Ducted Air Conditioning Running Cost in Perth (2026)
In Perth a ducted aircon's running cost depends on its efficiency rating, with the choice between refrigerated and evaporative the first decision.
Your ducted air conditioning running details
Check the outdoor unit compliance plate. Most Australian homes run 10kW to 18kW ducted.
Use the usage rate on your bill, not the daily supply charge.
Your estimate sits within the typical range.
Your estimate sits within the typical range.
Where the money goes
Estimated breakdown for your configuration
Ducted systems draw far more power at start-up and while pulling a hot house down to setpoint than while holding it there. Running a shorter, steadier schedule beats switching the system off completely and then blasting it cold when you get home.
Ways to save
- Use the zoning you already paid for. Most ducted installs include four to eight motorised zones and most households leave them all open out of habit. Conditioning the living zone during the day and the bedroom zone at night, rather than the whole floor plan, is the single largest saving available and costs nothing to implement.
- Move the thermostat to 24°C in summer and 20°C in winter. Every degree closer to the outdoor temperature cuts consumption by roughly 5 to 10 per cent, so shifting a habitual 20°C summer setpoint up to 24°C can reduce the cooling half of your bill by a third with almost no perceptible loss of comfort once the humidity is under control.
- Get the ducts pressure tested if the system is more than ten years old. Flexible duct in a hot roof cavity degrades, joins pull apart at the collars and insulation compresses, and a leaking run can dump a meaningful share of your conditioned air into the roof. Testing and resealing typically costs a few hundred dollars against hundreds a year in waste.
- If you have rooftop solar, shift the heavy lifting into daylight. Pre-cooling the house between 11am and 3pm on generation you would otherwise export at 5 to 8c/kWh, then coasting through the evening peak, changes the effective rate you pay for comfort more than any efficiency upgrade you can buy.
How we estimate this
## What ducted air conditioning actually costs to run
Pricing reviewed: October 2026.
What a ducted air conditioning running costs in Perth
A ducted aircon's running cost in Perth depends heavily on the efficiency of the system chosen, and the first decision is the type itself: a refrigerated reverse-cycle system is rated by its energy-efficiency ratio, while ducted evaporative cooling uses only a fan and a water pump and so draws a fraction of the power. In Perth's dry Mediterranean climate evaporative is genuinely viable, so the cheapest-to-run choice for much of the summer is often a different technology rather than simply a higher-rated refrigerated unit.
For a refrigerated system, the star rating is the lever, because a high-efficiency inverter unit delivers the same cooling for fewer kilowatt-hours than an old fixed-speed one, which matters across Perth's intense summer. Sizing to the home is important, as an oversized unit wastes power short-cycling. The low humidity means a refrigerated system is not burdened with heavy dehumidification, so it tends to hit its rated efficiency well here. Double-brick walls hold the cool and reduce the capacity needed. The isolation of the WA market rarely changes running cost but can affect the lead time for an efficient replacement unit or a specialist part.
Paying to run either system needs no licence, but the install is licensed: a licensed refrigeration or ARC-certified technician handles a refrigerated system's charge and a licensed electrician the wiring, under WA Building Services, while an evaporative unit's water supply is plumbing work. A correctly charged refrigerated system meets its rating. For a Perth home, the clearest way to think about a ducted aircon's running cost is the system type and its efficiency rating, with evaporative the low-draw option for the dry heat.
Compare against the national picture: Ducted Air Conditioning Running Cost in Australia →
Ducted Air Conditioning Running Cost in other cities
Frequently asked questions
What is the first running-cost decision in Perth?
The system type: a refrigerated reverse-cycle unit is rated by its energy-efficiency ratio, while ducted evaporative cooling uses only a fan and water pump and draws a fraction of the power, and evaporative is genuinely viable in Perth's dry climate.
Does the star rating matter for a Perth refrigerated system?
Yes. A high-efficiency inverter unit delivers the same cooling for fewer kilowatt-hours than an old fixed-speed one, which matters across Perth's intense Mediterranean summer, and the low humidity helps it hit its rated efficiency.
Does double-brick lower the Perth running cost?
It can. Perth's common double-brick walls hold the cool and reduce the capacity needed, and a correctly sized unit avoids wasting power short-cycling, so the building fabric works alongside the efficiency rating in Perth.
Do I need a licence for a ducted aircon in Perth?
Not to run it, but the install is licensed: a refrigeration or ARC-certified technician handles a refrigerated system's charge and a licensed electrician the wiring under WA Building Services, while an evaporative unit's water supply is plumbing work.