Split System or Ducted? Choosing the Right Air Conditioning for a Cairns Home

Every spring the same question lands: "Should we go ducted, or just put splits in?" It is the right question to ask before you get a single quote, because the answer decides the budget, the running cost, how the house feels in February, and what you are paying to service for the next fifteen years.

There is no universal answer. There is a right answer for your house, your family and the way you actually live in it. This is how we work through it with people across Cairns, the northern beaches, Edmonton, Gordonvale and the Tablelands.

Start with how you use the house, not the floor plan

Most Cairns families cool two or three rooms hard and leave the rest alone: the bedrooms overnight and the living area in the afternoon and evening. If that is you, split systems in those rooms are usually the better buy. Each unit only cools the room it is in, only runs when that room is in use, and the rest of the house costs nothing.

Ducted comes into its own when you genuinely use the whole house: a big family, people working from home in different rooms, guests, or a layout where the living areas flow into each other so one cold room just leaks into the next warm one. Ducted with zoning lets you cool the living zone by day and the bedroom zone by night from one system, and the house feels even rather than patchy.

What the wet tropics change

• Humidity is the real enemy, not just temperature. A system that is oversized for the room cools the air fast and switches off before it has pulled the moisture out, which is why some rooms feel cold and clammy at the same time. Correct sizing matters more up here than almost anywhere else in Australia, whichever type you choose.
• Roof space gets brutally hot. Ducted systems live in the ceiling, so the quality of the duct insulation and the location of the indoor unit matter. A poorly insulated duct run through a Cairns roof in January is losing cooling before it reaches the room.
• Salt and dust hit outdoor units hard. On the beaches from Machans up to Palm Cove, the outdoor unit placement and the yearly clean are what decide how long the system lasts. Splits mean several outdoor units to look after; ducted usually means one bigger one.
• Wet season drains matter. Every indoor unit makes water. Splits drain from the wall unit, cassettes and ducted drain from above the ceiling. A blocked drain in a ceiling shows up as a stain, so the drain run is part of the design, not an afterthought.

Running cost and what it costs to look after

A split system only cools the room it is in, so a house with three splits used sensibly will usually run cheaper than a ducted system cooling the whole house. Ducted systems close that gap with zoning, but only if the zones are set up properly and actually used. A ducted system with every zone open all day is the most expensive way to cool a house in Cairns.

On maintenance, each split is its own unit to clean and service once a year. Ducted is one indoor unit and one return-air filter, plus the ducting itself, which needs a look every few years. Neither is cheaper to own across the board; it depends on how many splits you would need to replace one ducted system.

The house itself: what makes one option hard

• Queenslanders and older homes on stumps. Usually easy for splits. Ducted depends on roof access and whether there is room for the indoor unit and duct runs above the ceiling.
• Modern estates with low or flat roofs. Roof space is often the deciding factor. Some flat-roof homes simply cannot take a ducted system, and a mix of splits or ceiling cassettes is the answer.
• Apartments and units. Body corporate rules and where the outdoor unit can go usually settle it. Splits or cassettes are the norm.
• Renovations and extensions. If the ceiling is open anyway, ducted becomes far cheaper to install than it would be in a finished house.

A simple way to decide

Count the rooms you would actually cool at the same time on a February evening. If it is one, two or three, splits are usually the right call. If it is most of the house, and the roof can take it, ducted with zoning is worth quoting. If it is somewhere in between, a mix is common: a ducted system across the bedrooms and a split in the living area, or the other way around.

Whichever way you lean, get the sizing done properly against the room, the ceiling height, the glass and the sun it cops. In Cairns the wrong size is a bigger problem than the wrong type. If you would like a straight answer for your place, tell us the suburb, the rooms and what the house is like and we will talk it through before anyone quotes anything.