How Do Ductless Air Conditioners Work?

Carolina Evans
Carolina Evans
Research Writer
Holds a Master’s degree in Engineering and is keen on her own home’s climate. Sometimes we think that Carolina owns every single product she writes about – that’s ho read more
Reviewed By
Richard Powell
Richard Powell
Expert Consultant
For 8 years, Richard had been working as an HVAC specialist and AC unit installer since his student years. Now, he’s our main consultant on every technical aspect that may read more
Last updated: August 08, 2023 is reader-supported. We may earn a commission through products purchased using links on this page. Learn more about our process here

Ductless air conditioners, also sometimes called ductless mini-split AC systems, are energy-efficient appliances. They allow you better control over your heating and cooling needs and are ideal for additions or smaller homes, but can be used for larger spaces and houses, too. Some homes don’t have ductwork, and that’s when a ductless mini-split AC system may be a great choice. If you’ve ever asked yourself: “How do ductless air conditioners work?”, well, it’s pretty simple. In a traditional AC system with ductwork, warm air is pulled from the indoor space into the AC unit, which cools the air by passing it over evaporator coils. The cooled air is then distributed through the ductwork of your home to your vents. Then the outside AC unit expels the hot air.

Ductless systems work the same way, but instead of relying on a large AC unit to pass the air through ductwork, it pumps the air directly where it’s needed, skipping any waste and quickly heating or cooling your space. This is why it can be such a great choice for houses that can’t rely on ductwork.

Main components of ductless Air Conditioners

How Do Ductless Air Conditioners Work?

Ductless air conditioners are different than your typical air conditioning system. Those use vents, ductwork, and a large external air conditioner unit to cool your home. Whereas ductless systems use the following components to cool your home their own way:

  • A blower/evaporator unit: with a ductless system, you have an indoor unit besides an outdoor unit. This is the blower/evaporator unit. It typically is connected to the wall of the room that needs to be cooled. It sucks in the warm air from the room and blows out cool air.
  • A conduit: Whereas a traditional AC system uses ductwork in a house, a ductless system relies on a conduit. This conduit connects the indoor and outdoor units. It’s a thin hose that keeps the power cable, and refrigerant and other components safe. It’s also how the hot and cold air travel between the indoor and outdoor unit.
  • A condenser: This is the outside unit. It takes all the heat sucked from your home by the indoor unit and pumps it outside.

As you can see, a ductless system works very similar to a more traditional air conditioner system, but without the need for ductwork throughout your walls, ceilings, and floors for the cooled air to travel room to room. This is why ductless systems can be such a great choice for smaller homes or older homes without existing ductwork.

Advantages and drawbacks of ductless AC units

A ductless mini-split AC system installation can be a great choice for smaller houses that either don’t have existing ductwork or can’t have traditional ductwork. Some benefits of this modern HVAC system can include:

  • Zoning — The ability to adjust the temperature in each individual room with an indoor unit.
  • Lower Energy Costs — Ductless systems are more cost-efficient than other AC systems. They only heat or cool specific areas in the home, which means energy is never wasted. This offers cost savings and is good for the environment too.
  • Easy to Install — Installation tends to be much easier and quicker than traditional AC systems because there’s no ductwork.
  • Better Air Quality — Because the unit filters the air it takes from the outside, it increases the air quality of your home. The filters can also be replaced more easily, to help keep you on top of your air quality needs.

But there are some drawbacks when it comes to ductless systems too, which is something to keep in mind. A ductless mini-split AC system requires professional installation, even though it doesn’t require ductwork to be added, removed, or rearranged in your home. This is because there may need to be small holes drilled to pass copper tubing, communication and power lines, and even condensation drain lines, which is something that should be left up to a pro. There are also some other drawbacks as well, including:

  • A higher up-front cost. Though this can often be offset with later savings
  • An indoor unit, which some homeowners may find unsightly
  • Multiple outdoor units if you’re planning on cooling more than 4 rooms

The pros and cons of ductless systems should all be weighed when considering what air conditioning system is right for the needs of you and your home and to find the best comfort all summer long.

Reasons to install a ductless AC unit

There are some times when a ductless system is not only a good choice for you and your home, it may be the best choice over a more traditional AC system. Let’s find out why:

  • Home additions: If you’ve added a new den, sunroom, even a garage or additional bedroom or living space, it’s often easier and more cost-efficient to add a ductless system to cool that space instead of trying to connect it to your existing AC system.
  • Downsizing larger homes: If you find that you just don’t use some of the rooms in your existing house, a ductless system may be a way for you to keep cool the spaces that you frequently use, while not wasting energy on cooling rooms that aren’t used.
  • Meeting everyone’s needs: If you live with a lot of people in your home who can’t seem to agree on what’s the best temperature for your spaces, a ductless system can let each room be adjusted accordingly.
  • Difficult ductwork: Many older homes don’t have existing ductwork installed, so if you want to add AC to your home, you either have to have ductwork installed (a process that is often costly, time-consuming, and isn’t even always possible for every home) or use an alternative solution. Ductless systems may be expensive to install up-front, but it’s less expensive than adding ductwork to an existing house, and it will often save you money in the long run.


How Do Ductless Air Conditioners Work?

As you can see, ductless mini-split cooling systems offer a variety of cooling opportunities for many homes and spaces. If your home is lacking ductwork, or you want cooling power without difficult installations, then a ductless mini-split AC system may be for you. Or if you’ve put an addition on your house, or have family members that constantly squabble over the temperature of a room, it may be the best choice for your home. Ductless systems may be expensive to install, but they often provide better air quality and can save you money on your utility bills. Now that you understand how a ductless air conditioner system works, you can decide whether it’s right for you and your home’s needs.

Leave a comment

Your email address will not be published. Required fields are marked *