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What temperature does a heat pump stop working?

New heat pump technology is ready for your freezing winter, and it can heat your home with much less electricity than a standard heating option.

New heat pump technology is ready for your freezing winter, and it can heat your home with much less electricity than a standard heating option.

At Sealed, we get the same heat pump questions a lot:

How well does a heat pump work in cold weather, anyway? Are there heat pumps that work below freezing temperatures? What temperature is a heat pump not effective?

These are great questions, and—for those of you in a hurry—we’ll answer the biggest one right away:

Contrary to popular belief, air-source heat pumps work amazingly well in winter—even in very cold climates.

In fact, heat pumps are now the best heating option just about everywhere on the planet. Below 0° Fahrenheit, heat pumps can still heat your home with more than twice the efficiency of gas heating or standard electric heating (such as electric furnaces and baseboard heaters). They’ve been tested and approved as far north as the Arctic Circle, and are popular options in very cold countries like Finland and Norway.

So if you’re worried about whether a heat pump can keep your house comfy, don’t be. New heat pump technology is ready for your freezing winter, and it can heat your home with much less electricity than a standard heating option.

  1. How we know that heat pumps can handle your winter
  2. Why most people (and a lot of HVAC companies) are misinformed about heat pumps
  3. Why new heat pumps are so much better at winter than older models
  4. What temperature is too cold for a heat pump
  5. Whether ductless heat pumps work in cold weather

How well does a heat pump work in cold weather? Here’s the research.

Heat pumps work great in freezing weather—but you don’t have to take our word for it.

According to the U.S. Department of Energy, heat pump technology has gotten so good in recent years that it’s now a great choice for homes in cold regions. In fact, since heat pumps move existing heat energy rather than produce new heat energy, they can deliver more than 3 times the amount of heat energy for the amount of electricity they consume compared to traditional HVAC systems.

Of course, efficiency is all well and good, but what you’re probably wondering is this: Do heat pumps produce enough heat to keep you comfortable on a very cold winter day?

Good question. To answer it, let’s head north (don’t worry, it’s only for a minute).

In 2018, a group of researchers from the Center for Energy and Environment did a field test of air-source heat pumps in the state of Minnesota, which boasts some of the coldest, most brutal winters in the U.S. The researchers wanted to see if air-source heat pumps worked in Minnesota’s frigid winters—and whether using them would save any energy.

The answer was a resounding yes—to both questions. Not only did heat pumps effectively heat the test homes throughout the winter, but the data from the test showed that Minnesota residents could reduce their heating energy usage by 35% to 50% by installing heat pumps.

That’s a huge efficiency margin, and it’s just one more piece of data in an avalanche of evidence that heat pumps work in cold climates. Heat pumps have been tested as far north as Alaska, they work at temperatures well below freezing, and heat pump adoption is increasing dramatically in areas with colder climates. (Even better news: There are programs in certain areas that can help you get a heat pump for no upfront cost.)

So if heat pumps are so efficient in cold temperatures, why do so many people think that heat pumps won’t work in severely cold weather?

How heat pumps got a reputation problem

Heat pump technology is ready for brutal winters now—but that wasn’t always the case.  The first wave of popular heat pumps from the 1980s worked well in moderate temperatures, but struggled when the temperatures got below freezing. As a result, most early heat pumps were installed in areas with a moderate climate, and heat pumps themselves got a bit of a reputation for being wimpy in cold temperatures. 

That reputation stuck around. It’s why the internet has a ton of old, inaccurate information about how heat pumps work in cold weather. And it’s also why most people think that heat pumps won’t keep their house warm enough.

In short? Like so many of us, the heat pump is still haunted by its poor choices in the 1980s and 90s. 

But here’s the thing: Heat pumps have gotten so much better since they were invented, and the new models are more than capable of handling whatever your winter can deal out—even if you have a large, old house.

Let’s look at why.

First, what is a heat pump and how does it work?

A heat pump is a complete replacement for your HVAC system—it can heat, cool, purify, and dehumidify your air, and it does it all for far less energy than a traditional AC or heating system.

A heat pump works by moving heat energy around. In the winter, it takes heat from outside your home and transfers it inside your home. In the summer, it reverses the process—it moves the heat energy from inside your home to the outside.

Since moving heat takes less fuel than producing heat, the heat pump is ridiculously efficient—it uses far less energy than standard heating and cooling systems.

Why new heat pumps are so much better than old ones

While the basic principle of the heat pump hasn’t changed, the individual components have gotten major upgrades recently—and those improvements have made a big difference in how heat pumps perform during the winter.

