How do ductless air conditioners work? We might be used to modern tech advancements, but this can still be a somewhat puzzling concept.

You have likely come across ductless systems and have a good idea of how they work. You still might want to know more.

If you haven’t, you should want to know what they are because these air conditioners offer much better performance than traditional units and total control over indoor temperatures. They can also be an extremely effective method of reducing monthly energy bills.

The main difference is that they do not need ducts to cool air temperatures throughout the home.

Same Function: Different Execution

Ductless air conditioners are still air conditioners. The main difference is that they do not need ducts to cool air temperatures throughout the home.

A conventional AC system places evaporator coils in the home’s existing ductwork to extract heat from the air as it passes through. The heated refrigerant in these lines then moves to an outdoor condenser to transfer the heat outside of the home.

This is an effective method but can be considered dated when compared to ductless systems.

Ductless systems place multiple indoor units throughout the home to extract warm air and dispense it outside the house with the use of a single outdoor unit.

What makes this method of air conditioning more effective is that multiple evaporators are present as opposed to just one. This means that each can work at variable rates to achieve desired temperatures instead of having to cool the entire house at once.

Parts of a Ductless Air Conditioning System

At their core, ductless systems are still air conditioners and share many of the same elements with central AC systems. The difference is how those elements are spread out. If you understand any type of air conditioning system, you already know how a ductless system works.  

Indoor Units

Ductless systems place blower/evaporator units throughout the home. These indoor units are placed on high standing walls and are easy to distinguish. Each unit has its own evaporator coils, blower motor, and air filter. The blower transfers air in and out of the unit, the evaporator coils extract the heat, and filters remove any impurities that can impact air quality.


Conduits can be found on each of these units. It contains power cables and refrigerant lines. Ductless systems still require refrigerant to leave each unit to extract the heat from the home. Inside the conduit, you will find a line transferring coolant between the indoor and outdoor units.

Outdoor Unit

Like with central AC, an outdoor unit is used with ductless systems. The outdoor unit uses condenser coils to transfer heat outside of the home. This process will also bring the refrigerant back to a liquid state needed to extract heat from the house.

Pros of Zoning

The primary advantage of using a ductless system is zoning capabilities. But what makes this such a desirable characteristic?

As we stated earlier, multiple evaporator units are placed throughout the home. This means that the workload spreads across various units. Spreading the workload out reduces strain and energy consumption.

These units are smaller and require less energy to perform their duties. When only a portion or even a single room needs cooling, the use of a smaller unit is much more energy-efficient than powering a large one.

Higher Upfront Cost (Better Value in the Long Run)

Zoning capabilities can provide better results while reducing energy costs. Most homeowners will debate whether it’s a worthy investment because ductless systems are about twice the cost of central AC systems.

To further complicate matters, central AC systems are still a viable option for cooling homes. They are also reliable and familiar systems that many folks are comfortable with.

Yes, the upfront costs are marginally lower, central AC produces higher energy bills than ductless systems. While it may only be a few dollars per month, this can ultimately define a central AC system as the more costly option.

HVAC system components will have a lifespan of 15-20 years. For at least 180 months, a couple of dollars can add up to a significant amount and make ductless systems the superior option.

To get even more out of a ductless system, we recommend pairing them with a programmable thermostat. This combines the ability to supply air conditioning to individual rooms with a schedule that can lower energy costs.

Maintenance of a Ductless System

There are more components in a ductless system, which does increase maintenance requirements. Each unit will need regular inspection and cleaning. While this may seem like a daunting task, it’s rather easy.

Over time, the air filter in each unit will collect dust and need cleaning or replacement. Additionally, the evaporator coils and drains will require inspection and cleaning from time to time.

Otherwise, one needs to take special care to ensure the exterior is dust-free. It also helps make sure no objects are nearby, which can restrict the unit’s airflow and performance.

Concluding Thoughts:

You may be considering whether or not you need a ductless system in your home. While there are benefits, it may not warrant removing a perfectly capable central AC system and existing ductwork.

However, if your system is nearing the end of its life, the efficiency and performance of a ductless system may warrant an overhaul of your home’s HVAC system.