Mixed heat pump system

Half-ducted house? Lousy airflow? Consider a mixed heat pump

Air source heat pumps come in two main types: if your house has ductwork, you’ll usually install a ducted heat pump. No ducts? Then it’ll be a ductless heat pump, also known as a mini-split system. They’re essentially the same highly efficient, environmentally friendly, cost-competitive technology for heating and cooling your home. All that’s different is the way that they move air.

But what if only some parts of your home are ducted? Or the ducts don’t heat or cool certain rooms very well? A system that combines both ducted and ductless heat pumps might be the best way to keep your whole home comfortable.


Key takeaways


  • A combined ducted and ductless heat pump system can be a great option for homes with at least some ductwork, but certain rooms with no vents, or very weak airflow from those vents.
  • These systems heat and cool your home with the same efficient, environmentally friendly technology as any other air-source heat pumps.
  • It’s almost always easier and less expensive to install a mixed system than to install new ductwork for an all-ducted system, or to fit each and every room with heads for an all-ductless system .
  • Going solar with EnergySage can power your heat pumps with the sun, and make them even more affordable to operate.

What’s in this article?

How do mixed heat pumps work?

A mixed ducted and ductless heat pump system works like any other air-source heat pump. In short, it uses electricity to heat and cool your home super-efficiently by absorbing free heat. Heat pumps use the same technology as air conditioners, plus a few tweaks that also let them heat your home. Plenty of heat pumps can work well in extremely cold winter temperatures, and you can also keep a backup heating system for peace of mind, if you’d like. You can read up on the technical details in this article.

Most often, a mixed ducted and ductless heat pump is really like two separate HVAC systems: Two outdoor condensers, running independently, and hooked up to different sets of indoor equipment. One condenser connects to a central air handler, which then serves heating and cooling through ductwork. The other condenser attaches to one or more ductless mini-split heads, typically installed high on a wall in any room where you want climate control.

But air source heat pumps are very flexible and customizable, and there are plenty of exceptions to this common setup. Some combo systems use a single condenser, others for large homes may use three condensers—it all depends.

As for costs, we don’t have great data on the relative price of mixed heat pump systems vs. all-ducted or all-ductless setups. It stands to reason than in homes with partial ductwork, mixed systems should be the most economical option because you get to piggyback off of some existing ductwork, without the expense and hassle of retrofitting new ductwork. But it’ll vary from home to home, so you’ll need to get detailed quotes from a contractor to be sure.

When are mixed heat pumps a good fit?

You already have ductwork in your home, but it doesn’t heat or cool every room. Some homes have partial ductwork: It reaches some rooms, but not all of them (often a finished attic or basement, or home addition). Other homes are fully ducted, but the airflow doesn’t reach every room. For example, your bedroom might be toasty, while your office stays frigid.

A mixed system gives you the opportunity to add mini-split heads to rooms without their own vents, or that need some help staying comfy. You’ll get excellent  temperature control without the expense and hassle of adding ductwork.

In a fully ducted home with poor airflow in certain rooms, you should consider the possibility that the ductwork could provide comfortable whole-home heating and cooling with some tweaks to the design and HVAC equipment. In other words, you might be able to solve the problem with a well-installed ducted heat pump, plus some improvements to your ductwork and insulation. A great installer can help you figure this out. But in many cases, it’ll just be easier, more cost effective, and more comfortable to add some mini-splits. 

You’re expanding your home. Whether it’s adding an in-law apartment, creating a finished basement, or converting the garage into livable space, you might feel some growing pains if your HVAC system isn’t up to speed. Adding a ductless mini-split system is often the most practical way to add comfort and climate control to new parts of your home. 

Mixed heat pumps make less sense if…


  • Your home has no ductwork at all. In this case, it usually makes the most sense to install an entirely ductless mini-split system.
  • Your home already has excellent ductwork. If you have no significant hot or cold spots, you can just replace (or supplement) your furnace and central air conditioner with a ducted heat pump. 

And all the other guidelines about when a heat pump makes the most sense in your home apply to mixed systems the same way that they do to fully ducted or ductless setups.  

Sound good? Next steps

1. Find a reputable and experienced HVAC contractor: make sure the company you are interested in has experience with both ductless and ducted heat pumps, since some companies may only offer one or the other. When shopping for and comparing air source heat pump installers and quotes, you’ll want to make sure to ask any questions to clarify your needs, the system design, and your equipment capabilities. The new (and still growing) EnergySage heat pump installer marketplace can help you find a vetted pro.

2. Receive an in-home consultation: before offering a quote, contractors will usually visit your home to assess your heating and cooling needs. They’ll review the layout, existing equipment, ductwork, and any nuances about your home that would impact your heat pump system’s design, setup, and configuration. 

3. Compare quotes: once you’ve received home consultations from companies, they will follow up with a quote which will include an itemized breakdown of cost, scope of work, additional services, warranty information, and potential rebates in your area. Read up on how to compare air source heat pump quotes in this article. Once you have determined the best proposal for your needs, you will proceed with the installation. 

How to make a heat pump work even better

Receive a home energy assessment: this service is usually offered at no cost through your utility provider. A home energy assessment (sometimes called an energy audit) is when a trained professional takes a look at your current energy consumption, then identifies upgrades that can make your home more efficient and comfortable. Some changes are cheap and quick, others more expensive and involved. The auditor will leave you with a report that might include recommendations for insulation and air-sealing improvements, which will help optimize your heat pump’s performance. And sometimes, audits are a prerequisite to qualify for rebates and incentives on heat pumps and other major efficiency upgrades.

Consider powering your heat pumps with solar energy: solar panels allow you to power anything that runs on electricity – including heat pumps – with renewable, zero-emissions electricity. Running your heat pump system with solar panels, even partially, can really shrink your utility costs, while decreasing your carbon footprint even more than grid electricity. If you are wondering how many solar panels are needed for an air source heat pump, check out this article.

Start your solar journey with EnergySage

The EnergySage Marketplace makes it easy to get quotes from local solar installers—some of whom also install air source heat pumps. Have some additional questions about solar panels and heat pumps? When you receive quotes, we’ll connect you with an Energy Advisor—a real person, here in our Boston office—who can answer your questions along the way.