Energy ratings explained: How does your air conditioner stack up? | Photo from: Northeast Ductless

With 78% of homeowners experiencing a notable increase in their electricity bill during summer usage of their air conditioning unit (with 28% recording a significant jump), it is wise to consider all factors when making a decision on which unit to purchase.

The cheaper unit on sale might save you a few dollars now, but over it’s lifetime it could cost you much more if it’s a less efficient model.

Where to start?

With so many different units, brands and sales on air conditioning units during summer, Gordon Hale of HRW Air Conditioning says it pays to do your homework before you set out to buy.

“Always consult a professional before running off to a big name shop to buy an air conditioner. Often the sales people don’t know enough to recommend the perfect air conditioner for your space,” he says.

And his recommendation is to spend more now, to ensure a better night’s sleep during intense heat waves. “If you want to put in an air conditioner, I’d recommend buying a more expensive, well-known brand. They’re quieter, which is important for when you’re sleeping.”

It’s written in the stars

The star rating system will help you to compare similarly sized machines and their running costs and greenhouse gas emissions. But be sure you are comparing apples with apples – there is no point comparing the star ratings on two wildly different machines. Star ratings are different for heating and cooling.

The Government’s energy rating website has more information about the star rating system for air conditioners. Or download the Energy Rating app by the Department of Industry here.

Size it up

You know you want to cool down, but ensure you are picking the right size unit for the size of the room you have to work with. So measure your room up before you go shopping.

Choose a model with equal or slightly greater capacity for the room so the unit can work efficiently. A unit that is too big or too small for the space will be inefficient and results in additional wear and tear on the unit and ultimately extra cost to you.

“As a general rule, for a domestic residence, I’d recommend getting an air con that’s 130 to 150 watts per square metre,” says Gordon Hale of HRW Air Conditioning.

air conditioner installation


Because you’ve measured up your room before choosing a unit, you will have picked the right size for the room. But also ensure you have a wall suitable for its mounting. It is advisable to install it on a longer wall in the room, but the outdoor unit of your split system needs to be mounted on a firm base or mounted to a wall within 15m of the inside outlet so keep this in mind as well.

It is advisable to consult a professional before you purchase to ensure you choose the right unit for the space you have to work with.

For more information on installation costs, check out our pricing guide here.