Electric heating options compared: reverse-cycle, panel, oil and underfloor

Every electric heater falls into one of two groups. Resistive heaters push current through an element that gets hot: fan heaters, oil-column heaters, panel and convection heaters, radiant bar heaters, infrared panels and electric underfloor systems. One unit of electricity in gives about one unit of heat out, and clever design doesn't change that.

Reverse-cycle air conditioners are heat pumps. They collect warmth from the outside air and release it indoors, moving three to five units of heat for each unit of electricity they use. The Victorian Government reports CHOICE calculations showing a reverse-cycle air conditioner costs about a third as much to run as an electric heater in the same space.

So within the resistive group, the choice is mostly about comfort and installation. Between that group and reverse-cycle, it is about running cost.

A wall split heats one room or open-plan area, a multi-head runs several indoor units from one outdoor unit, and ducted reaches the whole house through ceiling or floor outlets. All of them heat by moving warm air, so a room warms quickly once the unit is running, and the same system cools in summer.

Melbourne is in the Cold zone on the Zoned Energy Rating Label, where performance below 5.5 °C is critical, so compare the Cold zone heating figures. July's mean minimum at Laverton is 5.2 °C. On frosty mornings the outdoor unit pauses briefly to defrost, which is normal.

Installing a split system needs a refrigerant handling licence, and the electrical connection needs a licensed electrician. Air conditioners with a compressor need a lockable isolating switch beside the outdoor unit, and most need a dedicated circuit, so check the switchboard before choosing.

Wall-mounted panel heaters and freestanding convection heaters warm the air, which rises and circulates around the room. They are silent, have no outdoor unit and suit small rooms such as a study or bedroom where a split isn't practical.

Running cost is the catch. Being resistive, each unit of heat costs a full unit of electricity, so a panel heater running every winter evening in a living area costs far more than a reverse-cycle unit doing the same job. Hardwired panel heaters are electrical installation work, and larger ones may need their own circuit.

Oil-column heaters warm slowly and hold their heat, giving steady, quiet warmth in a closed bedroom. Fan heaters warm a small space quickly and suit a short burst in a cold bathroom or study. Radiant bar and infrared heaters warm the people and surfaces in front of them, which suits a spot rather than a whole room.

All of them are resistive and portable, so they suit occasional use. Plug them straight into a wall power point rather than a power board, keep them well clear of curtains, bedding and clothes, and switch them off when you leave the room. A heater that trips the safety switch should be unplugged and checked, not reset again and again.

In a rental, a portable heater doesn't meet the heating standard. Every rental needs a fixed heater in the main living area, and for agreements entered into from 29 March 2023 it must be energy efficient.

Electric underfloor heating uses heating cables or mats under tiles or timber, or set in a slab or screed. It warms the floor, which warms the room from the ground up. There is nothing on the walls, no air movement and no noise, and warm tiles in a bathroom on a July morning are hard to beat.

It is still resistive, so running costs are like other element heaters. Systems set in a thick slab take hours to warm up and cool down, which suits steady use on a timer. Thinner systems under tiles respond faster and are common in bathrooms.

It is best planned into a renovation or new build, because the floor has to come up. It needs its own circuit, a thermostat with a floor sensor and RCD protection; Energy Safe Victoria's guidance says the Wiring Rules require an RCD on every final sub-circuit in a home. Insulation underneath matters too, or much of the heat goes down instead of up.

For a living area heated most winter evenings, reverse-cycle is usually the clear choice on running cost. For a small room used occasionally, a resistive heater can be the sensible answer: a low upfront cost and no installation.

Many homes end up with a mix: reverse-cycle in the living areas, a heated floor or heat lamp in the bathroom, and an oil-column heater for the coldest bedroom on the worst nights.

A plug-in heater draws a lot of current for a household appliance. Two on the same circuit, or a heater sharing a circuit with the kettle and toaster, can trip the breaker. A heater that regularly trips a circuit is a sign the load needs spreading out or a dedicated circuit, not a bigger breaker.

Fixed heating, whether a reverse-cycle system, panel heaters or underfloor cables, usually needs its own circuit from the switchboard. An old board with no spare positions or no safety switches may need work first. Whenever a licensed electrician completes electrical installation work, they must give you a Certificate of Electrical Safety.