Friday, 28 June 2013

Ductless Multi Zone Air Conditioners Explained

People who have an interest in vent free air cooling solutions can read this and learn all about ductless multi zone air conditioners and how they function. On the surface, they may appear to be similar in functionality to regular ventless units that have been explained at length in previous articles on this site but dig a little deeper and you will discover some fascinating differences.

Whole House Air Cooling Solution

The first thing that you will notice about these setups is that they incorporate several units placed at strategic points around the home, qualifying them with the "multi-zone" label. They are computer controlled to insure the correct level of cooling in each room according to occupation.

That means the system will not waste energy cooling unoccupied spaces in your home, thus reducing power consumption dramatically. This is an important consideration in this day and age when fuel costs continue to rise at an alarming rate.

Not Portable

The next thing that you'll notice is that these systems are not made up of portable units as with individual evaporative cooling units described in previous articles here. In fact, these systems are comprised of true, two part air conditioning units that expel hot air to the outside via fanned condenser units mounted outside.

They use non-ozone depleting refrigerant gas in their system, making them kinder to the environment while still being able to provide highly efficient cooling in all climates including high humidity (where swamp coolers fall down).

Not Evaporative (Swamp) Coolers

While swamp coolers are excellent for cooling spaces in areas of low humidity and extremely cheap to run in comparison with true air conditioning systems, these multi zone systems offer a viable alternative for those living in humid climates. Costs are higher than evaporative solutions, but lower than conventional ducted aircon systems (HVAC).

These ductless split air conditioners and heat pumps offer a heating solution in winter as well as a cooling one in summer, making them highly versatile. However, heating by electricity is still an expensive method and one that should be considered before deciding on one of these systems.

Installation Considerations

Installing a system like this can be far less invasive than conventional HVAC, although it still requires creating exit vents to the outside for the inner and outer units to be connected through exterior walls. There is no unsightly ducting (or extensive remodelling to disguise ducting inside ceiling space or boxed into walls) making these units far more aesthetically suitable in a home.

Vent holes are created behind the internal unit, making it invisible to an occupant. Similarly, the exterior unit is placed over the exit vent making it invisible from the outside. Units run much more quietly than older systems, which is another important consideration.


Another important aspect of this kind of setup is its ability to dehumidify the indoors air in areas of high humidity. This can become an important consideration where long periods of very high humidity can create problems in the home.

These problems include damp forming in walls and ceilings, mold growing in closets and cupboards and an uncomfortable living atmosphere. By effectively extracting the humidity and expelling to the outside, this type of system becomes so much more than simply an effective cooling and heating solution.


While a ductless multi-zone air cooling (and heating) system will cost considerably more to install and run than a comparable evaporative system, it has several benefits especially for people who live in climates with high humidity where evaporative units are not so effective. This is a consideration that must be explored in this case as costs will still be lower than with a conventional heating, ventilation and air conditioning installation.

While truly ventless air coolers are effective, cheap to run and highly versatile in dry climates, not everyone can enjoy their benefits. That makes a true aircon system that can run at a much lower cost than conventional ducted systems a viable alternative where humidity is a problem. The choice, in the end, is up to the buyer as always.