Here how heat pumps have improved:

A completely redesigned compressor.
This is the big upgrade.  

The compressor is the “heart” of a heat pump—it circulates the refrigerant that moves heat energy from the outside of your home to the inside.  And now, new heat pump compressors  can automatically adjust their speed and energy consumption when the temperature changes. They work hard when they need to (like on really cold days) and then scale back when the temperatures are moderate. 

(In other words, old heat pump compressors were kind of like driving a stick-shift car, while new compressors are more like an automatic.)
This variable speed compressor technology wasn’t commercially available in heat pumps 10 years ago. Now that it is, it’s the game changer that’s made heat pumps fantastic at sub-zero temperatures.

An improved coil design. 
Most modern heat pumps (and all of the heat pumps that Sealed recommends) now use grooved-copper tubing. Since the new grooved tubing has a greater surface area than the older smooth tubing, heat pumps can exchange heat with the outside environment a lot more efficiently than they could in the past.

Efficient fans.
Heat pumps now use better, variable-speed fans—and these new fans cope a lot better with common winter challenges (like restricted ducts and dirty filters).*

Better motors.
For years, heat pump manufacturers have been researching ways to make their motors work better. That research has really paid off. The new heat pump motors work great in winter but still use a lot less electricity than more common heating systems.

That’s a lot of improved technology (we could go on). But the point, ultimately, is that the heat pump you install this month is significantly different than the heat pumps that were available 15 years ago. And that new, optimized heat pump will work beautifully in freezing temperatures (especially when your home has been properly air-sealed).

Common questions about heat pumps in cold weather

Do heat pumps work below 20 degrees?
Yes, air source heat pumps work below 20—in fact, they perform well below -10! If you’re worried—or if you live in Antarctica—you can get a heat pump with a supplemental heating system in case of emergencies (the vast majority of people never need it).

What temperature does a heat pump quit working?
As long as your house is properly air-sealed and insulated, an air-source heat pump can perform well down to temperatures of -20*! Below that, you’ll probably need to use supplemental heat (or consider switching to a ground-source heat pump).

Learn more about the different kinds of heat pumps.

Are heat pumps efficient in cold weather? 
Yes! The latest research shows that heat pumps are 2-3x as efficient in winter temperatures as gas or electric systems.

Do ductless heat pumps work in cold weather? 
Yes, ductless “mini-split” heat pumps are designed to work great in cold weather. They produce a fresh-feeling, continuously-circulating heat that people love. (And the mini-split system gives you precise room-by-room temperature control, so you can choose exactly the level of heat you need in every area of your home.)

Do heat pumps work in the Northeast US?
Yes, a heat pump is an ideal HVAC choice in the Northeast—including New York, New Jersey, Maine and Massachusetts—because it’s the one climate control system that can do it all.

On hot, muggy days when all your neighbors are complaining, a heat pump keeps your house cool, dry and fresh-feeling. And then, in winter, a heat pump will make your house warm and comfortable on the coldest of days.

Why heat pumps are a life upgrade

Sure, heat pumps will keep you cozy in the winter, but that’s just one of the reasons you should consider getting one. Here’s why so many people love heat pumps:

All-in-one HVAC system
A heat pump can replace both your cooling and heating systems (plus it also purifies and dehumidifies your air).

Amazing comfort
Because your heat pump circulates air continuously, your house will feel comfortable everywhere. (No more uneven temperature patches.)

Safe and easy to live with
Heat pumps are super quiet and don’t produce any weird smells—plus there’s no risk of explosion (always a benefit!).

Flexibility
As long as you have electricity, there’s a heat pump for you (even if you don’t have ductwork).

Green and clean energy
Heat pumps generate far less carbon dioxide than traditional heating methods. They’re the greenest HVAC available—better for our planet, better for you, better for future generations.

Learn more about the pros and cons of heat pumps at The Ultimate Guide to Heat Pumps.

In short, heat pumps are a life upgrade. And now, with Sealed, you may be able to get your heat pump installed at no upfront cost. We’ll take care of the initial charges and then you’ll pay us back little by little, based on the energy saved as a result of the work.

Even better: We hire the professionals, oversee the project, and then stand by our work 100%.  If you don’t save energy, we don’t get paid.

If that sounds interesting to you, call 888-985-7481 to talk to a Sealed specialist now. There’s no obligation and everyone is super friendly. (We’ll let you know if we can help you, and if we can’t, we’ll give our best tips for moving forward.)

October 6, 2021