Heat pump cooling: Do heat pumps work well in hot weather?

Heat pumps can cool your home in summer and heat your home in winter—and they do both efficiently.

Heat pumps can cool your home in summer and heat your home in winter—and they do both efficiently.

Thinking about switching from conventional AC to a heat pump? That’s smart! 

You likely have a lot of questions, like How does a heat pump work in summer? What’s the highest temperature a heat pump will work? How does it stay so efficient while running constantly?

We’ll answer all these questions (and more!) in this article.

But spoiler alert: YES!  Heat pumps provide superior home cooling.

It might surprise you to learn that, despite their name, heat pumps can cool your home in summer and heat your home in winter—and they do both efficiently. 

Plus, depending on where you live, you could get one at no upfront cost—eligible rebates included. Tap here to see if you qualify.

Table of contents:

Key points:

  • Heat pump technology operates and reliably cools the same as AC technology, with the added benefit of being able to reverse the process in winter via a reversing valve to heat your home.
  • By far, heat pumps are the most efficient way to keep your home comfortable year-round. Plus, some models have superior dehumidifying capabilities, which leaves your house feeling cool and fresh on hot, humid days.
  • Heat pumps have a broader temperature range than you might expect, and they use variable speed compressors to maintain a consistent temperature.
  • A high-efficiency heat pump will perform more efficiently than conventional AC (especially older AC models) and also has the benefit of running “dry mode” when you want to reduce humidity in your home. 
  • Because heat pumps are so energy efficient, plenty of financial incentives are available (like tax credits and rebates). And if your house qualifies to work with Sealed, you could get one for $0 upfront. Find out if you qualify for this program. 

Does a heat pump cool?

The question Does a heat pump cool? is pretty common, despite heat pumps being the most talked-about appliance in home efficiency. Why? Well, many people find a heat pump’s name confusing or misleading (1). 

“Heat pump” sounds like it’s just a home heating system, when in fact, it’s both—and heat pump cooling is just as powerful, comfortable, and superior as heat pump heating. 

Heat pumps work like air conditioners, but it’s as if they went to graduate school for advanced degrees—because they can heat your home too.

So even though its name would make it seem otherwise, yes, a heat pump superbly cools your home in summer. It’s also a powerhouse at dehumidifying inside when it’s hot and sticky outside (2).

Although they definitely are a home cooling (and heating!) system, it’s true that heat pumps are a little different from traditional air conditioning systems. Here’s a high-level look:

  • Traditional AC systems and heat pumps operate on similar cooling technology, but heat pumps are more efficient. 
  • Heat pumps dehumidify in summer significantly better than AC systems (3).
  • No ductwork? No problem! Heat pumps can be installed without it, so you don’t have to worry about a messy, intrusive (not to mention expensive!) ductwork installation.
  • Heat pumps have flexible zone-by-zone installation options. (For example: You could set your walk-out basement office and upstairs bedroom to different temperatures!)
  • Air conditioning systems can’t heat your house in winter, but heat pumps can. Plus, one appliance means less maintenance! 
  • Heat pumps are the most efficient way to heat your home available on the market and don’t produce fumes from natural gas use (like gas furnaces or boilers).

For a deeper dive, check out Heat pumps vs. AC: pros and cons. And if you’re here reading and are wondering if a heat pump can keep up (and provide relief) in your too-hot house, read Why is my house so hot? to learn more.

Do heat pumps work well in hot weather? (You bet! Here’s the research.)

You bet they work well in hot weather! While some people may assume that heat pumps are only useful for heating based on the name, the truth is they also effectively cool your home on hot summer days. (Or hot October days, too, if you live in Houston, Texas.)

Heat pumps were built to take on the heat. Even during a heat wave, heat pumps can use less energy and maintain more consistent temperatures than standard and high-capacity AC options, according to one study by Rocky Mountain Institute (4).

Why? Because they use less energy to transfer heat out of your house than many older air conditioning models, especially conventional window AC

So if you’re looking for a reliable and energy efficient way to keep your home cool during the hot summer months and cut energy waste year-round, a heat pump is the number-one choice. 

This was the SINGLE BEST THING we could have done for our home!!! I’m excited to see how the summer is now that our upstairs isn’t an oven! Thanks so much, Sealed team!!

Liz C., Sealed customer

Heat pump temperature range: What’s the highest and lowest temperature a heat pump will work?

Heat pumps are designed to provide comfortable, reliable cooling and heating in a variety of temperatures, from -22 degrees to 115 degrees Fahrenheit, depending on the model (5, 6). That’s a pretty impressive bandwidth!

Any home cooling appliance has decreased efficiency the higher the temps go. The hotter it gets, the harder it is to cool your house—for any HVAC system. 

It’s doubtful a traditional air conditioning system performs at its most efficient on a 116 degree day. It’s the same with a heater, too: A gas furnace isn’t going to feel as good (or be as efficient) at -10 degrees as it is at 10 degrees. 

The overall benefit of heat pumps is that they are superior HVAC technology and provide greater efficiency year-round.

