Understanding Reverse Cycle Air Conditioning: A Comprehensive Guide

Air conditioning has become an essential part of modern living, providing comfort and respite from extreme weather conditions. 

Among various types of air conditioning systems, reverse cycle air conditioning stands out as an efficient and versatile solution for both cooling and heating. 

In this article, we will delve into the workings of reverse cycle air conditioning, explore its advantages, compare ducted reverse cycle and split system options, and help you make an informed decision for your specific needs.

What is Reverse Cycle Air Conditioning?

Reverse cycle air conditioning is a technologically advanced system that enables both cooling and heating within a single unit. Unlike conventional air conditioners that can only cool the air, reverse cycle systems have a reversible refrigeration cycle that allows them to extract heat from the outside air and transfer it indoors during colder months. This process provides an effective heating solution, making reverse cycle air conditioning a year-round comfort solution.

The core components of a reverse cycle air conditioning system include an outdoor unit containing a compressor, condenser coil, and expansion valve, and an indoor unit comprising an evaporator coil and a fan. These components work together to facilitate the cooling and heating processes.

The primary function of reverse cycle air conditioning is to regulate indoor temperatures by removing heat from the indoor air during cooling mode and transferring it outside. Conversely, during heating mode, the system extracts heat from the outdoor air and transfers it inside. This versatile functionality ensures that you can enjoy comfortable living conditions regardless of the external weather conditions.

How Does Reverse Cycle Air Conditioning Work?

Let’s explore how does reverse cycle air conditioning work in detail:

The Refrigeration Cycle

The refrigeration cycle is based on the concept that when a liquid absorbs heat and changes into a gas, it can cool its surroundings. Conversely, when a gas releases heat and changes back into a liquid, it can provide warmth. This cycle involves four main components: a compressor, a condenser coil, an expansion valve, and an evaporator coil.

Cooling Mode

Step 1: The process begins with the refrigerant, a special fluid with low boiling and condensing points, in a gaseous state within the evaporator coil. The indoor fan pulls warm indoor air through the coil.

Step 2: As the warm indoor air passes over the cold evaporator coil, the refrigerant absorbs heat from the air, causing the refrigerant to evaporate and transform into a low-pressure gas.

Step 3: The low-pressure gas then travels to the outdoor unit where the compressor, which acts as the heart of the system, compresses the gas. Compression raises its temperature and pressure significantly, turning it into a high-pressure, high-temperature gas.

Step 4: The high-pressure refrigerant moves to the outdoor condenser coil. As the surrounding outdoor air cools the refrigerant, it condenses back into a liquid, releasing the heat it had absorbed from the indoor air.

Step 5: The process repeats as the liquid refrigerant returns to the indoor evaporator coil, and the cycle continues as long as the air conditioner is running.

Heating Mode

Let’s now understand how does reverse cycle heating work. The key to reverse cycle air conditioning’s heating capability lies in reversing the refrigeration cycle. Here’s how it works:

Step 1: The reversing valve, a critical component in the system, switches the flow of the refrigerant, causing it to move in the opposite direction compared to cooling mode.

Step 2: The outdoor unit now acts as the evaporator, and the indoor unit functions as the condenser. The refrigerant absorbs heat from the outdoor air and transfers it inside to provide warmth.

Step 3: The compressor compresses the refrigerant, raising its temperature, and it releases the heat into the indoor air as it condenses back into a liquid within the indoor coil.

Step 4: The warmed air is then distributed throughout the living space, effectively heating the room.

Temperature and Humidity Control

Reverse cycle air conditioning not only regulates temperature but also helps control indoor humidity levels. During cooling mode, excess humidity is removed from the indoor air as the air passes over the cold evaporator coil, which acts as a dehumidifier. In heating mode, the system does not dry out the air excessively, making it a more comfortable and healthy option compared to some other heating methods.

Efficiency and Environmental Impact

Reverse cycle air conditioning is considered highly energy-efficient, especially when compared to traditional heating methods like electric resistance heaters. By utilising the heat exchange process to provide both cooling and heating, these systems can offer substantial energy savings. Additionally, using electricity for heating reduces the reliance on fossil fuels, making reverse cycle air conditioning a more environmentally friendly option with lower greenhouse gas emissions.

Advantages of a Reverse Cycle Air Conditioning System

Energy Efficiency and Cost-Effectiveness

Reverse cycle air conditioning is highly energy-efficient, providing up to three times more heating or cooling output compared to the energy it consumes. This efficiency translates to lower energy bills and reduced greenhouse gas emissions, making it an environmentally friendly choice.

