How to Find The Best Cold Climate Heat Pump

By Kevin Purdy

How to Find The Best Cold Climate Heat Pump

Choosing the Best Cold Climate Heat Pump

Finding the best cold climate heat pump is no easy task. Look through a database like the Northeast Energy Efficiency Partnerships (NEEP) heat pump directory and you’ll find more than 30,000 models and a mind-numbing amount of specs. And while heat pumps definitely work in cold climates, if you choose the wrong model, it might struggle on the coldest days. 

In order to find the best cold climate heat pump, we talked to contractors, compared specs, and looked at what units people are actually installing in the coldest parts of the United States.

Based on our research, the best cold climate heat pump is Mitsubishi’s Hyper-Heating, or H2i. Listed as Mitsubishi’s M-Series or P-Series for home installation, these heat pumps maintain their full heating capacity down to 5F, and can produce useful heat down to -13F. 

H2i models range in HSPF ratings (heating efficiency) from 10.5 to 12, and SEER ratings (cooling efficiency) of 15 to 20. Mitsubishi’s heat pumps also maintain coefficients of performance (COP) as high as 2.88 at 5F.

Fujitsu cold climate heat pump

Mitsubishi Hyper-Heating comes in both ducted and ductless options. And Mitsubishi is a known entity in the heat pump industry—in fact, they are one of the inventors of the technology.

Fujitsu’s cold climate heat pumps, their “AOU” series, are our pick for the second best cold climate heat pump. Their variable-speed models produce 75-95% as much heat at 5F as they do at 47F, and are rated to work down to -10F.

Fujitsu’s heat pumps range in HSPF ratings from 9.5 to 11.5, and SEER ratings from 16.5 to 20.

Daikin cold climate heat pump

When we spoke to contractors and other HVAC experts, they told us that Mitsubishi and Fujitsu frequently trade spots in the best cold climate heat pump rankings. But another name that came up frequently was Daikin. Daikin’s Fit and Aurora lines have great cold climate specs. The Fit (RZQ) line can work at full heating capacity down to 5F, and is rated to work down to -4F. The relatively new Aurora (RXL) series can work down to -13F.

Aurora Fit heat pumps have HSPF ratings between 9 and 10.5, and SEER between 16 and 18.5.

In the sections below, we’ll explain how we picked out these cold climate heat pumps, how you should choose between them, and what to expect if you install one in your home.

The most important factor: the installer

A heat pump that works in frigid climates is a modern marvel of efficient, climate-friendly technology. But it will only improve your home, and cut your utility bills, if the right one is picked out for your home’s heating and cooling needs.

Andrew Kosick, owner of Creative Rebuilding in Midland, Michigan, puts it plainly: “Getting the sizing and installation right is honestly more important than a specific manufacturer.” John Semmelhack, an experienced heat pump consultant and contractor, went further in a tweet: “Heating + cooling is a system. Best product + poor design/install = poor performance.”

Nate Adams, a.k.a. Nate the House Whisperer, notes that client goals, house design, and budget determine what actually gets installed. Cold climate heat pumps are “changing INSANELY fast right now,” Nate wrote us—something echoed by This Old House’s Ross Trethewey.

So choosing the right installer, with the right mindset, is valuable far beyond work ethic and craftsmanship. A heat-pump-friendly HVAC contractor can assess your home’s energy retention and needs, properly size the system you need for its design and weather patterns, and set you up for the most comfort and savings.

Most installers will have a limited number of heat pump brands they offer, or perhaps only one. As with any major home project, it’s important to get recommendations, seek multiple quotes, and ask questions of your installer.

You can find Mitsubishi, Fujitsu, and Daikin’s installers by clicking one of the links below: 

Why proper heat pump sizing matters

Heat pumps are different than furnaces, electric baseboards, and most other heating systems in one important way: They produce a different amount of heat depending on the temperature.

In order to understand why, it’s helpful to consider how heat pumps work. Even on a cold day, there is energy in the air outside. A heat pump expands and compresses refrigerants to draw in this heat energy and deliver it inside your home.

Because the amount of heat energy outside decreases as it gets colder, the capacity of a heat pump decreases with it. The capacity is the amount of heat (or cooling) that a HVAC system can supply. If that capacity is less than the amount of energy your home needs to stay comfortable (the “load”), you’ll have to rely on some combination of expensive backup heat, blankets, and/or fortitude.

