What reverse-cycle heating costs in a Sydney winter
Energy & costs

What reverse-cycle heating costs in a Sydney winter

Published 7 min read

In the official Sydney-zone figures, every one of the 275 rated models we install uses more energy heating than cooling. A bedroom split runs $86 to $125 a winter at the Sydney median rate, a 7 kW living-room split $283 to $363, a 14 kW ducted system $570 to $874.

Winter is the bigger row on the label

0%25%50%75%100%heating and cooling equal2.5 kW2.5 kW: heating is 68% of the annual kWh across 27 rated models2.5 kW: cooling is 32% of the annual kWh across 27 rated models68% heatingSmallest heating share at 2.5 kW: Mitsubishi Electric SEZ-M 2.5kW, 63% (392 kWh heating, 226 kWh cooling)5 kW5 kW: heating is 63% of the annual kWh across 35 rated models5 kW: cooling is 37% of the annual kWh across 35 rated models63% heatingSmallest heating share at 5 kW: Mitsubishi Electric SLZ-M 5kW, 59% (744 kWh heating, 516 kWh cooling)7 kW7 kW: heating is 62% of the annual kWh across 34 rated models7 kW: cooling is 38% of the annual kWh across 34 rated models62% heatingSmallest heating share at 7 kW: Panasonic Adaptive 7.1kW, 55% (993 kWh heating, 805 kWh cooling)10 kW10 kW: heating is 63% of the annual kWh across 17 rated models10 kW: cooling is 37% of the annual kWh across 17 rated models63% heatingSmallest heating share at 10 kW: Panasonic Adaptive 10kW, 59% (1,192 kWh heating, 838 kWh cooling)14 kW14 kW: heating is 63% of the annual kWh across 13 rated models14 kW: cooling is 37% of the annual kWh across 13 rated models63% heatingSmallest heating share at 14 kW: Panasonic Adaptive 14kW, 59% (1,793 kWh heating, 1,257 kWh cooling)20 kW20 kW: heating is 61% of the annual kWh across 5 rated models20 kW: cooling is 39% of the annual kWh across 5 rated models61% heatingSmallest heating share at 20 kW: Rinnai D Series Ducted 20kW, 58% (3,050 kWh heating, 2,169 kWh cooling)
The figures behind each bar (GEMS data, October 2026)
SizeRated modelsHeating shareSmallest shareLargest share
2.5 kW2768%63% (Mitsubishi Electric SEZ-M 2.5kW)73% (Rinnai T Series 2.5kW)
5 kW3563%59% (Mitsubishi Electric SLZ-M 5kW)70% (ActronAir Serene 5kW)
7 kW3462%55% (Panasonic Adaptive 7.1kW)67% (Rinnai T Series 7kW)
10 kW1763%59% (Panasonic Adaptive 10kW)68% (Samsung S2 Ducted 10kW)
14 kW1363%59% (Panasonic Adaptive 14kW)73% (Rinnai D Series Ducted 14kW)
20 kW561%58% (Rinnai D Series Ducted 20kW)63% (Daikin Inverter 20kW)
How much of the annual energy figure is heating at each common size, summed across every rated model we list at that size, live from the GEMS data. The amber tick is the model with the smallest heating share at that size, and none of them reaches back to the half-way line.

Every air conditioner sold here carries two annual energy figures on its label, one for cooling and one for heating, measured for the climate zone Sydney sits in. The running costs guide works from the cooling row.

This post is about the other one, and it is the larger of the two: of the 275 models we install with both figures in the GEMS registration data (synced 1 September 2026), every single one uses more energy heating than cooling in the Sydney-zone test.

Across our wall splits heating is 64 per cent of the annual figure; across ducted systems it is 62 per cent.

The dollar figures below multiply that heating energy by the Sydney median usage rate including GST, 31.79 cents per kWh across 170 Ausgrid plans in the September 2026 plan data, the same way every model page on this site prices a year of running.

The Endeavour median for Western Sydney and the Illawarra, 30.65 cents, is about four per cent lower; a later section shows what that moves.

A bedroom split: $86 to $125 for the season

Twenty-three of the wall splits we install sit at 2.5 or 2.6 kW, the size for a bedroom or a study, and their heating figures run from 271 kWh to 392 kWh a year.

