How does an Inverter air conditioner work?

There are number of terms that you will hear when looking at making a choice between various type of air conditioners - cooling only, reverese cycle, fixed speed, inverter andthe list goes on. As a consumer, it can be a bit confusing understanding what exactly is what when it comes to air conditioners.

One of the more common terms you will hear in the current market regarding air conditioners is - an inverter air conditioner. If you're wondering what exactly an inverter air conditioner is, then you're in the right place. Here, we break down what it is, how it works, what size you'll need and how much they cost, as well as some of the benefits associated with installing an inverter air conditioner.

What is an inverter air conditioner?

An inverter is actually a piece of technology that is designed to transform direct current (DC) into alternating current (AC) and at any frequency and voltage. In an air conditioner, it works to control the speed of the compressor motor. Traditional, non-inverter air conditioners run their compressor at a fixed speed, and manage response to cooling demand by turning the motor on and off, which uses additional energy. The technology of an inverter system allows the motor to be slowed or sped up, without actually turning the motor off. The act of this regulates the temperature and saves a considerable amount of energy.

Not only do inverter systems preserve energy costs, but they also provide a more reliable system, which, in turn, means fewer breakdowns and less maintenance, resulting in lower costs.

How do inverter air conditioners work?

The process of how inverter air conditioners actually work is quite technical. Put simply, an inverter air conditioning system works through the use of magnets and electric current that maintain and control the rotational speed of the compressor.

The compressor controls the refrigerant flow within the system, and an inverter conditioner ensures that an appropriate variable speed is reached, depending on the current conditions in the house, room or space.

What type of AC systems have inverted technology?

Almost all air condtioners sold into the residential air conditioning market in Australia us inverter technology. There are still some commercial systems sold that use non-inverter technology.

What size inverter air conditioner do I need?

Inverter air conditioners are similar to non-inverter air conditioners, in the sense that big systems are required to cool bigger areas. However, because of their energy efficiency, an inverter air conditioner has the capability to cool a larger area than one without inverter technology.

All air conditioners will have a wattage or kilowattage marked on them. This is the amount of energy that is required to heat an area per hour.

To calculate what size unit is best, you'll need to first calculate the size of the area that's being cooled.

You can do this by multiplying the width of the room by the length in metres. Aussie households will normally require about 150-180 watts of power per square metre to cool an area with a non-inverted system. Inverted systems on the other hand will only need about 105- 125 watts of power per square metre to cool the area. Keep in mind that there are 1000 watts in a kilowatt (kW).

In mathematical terms, the equation to work out how much power you'll need looks like the below:

[(square metres of the room) x 115 (average wattage)] ÷ 1000 (to convert into kW) = the minimum size of unit your room requires.

Below is an approximate breakdown of how many kilo wattages will be required for an inverter system to cool a specific sized area.

Small room

A room 10m2 - 20m2 will require a 1.75kW unit to cool the room.

Medium room

A room 20m2 to 30m2 will require a 2.45kW unit to cool the room.

Large room

A room 30m2 to 45m2 will require a 3.5-4.2kW unit to cool the room.

Extra-large room

A room 45m2 - 65m2 will require a 5-5.6kW unit to cool the room.

Running costs of inverter air conditioners

We've touched on the fact that inverter air conditioners are considerably cheaper than non-inverter air conditioners to run, but how much cheaper are they? Most manufacturers state that you can save around 30% on your energy bills when engaging an inverter air conditioner.

Air conditioners energy output is based on the number of watts or kilowatts they use. It is important to note that different states have different energy costs because they come from different providers.

Below are the average costs per kW per state:

  • NSW - 26.53 cents
  • VIC - 25.86 cents
  • QLD - 22.20 cents
  • SA - 35.32 cents
  • ACT - 22.81 cents
  • TAS - 26.59 cents

To calculate how much an inverter air conditioning system will cost to run, it's vital to know how much energy it consumes. This information is usually located on the unit itself, on its box or in the manual.

One yu know the amount of energy the unit consumes, you can go ahead and use the below equation to figure out the approximate cost of running your air conditioner.

kW (capacity of unit) x price/ hour (based on the electricty retailer in your state) =cost to run per hour (price/ kWh)

This equation will help you figure out the cost per hour of running your air conditioner. From here, if you'd like to determine the cost per day, week, month or year you can use the below equations.

