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What is Ductless Air Conditioning?

B. Turner
B. Turner

Ductless air conditioning is a system of cooling the home without the use of central air duct systems. While this can be achieved using window-mounted units, a more efficient technique involves the use of split system air conditioning units. These are a type of ductless air conditioning made up of two components: an indoor fan unit used to disperse cool air, and an outdoor refrigerant unit which cools air and disposes of condensation. A series of flexible lines connect the two units, allowing electricity, refrigerant, and condensate to run between the indoor and outdoor units.

Split system ductless air conditioning units are generally designed to cool a single room, though some are equipped with multiple fan units that connect to a single outdoor condenser. In this case, a fan can be placed in several rooms, though all are controlled by the same thermostat. The fan on a ductless air conditioning system can be mounted in the wall, within a drywall ceiling, or in a soffit. These fan units are generally small and unobtrusive, and many offer decorative grilles and covers to help them blend into a home's décor.

A thermostat connected to a ductless air conditioning system.
A thermostat connected to a ductless air conditioning system.

These split air conditioners are used in a variety of settings. First, they may be used in homes that are not equipped with a central duct system, or those that have heating ducts but no central air system. Not only is ductwork itself expensive, but one must often remove and replace walls and ceilings to accommodate new ducts, which can be both costly and messy. These units are especially beneficial in cooler climates, where air conditioning is only used for a few months out of the year. Ductless air conditioners are also useful for cooling a garage or home addition without extending the existing duct network.

There are several benefits to using a split air conditioning system instead of another type of unit. First, the cost of a split system is much lower than a ducted system as there is no need to install and maintain ductwork. Because ductless air conditioning systems run on a thermostat, they offer a high level of energy efficiency, and can maintain a steady temperature. Cold air is directed into the room where it is needed, and is not wasted on unoccupied rooms. Finally, these split systems are quieter and more efficient than window units, and do not have to be removed and reinstalled at the start and end of the summer season.

Discussion Comments


Literally, an excellent explanation given about the ductless air conditioners. Thanks mate, for sharing this wonderful post.


@Azuza - Going without air conditioning is torturous in the summertime. My middle school and my high school were both not air conditioned and I remember it being pretty awful. I was happy to get to college just so I could have some AC!

Seriously though, I think my high school probably could have sprung for a ductless air conditioning system. I grew up in a fairly affluent county. And at the very least, I think it would have improved student concentration!


I'm glad these ductless air conditioning systems exist. A few of my friends live in houses without air conditioning and window units really help them during the summer time!

I think these systems sound like they would be a lot easier to clean too. I know having your air ducts cleaned can be extremely expensive, but necessary especially if you are an allergy sufferer.


@sinbad - I am the same way. I am always the one who is cold in a room and loves a hot summer day. I will be sure to sleep in the farthest bed, when I stay in a hotel with my friends who love the air conditioning to be on high!

Although the duct systems seem to work better at keeping things at a even cool or even warmth, I wish that the school I work at would go to a ductless system!

It is always too cold or too hot in my school and I think we must be spending a fortune of our taxpayer's dollars in trying to keep it so cold or so warm.

If everyone was able to keep their room at a comfortable level I bet the bills would decrease, not to mention the money they would save in putting in a ductless system versus a duct system in new school buildings!


I have never seen a hotel use anything but a ductless air conditioning system. I am cold-natured so when I am in a hotel with friends I make sure to take the farthest bed from the air conditioning unit.

I wondered why a hotel or anybody else would use a ductless system as the duct systems seem to cool evenly much better. But now I know that they have good reason - much more inexpensive. And it makes sense for hotels to want their customers to put the room at a temperature of their liking.

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    • A thermostat connected to a ductless air conditioning system.
      By: Dave Friedel
      A thermostat connected to a ductless air conditioning system.