Plus, when you have a properly insulated and air-sealed house, your home will do a better job of keeping cool air in and heat out during the summer months. This optimizes your heat pump—or any HVAC system, for that matter—but if you’re investing in stopping energy waste at home or care about reducing your carbon footprint, insulation and air sealing can give your heat pump rocket-boosters. 

And since heat pumps are ideal for both summer and winter, if your region gets super-cold temps, you have a few reliable heat-pump options. 

Cold-climate heat pump models have the broadest temperature range of air-source heat pumps, and geothermal heat pumps can heat your home efficiently at a range even lower than -22 degrees (which is helpful if you live in the Arctic!). Read geothermal vs. air source heat pumps for more.

Now, let’s discuss exactly how heat pumps cool your home in the summer.

Here’s how a heat pump works in summer

Here’s the deal: Heat pump technology operates the same as conventional AC technology to reliably cool your home—with the added benefit of being able to reverse the process in winter to heat your home via a reversing valve.

That’s the primary difference between a heat pump vs. AC.

During the hot summer months, a heat pump does the job of an air conditioner and removes heat from the inside of your home, transfers it outside, and provides fresh, cool air in the process. A heat pump dehumidifies your home in the summer, too (and better than conventional air conditioning), so your home is left feeling fresh and cool. 

Have a house that doesn’t feel comfortable in summer? Read Why is my house so hot? to learn why and how to fix it.

diagram illustration of how ductless heat pumps work in summer
This diagram shows how heat pumps move heat energy (represented by red arrows) outside your home and intake fresh air (represented by blue arrows) from outside, dehumidifying, filtering, and cooling the air to keep you comfortable indoors.

Curious for in-depth details on how heat pumps work in summer? (If not, tap here to skip ahead.)

A heat pump uses refrigerants in a cycle to regulate your home’s temperature year-round. At its core, it pumps heat out of your house in summer and into your house in winter. 

During warmer months, this is how a heat pump cooling works:

  1. A heat pump’s compressor (which is part of the outdoor unit) pumps the refrigerant to absorb heat from inside your home.
  2. The indoor coils are filled with cold refrigerant, which not only attracts heat from your indoor air and moves it outside, but the coils also help transform that stuffy, warm air into a cool breeze. 
  3. The cool air is then sent back into your home through the air handler, while the warmed refrigerant is sent to the outdoor unit to move the heat out of your house.

Although this is a simplified look at the details of how a heat pump keeps your home comfortable, the main thing to know is this: 

Heat pump cooling works just like an AC, removing heat and humidity from the air inside your home and replacing it with fresh, cool air—so your house feels amazing when you walk in after spending a humid July morning cutting the grass.

Even during a heat wave, heat pumps can use less energy and maintain more consistent temperatures than standard and high-capacity AC options.

Rocky Mountain Institute

Another key thing to remember? To really shine like a superstar, a heat pump needs to be properly installed for optimum cooling (and heating!) performance. It’s not a DIY project.

Before we move on, there’s one last thing to keep in mind here: Many HVAC pros are cold-climate heat pump newbies (it is an improved technology, after all!), so make sure you find a pro who can correctly size and install it for prime efficiency during both summer and winter. 

(Talk to Sealed. We can get the right heat pump for your house.)

Heat pump cooling efficiency in hot weather: Why are heat pumps so efficient?

With variable speed compressors and advanced controls, heat pumps take the lead in efficient year-round indoor temperature regulation.

Similar to high-efficiency AC systems, the variable speed compressors in heat pumps enable them to run at the precise speed needed to cool your home to the temperature you set—and keep it there. 

Depending on the heat pump model you choose, ductless heat pumps can come with the benefit of “dry mode,” which allows you to reduce that stuffy, humid feeling in your home without using excess energy to run the cooling function. So humid spring days have met their energy efficient match. Finally!

And if you aren’t into the ins-and-outs of compressors… in plain-language, this all just means that heat pumps are more technologically advanced—hands down. And that’s what makes them so efficient! 

Really. Read the Tesla of HVAC for a detailed explainer.

When selecting a heat pump, pay attention to its seasonal energy efficiency ratio (SEER) rating. The higher the SEER rating, the more efficient the heat pump is at providing cooling output relative to the amount of electricity it uses.

An important note here: Even though higher SEER-rated, newer AC systems might perform comparatively to high-efficiency heat pumps, homeowners do not get the benefit of their appliance also working as a super-efficient heating system in the winter. If you ask us, there’s really no comparison.

SEER is just one factor that plays into the efficiency of a heat pump. Other things can affect how well your heat pump works, too, including:

  • The size of the unit
  • If your heat pump is properly installed 
  • How well your home is insulated
  • If your house has been air sealed

Speaking of insulation and air sealing, that brings us to our next topic: Making the most of high-efficiency heat pump cooling systems, no matter how hot the summer gets.

