What is 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 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 ducted and ductless heat pumps might be the best way to keep your home comfortable.

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. 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 plenty of exceptions exist to this common setup. Some combo systems use a single condenser, and 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 that 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.

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 (often a finished attic, 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 allows you 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 a 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.

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: contractors will usually visit your home before offering a quote 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 that includes an itemized breakdown of cost, scope of work, additional services, warranty information, and potential rebates in your area. Read up on comparing air source heat pump quotes in this article. Once you have determined the best proposal for your needs, you will proceed with the installation.

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 looks 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 insulation and air-sealing improvement recommendations, 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 shrink your utility costs while decreasing your carbon footprint even more than grid electricity. If you wonder how many solar panels are needed for an air source heat pump, check out this article.

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 natural person in our Boston office—who can answer your questions along the way.