Split System Air Conditioning

Split Systems get their name as they are ‘split’ into 2 parts; an indoor and an outdoor unit.

To heat and cool, it utilizes energy efficient refrigerant technology. On a basic level, the process involves a refrigerant which circulates through the system, turning from a liquid into a gas and back again.

When using cooling mode, the indoor unit draws in warm air from inside the room which is then passed over refrigerant coils. The refrigerant coils absorb the heat and the cooled air is distributed back into the room. When using heating mode, that process is reversed.

There are 3 different air conditioning functions you can use – heating, cooling or just fan. There are cooling-only split systems on the market, but they are generally not installed in Victoria.

Ductless Air Conditioning

Split System ACs don’t require ducts to be installed.

The indoor unit, or ‘head’ is attached to a wall inside your house and provides heating and cooling to the room they are installed in. The outdoor unit, or compressor is located outside your house.

Multi Splits are a great option if you want multiple rooms air conditioned, but your house design doesn’t allow for the installation of a ducted system. For example, townhouses with no roof cavity for ducts.

They use 1 outdoor compressor unit to run multiple indoor heads.

Although Multi Splits operate in the same way as regular Split Systems, they differ in two main ways:

1. The one outdoor unit can run multiple indoor units
2. The indoor units come in various designs

Outdoor unit sizes

Multi Split system outdoor units come in a range of sizes, most commonly from 7.5kw to 12kw.

How many indoor units can be connected to them varies depending on the brand and model, but it’s usually 3-5 indoor units.

In determining what size outdoor unit you need, you first need to consider how many rooms you want air conditioned and the size of the rooms.

For example, if you have 3 small rooms which require a 2.5kw air conditioner, you will need at least a 7.5kw outdoor unit to run them (3x 2.5kw).

Indoor unit designs

The indoor units can be:

• Regular wall-hung split system indoor units
• Slimline grills (dependent on your house design)
• Multi-directional ceiling cassettes
• Floor consoles

More info

Find out more – visit our Multi-Split System page.

Split Systems use energy-efficient refrigerated technology that isn’t just for cooling – it also provides effective heating.

That’s why some people refer to them as refrigerated heating and cooling systems. The same technology is found in ducted reverse cycle air conditioners, often called ducted split systems.

An advantage of refrigerated systems is that you can set your preferred temperature, and the system will reach and maintain it automatically.

For this reason, many homeowners prefer refrigerated cooling over evaporative cooling, which, although it has very low running costs, it doesn’t allow precise temperature control.

The quickest and cheapest option is to install the outdoor unit directly on the other side of the wall to the indoor unit, as additional pipework is not required. However, this is not always possible, especially if the indoor unit is on an internal wall.

The outdoor unit can either sit directly on the ground on a concrete pad or pavers or attached to the wall with brackets. Less commonly, it can be installed on top of a roof.

Our staff will be able to assess the most suitable location for your outdoor unit.

Split Systems come in a range of sizes from 2.5kw to 9kw.

The size of the area that you want to heat or cool, along with other factors such as orientation, insulation, the amount of sunlight entering the room and ceiling height will determine what size system you need

.2.5kw is the smallest size, considered a “mini split” and is suited to small rooms such as bedrooms and studies.

5kw and 6kw are suited to medium sized rooms.

And 7kw, 8kw and 9kws are commonly used in large open plan areas such as a kitchen/dining/family area.

Sizes can slightly vary between brands, for example, not all brands offer a 9kw. Please let us know if you have a brand preference.

The importance of getting a correctly sized air conditioner

If you get a unit which too big,  it can heat or cool your room quickly then turn off. Then turn back on when the room temperature rises or falls again. This on/off cycling draws extra power than a properly size air conditioner would.

If you get a unit which is too small, it will constantly be trying to reach desired temperature which can cause the outdoor compressor to constantly run at a high level, which will utilize more power. It may also  not effectively heat or cool your room.

Our Split System Air Conditioner Room Size Chart can help you calculate which Split System may be right for your home, but our technicians will always verify your house’s details with you to ensure you are getting the correct sized unit.