What is a Mini-Split Heat Pump?

An Image Of A White Mini-Split Heat Pump.
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Mini-split heat pumps are becoming all the rage among homeowners looking for a more efficient way to regulate temperatures in their homes. But many home homeowners are unfamiliar with them. So what is a mini-split heat pump?

Mini-splits are air-source heat pumps that provide both cooling and heating to individual rooms or zones of the home, offering quiet operation, energy efficiency, and flexibility in design.

Another name for mini splits is ductless heat pumps because they can be installed in existing homes with minimal disruption to walls, ceilings, or other structures. This makes them an ideal choice for homeowners wanting a more efficient system without having to take on major renovation work.

In this article we will discuss how mini-split heat pump systems work and why they are becoming so popular. Let’s start with the basics.

What is a Heat Pump?

Heat pumps have been around for years and use technology that every homeowner is already very familiar with. The science behind them is actually quite simple.

A heat pump works the same way as a refrigerator in that it circulates warm air from inside through a compressor, cooling it down before pushing the cool air back inside and expelling any extracted heat out through a vent.

And it’s important to note that, even when the air inside of your fridge is cold, it can still extract yet more heat from it and still push warm air out.

Now, what if that fridge were the size of a house, and its compressor was both larger and much more efficient? That same process would be a pretty good way to keep a house cool in the summer.

And if that entire process could be reversed so that it took cool air from outside, extracting heat from that air and pumping it back into the house, that would also be an effective way of keeping a home warm in the winter.

An Image Of The Outdoor Part Of A Split Type Heat Pumps.
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Here you can read more about Heat Pump Basics

What is a Mini-Split Heat Pump?

So if a heat pump is basically a compressor that is pushing air into your house, the next question becomes, How is that air distributed throughout the house so that the homeowner can comfortably control the temperature in each individual room?

There are two ways to do this. One is through a series of ducts in the walls or under the floors. Many houses have these ducts, particularly if they were built with central air conditioning or forced air heating systems.

But many homes don’t have these and, for them, the cost of adding ducts after the house has been built can be prohibitively expensive. What’s more, even for homes that do have them, Energy Star says that ducts are responsible for 20-30% air loss in the average home.

And that’s where mini-splits come in.

A mini-split heat pump is an appliance for heating, cooling and dehumidifying your house that doesn’t require duction work. That’s why they’re sometimes referred to as ductless mini splits.

In fact, it can be quite confusing because mini-splits go by lots of different names. You might hear them referred to as mini-split heat pumps, mini-split air conditioners, ductless AC or a ductless mini split system. (Someone really needs to come up with a universal name for these things).

For simplicity, I’m going to refer to them as mini-split heat pumps or mini-splits for short.

How Does a Mini-Split Heat Pump Work?

A mini-split heat pump is made up of two components:

  • An outdoor compressor
  • An indoor air handling unit called the ‘head’

The outdoor compressor and indoor head are connected by two thin pipes that carry refrigerant. The refrigerant removes heat from the air. 

In the summer it removes heat from the air inside the house and sends it outside, blowing cooled air into the house through the head. In the winter, the refrigerant cycle is reversed, so that it removes heat from the air outside (even if that air is really cold) and blows warm air inside.

A Youtube Image Explaining The Function Of A Heat Pump.
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The heads are ideally placed high up (so that the cold air they blow in the summer “falls” into the rest of the room), but still about six inches from the ceiling (so that warm air they blow in the winter can circulate).

More than one head can be connected to one compressor. And heads can be distributed throughout the house to create zones. Those zones mean that mini split systems are excellent for giving you more control over the temperature in different parts of your home.

Pros and Cons of Mini-Split Heat Pumps

Whenever you discuss the pros and cons of anything, it’s important to remember that these things are often subjective. What one person thinks is ugly, another person describes as sleek. What one person considers expensive, another might think is a bargain. 

With that said, some advantages of mini split heat pumps include zone-by-zone temperature control, reduced energy costs, healthier air, the convenience of having an all-in-one system, and, of course, they’re much better for the planet.

Disadvantages include the high upfront cost (although there are plenty of state and federal tax incentives to help offset those costs), and some people think they’re kind of ugly (though have you looked at a window air conditioning unit lately).


So what is a mini-split heat pump? It’s a great way for homeowners to control the temperature in their home, while also saving money and energy. They are easy to install with minimal disruption and can be used for cooling, heating and dehumidifying your home all in one system. They also provide zone-by-zone temperature control and healthier air quality, as well as being highly efficient and eco-friendly.

For these reasons, mini split heat pumps are becoming increasingly popular among homeowners who want more flexibility when it comes to regulating temperatures in their homes.