The Main Types of Air Conditioning Systems Explained
Walk into any appliance store or browse online and you will quickly find yourself staring down a wall of specs, brand names and model numbers with no clear idea of where to start. Choosing between the different types of air conditioning systems is one of the most common headaches Australian homeowners face, and getting it wrong can cost you thousands. This article covers the four main options you will come across: split systems, ducted systems, multi-head split systems and portable or window units. By the time you finish reading, you will have a clear picture of how each one works, what it costs and which setup suits your home.
Key takeaways
- Split systems are the most popular types of air conditioning systems for single rooms and apartments.
- Ducted systems provide whole-home coverage but require higher upfront investment and roof space.
- Multi-head and portable units offer alternatives for specific situations like strata properties or rentals.
Split System Air Conditioners: The Most Popular Choice
A split system air conditioner is the most common type of air conditioning system sold in Australia, and for good reason. It consists of two units: a wall-mounted indoor head that delivers conditioned air into the room and an outdoor compressor that handles the refrigeration cycle. Installation is straightforward, running costs are low compared to older fixed-speed units, and modern inverter models can both heat and cool, making them a genuine year-round solution for most Australian homes.
The inverter technology in today's split systems is worth understanding. Rather than switching the compressor on and off at full power, an inverter unit ramps the motor up and down to maintain your target temperature. This uses significantly less electricity than older non-inverter models and keeps the room at a steadier, more comfortable temperature without the constant cycling.
Most current split systems also include built-in WiFi as standard, so you can control the unit from your phone before you even get home. This is now a baseline expectation rather than a premium feature on mid-range and above models.
For a practical entry point, the Daikin 3.5kW Cora Inverter Split System (FTXV35WVMA) is priced at $1,287 and covers a medium-sized room of around 20 to 35 square metres comfortably. It is a reliable, no-fuss unit that suits bedrooms, home offices and living areas in smaller apartments. If you want to step up, the Daikin 3.5kW ALIRA X Inverter Split System (FTXM35AVMA) comes in at $1,447 and adds built-in WiFi along with a sleeker design and improved air filtration. Both are solid choices at the 3.5kW capacity, which is the most popular size sold in Australia.
The main limitation of a split system is simple: one indoor unit cools one zone. If you want to air condition your living room, two bedrooms and a study, you are looking at four separate units, four separate installations and four separate running costs. For multi-room coverage, a ducted or multi-head system will make more sense, which we cover further below.
Split systems are the right fit for renters who want a portable investment they can take with them, apartment dwellers, anyone cooling a single room or zone, and buyers who want the best performance per dollar spent upfront. Browse our full range of split system air conditioners to compare models and prices across all major brands.
Pros and Cons of Split Systems
- Affordable upfront cost: Entry-level units start from around $800 to $900 for supply only, making them accessible for most budgets.
- Energy efficient: Inverter technology keeps running costs low, and most models carry strong energy star ratings.
- Quiet operation: Indoor units typically run at 19 to 22 decibels on low fan speed, quieter than a whispered conversation.
- Reverse-cycle heating and cooling: One unit handles both summer and winter, removing the need for a separate heater.
- Quick and clean installation: A standard single-phase installation takes a licensed electrician around two to four hours.
- One unit, one zone: Each indoor head only conditions the room it is installed in. Whole-home coverage requires multiple units.
- Visible wall unit: The indoor head is mounted on the wall and is always visible. Some people find this intrusive in living areas.
- Not suited to whole-home cooling: Running four or five separate split systems across a large home is less efficient and more expensive than a properly zoned ducted system.
Ducted Air Conditioning: Whole-Home Comfort
A ducted air conditioning system uses a single central unit, typically installed in the roof cavity or under the floor, to push conditioned air through a network of ducts and ceiling vents across every room in the home. The result is whole-home heating and cooling from one system, with no wall-mounted heads in sight. For a deeper look at how the system works, see our guide to What Is Ducted Air Conditioning and How Does It Work?
The biggest appeal of ducted systems is the invisible installation. Once the vents are fitted into the ceiling, there is nothing on the walls and nothing cluttering the room. This makes ducted systems a popular choice for new builds and major renovations, where ductwork can be planned into the design from the start rather than retrofitted around existing ceilings and walls.
Modern ducted systems also support zoning, which lets you divide the home into separate areas and only condition the zones that are actually in use. A well-configured zoning setup can meaningfully reduce running costs compared to cooling every room at once, which is one of the strongest arguments for ducted over multiple split systems in a large home.
