Choosing between ducted and split system air conditioning is one of the bigger comfort decisions you will make for your home. Both cool and heat effectively, but they solve different problems. Ducted systems condition the whole house through hidden ductwork and ceiling vents. Split systems condition individual rooms through separate indoor and outdoor units. The right answer comes down to your home’s size, layout, budget and how you actually use your rooms.
If you are weighing up ducted air conditioning from BG Electrical & Air Con against a split system, here is how the two compare on operation, installation, running costs and suitability.
How each system works
A ducted system runs from a central indoor unit installed in the roof cavity, connected to an outdoor condenser by refrigerant lines and electrical cabling. Insulated ductwork carries conditioned air through the ceiling to vents in each room, and return air grilles draw air back through filters. Most modern units are reverse cycle, so they heat and cool, and most offer zoning so you can shut off areas you are not using.
A split system has two parts: an indoor head mounted on the wall and an outdoor unit housing the compressor and condenser, joined by insulated pipework running through a small hole in the wall. Each unit conditions one room. If you need several rooms covered, a multi split can run up to around six indoor heads off a single outdoor unit, each with its own temperature setting.
Both rely on the same refrigeration cycle. The difference is distribution. Ducted treats the whole home at once, split targets the room you are standing in.
Installation and upfront cost
Ducted installation is the bigger job. It usually involves a team of three or four trades across one to three days, depending on the size of the home and the number of zones. Installers mount the indoor unit in the roof space, run ductwork to every room, fit the vents, site the outdoor condenser and complete the electrical work.
The trades doing it need to be licensed. Refrigerant handling requires an ARC licence, and electrical work must be carried out by a licensed electrical contractor who issues a Certificate of Testing and Compliance on completion. Keep that paperwork, as it generally underpins your warranty.
Roof access, ceiling height and structural constraints all affect complexity. Double storey homes need extra ducting drops and longer runs, plus zoning to balance the levels. Larger systems may also need a three phase power upgrade before installation can proceed.
Split system installation is far simpler. Two technicians can usually complete a single head in three to six hours. They bracket the indoor unit, core a hole through the wall, run copper pipework and cabling to the outdoor unit sited nearby, then commission and test.
On cost, ducted sits well above split. Ductwork, longer labour hours, bigger crews and zoning hardware all add up. Split systems need minimal structural work, so they are cheaper to get in. That said, once you are installing four or five heads across a house, the total can start creeping towards ducted territory.
Running costs and maintenance
Efficiency depends as much on how you run a system as on which one you choose. Split systems are efficient when you are conditioning one or two occupied rooms, especially inverter models that modulate output rather than cycling on and off. Ducted systems come into their own across larger homes, particularly with zoning and a smart controller so you are not paying to cool empty bedrooms.
As a general guide, a split system draws around 0.9 to 1.2 kilowatt hours per hour of operation, while a ducted system typically sits nearer 3 to 4. Heating and cooling makes up a substantial share of household energy use, and every degree you adjust the thermostat can shift consumption by around 10 per cent.
Both need an annual professional service. Filters are the main homeowner task. Check ducted return air filters roughly quarterly, and clean split system filters every one to three months. Clogged filters can push energy use up by 5 to 10 per cent. Split systems are easier and generally cheaper to service, since roof mounted ducted components are harder to reach.
Which system suits your home
Ducted wins on appearance. Small ceiling vents disappear into the ceiling and the hardware stays out of sight, which matters in design led interiors and character homes. Split systems put a visible head in every conditioned room, and several of them around the house can look busy.
Ducted suits larger homes of three or more bedrooms where you want consistent comfort throughout. It is easiest to install during a new build or major renovation while the ceiling is accessible. Double storey homes benefit in particular, provided the zoning is set up properly.
Split systems suit apartments, townhouses and smaller established homes where running ductwork is difficult or disruptive. They are also the practical choice when you only need one or two rooms covered, or when budget rules out a whole home system for now.
Making the call
Start with how you live in the house. If most rooms are occupied through the day, ducted delivers even comfort across the whole floor plan. If your family spends its time in one or two spaces, split systems avoid conditioning rooms nobody is in.
Layout matters too. Open plan homes suit the even distribution ducted provides, while homes with distinct closed rooms suit the individual control of splits, which helps when family members prefer different temperatures.
From there, weigh the upfront cost against running costs over the years you expect to be in the home. Cheapest to install is not always cheapest to own.
Whichever way you lean, have an air conditioning specialist assess the property first. Sizing, zoning and placement affect comfort and running costs more than the choice of system on its own.