ModelHeating starsHeating kWh a yearA winter's heating
ActronAir Serene 2.6 kW3.5271$86
Rinnai PB Series 2.6 kW3.5276$88
Carrier Indigo 2.5 kW3.5281$89
Daikin Alira X 2.5 kW4307$98
MHI Avanti Plus 2.5 kW4320$102
Fujitsu Lifestyle 2.5 kW3351$112
Mitsubishi Electric MSZ-AP 2.5 kW3351$112
Panasonic Z Series 2.5 kW3355$113
Samsung WindFree 2.5 kW3380$121
TCL BreezeIN 2.0 2.6 kW3392$125

Mitsubishi Heavy Industries' Avanti Plus and Daikin's Alira X are the only models at this size with 4 heating stars, yet three units with 3.5 stars use less than either. Most of the field sits between 350 and 380 kWh.

At the bottom is the TCL BreezeIN 2.0 at 392 kWh. Same room, same size, $39 a year apart. Counting cassettes, bulkheads and floor consoles too, the dearest to heat at this size is Mitsubishi Electric's MFZ-KW floor console, 430 kWh or $137, the high end of the 2.5 kW bar in the chart further down.

Not sure what size you need?Answer five quick questions and get a kW recommendation with matching systems.Size it for me

A living room at 7 kW: $283 to $363

Eighteen wall splits in our range sit between 7 and 7.2 kW, and their winters cost $283 to $363 at the Sydney rate. The lowest is the Daikin Alira X 7.1 kW at 889 kWh. Next is TCL's BreezeIN 2.0 7.2 kW at 893 kWh, the brand that finishes last at bedroom size, so read the model, not the badge.

ModelHeating starsHeating kWh a yearA winter's heating
Daikin Alira X 7.1 kW3889$283
TCL BreezeIN 2.0 7.2 kW3893$284
Carrier Indigo 7 kW2.5980$312
Panasonic Z Series 7.1 kW2.5982$312
ActronAir Serene 7.2 kW3989$314
Daikin Skywall 7.1 kW21,141$363

The Skywall's cooling row is 726 kWh, about $231, so for that one unit winter is $132 dearer than summer.

Ducted units at the same capacity run a little higher again: the twelve between 7 and 7.1 kW span 940 kWh (Carrier QSM, $299) to 1,179 kWh (Rinnai D Series, $375), and the ducted cost guide covers what else separates them.

A whole house: ducted at 10, 14 and 20 kW

$0$500$1,000$1,5002.5 kW2.5 kW: 27 rated models, heating $86 (ActronAir Serene 2.6kW) to $137 (Mitsubishi Electric MFZ-KW 2.5kW) a year$51 gap5 kW5 kW: 35 rated models, heating $197 (Daikin Alira X 5kW) to $271 (Daikin Inverter Ducted 5kW) a year$74 gap7 kW7 kW: 34 rated models, heating $283 (Daikin Alira X 7.1kW) to $375 (Rinnai D Series Ducted 7kW) a year$92 gap10 kW10 kW: 17 rated models, heating $379 (Panasonic Adaptive 10kW) to $632 (Daikin Inverter Ducted 10kW) a year$253 gap14 kW14 kW: 13 rated models, heating $570 (Panasonic Adaptive 14kW) to $874 (Rinnai D Series Ducted 14kW) a year$304 gap20 kW20 kW: 5 rated models, heating $937 (Daikin Premium Inverter Ducted 20kW) to $1,343 (Daikin Inverter 20kW) a year$406 gap
The heating figures behind each bar
SizeRated modelsLowestHighestGap
2.5 kW27$86 (ActronAir Serene 2.6kW, 271 kWh)$137 (Mitsubishi Electric MFZ-KW 2.5kW, 430 kWh)$51
5 kW35$197 (Daikin Alira X 5kW, 621 kWh)$271 (Daikin Inverter Ducted 5kW, 854 kWh)$74
7 kW34$283 (Daikin Alira X 7.1kW, 889 kWh)$375 (Rinnai D Series Ducted 7kW, 1,179 kWh)$92
10 kW17$379 (Panasonic Adaptive 10kW, 1,192 kWh)$632 (Daikin Inverter Ducted 10kW, 1,987 kWh)$253
14 kW13$570 (Panasonic Adaptive 14kW, 1,793 kWh)$874 (Rinnai D Series Ducted 14kW, 2,749 kWh)$304
20 kW5$937 (Daikin Premium Inverter Ducted 20kW, 2,947 kWh)$1,343 (Daikin Inverter 20kW, 4,224 kWh)$406
At each common size, the bar runs from the lowest annual heating cost in our range to the highest, at the September 2026 Sydney median rate, including GST. The label is the gap between the two ends: what the heating row is worth, per winter, at that size.