The trade-offs are real, though. Ducted systems require adequate roof space for the central unit and ductwork, which rules them out for some homes entirely. Installation is a significant job that must be carried out by a licensed professional, and the upfront cost is considerably higher than a single split system. They also suit larger homes best. In a two-bedroom apartment, a ducted system is almost certainly overkill.
As a real-world example, the Mitsubishi Heavy Industries 10kW Inverter Ducted System (FDUA100AVNAWVH) is priced at $4,046 supply only. A 10kW capacity is well suited to a medium-to-large home of around 100 to 150 square metres, and Mitsubishi Heavy Industries is one of the most trusted names in Australian ducted installations.
| Feature | Detail |
|---|---|
| Best suited to | Homes with 3+ bedrooms, new builds, major renovations |
| Installation requirement | Roof cavity or underfloor space, licensed installer essential |
| Key advantage | Whole-home coverage, no visible wall units, zoning capability |
| Key trade-off | High upfront cost, not suited to smaller homes or apartments |
| Supply-only starting price | From around $4,000 |
Is Ducted Air Conditioning Worth the Cost?
Ducted air conditioning is worth the cost for larger homes where whole-home coverage is the goal, but it requires a realistic budget that accounts for both the unit and a substantial installation bill. Supply-only ducted units start from around $4,000, and installation typically adds several thousand dollars on top of that, depending on the size of the home, the number of zones and the complexity of the roof space. Our ducted air conditioning cost guide breaks down what you can expect to pay across different home sizes.
The per-room cost comparison is worth doing before you decide. Equipping a four-bedroom home with individual split systems in every room could easily cost $6,000 to $8,000 in supply and installation combined. A ducted system covering the same home may land in a similar range once you factor in zoning, and it delivers a cleaner result with lower long-term maintenance complexity. For smaller homes or anyone cooling just one or two rooms, a split system will almost always be the better value choice.
Multi-Head Split Systems: One Outdoor Unit, Multiple Rooms
A multi-head split system connects a single outdoor compressor to two, three, four or five indoor units installed in separate rooms. Each indoor head operates independently, so you can run the bedroom at 20°C while the living room sits at 24°C, all from one outdoor unit. Browse our range of multi-head split systems to compare brands and configurations across all major capacities.
The main advantage over installing multiple standard split systems is the reduction in outdoor units. Instead of three compressors bolted to the side of the house or taking up ground space, you have one. This matters a great deal in strata-titled properties where body corporate rules often restrict the number of outdoor units allowed, and it also makes a practical difference on homes with limited wall or ground space on the exterior.
The trade-off that catches people out is the single point of failure. If the outdoor compressor develops a fault, every indoor unit in the house stops working at the same time. With separate split systems, a fault on one unit leaves the others running. This is worth weighing up, particularly in climates where air conditioning is relied on heavily through summer.
Multi-head systems also carry a higher upfront cost than a single split system, though that is expected given the additional indoor units. The installation is more complex than a standard split, and not every installer works with multi-head configurations, so it pays to confirm your installer's experience before committing.
This type of system suits homes with two to four rooms to condition, limited outdoor space for multiple compressors, or strata properties with restrictions on external equipment. For anyone in that situation, a multi-head system is often the most practical path to whole-home comfort without the cost and complexity of ducted. For a thorough comparison of the pros and cons, see our article on Multi Head Split System Air Conditioners: Are They Worth It?
Portable and Window Air Conditioners: Flexible but Limited
Portable and window air conditioners are the only types of air conditioning systems that require no permanent installation, making them the go-to choice for renters, temporary spaces, or rooms where a split system simply cannot be fitted. Portable units stand on the floor and exhaust heat through a flexible hose vented out a window or door gap. Window units are permanently fitted into a window frame opening. Both cool a single room, and both cost far less upfront than a split system or ducted setup.
The key limitation of a portable unit is efficiency. Because the unit itself sits inside the room it is trying to cool, it generates heat that partially offsets its own cooling output. The exhaust hose also creates a slight negative pressure in the room, drawing warm air in through gaps around doors and windows. The result is that a 2.6kW portable unit will not cool as effectively as a 2.6kW split system running at the same capacity. You are paying a convenience premium in running costs every time you use it.
The Rinnai 2.6kW Portable Air Conditioner (RPC26MC) at $689 is a practical entry-level option for a small bedroom or study up to around 20 square metres. If you need more grunt for a larger room, the Rinnai 3.5kW Portable (RPC35MC) steps up to $849 and handles spaces up to around 30 square metres. Neither unit requires a licensed installer, which keeps the total cost of ownership low for short-term or rental situations.
