Ducted Air Conditioning Cost Calculator
Estimate the supply and install price for a home in Melbourne South East from our own prices, including GST: from about $8,230 for a 7.1 kW system reusing your ducts. Pick your options, then send your details for a written quote after a $50 site assessment.
An estimate from our standard prices. Your final price is confirmed in a written quote after a $50 site assessment.
What the ducted air conditioning cost calculator includes
On our standard prices, the calculator puts ducted reverse cycle air conditioning at about $8,230 for the smallest system (7.1 kW, reusing your ducts and existing circuit) and, in the worked examples below, about $13,700 to $15,900 for a new 12.5 to 16 kW system with outlets, zones and our electrician, including GST. Every figure is a supply and install estimate.
Ducted reverse cycle air conditioning heats and cools the whole house from one indoor unit in the roof space or under the floor, with ducts running to an outlet in each room and an outdoor unit outside. This is what each choice adds:
- System size: 7.1 kW to 25 kW. The 18, 20 and 25 kW systems are three-phase. As a guide, the Victorian Government suggests 1.1 to 1.4 kW of heating output for every 10 m² a ducted system covers, depending on the home; our air conditioner size calculator gives a first estimate.
- Type of installation: ceiling or roof space adds nothing; underfloor adds 3% to the whole estimate.
- Outlets: each new outlet adds about $187 for a round outlet, $193 for a square multi-directional outlet, $242 for a square metal grille, $308 for a floor bar grille and $418 for a long linear grille. Enter zero if you are reusing the ducts and outlets you have.
- Zones: each zone adds about $154. Zones let you heat or cool only the rooms you are using, and standard controllers take up to 8.
- Electrical: our electrician running the outdoor unit's own circuit back to the switchboard adds about $605; your own electrician or an existing circuit adds nothing.
- Two storeys: about $660, for the dropper ducts (the calculator allows for three) that run from the upstairs ceiling to the downstairs ceiling, usually through a cupboard.
The calculator has no field for three-phase supply work, a switchboard upgrade (if your board needs one: typically $1,250 to $2,500 including GST for a home, a small board at the low end) or the VEU discount for replacing a ducted gas heater (see below). Those are worked out at the site assessment.
Ducted air conditioning prices: worked examples
These are calculator estimates, including GST, so you can check your own numbers against them.
| Home | Floor area it suits* | Choices | Calculator estimate |
|---|---|---|---|
| Replacing a system, reusing the ducts | 71 to 91 m² | 10 kW, ceiling, 0 outlets (reusing the ducts and outlets), no new zones, existing circuit, single storey | $9,220 |
| New install, single storey | 100 to 127 m² | 14 kW, ceiling, 8 round outlets, 4 zones, our electrician, single storey | $13,722 |
| New install, double storey | 114 to 145 m² | 16 kW, ceiling, 10 square multi-directional outlets, 6 zones, our electrician, double storey | $15,884 |
| Underfloor, single storey | 89 to 114 m² | 12.5 kW, underfloor, 7 floor bar grilles, 3 zones, our electrician, single storey | $13,701 |
*At the Victorian Government's guide of 1.1 to 1.4 kW of heating output per 10 m² (our arithmetic), taking the system size as its heating output. Check the model's heating output in its specifications, and use our air conditioner size calculator for your rooms.
Your final price is confirmed in a written quote after a $50 site assessment, where we look at the rooms, the existing heater and ducts, the roof or underfloor space, your switchboard and where the outdoor unit can go. It can differ from the estimate, mostly because of that space, the condition of any ducts being reused and your switchboard. Run your own choices in the calculator above and send them with the form (back to the calculator ↑); we will call you back within 2 business hours.
Ducted, multi-split or split system?
A multi-split runs several indoor units from one outdoor unit. Installed, with no rebate and including GST, a 12 kW Mitsubishi Electric, 12.5 kW Fujitsu or 10 kW Panasonic multi-split with 3 to 4 indoor heads is about $10,000 to $11,000, and a 19 kW Rinnai with 5 to 6 indoor heads, or a 17 kW Carrier or 19 kW Midea, is about $12,000 to $13,000. For one room, a split system on a standard back-to-back installation starts at $1,618 (Haier 2.5 kW, including GST).
Ducted suits a house that needs every room heated and cooled and has the roof or underfloor space for the indoor unit and ducts. The Victorian Government recommends zones for ducted systems; running costs are compared in the questions below. You can see our split and multi-split prices.