Ducted heating is where the winter figure gets serious. The lowest and highest ducted units we install at each size:

SizeUnitsLowest winterHighest winter
10 kW14Panasonic Adaptive, 1,192 kWh, $379Daikin Inverter Ducted, 1,987 kWh, $632
14 kW13Panasonic Adaptive, 1,793 kWh, $570Rinnai D Series, 2,749 kWh, $874
20 kW5Daikin Premium Inverter, 2,947 kWh, $937Daikin Inverter Ducted, 4,224 kWh, $1,343

At 10 kW, Panasonic's Adaptive and Daikin's Slimline carry 3 heating stars, the most of any ducted unit in our range; the Daikin Inverter Ducted at the same size carries 1.5.

Two things soften those numbers in a real house: a zoned ducted system heating the living areas by day and the bedrooms at night conditions only part of the house at a time, and the figure is for the average zone, not your street, which a later section comes back to.

Why the same power buys three to six times the heat

A plug-in heater: one kilowatt hour of electricity in, one kilowatt hour of heat out.a plug-in heater1 kWh of electricity1 kWh of heatA reverse-cycle unit: one kilowatt hour of electricity plus heat drawn from the outside air, about four kilowatt hours of heat into the room.a reverse-cycle unitheat in the outside air1 kWh of electricityabout 4 kWh of heat
A plug-in heater turns a kilowatt hour of electricity into a kilowatt hour of heat. A reverse-cycle unit spends the same kilowatt hour moving heat out of the outside air and into the room, three to six kilowatt hours of it for the models in our range, which is what the ACOP figure counts.

A reverse-cycle unit does not make heat from electricity, it moves heat from the outside air into the room, and that is why it wins on a winter bill.

The heating figure in the GEMS data comes with an efficiency ratio, the ACOP, and across our range it runs from 3.12 (Daikin's 25 kW ducted unit) to 5.95 (Daikin's Alira X 2.2 kW): every kWh of electricity delivers between three and six kWh of heat.

A fan heater, an oil column or a panel heater returns one for one; energy.gov.au puts reverse-cycle units at 300 to 600 per cent efficient against roughly 100 per cent for a standard electric heater.

The ActronAir Serene 2.6 kW's 271 kWh of electricity is, at its ACOP of 5.39, about 1,460 kWh of heat into the bedroom; the same heat through a resistive heater takes about 1,460 kWh of electricity, roughly $464 against $86.

At living-room size the Daikin Skywall's 1,141 kWh becomes about 3,770 kWh of heat, $1,198 through a heater against $363. Even the unit with the fewest heating stars in our range beats a plug-in heater by more than three to one.

Ausgrid or Endeavour, coast or west

The electricity rate is the smaller of the two local factors. At the Endeavour median of 30.65 cents instead of Ausgrid's 31.79, about a four per cent shift:

  • ActronAir Serene 2.6 kW: $83 a winter instead of $86
  • Rinnai D Series 14 kW: $843 instead of $874

Western Sydney and Wollongong pay that rate; the Eastern Suburbs, the Northern Beaches, the Inner West and the Central Coast are on Ausgrid.

The climate moves it more, and the label cannot show it, because the average zone is one set of figures for the whole of Sydney.

The Bureau of Meteorology's July mean minimum is 8.1 degrees at Observatory Hill and 3.8 degrees at Richmond RAAF, four degrees colder on the same morning, and a unit in Richmond runs longer than the same unit in Bondi.

Treat the figures above as a fair comparison between models, not a forecast of one bill: expect the west to sit above them and the coast below.

Reading this when you choose

Compare the heating row before the cooling stars if winter is when you feel the bills, and only against other models of the same capacity; what a star is worth shows how far the two rows can disagree.

Size the unit to the room with the calculator, plan a ducted system's zones around the rooms you heat at night, and clean the filter before the cold arrives, because a blocked filter makes the unit run longer for the same warmth (a clean is a small job).

Every model page here shows both figures with the date beside them, and the compare tool puts models side by side.

Sources

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