Window units sit a step above portables on efficiency because the compressor is partially outside the room, reducing the heat load problem. The trade-off is that installation is permanent and requires a suitable window opening of the right dimensions. They are harder to find in Australia than they once were, with portables having largely taken over the low-cost, no-installation segment of the market.
Both types suit renters who cannot modify walls, holiday homes used only part of the year, or rooms in older homes where running refrigerant lines for a split system is not practical. For a detailed side-by-side breakdown of how the two formats compare, see our article on portable vs window air conditioners.
Comparing All Types of Air Conditioning Systems: Quick-Reference Table
No single type of air conditioning system is the best choice for every home. The right system depends on how many rooms you need to cool, how much you want to spend upfront, and whether you are renting or renovating. The table below puts all four system types side by side so you can compare the key factors at a glance.
| System Type | Best For | Upfront Cost (Supply Only) | Installation Complexity | Whole-Home Coverage | Reverse Cycle |
|---|---|---|---|---|---|
| Split System | Single rooms, apartments, renters | From ~$800 | Low (2 to 4 hours, licensed installer) | No (one unit, one zone) | Yes (most models) |
| Ducted | Larger homes, new builds, renovations | From ~$4,000 | High (roof space required, multi-day job) | Yes | Yes |
| Multi-Head Split | 2 to 4 rooms, strata properties, limited outdoor space | From ~$2,500 | Medium (more complex than single split) | Partial (multiple zones, one outdoor unit) | Yes |
| Portable / Window | Renters, temporary spaces, single rooms | From ~$689 | None (portable) or minimal (window) | No (one room only) | Some models (cooling only is more common) |
There is no universally 'best' system, only the right system for your specific situation. A renter in a one-bedroom apartment and a family in a four-bedroom house have completely different needs, and the correct answer for each will be different. Use the table above as a starting point, then factor in your home's layout, your budget for both supply and installation, and how you actually use the space day to day.
How to Choose the Right Air Conditioning System for Your Home
The right air conditioning system comes down to four practical questions: how many rooms do you need to cool, what is your upfront budget versus your tolerance for ongoing running costs, do you rent or own, and do you need heating as well as cooling? Work through those four questions honestly and the right system type will become clear without much guesswork.
For most Australian homes, the answer lands on one of two options. A reverse-cycle split system is the best fit for single rooms, apartments and renters. It is affordable upfront, efficient to run, handles both heating and cooling, and can move with you if you change address. A ducted system makes more sense for larger homes of three or more bedrooms where whole-home coverage and a clean, vent-only aesthetic are the priority, provided the budget and roof space are there to support it.
Multi-head systems fill the gap between those two, particularly for strata properties or homes with limited outdoor space. Portable and window units are the right call only when a permanent installation is off the table entirely.
If you are still weighing up your options, our team is happy to help you match the right system to your home. Browse our full range of split system air conditioners or get in touch with the AusAir team for straightforward advice with no pressure.
Frequently Asked Questions
What are the four types of air conditioners?
The four main types of air conditioners are split systems, ducted systems, multi-head split systems and portable (or window) air conditioners. Split systems cool or heat a single room via a wall-mounted indoor unit paired with an outdoor compressor. Ducted systems distribute conditioned air through ceiling vents across an entire home. Multi-head splits connect multiple indoor units to one outdoor unit, while portable and window units require no permanent installation.
What are the three types of AC systems?
Some classifications group AC systems into three broad categories: split systems (covering both single and multi-head units), ducted or central systems and portable or window units. The number of 'types' really depends on how granularly you classify them. In Australian homes, split systems and ducted systems account for the vast majority of installations, with portable units filling a niche role where permanent installation is not practical.
What is the best type of air conditioning system?
The best type of air conditioning system depends on your home size, budget and how you use it. For most Australian homes, a reverse-cycle split system offers the best balance of upfront cost, energy efficiency and straightforward installation. For larger homes wanting whole-home comfort from a single system, a ducted air conditioner is typically the better long-term investment despite the higher installation cost.
Which type of AC is used in Australia?
Split system air conditioners are by far the most common type used in Australian homes, valued for their affordability and reverse-cycle capability that handles both heating and cooling. Ducted systems are popular in larger homes and new builds where whole-home climate control is a priority. Evaporative coolers are also widely used in drier inland climates such as Victoria and South Australia, where low humidity makes them highly effective.