Replacing gas ducted heating: the VEU discount
If a new ducted reverse cycle system replaces a ducted gas heater that is the home's main heating, the Victorian Energy Upgrades (VEU) program offers an indicative discount of up to $2,520 for a 10 kW system, $4,200 for 16 kW and $5,530 for 22.4 kW, by the Victorian Government's heating and cooling discounts table. The Victorian Government puts the saving at up to $1,140 a year.
Since 30 September 2026, a ducted system installed with a VEU discount carries a minimum co-payment of $3,000, including GST. The old gas heater is decommissioned so it can't be used again, and removed where that is practical and safe.
Talk to an accredited provider before you buy or install. Helcro Electrical is VEU Accredited Provider A003039: you sign the VEEC assignment form and we create the certificates that fund your discount. The calculator shows the price before any discount; your written quote shows any VEU discount you qualify for. If the new system will replace a ducted gas heater, say so under Additional Details when you send the form. The full rules are on our Victorian Energy Upgrades page.
WHAT OUR CUSTOMERS SAY
David Jameson, Google review, ducted gas heating replaced with a reverse-cycle system
Ducted air conditioning cost: common questions
How much does ducted air conditioning cost?
On our standard prices, the calculator gives from about $8,230 (a 7.1 kW system reusing your existing ducts and circuit) to about $15,900 in our largest worked example (a new double-storey 16 kW system with 10 outlets, 6 zones and our electrician), including GST. The three-phase 18 to 25 kW systems, more outlets and more zones cost more. Use the calculator for your own choices; the written quote follows a $50 site assessment.
How much does it cost to install a ducted air conditioner?
The calculator’s figure is a supply and install price: the system, the installation, the outlets and zones you choose and, if you pick it, our electrician’s circuit. Each new outlet adds from about $187 and each zone about $154, including GST.
Is ducted cheaper to run than a split system?
It can cost more. The Victorian Government’s factsheet Choosing the right size reverse cycle air conditioner says ducted systems can be more expensive to install and run, and recommends zones, which give you more control over which areas you heat and cool. Replacing a ducted gas heater with an efficient reverse cycle system can save up to $1,140 a year, by the Government’s figure.
Can I reuse my existing ducts?
The calculator lets you enter zero outlets when your existing ducts and outlets are being reused. When equipment is reused, the Victorian Government advises asking your installer to confirm it is suitable and meets current standards, and its factsheet says new ducting should be appropriately insulated and correctly sized for your heating and cooling needs. If your ducts served a gas ducted heater, plan on new ones: AIRAH’s best practice guide says “Existing gas fired heating ductwork is generally too small to be used successfully with ducted reverse-cycle air conditioning”, and the Essential Services Commission recommends replacing ductwork and fittings on these systems. Whether yours can stay is checked at the site assessment. For installation detail, the Government points to AIRAH’s Victorian Air Conditioning Residential Best Practice Guide.
Does the estimate include the VEU discount?
No. The calculator shows the price before any discount. If the job qualifies, the discount is shown on your written quote, and you still pay at least the $3,000 minimum co-payment.
Do I have to replace my gas ducted heating?
If you live in a home you own, no: there is no requirement to replace existing gas space heating, and for existing homes the 1 March 2027 change is about gas hot water. In a rental, when a fixed heater, including gas ducted, fails and can’t be repaired from 1 March 2027, it must be replaced with energy-efficient fixed electric heating, such as a reverse cycle system, with an outlet in the main living area, unless an exemption applies; see our Victoria gas ban guide.
Which ducted air conditioning brands do you install?
Mitsubishi Electric, Mitsubishi Heavy Industries, Rinnai and Carrier. We don’t rank them: the right model depends on the house.
Get a quote for ducted air conditioning
In business since 2006 · Registered Electrical Contractor REC 35448, registered with Energy Safe Victoria · ARC Refrigerant Trading Authorisation AU50700 · VEU Accredited Provider A003039 · 5-year workmanship warranty on air conditioning installation
Our own team installs ducted air conditioning across Melbourne South East from our Cheltenham workshop, and our air conditioning work carries a 5-year workmanship warranty on top of the manufacturer’s. Send the form above (your calculator choices go with it automatically; a floor plan helps) and we will call you back within 2 business hours. Back to the calculator ↑
Prices and rules on this page checked 29 October 2026.