near cold enough to challenge today’s heat pumps: 

And the coldest temperature ever recorded in New York City? -15F in 1934, right in the range of what Mr. Cool and Carrier heat pumps above can comfortably heat in. 

The point is, the vast majority of residents of the U.S. do not live in a city that ever gets cold enough to challenge modern day heat pumps. Basically, unless you live in the northern rural territories of Alaska, modern heat pumps should work just fine by themselves, even without a gas furnace as backup. 

Zero: The number of failed Heat Pumps in Maine During a Recent -19F Cold Spell

In this great article about heat pumps from Main Public, a heat pump installer who has installed around 1500 heat pumps said they got zero calls about any failures from any customers during a 2023 cold spell where temperatures reached -19 F. 

In fact, in his personal heat pump at home, he measured the temperature of air coming out of the great pump at 106 F even when the temperature outside was -19F. This is exactly what we are talking about in our first stat above: even in sub-zero temperatures, there is “heat” in the air that the refrigerants of heat pumps can capture and pump into your home.

The best quote from the article comes from Michael Stoddard of Efficiency Maine who says: 

Home builders, managers, and HVAC folks are also saying on social media that heat pumps they’ve installed have worked great in subzero temperatures:

60%: The Percentage of Households in Norway With Heat Pumps Installed

Speaking of cold places, the countries with the highest per capita installed heat pumps are in Scandinavia or northern Europe, according to multiple sources. You can see it in this great graph by The Eco Experts: 

In terms of heat pumps installed per household, according to, again, multiple sources, an amazing 60% of households have heat pumps installed, followed by 43% in Sweden and 41% in Finland. 

Why do these cold Scandinavian countries have so many heat pumps installed? Because they save people money. And it’s residents of cold areas that spend a lot of money heating their home. So they’re the ones who care to find the most efficient, cost-effective heating source. For example, a story on Reasons to Be Cheerful profiles Oslo resident Kern Lindberg, who reduced her home’s energy usage from 35,000 kWh per year to 8,500 kWh per year by replacing the home’s oil boiler system with a heat pump. 

That amount of savings is not surprising considering the high heating costs of oil based boilers. This handy table from the folks at Carbon Switch shows their analysis on how much the typical U.S. household could save annually switching from a traditional heating source to a heat pump (based on U.S. National Renewable Energy Laboratory data): 

You can see that fuel oil boilers are one of the most expensive optoins (so can create one of the largest savings if you switch from it to a heat pump). 

So the reason heat pumps installed per capita is so high in cold countries like Norway and Finland is because cold climates are where people care about heating costs. They spend a lot of money on heating from these traditional fuel based methods (furnaces, boilers), so if they can switch to a heat pump that’s more efficient, they’ll do it. 

But overall, if cold Scandinavian countries are switching most of their heating to heat pumps, it tells you all you need to know about whether heat pumps can work in cold climates. They can. 

And if you live in a cold place and spend a lot on heating costs, they can probably save you money too.