Cold climate heat pump capacity chart

It might seem like an easy fix–pick a heat pump with a capacity slightly bigger than your home’s load, or just buy a heat pump with the same capacity as your furnace or other existing heating system. But Kosick believes most furnaces are oversized (often due to bad rules of thumb), and the wrong comparison for heat pump sizing. And “an oversized heat pump is actually worse than a slightly undersized one,” Kosick writes.

The most comfortable and efficient use of a heat pump is when it’s constantly running, at variable speeds, keeping warm air moving through a home, according to Kosick. A heat pump that’s too large will start and stop more, waste energy, wear on the system, and create hot and cold zones. Picking too small a heat pump, as noted, creates more obvious under-heating problems.

We have a whole guide to properly sizing a heat pump for your home. Having a good smart thermostat can help you figure out exactly how much energy your heating system used on one of the coldest days of the year, making sizing even easier. 

Why the Mitsubishi H2i is our pick

When we asked about the best cold climate heat pumps on Twitter, and spoke to contractors, Mitsubishi’s name came up often. It’s easy to see why. Its heat pumps have higher heat capacity at lower outdoor temperatures, produce heat down to the lowest temperatures, and have wide support and distribution among installers.

On pure stats, Mitsubishi’s Hyper-Heating (H2i) series stands out. As low as 5 Fahrenheit, an H2i heat pump produces its full rated heating capacity. For some areas, that be the entire winter. If your home is well-insulated and there’s an H2i heat pump that fits your home’s load, you’re almost certainly ready to switch.

If your winter is brutal, you’re not out of luck though. As low as -13F, an H2i pump keeps working, supplying roughly 80% of its total heat capacity. Depending on your home, that might mean turning down the thermostat and bundling for brief spells, or having backup heat available for extended freezes, whether that means keeping your existing system or installing electric backups.

Mitsubishi heat pumps don’t just work well on paper–they’re greatly preferred in real cold regions. We know this because the Massachusetts Clean Energy Center has a database of heat pumps installed in that state through 2019. Mitsubishi heat pumps are installed at a rate of 2.8 times more than the next brand, Fujitsu. Download the data and look around, and you’ll see a wide range of home sizes and heating needs, across a state with winter temperatures that frequently dip below 0° F.

Our second favorite: Fujitsu

Fujitsu cold climate heat pumps (AOU line) have a lot in common with Mitsubishi’s. But instead of delivering 100% of their capacity down to 5F, all but the smallest Fujitsu models offer 75-95% of their capacity. They’re rated to work down to -10F, just above Mitsubishi’s -13F.

Fewer people in Massachusetts installed Fujitsu models than Mitsubishi pumps, but far more than the next most popular brand, Daikin. Fujitsu was mentioned a number of times by installers and consultants we spoke with. Like our other picks, the brand is also well-established, and has a decently large network of authorized installers around the U.S.

One more option: Daikin Fit & Aurora

Daikin’s Fit line (RZQ outdoor pumps) is well-regarded, if new, among installers, and maintains its full heating capacity down to 5F, like our top recommendation, Mitsubishi. They don’t work to as low a temperature, however, stopping at -4F. 

Daikin’s new Aurora (RXTQ) cold climate heat pumps look promising. They provide 100% heating capacity down to 5F, then keep working at a slightly slower capacity to -13F, like the H2i series. The Aurora is too new for many of our installers to have worked with, but it seems promising.

Why you should consider other brands

Our recommendations are by no means exhaustive, exclusive, or guaranteed to cover everyone’s particular winter in their unique home. There are many reasons you might pick a heat pump from a brand we didn’t recommend here.

For one thing, we focused on the coldest climates for this guide–those covered by “Cold” and “Very Cold” on the Pacific Northwest National Laboratory’s climate map.

Map of climate regions in the US

Even inside those cold zones, winters vary. While your winter may occasionally, memorably dip below freezing, most of your winter may not require a heat pump that can deliver a full load down to almost zero.  

Some contractors, and homeowners, value other things beyond pure cold climate performance. Nate Adams, a heat pump installer in Ohio, highly values the energy monitoring, airflow adjustments, pressure, dehumidification, and other features of Carrier’s Greenspeed heat pumps. He’ll pick that if it fits a job, he said, even if other heat pumps beat the Greenspeed on deep cold performance.

There’s also the reality that, in your region, reliable contractors may only represent certain heat pump brands. After assessing your energy needs, climate, controls, and other factors, you and your contractor may settle on a heat pump from a brand not mentioned here–and you’ll still get efficient, money-saving, carbon-free comfort.

All of that’s to say that looking at the specs is important, but when it comes to finding the best cold climate heat pump for your home, it’s not the only thing to consider.

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