Choosing heating, cooling or hot water for an Australian home comes down to three questions: what suits your climate, how much of the house you need to cover, and what the system will cost to run over the years you own it. As a starting point, a split system costs around $1,500–$5,000 installed, ducted evaporative cooling $3,000–$7,500, and ducted reverse cycle air conditioning $9,000–$20,000 or more (AUD, prices include GST, September 2026).
The guides in this section help you work through those questions before you ask for quotes. This page gives you the short version of each decision, with the numbers behind it.
Your climate decides which systems are even on the table, so settle it before you compare prices. Australia’s building code (the National Construction Code) splits the country into climate zones, and the major cities fall into three quite different groups:
| City | NCC climate zone | What it means for your system |
|---|---|---|
| Brisbane | Zone 2 (warm, humid summer) | Humidity rules out evaporative cooling; reverse cycle is the realistic option |
| Sydney | Zone 5 (warm temperate) | Coastal humidity makes reverse cycle the usual choice |
| Perth | Zone 5 (warm temperate, dry) | Dry summers make evaporative cooling a genuine, cheaper option |
| Adelaide | Zone 5 (warm temperate, dry) | Evaporative cooling is widely used and works well |
| Melbourne | Zone 6 (mild temperate) | Heating matters as much as cooling; many homes still run gas ducted heating |
Two things follow from that table. First, evaporative cooling only makes sense where the air is dry: it cools by evaporating water, and in humid air it runs out of room to do that. Our evaporative cooling cost guide puts numbers on it. Second, if you need heating as well as cooling, reverse cycle does both from one system, while an evaporative cooler only cools.
Perth, Sydney and Adelaide share the same climate zone, yet Sydney is noticeably more humid. When you read a cost guide for your city, local humidity and your electricity tariff tell you more than the zone number alone.
Once you know which systems suit your climate, the next question is how much of the house you need to cover. That decides the price far more than the brand does.
| System | What it covers | Typical installed cost |
|---|---|---|
| Split system (single room) | One room | $1,500–$5,000, depending on size (kW) |
| Multi-split (one outdoor unit, several indoor heads) | Two or more rooms | From about $4,200–$4,500 for a premium two-head system, plus $1,000–$1,500 per extra head |
| Ducted reverse cycle | Whole home, heating and cooling | $9,000–$20,000+ |
| Ducted evaporative (new) | Whole home, cooling only | $3,000–$7,500 |
| Ducted evaporative (replacement on existing ducts) | Whole home, cooling only | $2,800–$5,500, depending on brand |
| Portable evaporative cooler | One room | $50–$800 |
Prices include GST (September 2026). Each range is drawn from installer and retailer pricing, triangulated across at least three independent sources where they exist.
A few patterns hold across all of them:
The purchase price is a one-off. The running cost comes back every summer and winter, and it can reverse which system looks cheaper over ten years.
What you pay per kWh depends on your state. These are the regulated reference tariffs for 2026–27, set each year from 1 July:
| State | Electricity price | Daily supply charge | Source |
|---|---|---|---|
| Queensland (South East) | 28c/kWh | 176c/day | AER Default Market Offer (Energex area) |
| Victoria | 21–48c/kWh, depending on time of day and distribution zone | 119–138c/day | Victorian Default Offer (ESC) |
| Western Australia | 33.26c/kWh (flat rate) | 119c/day | Synergy A1 tariff (WA Government) |
In Queensland and Victoria these are the caps for standard “standing offer” plans, so if you’re on a market plan you’re probably paying less. In WA, most households pay the single regulated rate. Check the rate on your latest bill before you use any running-cost figure, including ours.
Sustainability Victoria publishes one of the few neutral comparisons, modelled on a 220 m² home in Melbourne’s climate. Per year, for cooling:
| System | Annual cooling cost |
|---|---|
| Ducted evaporative, inverter | $25 |
| Ducted evaporative, standard | $42 |
| Multi-split reverse cycle, 3.5 stars | $124 |
| Ducted reverse cycle, 3 stars, no zoning | $172 |
| Multi-split reverse cycle, 2 stars | $177 |
| Ducted reverse cycle, 1.5 stars, no zoning | $258 |
You’ll often see evaporative cooling described as “10 times cheaper to run”. That figure compares it with a 1.5-star ducted system with no zoning, the least efficient option in the table. Against a 3-star reverse cycle system, the gap is closer to four times. Evaporative is still cheaper to run where it works; the size of the saving depends on what you compare it with.
These annual figures assume Melbourne’s mild summers and fairly light use. Installers in Perth and Melbourne who model a long, hot summer of daily use put evaporative running costs at $200–$300 a season, or roughly $0.14–$0.35 an hour. Your own cost depends mostly on how many hours you run it.
For a single room, a split system is the cheapest type of air conditioning to run in Australia, at about $0.62 an hour on average nationally (Finder, using energyrating.gov.au data for 4,066 models).
Hot water follows the same logic: the cheapest system to buy is often the most expensive to run.
| System | Typical installed cost | Running cost per year (3-person home) |
|---|---|---|
| Electric storage | $1,000–$2,800 | $650 off-peak, $840 peak |
| Gas storage | $1,200–$2,800 | $645 |
| Gas continuous flow | $1,500–$3,000 | — |
| Heat pump | $3,000–$6,000 before rebates | $170 off-peak, $230 peak |
| Solar (electric or gas boosted) | $3,500–$8,000 | Depends on the booster and your roof |
Installed prices include GST (September 2026). Running costs come from RACV’s comparison for a three-person household, which doesn’t cover continuous flow; a heat pump paired with rooftop solar drops to about $105–$120 a year.
If your hot water system has just failed, a like-for-like replacement is usually the fastest option, often done the same day. If you’re planning ahead, compare the running cost column before the price column: over ten years, a heat pump’s lower running cost can outweigh its higher upfront price. Federal certificates (STCs) and state programs cut the upfront cost of heat pump and solar systems, but their value changes with your location and the system, so ask your installer to show the rebate as its own line on the quote. Our hot water system cost guide covers installation and replacement prices by system type.
The price ranges above only help if the quotes you get can be compared with them. A few habits make that possible:
A ducted evaporative cooling system costs around $3,000–$7,500 installed for most Australian homes (AUD, prices include GST), and roughly $0.15–$0.35 an hour to run. Replacing an existing unit on the same ductwork costs less, typically $2,800–$5,500 depending on the brand. Your climate decides whether it’s the right choice: evaporative cooling works well in dry cities…