Year-Round Usability

One of the most significant advantages of reverse cycle air conditioning is its year-round usability. The system can efficiently cool your home during hot summers and keep you warm and cosy during cold winters. This eliminates the need for separate heating and cooling systems, saving both space and money.

Environmental Benefits

Reverse cycle air conditioning systems predominantly use electricity for their operations. By extracting heat from the outdoor air for heating, they significantly reduce the reliance on fossil fuels and contribute to lowering carbon emissions, making them an eco-conscious choice for environmentally responsible households.

Versatility and Flexibility

Reverse cycle air conditioning systems come in various configurations, such as wall-mounted split systems and centrally ducted systems. This versatility allows users to choose the best setup for their specific needs, considering factors like room sizes, layout, and design preferences.

Improved Indoor Air Quality and Filtration

Most reverse cycle air conditioners are equipped with advanced air filtration systems that capture and remove airborne particles, dust, and allergens from the indoor air. This not only improves indoor air quality but also creates a healthier living environment, particularly beneficial for individuals with respiratory issues or allergies.

Ducted Reverse Cycle vs. Split System

Ducted Reverse Cycle Systems

Ducted reverse cycle systems consist of a central outdoor unit that connects to a series of ducts running through the ceiling or floor. These ducts distribute conditioned air to various rooms through vents or diffusers. The system is controlled via a central thermostat, providing consistent temperature throughout the entire home.

Split System Air Conditioning

Split systems, on the other hand, consist of two units: an outdoor condenser unit and an indoor evaporator unit. The indoor unit is usually mounted on a wall and cools or heats a specific room or area. Each split system operates independently, and multiple units can be installed to provide zoned temperature control.

Comparison of Their Features and Benefits

Ducted Reverse Cycle

Ducted systems provide centralised control and a seamless aesthetic as the ducts are concealed within the walls or ceiling. They offer zoned temperature control, allowing different areas of the house to be independently regulated. However, reverse cycle air conditioning installation costs can be higher, and they may not be as suitable for smaller living spaces.

Split System

Split systems are generally more cost-effective and easier to install than ducted systems. They are ideal for cooling or heating individual rooms or small areas. Additionally, the ability to create specific temperature zones can lead to increased energy savings. However, they might not offer the same level of uniformity in temperature distribution as ducted systems.

Considerations for Choosing Between the Two:

When deciding between ducted reverse cycle and split system air conditioning, there are many factors that need to be kept in mind. Let’s have a look at some of them:

Considerations Ducted Reverse Cycle Split System
House Size and Layout Ideal for larger homes Suitable for smaller spaces
with multiple rooms or individual rooms
Installation and Cost Higher installation Easier and less expensive
costs, especially if installation
no existing ductwork
Zoning Capabilities Offers zoned control, Individual temperature control
customizable settings for each room or area
Aesthetics and Space Provides a seamless Wall-mounted indoor units may
Requirements look with hidden ducts be less aesthetically pleasing
in walls/ceiling
Level of Control Centralised control Individual remote controls
from a single point for each indoor unit
Long-Term Energy Efficiency Highly energy Can be energy-efficient, but
efficient, potential may be less efficient when
for significant operating multiple units
energy savings simultaneously
Climate Considerations Suitable for areas Effective for moderate climates,
with fluctuating but may struggle in harsh
temperatures and winters
distinct seasons

Which is The Best Choice?

Choosing the best air conditioning system depends on individual requirements and circumstances. Ducted reverse cycle systems are an excellent choice for larger homes where whole-house temperature control and aesthetics are paramount. They offer consistent performance and zoning capabilities, making them ideal for families seeking total comfort.

On the other hand, split systems are more suitable for smaller residences or for those who wish to cool or heat specific areas. Their lower installation costs and zoning flexibility can be appealing to budget-conscious individuals or those seeking custom temperature control.

Ultimately, the best choice will depend on your specific needs, preferences, and budget considerations.


Reverse cycle air conditioning presents an efficient and versatile solution for maintaining a comfortable living environment throughout the year. With the ability to provide cooling during hot summers and heating during chilly winters, these systems offer energy-efficient performance, cost-effectiveness, and a reduced carbon footprint. 

Whether you opt for ducted reverse cycle or split system air conditioning, making an informed decision based on your unique requirements will ensure that you enjoy the benefits of reverse cycle air conditioning for years to come. 

By understanding the workings and advantages of this innovative technology, you can create a cosy and welcoming living space regardless of the weather outside.