How Much Does It Cost To Run A Split System Air Conditioner?
Worried about electricity bills? This guide explains what affects air conditioner running costs, how different system sizes compare, and how to keep your home comfortable without wasting power.
Quick Answer
For most Perth homes, a modern split system air conditioner may cost anywhere from a few cents to just over a dollar per hour to run, depending on system size, efficiency, electricity tariffs and operating conditions.
| System Size | Estimated Running Cost Per Hour* | Common Use |
|---|---|---|
| 2.0kW | $0.15 - $0.30 | Small bedrooms and home offices |
| 2.5kW | $0.20 - $0.35 | Standard bedrooms |
| 3.5kW | $0.25 - $0.45 | Large bedrooms and small living rooms |
| 5.0kW | $0.35 - $0.60 | Living rooms and family rooms |
| 7.1kW | $0.50 - $0.85 | Large living areas |
| 8.0kW - 9.5kW | $0.60 - $1.10 | Open-plan living, dining and kitchen areas |
*Figures are estimates only and will vary based on system efficiency, electricity tariffs, insulation, weather conditions and usage habits.
Why Air Conditioner Running Costs Vary
System Size
Larger systems generally use more electricity, but they are also designed to cool larger spaces more efficiently.
Energy Efficiency
Higher star ratings generally mean lower electricity usage and reduced running costs over time.
Outdoor Temperature
Perth's hottest summer days make your air conditioner work harder, increasing energy consumption.
Home Insulation
Well-insulated homes stay cooler for longer and reduce the load on your air conditioner.
Usage Habits
Timers, schedules and sensible temperature settings can make a big difference to running costs.
Room Layout
Open-plan areas, high ceilings and large windows can increase the amount of work your system needs to do.
Heating vs Cooling Costs
Reverse Cycle Heating Is Surprisingly Efficient
Many homeowners are surprised to learn that reverse cycle heating is often one of the most efficient forms of home heating available. Compared with electric fan heaters, oil heaters and portable electric heaters, a reverse cycle air conditioner can produce significantly more heat per unit of electricity consumed.
This makes a split system a practical year-round investment for both Perth summers and cooler winter nights.
Which Air Conditioner Is Cheapest To Run?
Bedrooms
2.0kW – 2.5kWUsually the cheapest systems to operate because they are smaller and designed for enclosed rooms.
Living Rooms
5.0kW – 6.0kWA good balance of comfort and efficiency for many family living spaces.
Open Plan Areas
7.1kW – 9.5kWUsually the most efficient choice when correctly sized for the full open-plan space.
Does A Bigger Air Conditioner Cost More To Run?
Not always. A correctly sized larger system can be cheaper to run than an undersized smaller system constantly operating at maximum output. Correct sizing is often the single biggest factor affecting comfort and running costs.
Ways To Reduce Running Costs
Cooling
Generally recommended for efficient summer cooling.
Heating
Usually comfortable and efficient for winter heating.
Use Timers
Schedule operating times and avoid leaving the system running unnecessarily.
Clean Filters
Dirty filters reduce airflow and force the system to work harder.
Close Doors & Windows
Keeping conditioned air inside the room significantly improves efficiency.
Use Ceiling Fans
Fans help circulate conditioned air and reduce load on your air conditioner.
Avoid Extreme Settings
Every degree lower in summer or higher in winter can increase energy usage.
Choose Efficient Systems
Premium systems can cost more upfront but may reduce long-term power usage.
Running Cost Examples
Bedroom Air Conditioner
2.5kW systemUsed 8 hours per night for summer cooling.
Approx. $1.50 - $3.00 per day
Living Room Air Conditioner
6.0kW systemUsed 6 hours per day in a family room.
Approx. $2.00 - $4.00 per day
Open Plan Air Conditioner
8.0kW systemUsed 8 hours per day in a larger open-plan space.
Approx. $4.00 - $8.00 per day
Why Choosing The Right Size Matters
- Improves comfort
- Reduces running costs
- Increases system lifespan
- Maintains more consistent temperatures
- Reduces unnecessary energy consumption
Need Help Choosing An Efficient Air Conditioner?
If you're unsure which system will provide the best balance of comfort and running costs, our team can help recommend the right air conditioner for your home, lifestyle and budget.