What Is an Inverter Air Conditioner?
An inverter air conditioner can vary the speed of its compressor and fans instead of switching on and off at full power. It ramps up to reach your set temperature, then slows down to hold it. Compared with a fixed speed (non inverter) system, this uses energy more efficiently, keeps the room temperature steadier and runs more quietly.
How inverter technology works
Mains electricity, whether it comes from the grid or from renewable sources such as solar, is supplied as alternating current (AC). An inverter air conditioner uses electronics to convert this into direct current (DC) and then precisely control the power going to the compressor and fan motors, so they can run at variable speeds rather than simply on or off. Toshiba was the first manufacturer to put an inverter into an air conditioner.
Starting a motor from rest takes a high electrical load, so it is more efficient to keep the compressor running at a fraction of its total capacity than to keep starting and stopping it as the temperature in the room changes. Less stopping and starting also means less wear on the fans, motors and compressor.
Inverter vs non inverter air conditioners
A good example of a traditional, non inverter refrigeration system is an old refrigerator. It seems to sit dormant for a while, then the compressor runs flat out to bring the temperature down, switches off, and repeats the same process many times an hour.
A non inverter air conditioner works the same way. If it is set to 21°C, the room may need to reach 22°C before the thermostat turns the compressor on, and the system then cools until the room reaches 20°C and switches off. That constant swing of 2°C means feeling too cold one moment and too warm the next, in a lounge room, bedroom or office.
An inverter system avoids this. If it is holding 21°C in cooling mode and extra heat enters the room, for example the sun comes out from behind the clouds or several people walk in, it raises the speed of the compressor and fans to hold the target temperature, without jumping from 0% to 100% in a short period.
Benefits of an inverter air conditioner
- High energy efficiency. Running at variable speed avoids the energy wasted by constant stopping and starting.
- Precise temperature control. The system can vary the flow of refrigerant quickly in response to changes in the room.
- Better comfort. The room stays close to your set temperature instead of swinging up and down.
- Low noise. The compressor, motors and fans spend most of their time running at low speed, so operation is consistently quieter.
Comparing efficiency between models
To compare how efficient different air conditioners are, read our guides on how to read a split system energy label, which explains the coefficient of performance (COP) in heating and energy efficiency ratio (EER) in cooling, and the Zoned Energy Rating Label.
When you are ready to choose a system, explore our split system installation, multi-split and ducted reverse cycle options, or browse brands such as Fujitsu, Toshiba and Daikin.
Frequently asked questions
What does inverter mean on an air conditioner?
It means the air conditioner uses inverter electronics to control the speed of its compressor and fans, so it can run anywhere between low and full output instead of only switching on and off.
Do inverter air conditioners use less power?
Compared with an equivalent fixed speed system, an inverter usually uses energy more efficiently because it avoids the high load of repeatedly starting the compressor and can run at a fraction of its capacity once the room is comfortable.
Are inverter air conditioners quieter?
Yes. Because the compressor, motors and fans spend most of their time at low speed rather than cycling on at full power, inverter systems run more quietly.
Can an inverter air conditioner run on solar power?
An inverter air conditioner runs on normal household electricity, so it can use power from the grid, from rooftop solar or from a home battery.
Related guides
Keep reading with these related EZYAIR guides:
- What Is a Split System Air Conditioner?
- How Does a Split System Air Conditioner Work?
- What Is a Reverse Cycle Air Conditioner?
- How to Read a Split System Energy Label
- Zoned Energy Rating Labels (ZERL) for Air Conditioners
Talk to EZYAIR
Ezy Air Conditioning & Heating Pty Ltd (EZYAIR) has been helping Melbourne homes and businesses with heating and cooling since 2007. If you have a question about inverter air conditioners or would like a quote, contact our team or call 1300 399 247, Monday to Friday, 9am to 5pm.
Our head office and display centre is at 49 Huntingdale Rd, Burwood VIC 3125.
