Ducted air conditioning cost in Australia, 2026

How much does ducted air conditioning cost in 2026?

Ducted price follows the house more than the brand. Bedrooms tell you roughly how much capacity and how many outlets you need; storeys and roof space tell you how hard it is to get the ducts there. The figures below are supply and install for a new ducted reverse cycle system with zoning and a wall controller.

By capacity, the same evidence puts a standard install at about $6,500 to $10,500 under 10 kW, $8,000 to $15,000 for 10 to 14 kW, $10,000 to $17,000 for 14 to 18 kW and $12,000 to $20,000 from 18 kW up.

Our price checker runs the same sum from your postcode and bedrooms, and shows the rebate on the same screen. It's the closest thing to a ducted air conditioning cost calculator that doesn't ask for your phone number first.

How much does ducted air conditioning cost for a 4 bedroom house?

A single storey 4 bedroom house is usually $12,000 to $18,000 for ducted reverse cycle in 2026. Two storey is more often $15,000 to $20,000. Most 4 bedroom homes end up with something in the 12.5 to 16 kW range and four to six zones.

Where a 4 bed lands in that range comes down to the roof and the layout. A low-pitched tile roof with a long hallway means more duct and more crawling. A family room and a separate lounge often means one extra zone. A home office on the western side may need its own outlet and a bigger unit than the bedroom count suggests.

Sizing up "to be safe" costs twice: once on the quote and again on the bill, because an oversized ducted system cycles on and off and never dehumidifies properly. Ask what heat load they calculated and for which rooms. How to size an air conditioner covers the questions.

What drives the price of ducted air conditioning?

• Roof space. Plenty of height and a clear run is cheap. A low pitch, a flat roof, or a roof full of trusses and old insulation means more hours and sometimes bulkheads.
• Duct length and outlets. Every extra outlet is a run of flexible duct, a diffuser and a hole in a ceiling. Long, narrow houses cost more than square ones of the same area.
• Capacity. Stepping up a size costs more on the unit and can need a bigger electrical supply.
• Zones. Each zone adds a motorised damper and wiring, and more zones need a better controller.
• Brand tier. Premium Japanese brands and local specialists like ActronAir price differently to budget ranges. The gap is usually smaller than the gap between installers.
• Controller. A basic wall controller is standard. Room sensors, smart apps and per-room temperature control cost extra.
• Outdoor unit location. A unit that has to go on a roof, a side passage with no access or needs a crane is an extra line.
• Electrical. A new dedicated circuit is about $300 to $900; a switchboard upgrade is more like $1,000 to $3,500.

Comparing brands for the job itself: ActronAir vs Daikin and the best ducted air conditioning shortlist.

How much does zoning cost, and is it worth it?

The ranges above assume a sensible number of zones for the house, usually four to six. Each extra zone is a damper motor and some wiring, which is small money next to the whole job. Ask the installer to list zoning as its own line so you can see it.

It's worth it. Zoning is what lets you run the living areas in the afternoon and the bedrooms at night instead of conditioning the whole house all day. Without it, ducted really is expensive to run. With it, the living zone on a hot afternoon behaves more like a large split.

A zone is not the same as a room. Two kids' bedrooms on one zone is fine. The main bedroom and the lounge on one zone is a mistake you'll notice every night.

Ducted air conditioning replacement cost

Replacing an old ducted reverse cycle system is often cheaper than a new install, because the ductwork, outlets and controller wiring may be reusable. That's a big "may". Old flexible duct sags, splits and loses insulation. A good installer will inspect it and tell you which runs to keep. Price a straight unit swap and a unit-plus-duct replacement side by side.

Replacing gas ducted heating with ducted reverse cycle is the job Victoria pays for. The Victorian Energy Upgrades program lists these indicative household discounts for an efficient ducted reverse cycle system:

Gas ducted outlets are usually in the floor or low on walls; reverse cycle wants ceiling outlets, because cold air falls. Expect new ductwork in most gas-to-reverse-cycle swaps. The Victorian rebate page walks through the steps, and New South Wales has a smaller scheme on the NSW page.

Replacing evaporative ducting is similar. Evaporative ducts are bigger and not built for refrigerated air. Some installers will talk about reusing them; make them prove the ducts are sound and sized right before you agree.

Cost of ducted air con per room, and when splits are cheaper

Divide a single storey 4 bedroom job ($12,000 to $18,000) by the six or seven rooms it serves and you get roughly $2,000 to $2,600 a room. A 2.5 kW split is $1,500 to $2,500 installed. Per room, the numbers are closer than people expect.

The difference is how you live. If you use three rooms and ignore the rest, two or three good splits will cost less to buy and less to run. If you want every room even and quiet, with nothing on the walls, ducted is the better house to live in. A multi-split sits in between and suits homes where ducts won't fit. Split, multi-head or ducted has the longer version.

What does ducted air conditioning cost to run?

It depends almost entirely on zoning and habits. Running one zone of a well-sized ducted system is in the same territory as running a large split. Running the whole house with the thermostat in the hallway is how bills blow out.

For your tariff and system size, use the running cost calculator. The running costs guide explains what moves the number.

How to read a ducted air conditioning quote

• Indoor and outdoor model numbers and the capacity in kW. If it just says "14 kW ducted", ask.
• Number of outlets and where they go, and the size of the return air grille.
• Number of zones, which rooms are on each, and the controller model.
• Whether the condensate drain, the outdoor unit slab or bracket, and any crane are included.
• Electrical scope: new circuit, isolator, switchboard work.
• Removal of the old system, and in Victoria, the VEU discount as a line item.
• Warranty on the unit and, separately, on the installation workmanship.

Two ducted quotes $4,000 apart usually differ in scope, not margin. Line them up item by item. Our quote checklist is the fuller version.