What Is a Mini-Split Heat Pump and How Does It Work?

If you’ve started shopping around for a new home heating system—or if you’re trying to replace the one you have—you may have heard about a mini-split heat pump. This is a unique method of providing heat to the home that comes with a number of benefits, particularly if your home doesn’t have the infrastructure in place for a more common forced-air heating system.

How Your Home Is Heated

Most houses are heated with an elaborate system of ductwork. Air is heated in a furnace, which might be located in a basement or outside of the house. Fans and vents then push the heated air through the ducts. This is a tried and true method of heating the home, not to mention versatile: depending on your furnace, you can use coal, propane, wood, or oil as your fuel source. Forced-air heaters, however, do depend upon the home having that complex system of ductwork in place. Putting ducts into homes that don’t already have them can be both expensive and invasive.

The forced-air method is probably the most common, but it’s far from the only option. Electric space heaters are great for heating individual rooms, although impractical for whole homes. On the same token, a wood or gas fireplace can be great for heating one room but not an entire house. Cast iron stoves can be better for heating whole homes, as can steam boilers and plenty of other methods.

One of the most popular modern methods, however, and one that doesn’t require a massive existing system of ductwork, is the mini-split heat pump.

What Is a Mini-Split Heat Pump?

A mini-split heat pump is also referred to as a “ductless” heating system. As the latter name suggests, this method of heating your home doesn’t require ductwork. It utilizes two main parts to operate: an outdoor condenser and an indoor air-handling unit. A power cable and refrigerant tubing connect these two components.

Instead of heating individual rooms in the home, your mini-split heat pump will heat “zones,” that is, areas of the homethat may include several rooms. For larger homes, you might need to have several indoor air-handling units, all connected to one outdoor condenser. You can usually attach up to four indoor air-handling units to one condenser.

How Does It Work?

Most forced-air heating systems work by burning some sort of fuel; wood, coal, oil, propane, or natural gas are among the most common. Mini-split heat pumps, on the other hand, work by actually moving heat energy from outside the home to the inside.

Outdoor air moves through the condenser, where the heat is drawn out of it by the refrigerant. The refrigerant moves through the refrigerant tubing into the home, where it expands and releases the heat into your home. This process creates condensation, which is collected and drained away through another, separate tube in the outdoor part of the heating unit.

Because of its particular method of moving heat energy from place to place, mini-split heat pumps can be used for both heating and cooling. This method of moving heat energy from outdoors to indoors can also be reversed. This cools the indoor air and saves you the need for a separate air conditioning unit.

The Advantages

A mini-split heat pump has several advantages over other heating methods, with the lack of ductwork being one of the primary ones. Many older homes don’t have existing ductwork, and having it installed can be costly. You can avoid this with ductless heating.

Since they’re smaller and simpler than forced-air heating units, mini-split heat pumps are often a good deal less expensive than other methods of heating your home. You’ll save money at the point of purchase, as well as during the installation process. Maintenance may be cheaper as well.

Because they don’t utilize ducts, mini-split pumps are also a good deal more energy-efficient than other methods. A lot of heat energy is lost through the ducts in your home, driving your energy bill up. But ductless mini-split heat pumps don’t have this problem.

The added energy efficiency of mini-split heat pumps also makes them an excellent “green” option. These days, many homeowners find environmental concerns to be of paramount importance, leading them to look for alternative methods of heating and cooling their homes. Because mini-split pumps don’t utilize a combustible fuel, such as coal or propane, they’re a much more environmentally choice.

The added energy efficiency of a mini-split heat pump may also mean you’re eligible for a tax rebate when utilizing one. Check your local laws to discover tax credits offered in your area.

Any Down Sides?

There are a few possible disadvantages to consider when installing a mini-split heat pump, although, these are rarely insurmountable. For example, you’ll need to find a suitable outdoor location for the condenser. This may be easier in some places than others.

One key issue, however, may be important if you live in an especially cold climate: in areas where the temperature regularly dips below freezing, a mini-split heat pump may not be powerful enough to sufficiently heat the home.

If it gets extremely cold—in areas such as the American Midwest—the outdoor condenser unit may freeze over and cease to function until it can be thawed. If you live in an area that’s this cold, you may want to have an alternative furnace, such as a propane one, which burns hotter and is less liable to fail during subzero temperatures.


An experienced professional should install your mini-split heat pump: look for licensed contractors in your area to do the job. Read online reviews, check references, and ask for referrals to find the best team for the job near you.

If you live in the Portland, Oregon, area, look to Watts Heating and Cooling for your mini-split heat pump needs. Their experienced team will do the job quickly and effectively, and they offer a maintenance program once the installation is complete. They also offer financing to take the financial sting away from purchasing an entirely new heating system for your home.