What Are The Sizes Of Air Conditioners

What size air conditioner do I demand?

Choosing the right size can salvage you coin and reduce your energy use.

man looking at size of air conditioner on wall

Final updated: xix Oct 2021

Need to know

Room size is important, only information technology's not the just important gene
Insulation, location and orientation also have significant impact
Choosing the right size is vital to maximise performance and minimise running costs

No thing how hot nether the collar yous become, ownership an air conditioner should never exist an impulse purchase. It's an expensive, long-term commitment that has big implications for your ability pecker and condolement levels alike – so it's important to practise your homework before installing one.

While it's tempting to simply opt for the biggest air conditioner you tin can get, bigger isn't e'er better. So how tin yous discover out the capacity you need? We'll walk you through it.

What size air conditioner should y'all get?

CHOICE air conditioning proficient Chris Barnes explains the factors that affect what size air conditioning unit you need.

The big four

While room size is an of import consideration, every home is unlike and at that place are many other factors that volition bear upon your air conditioning capacity requirements.

I saved hundreds on my final air conditioner purchase past calculating that a smaller capacity model would suit my home.

"Take some time to assess the room and figure out which size air conditioner you lot demand," says CHOICE'south air con expert Chris Barnes.

"I saved hundreds on my last air conditioner purchase by calculating that a smaller capacity model would arrange my dwelling."

These four things have the biggest impact on what size ac unit y'all'll need:

Room size: What'due south the length, width and ceiling height? While floor space is important, so is total volume – a room with loftier ceilings will require more than energy to absurd.
Insulation: Are the ceilings and walls insulated? What's underneath and on meridian of the room? Ceiling insulation is 1 of the biggest factors in making your home thermally efficient.
Location: Where do you alive? A room in Darwin will need a more powerful air conditioner for cooling, compared to an otherwise identical room in Hobart.
Orientation: Which mode does the room face up? A large north- or west-facing window can let in a lot of estrus in summer, whereas a shaded, southern-facing window will be libation.

CHOICE tip: Ceiling insulation has the biggest bear on on how large an air workout unit of measurement you'll need. If you lot don't have roof insulation, consider installing it – it'll save you money in the long run, every bit you tin get away with a smaller, cheaper air conditioner, as well as ongoing running costs.

Room size

Hither'due south our rough guide to the air conditioner capacity (size) y'all'll need to cool a particular room size.

Air conditioning capacity requirements per room size
Room size	Example	Approx. capacity	Toll guide
Small (upwardly to 20m²)	Bedroom, study, pocket-size kitchen	2–2.5kW	$600–$2800
Medium (twenty–40m^two)	Bedroom with ensuite, small-scale lounge	two.5–5kW	$700–$3000
Large (twoscore–60m^two)	Large chamber, mid-sized lounge, large kitchen	4–6kW	$g–$4000
Extra large (60+yard^two)	Open-plan areas, large lounges	5–9kW	$1000–$5000+

Size matters

This is a ballpark guide, but we recommend that yous do an accurate calculation then you lot don't end up with a system that's drastically over- or under-sized. Don't be tempted to become smaller to save money, or larger to go along your firm feeling like a fridge. Remember, too, that the size of the unit of measurement could affect the cost of installation and replacement.

"Bigger isn't e'er better, and smaller isn't e'er more economical," says Selection's air con expert Chris Barnes. "Aim for the sweet spot."

Here's what can happen if you super-size or skimp on your air con:

Too big: The unit may run frequent short cycles to achieve the target temperature. This can mean:
- the room gets likewise hot or cold
- the unit of measurement doesn't dehumidify the air enough (so the room feels less comfortable)
- ability use increases
- running costs increase
- more wear and tear on the system.
Also small: The unit of measurement may have to run at maximum output more frequently. This can mean:
- the unit dries out the air too much
- more than habiliment and tear on the system
- power utilise increases.

CHOICE tip: Cull a model with capacity that'southward either just right, or slightly more than you'll need for the room. For example, if the room needs a 6kW model, then go for a unit of measurement with a rated cooling chapters in the range of half dozen–half dozen.5kW.

Calculators

Some installers and online calculators offer only a simplistic assay and may tend to recommend a larger capacity than you really need.

Find a estimator that takes all of the room'due south details into account, including window size, shading, window coverings, insulation, local climate, etc. The more information you tin include, the more accurate the calculation will be.

The cooling load and heating load calculators on fairair.com.au, by the Australian Found of Refrigeration, Air Conditioning and Heating (AIRAH), are worth using; they allow y'all to factor in a lot of details about the room, its insulation, window orientation and more, to get an authentic guide to the right air-conditioner size.

Omnicalculator.com also has a size reckoner you might try. Alternatively effort the calculators on manufacturer and installer websites, but we remember these tend to overestimate the capacity yous demand.

Our air conditioner ownership guide has lots of info about buying the best air con for your needs, and you can easily compare the cooling capacities of different models in our air conditioner reviews.