How to make the most of heat pump cooling

Every homeowner needs to know this: 

Insulation upgrades and professional air sealing can extend the life of your HVAC system and increase your cooling efficiency—whether you have a super-efficient heat pump or not.

This is a no-brainer: Insulation breaks down over time. So even if you updated your insulation 10 years ago, you might be due for another energy audit to make sure it’s still in good shape and doing its job.

But you can really cut down on your overall home energy waste when you combine expertly installed insulation and air sealing with a heat pump HVAC system.

In our experience, we’ve seen homes reduce energy consumption up to 50% with the right combination of insulation, air sealing, and heat pump upgrades. 


  • 51% of a home’s average energy use is for heating and cooling alone (7). That means you can make your biggest efficiency gains by keeping outdoor air out and indoor air in.
  • Air leaks can cause you to waste anywhere from 15 to 45% of the energy you’re using to heat and cool your home, depending on the study you consult (8, 9). Air leaks happen as your house ages (every home has them!), and professional air sealing is the right fix.
  • 90% of homes are under-insulated, which means there’s a 9 out of 10 chance you’re paying for energy you don’t have to, all while sitting in a stuffy, too-humid house with your AC on full blast (10).

Heat pump cooling and heating will go to great lengths to conserve energy and improve your comfort year-round… but if your house is leaky and poorly insulated, you’re still going to lose efficiency and decrease the lifespan of your fancy-new heat pump system.

In fact, the federal government knows how critical these home upgrades are, too, which is why financial incentives like insulation tax credits and rebates and heat pump tax credits and rebates exist.

Check out the Sealed Inflation Reduction Act home energy rebates guide to learn more.

Ready to make the switch? There are plenty of reasons to do so—eligible rebates and tax credits included!

Sealed’s advisor went above and beyond to make sure our needs were addressed…. I wouldn’t hesitate to recommend Sealed for HVAC and insulation upgrades.

Matt R., Sealed customer

Get a super-efficient heat pump at no upfront cost if your house qualifies

Heat pumps, by far, are the smarter way to heat and cool your home. They’re a life upgrade!

With Sealed, you may be able to get a heat pump installed at no upfront cost.

Then you’ll pay for the work done with one of the flexible payment options that’s best for you. Sealed shoulders the risk so you don’t have to. We’re so confident in our energy performance methodology that we offer a money-back guarantee. 

Even better: We hire and vet your installation professionals, oversee the project, and then stand by our work 100%—that way, you know it’s done right. If you don’t save energy, we take the hit.

See if your house qualifies for a heat pump at $0 upfront cost with Sealed.

heat pump condenser unit on beautiful summer day on exterior of home

Common questions about heat pump cooling

Interested in switching to a heat pump, but don’t see your question answered here? Talk to Sealed at 917-382-3729.

How long should a heat pump run in the summer?

If you’re experiencing really hot days, a heat pump may run more throughout the day to maintain a comfortable temperature (this is what they’re designed to do—all while still maintaining a higher level of efficiency than traditional air conditioning).

Heat pumps adapt to the needs of your house, so the runtime varies based on a few factors, including:

  • Outdoor temperature
  • Indoor temperature set for your system
  • Your heat pump’s size and efficiency
  • How well your home is insulated and air sealed

Heat pumps may run longer (just like conventional AC) on very hot days when they have a higher cooling load.

The best way to know how long your heat pump should run? Consult your model’s manufacturer guidelines or an HVAC pro. 

Should a heat pump run constantly in summer?

Not usually. If your heat pump is cycling continuously without stopping, you’ll need to get it checked. Heat pumps are designed to be a “set it and forget it system,” working efficiently through temperature changes to keep cooling your home to the temp you set. They’ll run more often or for longer on hotter days (just like conventional AC), but they shouldn’t run nonstop without breaks.

It is important to know that turning your heat pump system off and on (or regularly changing the temperatures throughout the day) will can cause it to work harder and less efficiently. Read how one couple learned this lesson the hard way. 

Does a heat pump work in extreme heat?

Yes! Heat pumps can cool your home efficiently, even in extreme heat. Just like any HVAC system, the hotter it gets outside, the harder the system has to work. But heat pumps are the most efficient way to keep your home comfortable year-round—and pairing a heat pump with home insulation and air sealing upgrades can help them be better-optimized for any weather that comes your way. 

Do heat pumps cool as well as air conditioners?

Heat pumps cool just as well as air conditioners. In fact, they are air conditioners—that have super powers. The higher the SEER rating of your heat pump model, the better they’re expected to perform at home cooling. 

To use a simile: Heat pumps work like air conditioners, but it’s as if they went to graduate school to get additional certifications—because they can heat your home too. Plus, depending on the model you choose, heat pumps can dehumidify more effectively than conventional AC on hot, humid summer days (11). 

Tap here to learn more: Heat pumps vs. AC.

Do yourself a favor: When you’re ready to upgrade your HVAC system, switch to a heat pump. (Your house would thank you—if it could talk.)

Plus, if you qualify, you could get one at $0 upfront cost with Sealed.

May 26, 2023