How Does Reverse Cycle Air Conditioning Work (+ Ups & Downs)

For most people, an air conditioning system is about keeping the space cool during the summer heat. But if you live in a state where it gets chilly in the winter, you will need a heating system.

Yes, we Brisbanites may like to brag about our scorcher, but there are times of the year when even we need heating.

This is where a reverse cycle air conditioner can be a must for a home or office space. It may be a mouthful, but it actually looks like a standard split air conditioning system. With one difference in functioning: It can do both your heating and cooling.

Let us take a closer look at reverse cycle aircon systems and find out how they function.

A Look Under the Hood of a Reverse Cycle Air Conditioner

A reverse air conditioner contains the same working principal components as a standard split air conditioner. However, you can shift between heating and cooling by simply flicking a switch that reverses the heat exchange process. 

The main component of the system is the heat pump that performs the heating and cooling. This controls the refrigerant which flows through the system and acts as the heat transfer medium. In winter, the pump absorbs heat energy from outside through the refrigerant and releases it in the room to raise the indoor temperature. The opposite happens when the room temperature needs to be lowered.

For proper understanding, let’s take a look at the four processes of a vapour compression refrigeration cycle.

• Compression: A compressor is the heart of the system and increases the temperature and pressure of the refrigerant gas.
• Condenser or heat exchanger: The refrigerant flows through the condenser where it gains or loses heat.
• Throttling: This is a valve through which the refrigerant passes and undergoes a change in pressure.
• Evaporator: In this stage, the refrigerant gains heat and changes into vapour state.

In a reverse cycle split system air conditioner, a special reversing valve is used that reverses the flow of the refrigerant spending on your requirement. For example, in heating mode, the outside air is the heat source and heats the refrigerant. Now, the indoor evaporator acts as the heating coil.

Even when the outside air temperature is low in winter, the AC can absorb heat from the surroundings. The gained heat is released inside a colder room. In cooling mode, the process is reversed and heat is absorbed from the room and released outside.

The reverse cycle is also used in ducted air conditioning systems for cooling or heating the entire house. The only difference is, the air is channelled through hidden ducts running along the ceiling. In general, ducted systems are best suited for larger spaces. If you want to heat one or two rooms, a split unit is a better choice.

Is Reverse Cycle Air Conditioning Expensive to Run?

If the weather in your location needs heating one day and cooling the next, a reverse cycle air conditioner is a great option. Since a single machine performs a dual function, you do not need two separate setups.

Coming to the costs, reverse cycle air conditioners are more expensive to install. Depending on the size of the unit, the total cost can be anywhere between $2,000 to $15,000. The installation process takes time too. 

However, the long-term cost savings can make them a great investment. Moving heat by using electricity is cheaper than generating heat by fuel combustion. Moreover, being a 2-in-1 air conditioning system in a single unit, it’s easier to use.

A standard air conditioner can generate around three kilowatts (kW) of heat for each kilowatt of electricity consumed. One report suggests that the annual cost of gas heating is around $1,444.85 in SA. With reverse-cycle air conditioning, the heating costs can be as low as $476.61. As energy costs across Australia continue to rise, kicking the gas habit will help you save more.

Bonus Advantages of Reverse Cycle Air Conditioning

It goes without saying: Air conditioners are more efficient than portable electric heaters or gas heaters. A gas heater uses radiant heat generated from the combustion of the fuel. So the heating is localised and is not distributed uniformly. 

In contrast, an air conditioner delivers warm air for more uniform heating or cooling (especially if the system is zoned!) and can control the temperature of larger spaces. 

Modern reverse air conditioning systems are highly efficient and can perform in extreme conditions as well. The high-end units can heat your space even when outside temperatures are as low as -15°C. That said, to get the best performance from the AC in extreme conditions, you need to ensure that your home has proper insulation and draught sealing.

Besides, there are potential health and safety risks associated with gas heating. 

A reverse cycle air conditioner will not only control temperature but will also improve the air quality by using filters. Manufacturers use cutting-edge technology to remove microorganisms and odour from the indoor air. In addition, you get bonus features like multiple fan settings, temperature sensors, and built-in Wi-Fi.

Burning natural gas produces less emissions compared to burning coal to generate electricity. However, an electric reverse cycle air-conditioner is more environmentally friendly when electricity is generated from renewables. Also, Australia’s refrigeration and air conditioning industry has made remarkable progress in reducing the use of ozone-depleting refrigerants like R22. 

Frequently Asked Questions

Do reverse cycle air conditioners use a lot of electricity?

The electricity consumption of a reverse cycle air conditioner depends on the size of the unit and its operating efficiency. However, the electricity consumption is much lower than other systems of heating and cooling.

Is reverse cycle AC a heat pump?

Yes, a reverse cycle AC is a heat pump system. It can pump heat into or out of a room depending on your needs.

What is the difference between a reverse cycle and a split system?

All split systems do not operate based on a reverse cycle and can only provide cooling. On the other hand, reverse cycle ACs can be split or ducted types.

What is the most common air conditioner in Australia?

The wall-mounted split system air conditioners are the most popular choice in Australia.