What Are the Different Types of Air Conditioning System?

This guide has been compiled to outline what the different types of air conditioning systems are, as well as highlight important points typical for each.

There are several variants of air conditioning equipment, each with its own pros and cons that are necessary to appreciate if you're looking to purchase an air conditioner.

different types of air conditioning systemEach air conditioner has its own unique features and quality.

A modern, energy-efficient multi-head split unit will doubtless be seen to be more efficient than an older model in its class.

It is therefore important to carefully examine each model. You can compare air conditioner energy consumption using the energy rating star system.

However, it's important to look at the equipment's outputs and inputs for more in-depth details.

Ducted Central Air Conditioning

Central air conditioning (also known as ductless air conditioning) often comes out top in terms of energy efficiency and in many cases is the best choice for cooling an entire home.

A ducted system consists of a compressor located outside the building, an internally installed evaporative unit and a house-wide system of ducts that deliver conditioned air to different rooms via vents.

You will need to make some modifications to your home to install a new ducted system. This type of cooling system also comes with a significant initial cost.

These systems can be used to control the temperature in a home or office. They are often cheaper to run, room by room than mini-split systems, window units or portable AC units.

With the compressor situated outside the building, the internal workings are virtually invisible with the exception of the controls and vents.

Split Air Conditioners

Modern home dwellers are quite familiar with ductless AC systems, also referred to as zoned, split or mini-split systems.

They consist of two units:

  1. One or more condenser units that provide cooled air located inside the house
  2. The compressor unit located outside the house

You can use these AC systems to heat or cool a single area, or you can install multi-zone systems that cater for two or more rooms. With a single compressor outside the building and several indoor units that condition the air in different areas of your house, this type of system is relatively unobtrusive.

Indoor units are often mounted high on a wall, keeping them out of the way of furniture and this should be taken into account when designing your space.

Multi-head split and wall split systems are typically smaller and less powerful than central ducted systems. The units are connected with piping instead of large ducts.

The indoor units are highly visible because of their size, which can be considered less appealing asthetically than the more discreet vents deployed in ductless systems.

While wall-hung split and multi-head split systems are generally more expensive than the smaller self-contained types of air conditioners (window and portable), they have lower on-going running costs.

Installing wall-hung or multi-head ductless split AC systems will require some modifications to the home including creating openings in walls for the pipes. It is recommended to engage a professional to install a new mini-split system.

Self-Contained AC Systems

Aside from the larger central and split AC systems for cooling homes, there are also smaller, lower-cost self contained AC units available for cases where the household budget won't extend to the purchase of a larger system.

These units are described as being self contained as both the compressor and condenser functions are both housed in a single unit that can be placed in strategic locations in the home.

Included in this class of air conditioning equipment are the window AC units, PTAC (packaged terminal air conditioners), VTAC (vertical terminal air conditioners) and portable units. Let's look at each type in more detail:

Window Air Conditioners

Window AC units are a popular choice to control the temperature of small rooms or places with few rooms such as apartments.

These units contain the condenser and coils, as well as the evaporator, all in one unit. Window AC units can be installed in most window openings and don't require any modifications to the home.

These AC units are generally more affordable to purchase, while split or ducted systems are better if you're looking to cool multiple rooms.

Window air conditioners are not permanently fixed and if necessary, can be moved with you when you move. They are a good choice for people who rent or plan to move in the near future.

Window air conditioners operate in cycles. They turn on and off to heat or cool the room, and then switch off when the temperature is at the desired level.

Once the room begins to heat up, they turn back on to resume cooling. They are not as efficient in consuming energy as central or split systems, but more efficient than portable units.


Packaged terminal AC units are similar in function to window AC units with the exception that they are generally installed below a window or if this is not possible, anywhere against an external wall.

The venting is achieved by creating a hole in the wall through which the unit can exhaust its hot air to the outside, thus negating the necessity for a window to be present.

Vertical terminal AC units are similar to PTAC with the exception that they are vertically oriented to enable them to be stored out of sight, for instance inside tall, narrow closets.

These units are more commonly found in installed in individual hotel and motel rooms as well as rooms in older hospital and health center buildings. Their main appeal over window units is they don't obscure natural light coming into a room from a window.

Portable Air Conditioners

Although portable air conditioners can be moved easily, they are not necessarily as easy to transport as their names suggest.

It is easier to move house with portable air conditioners because you can carry around your cooling needs.

While being essentially portable, on wheels, they still need to be connected to a window or wall vent via a flexible vent hose to exhaust the hot, moist air they produce as a result of the refrigeration process.

These systems draw in warm air and cool it internally before returning the chilled air to the room. Some portable AC units are self-evaporating, meaning they remove much of the moisture that condenses inside the unit through the exhaust vent.

There are two types of hose configuration:

  1. Single hose (most common)
  2. Dual hose

Single hose units pull warm air from the room and cool it. The hot air is then blown outside through its vent hose connected via a window fixing kit that is provided with the unit upon purchase.

This action creates negative pressure in the room and allows more warm air to enter the home from the outside. Single hose models are the most inefficient type because of this.

Portable AC units with dual hoses draw air in from the outside to be cooled internally. This action greatly reduces any negative air pressure problems. Double hose models are more efficient than single-hose models, however they are still less efficient than other types of air conditioners already covered above.

The big advantage is that portable air conditioners are generally most affordable to purchase. They will, however, end up costing more in electricity usage over other options.

If you don't move house very often, have a larger space to cool, or plan on more frequent use, it would be better to consider other types of AC equipment.

Evaporative Coolers and Fans

Another type of portable, self-contained cooling appliance is the evaporative or swamp cooler. These coolers are not true AC and are covered in their own article on the pros and cons of evaporative coolers.

Lastly, when the budget is so tight that you can't afford any of the above cooling solutions, there are a variety of fans that at least can circulate some air in a room and make you feel a little cooler when you position yourself in the air stream.


While there are a number of different types of air conditioners, each one has its own advantages and disadvantages.

Although ducted, central air conditioning is generally the most efficient, it may not be appropriate or the best choice for those who only need to cool or heat up a single room or a very small apartment.

While portable AC units are a good choice for people who move home frequently as they can simply take their appliance with them, the higher running cost may cause you to think twice before committing to this option.

In all cases, it is best to determine your air conditioning needs and then choose the right type of system for you.

Posted: June 12, 2022

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