Types of air conditioning, explained
What are the different types of air conditioning systems, and which one suits my building?
Published 17/09/2026. Written by the Pristine Cooling team, Kalgoorlie.
There are six types you will actually be offered for a commercial building in Kalgoorlie: split, multi head, cassette, ducted, VRV, packaged, plus evaporative which works on a different principle altogether. None of them is better than the others. The right one is decided by the building, by how the rooms get used, by where plant can physically go, then by what it costs to run for the next fifteen years. Here is what each one actually is.
The ones that do a room or two
Split system
The familiar one. A box on the wall inside, a box outside, two copper lines between them. One indoor unit, one outdoor unit, one space.
They suit a single office, a shop front, a site hut, a server room, anywhere with one area to look after. They are the least disruptive to install into a building that already exists, because the only structural work is a hole through a wall.
The catch is that they only ever do the room they are in. Four rooms means four of them, four outdoor units, four sets of pipework on the wall.
Multi head split
One outdoor unit, several indoor heads running off it. It solves the wall full of outdoor units problem.
The trade off is that the heads share a system. They are all heating or all cooling at the same time, so the sunny side of the building and the shaded side have to agree with each other.
Cassette
The same idea as a split, except the indoor unit sits up in the ceiling with a flat square grille flush with the tiles, blowing out in four directions.
Common in offices, retail, waiting rooms, anywhere a wall unit would look wrong or where there is no wall left to put one on. It needs a ceiling cavity deep enough to take it, which is the thing to check before anyone gets attached to the idea.
The ones that do a whole building
Ducted
One indoor unit hidden in a roof space or a plant cupboard, pushing air through ductwork out to vents in each room. From inside the room all you see is a grille.
It is the usual answer for a whole office floor, a medical suite, a clubhouse. It gets you an even result across a lot of rooms with no boxes on any wall. Zoning lets you shut off parts of the building that are not in use, which matters more out here than people expect, because cooling empty rooms through a Goldfields summer is money straight out the window.
What it needs is somewhere to live. A roof space deep enough, a path for the ducts, access to service it later. On a retrofit that is the question that decides whether it is possible at all.
VRV and VRF
Step up again. One outdoor unit serving many indoor units, with the refrigerant flow varied to suit what each area is asking for at that moment.
The point of it is that different parts of the building can do different things at the same time. A meeting room full of people can be cooling while a storeroom on the shaded side sits idle. It scales to multiple floors, it runs a long way from the outdoor unit, it wastes far less on a building where load moves around during the day.
It is the right answer for a bigger commercial fitout and the wrong answer for a two room office, because the cost only pays back when there is enough building to use it properly.
Packaged units
Everything in one box, normally sitting on the roof, with ductwork straight down into the space.
They suit big single volumes. Workshops, halls, messes, retail floors, a dining room that needs a lot of air moved. All the gear is outside the building, which keeps the plant noise and the servicing out of the occupied space.
We supply Temperzone and Rinnai APAC packaged units. On a build they usually come in under a mechanical services scope rather than on their own, because a roof mounted unit needs structural support, penetrations, electrical and sometimes a crane, all sequenced with the builder. That side of it is on our mechanical services page.
Evaporative is a different thing entirely
Everything above is refrigerated. It runs a refrigerant cycle to move heat out of the building. Evaporative does not. It pulls outside air across a wet pad, water evaporates, the air comes out cooler. It is the same reason a wet shirt feels cold in the wind.
That works well in dry heat, which is most of a Kalgoorlie summer. It uses less power than refrigerated for the same air movement. It also needs windows or vents open, because it works by pushing a constant stream of fresh air through the building rather than recirculating what is already there.
Two honest limits. It adds moisture to the air it delivers, so it loses ground on a humid day, which does happen here even if it is not the norm. And it cannot hold a set temperature the way refrigerated can, so it does not suit a space with a number it has to meet.
We supply commercial evaporative coolers from Seeley Coolair and Braemar. We also supply Climate Wizard, which is an indirect type: the outside air is cooled through a heat exchanger rather than by having water evaporate into it, so the supply air does not pick up the moisture on its way in. Which of the three suits a building depends on the building, which is the theme of this whole article.
What actually decides it
In the order the questions get asked on site:
- What is the building, how many separate areas does it have, do they get used at
different times
- Where can plant physically go, is there roof space, is there a plant area, can
a crane get in
- What power is available
- Does any space need to hold an actual temperature rather than just be
comfortable
- How much of the year will it run, because the running cost outlives the install
cost by a long way
- Who services it, how do they get to it, what happens when it fails in February
That last one gets skipped more than any other. Plant crammed into a space with no room to work on it costs more every year for the rest of its life, then costs more again the day it needs replacing.
We are a Daikin Specialist Dealer, which is the tier Daikin hand picks and trains rather than the one anybody can sign up to, so the Daikin range covers splits, cassettes, ducted and VRV. Alongside that we supply Temperzone and Rinnai APAC packaged units, plus evaporative from Seeley Coolair, Braemar and Climate Wizard. What goes in is chosen per job, not because it is what we happen to have.
Two things we will not do
We do not install a unit you bought somewhere else. Not a pricing question, not a scheduling one. If we did not supply it we will not put it in, because standing behind an install means standing behind the whole thing.
We do not quote an installation over the phone. Someone comes and looks first, every time. A number guessed from a description is a number that gets corrected later, usually badly, usually after you have already made a decision based on it.
If you are working out which of these suits a building, get in touch and we will come and look at it. More detail on what we install is on the air conditioning page.
Related pages
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