Short answer
Reverse cycle usually wins. Energy Rating says it moves 3 to 5 units of heat per unit of electricity↗, where a standard electric heater makes about 1 unit of heat per unit of electricity↗. For gas, Victoria estimates that replacing ducted gas heating with efficient reverse cycle saves up to $1,140 a year↗. Your own saving depends on your tariffs and how much you heat.
Why does reverse cycle use less electricity for the same heat?
A plug-in heater turns electricity into heat, one for one. A reverse cycle system does something cleverer: it uses electricity to move heat that is already in the outside air, even on a cold night, into the room.
Show the numbers
| Standard electric heater | about 1 unit |
|---|---|
| Reverse cycle air conditioner | 3 to 5 units |
What does an hour of heating actually use?
Take a 2 kW plug-in heater warming a Canberra bedroom. It draws about 2 kW. Getting the same 2 kW of heat from reverse cycle, at 3 to 5 units of heat per unit of electricity↗, draws about 0.4 to 0.7 kW.
| Heater | Electricity drawn for 2 kW of heat | In one hour |
|---|---|---|
| Standard electric heater | about 2.0 kW | about 2.0 kWh |
| Reverse cycle | 0.4 to 0.7 kW | 0.4 to 0.7 kWh |
To turn kilowatt-hours into dollars, multiply by the usage rate on your electricity bill. We deliberately do not print a single rate here: it differs by retailer, network and plan, and a wrong rate would make every figure on this page wrong.
What about gas heating?
Energy Rating's comparison covers electric heaters, not gas. For gas, the clearest official numbers come from Victoria, where most homes still heat with it. Replacing ducted gas heating with efficient reverse cycle is estimated to save up to $1,140 a year↗, and replacing a gas room heater up to $460 a year↗.
Those are estimates for the heater swap. They do not model your whole gas bill, so if you still cook with gas, look at what happens to that account too.
When does switching make less sense?
- Your gas heater is nearly new. In Victoria it will not attract the upgrade discount unless it is more than 2 years old↗.
- You heat one room for an hour on a handful of nights. The saving is real but takes longer to repay an install.
- The room has nowhere sensible for an indoor and outdoor unit. A cramped install can cost more than it saves.
If you do switch in Victoria, the discount is up to $5,530↗ for ducted gas. Here is how to claim it. To size a system for a room, use the calculator.