6 kW class
6 kW split systems, compared on the figures that matter.
A 6 kW unit typically suits a large living area — roughly 28 to 55 square metres depending on which way it faces, how well it is insulated and how many people use it. 44 models in this class are registered for sale in Australia across 5 brands.
Quick answer
A 6 kW split system air conditioner suits a room of roughly 28 to 55 square metres — typically a large living area — with the exact figure depending on orientation, insulation, ceiling height and occupancy. 44 distinct 6 kW-class models are registered with the Australian Government's GEMS database across 5 brands: Carrier, Daikin, Fujitsu, Mitsubishi Electric, Mitsubishi Heavy Industries. In this class the best cooling efficiency figure is AEER 4.04 and the best heating efficiency figure is ACOP 4.46, and the lowest declared indoor noise level is 57 dB. Thunderman Electrical and Air Conditioning Services supplies and installs units in this class across Greater Melbourne under ARCtick certification, with electrical work by REC 28523.
What this size means on the job
The part a showroom won't tell you.
The 6 kW class is narrower than the ones either side of it — five of the eight brands compete here — and it tends to be chosen for a living area that is larger than average but still one room. What separates the models at this capacity is less the cooling figure than how hard they work to deliver it: the input power differs enough across the register that two units with the same rated output do not cost the same to run. That gap is exactly what the AEER and ACOP columns exist to show, and it is the reason a specification sheet beats a sticker.
Quietest in this class
Ranked by declared indoor noise.
In this class the declared indoor noise levels run from 57 dB to 64 dB — a spread of 7 dB between the quietest and the loudest, which is a difference you would hear plainly in the same room.Capped at three models per brand so one range cannot fill the table.
| Model | Cooling | Heating | Indoor noise | AEER | ACOP | Stars | Registration |
|---|---|---|---|---|---|---|---|
| Mitsubishi Heavy IndustriesDXK21ZRA-WF1+1 variant | 6.3 kW | 7.1 kW | 57 dB | 3.96 | 4.41 | 3.5 / 3 | AAC8228 |
| Mitsubishi Heavy IndustriesDXK63ZRA-WF+2 variants | 6.3 kW | 7.1 kW | 57 dB | 3.96 | 4.41 | 3.5 / 3 | AAC7759 |
| Mitsubishi ElectricMSZ-AP60VGD+3 variants | 6 kW | 6.8 kW | 58.5 dB | 3.77 | 4.11 | 4 / 2.5 | AAC7702 |
| Mitsubishi ElectricMSZ-AP60VGD+3 variants | 6 kW | 6.8 kW | 58.9 dB | 3.77 | 4.06 | 3.5 / 2.5 | AAC6353 |
| Mitsubishi ElectricMSZ-LN60VG3B+3 variants | 6.1 kW | 6.8 kW | 59.5 dB | 3.52 | 3.77 | 3 / 2.5 | AAC7434 |
| Carrier42QAF060N8 | 6 kW | 6.5 kW | 59.56 dB | 3.45 | 3.81 | 3.5 / 2.5 | AAC9372 |
| Carrier42QRF060N8 | 6 kW | 6.5 kW | 59.56 dB | 3.45 | 3.81 | 3.5 / 2.5 | AAC9457 |
| Carrier38QUH060N8PB | 6 kW | 6.5 kW | 59.56 dB | 3.45 | 3.81 | 3.5 / 2.5 | ZAC0850 |
Cooling and heating are rated capacity. AEER andACOP are the annual efficiency figures for cooling and heating — higher is cheaper to run. Stars are shown as cooling / heating for a mixed climate zone, which is the one Melbourne sits in. Indoor noise is the manufacturer's declared sound level for the indoor unit. Every figure is as registered with the Australian Government's GEMS register, and the registration number is there so you can look it up yourself.
Cheapest to run — cooling
Ranked by AEER.
Cooling efficiency in this class runs from AEER 3.21 to 4.04 — the best unit here delivers about 26% more cooling per unit of power than the weakest. That gap is what you are choosing between, and it does not show up on the star sticker, because stars are banded.
