How Much Electricity Does an AC Use?

Last updated on August 11, 2025

Right. So you’ve just opened your power bill, had a little cry, maybe gone catatonic and stared into the void for a spell. Now, here you are: Googling how much electricity an AC uses like someone’s dodgy uncle trying to DIY their way out of a second mortgage.

Fair play, let’s talk about it.

For those trying to keep the house at a liveable temperature without having to sell a kidney or take on a third job, this is for you. We’ll cover what kind of air con chews the most power, how to keep it from turning your bill into a horror story, and why 25 degrees is the sweet spot (no, seriously).

Not All Air Cons Are Equal

First off, it depends on what sort of beast you’re running. Here’s the quick and dirty rundown:

Split-System (Reverse Cycle)

Power usage: ~0.9–1.6 kWh/hour
Cost/hour: Around 30–50 cents
Common as chips — If you’ve got one of these, congrats, you’re playing it safe. It’ll still sting the bill, but it’s efficient and usually quiet enough to hear the telly.

Ducted System

Power usage: 2.0–6.0+ kWh/hour (can be higher for Mc Mansion-sized places)
Cost/hour: $0.60 — $1.80+
Looks flash, drains cash — Great if you love comfort. Not great if you enjoy having savings. These bad boys cool every room whether you’re in it or not, which is grand until you realise your linen closet is colder than your bedroom.

Portable Units

Power usage: 1.0 – 2.5 kWh/hour
Cost/hour: $0.30 – $0.75
Basically a loud box that farts cold air – Works for small rooms, but don’t expect miracles. They’ll chew through power while doing the bare minimum, a bit like that one bloke at work who’s always “on break.”

Window Units

Power usage: 0.8 – 1.5 kWh/hour
Cost/hour: Similar to split systems
The OG – Still kicking around in older homes. Loud, cranky, gets the job done. They rattle the walls, sound like they’re fighting a possum internally, but they blow cold.

So, How Much Does It Really Cost?

Let’s say you’re running a 2.5kW split system for six hours a day during a proper scorcher.

That’s around 7.5 kWh/day.
Multiply that by your local electricity rate, say, 30 cents/kWh.
You’re looking at $2.25/day, or $67.50/month if you’re consistent.

Now scale that up to a ducted system for the whole house? Easily $200+ a month.

Possibly more if you’re blasting it like your house is a fridge and you’re the beer. And if you’re letting it run all night? Add another $60 to the monthly sting.

What Makes It Worse?

A few things, all of which you’ve probably ignored at some point:

Thermostat wars – Every degree below 24°C adds about 10% more power use. So if you’re cranking it to 18°C just to “feel something again,” that emptiness is going to cost you.
Crap insulation – If your home leaks air like a colander, you’re basically cooling the footpath. Got single-pane windows and a tin roof? That’s a convection oven, not a house.
Old unit – If it was installed during the Rudd government, it might be time to upgrade. Technologies have come a long way. Modern units sip electricity. The old ones chug it like a festival dad on his fifth VB.
Clogged filters – That layer of dust and pet hair is basically making your AC try to breathe through a dirty sock. Clean it. It takes five minutes. You’ll remember how it’s supposed to sound.

How to Keep Cool Without Melting Your Paycheque

We’re not monsters. You deserve to be comfy. But here’s how to stay chill without having to skip dinner:

Set the temp to 24 – 25 °C. Your body won’t know the difference. Your wallet will.
Use ceiling fans or pedestal fans to help circulate the cool air. They’re cheap to run and make your AC work half as hard.
Close the blinds. Sunlight is lovely but can also be an irascible curse. Especially in rental flats where the window faces directly west. You’re not growing tomatoes in the lounge.
Seal up the house like a tomb. Use door snakes, shut off unused rooms, and plug every air gap you can find. Makes a difference.
Turn it off when you leave. It’s not a pet. It doesn’t get lonely. Unless you’re cooling down the cat, switch it off.
Clean your filters. Again. Just do it. Don’t make me come over.

And for the hardcore: try evaporative cooling if you’re in a dry climate. It’s like air con’s frugal cousin, less effective, but dirt cheap to run.

Real Talk: Is Air Con Worth It?

Emphatically yes.

This country turns into a frying pan for five months a year. We’ve got places where the weather forecast just says “No.” So should you sit in a hotbox and tough it out like your dad did in the ‘70s? No thanks.

But should you run it like it’s free? Also no.

You wouldn’t leave the oven on all day just to heat the lounge room. Same logic. Respect your air con and it’ll respect your bank account. Maybe. At the very least, it won’t punish you quite as much.

Final Thoughts

So, how much electricity does an AC use?

Enough that you should pay attention, but not so much that you have to suffer through 40°C in silence. If you plan ahead, use your settings wisely, and don’t try to recreate Antarctica in your living room, you can have your chilled air and afford it too.

It’s not about being fancy. It’s about being smarter than the heat.

Now go clean your filters and close the damn blinds.