Daily: times the above figure by the number of hours you use your air conditioner per day.

Weekly: times the 'daily' figure by the number of seven.

Monthly: times the 'daily' figure by 30.436875 (this is the average amount of days in a month).

Yearly: time the 'monthly' figure by 12.

Considering that 8kw unit costs about $5818.31 to cool a 45m2 - 65m2 per year, this means that an inverter system can shave around $1750 off the running costs.

Benefits of inverter air conditioning

Lower running costs

The thought of lower AC running costs is intriguing to most homeowners who pay their own energy bills. The energy reduction payoff of engaging an inverter air conditioner is high. It can reduce bills by up to 30% as compared to normal non-inverter air conditioners due to their economical features.

The key benefit of an inverter air conditioner is that it means your air conditioning system has variable capacity. This means you have more air conditioning when you need it - but also means the air conditioner is not consuming energy when it is not needed.

For example a Daikin Cora (FTXV71WVMA) which is suitable for a large room (combined living and dining) is an inverter air condioner. It has a rated capacity of 7.1kW. But as an inverter air conditioner it has an operating range of 2.0kW to 8.9kW. That means when the room is very hot the air conditioner can call on up to 8.9kW of cooling capacity - and consume energy accordingly. But once the room has been cooled down the air conditioner can operate with a capacity as low as 2.0kW - effectively using a small amount of energy to maintain the room at the set temperature - saving energy consumption. Once the room has reached set temperature the air conditioner will turn itself off entirely.

Inverter air conditioners have a longer lifespan

Inverter technology ensures that an air conditioner's motor isn't turned constantly turned off and on, and that the motor only runs at the speed that's required to cool the area. This means less wear and tear on the motor and a longer life span for the unit.

Because the AC unit is used economically, less serving is required, too. Both of these benefits mean fewer costs for the user, down the line.

Inverters mean cooling time is reduced

If you've ever used an air conditioner, you'll probably have noticed that once you switch the temperature, it takes a little time for the room to cool and the air con to really kick in. An inverter speeds up this process and as a result, the area is cooled quicker.

Because the air conditioner motor isn't constantly switching on and off, you won't need to wait for the motor to start from scratch when you change the temperature. Instead, the motor, which is already running, will quickly adjust to the speed that's required to reach your desired temperature.

Inverter air conditioning systems are very quiet

Even on very quiet non-inverter air conditioners, you will usually notice a sound when the compressor motor turns on and off. On an inverter air conditioner, the compressor motor won't turn off unless you physically turn the air conditioning unit completely off. This means less noise is made, it's very rare to hear any noise at all with an inverter air conditioner.

Furthermore, an inverter air conditioner uses less power than a non-inverter air conditioner, this will also reduce the noise of the system.

Inverter air conditioners are more eco-friendly than non-inverter air conditioners

While the lower running costs because of the lower energy consumption is certainly a plus, it's important to note that an inverter air conditioner is more eco-friendly for the same reason. There's no debating that using energy will have a negative effect on the environment.

Environmental problems related to energy consumption include air pollution, climate change, water pollution, thermal pollution, and solid waste disposal. By reducing the energy consumed through the use of an inverter system, the negative effects of energy consumption are reduced, too.


Are inverter air conditioning systems expensive?

No. Almost all air conditioners sold in Australia have inverter technology, with main exceptions being some large commercial systems.

Can all technicians install inverter aircon

The inverter system is actually part of the unit, so if a technician is able to install the specific type or air conditioner (Eg, split system or ducted), they'll be able to install an inverter version of this unit. If you're unsure about whether a technician is able to install the system, and want to enlist the help of a skilled professional, we have many technicians on our team that are very experienced with installing inverter air conditioning units. Get more information on installing an inverter air conditioner.

Time to call the experts?

If you are looking for more information on inverter air conditioners - it is time to call in the experts. Our Brisbane-based air conditioning team are on hand to give you the assistance you need. Call us on 07 3283 5566 or fill out a quick quote to get your air con back up and running! 

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