| Model | Cooling | Heating | Indoor noise | AEER | ACOP | Stars | Registration |
|---|---|---|---|---|---|---|---|
| DaikinFTXM60AVMA | 6 kW | 7.2 kW | 64 dB | 4.04 | 4.46 | 4.5 / 3 | AAC10040 |
| DaikinFTXM60W2VMA | 6 kW | 7.2 kW | 64 dB | 4.04 | 4.45 | 4.5 / 3 | AAC6756 |
| DaikinFTXM60WVMA | 6 kW | 7.2 kW | 64 dB | 4.04 | 4.46 | 4.5 / 3 | AAC10192 |
| Mitsubishi Heavy IndustriesDXK21ZRA-WF1+1 variant | 6.3 kW | 7.1 kW | 57 dB | 3.96 | 4.41 | 3.5 / 3 | AAC8228 |
| Mitsubishi Heavy IndustriesDXK63ZRA-WF+2 variants | 6.3 kW | 7.1 kW | 57 dB | 3.96 | 4.41 | 3.5 / 3 | AAC7759 |
| FujitsuASTG22KMTC | 6 kW | 7.2 kW | 62 dB | 3.79 | 4.23 | 4 / 2.5 | AAC8711 |
| FujitsuASTH22KMTD | 6 kW | 7.2 kW | 62 dB | 3.79 | 4.23 | 4 / 2.5 | AAC7552 |
| Mitsubishi ElectricMSZ-AP60VGD+3 variants | 6 kW | 6.8 kW | 58.9 dB | 3.77 | 4.06 | 3.5 / 2.5 | AAC6353 |
Best for a Melbourne winter
Ranked by ACOP — the heating figure.
Heating efficiency here runs from ACOP 3.24 to 4.46, a spread of about 38%. Because Melbourne runs a reverse-cycle system for warmth far more of the year than for cooling, that spread costs more over time than the cooling one does — and this ranking is rarely the same as the one above it.
| Model | Cooling | Heating | Indoor noise | AEER | ACOP | Stars | Registration |
|---|---|---|---|---|---|---|---|
| DaikinFTXM60AVMA | 6 kW | 7.2 kW | 64 dB | 4.04 | 4.46 | 4.5 / 3 | AAC10040 |
| DaikinFTXM60WVMA | 6 kW | 7.2 kW | 64 dB | 4.04 | 4.46 | 4.5 / 3 | AAC10192 |
| DaikinFTXM60W2VMA | 6 kW | 7.2 kW | 64 dB | 4.04 | 4.45 | 4.5 / 3 | AAC6756 |
| Mitsubishi Heavy IndustriesDXK21ZRA-WF1+1 variant | 6.3 kW | 7.1 kW | 57 dB | 3.96 | 4.41 | 3.5 / 3 | AAC8228 |
| Mitsubishi Heavy IndustriesDXK63ZRA-WF+2 variants | 6.3 kW | 7.1 kW | 57 dB | 3.96 | 4.41 | 3.5 / 3 | AAC7759 |
| FujitsuASTG22KMTC | 6 kW | 7.2 kW | 62 dB | 3.79 | 4.23 | 4 / 2.5 | AAC8711 |
| FujitsuASTH22KMTD | 6 kW | 7.2 kW | 62 dB | 3.79 | 4.23 | 4 / 2.5 | AAC7552 |
| Mitsubishi ElectricMSZ-AP60VGD+3 variants | 6 kW | 6.8 kW | 58.5 dB | 3.77 | 4.11 | 4 / 2.5 | AAC7702 |
Not sure this is the right size?
Look either side.
All figures from the GEMS registration database (Australian Government). Every model above carries its registration number so you can check it atthe register.
6 kW air conditioners — common questions
What is the difference between two 6 kW units with the same star rating?
Usually the input power, and therefore the running cost. Star ratings are banded, so two units can sit on the same star figure while drawing measurably different amounts of electricity for the same rated output. The AEER and ACOP numbers are the finer measure — they are ratios of output to input, so a higher figure means the same cooling or heating for less power. Both are published on the GEMS register for every model sold in Australia.
How many 6 kW models are sold in Australia?
44 distinct models in this capacity class are currently registered with the Australian Government's GEMS database, across 5 brands: Carrier, Daikin, Fujitsu, Mitsubishi Electric, Mitsubishi Heavy Industries. That count is registrations rather than shelf listings — a single registration often covers several colourways of the same unit, which is why a retailer's catalogue looks larger.
What is the quietest 6 kW air conditioner?
The lowest declared indoor sound level in this class is 57 dB. Noise figures are declared by the manufacturer at a stated fan speed, so they compare like with like between models but will not match what you measure in a room — where the mounting position, the wall and the furnishings all change what you hear. A unit that is quiet on paper and badly positioned will still be the loudest thing in a bedroom.
Does a 6 kW unit heat as well as it cools?
Not necessarily, and in Melbourne that is the question worth asking. In this class the best cooling efficiency figure (AEER) is 4.04 and the best heating figure (ACOP) is 4.46, and they usually belong to different models. Because a reverse-cycle system here runs for warmth far more of the year than for cooling, the heating figure generally deserves more weight than the cooling star rating a showroom will point at.
Right size, wrong switchboard is still the wrong job.
Yiannis will confirm the capacity against the actual room, check the board can carry it, and quote the whole job rather than the easy half. Free quote, ARCtick certified, REC 28523.