What Is a Reverse Cycle Air Conditioner?

A reverse cycle air conditioner is a heat pump that can both heat and cool your home. In summer it moves heat from inside your home to the outside. In winter it reverses the flow of refrigerant, absorbing heat from the outside air and releasing it indoors. Because it moves heat rather than burning fuel or relying on a heating element, it is a very efficient way to heat a home with electricity.

How reverse cycle heating works

Reverse cycle split systems, also known as reverse cycle heat pumps, operate on the vapour compression refrigeration cycle. Electricity powers a compressor that raises the pressure and temperature of the refrigerant until it is hot enough to heat the air.

A reverse cycle air conditioner does not take air from inside and send it outside, or the other way around. Instead, heat is absorbed from the outside air and transferred inside through the refrigeration process. This is exactly the same process the system uses to cool, only in reverse, which is where the name comes from. A reversing valve inside the system changes the direction the refrigerant flows.

Because the heat is moved rather than generated, no expensive heating elements are used and no fossil fuels are burnt in your home. The electricity can come from the grid, from solar panels or from batteries.

Heating in cold weather

Heat is present in the outside air at any temperature above absolute zero (-273.15°C). That means a reverse cycle air conditioner can absorb and transfer heat effectively even when it is below zero outside. Heating output does fall as the outdoor temperature drops, so choosing the right size system for your home matters. Our heatload calculator is a good starting point.

This makes reverse cycle systems a good option for homeowners who want to use their solar and batteries, reduce what they spend on heating or move away from gas.

Reverse cycle vs cooling only

The cost of manufacturing a reverse cycle split system is very close to that of a cooling only system. The refrigeration process is the same, and the main addition is the reversing valve (a four way valve). For this reason the price difference between cooling only and reverse cycle systems is usually small.

Why reverse cycle heating is efficient

When you read an energy label, you will notice that split systems usually have a higher efficiency in heating (the coefficient of performance, or COP) than in cooling (measured by the energy efficiency ratio, or seasonal energy efficiency ratio). In heating mode, the energy used by the compressor ends up as heat in your room too, on top of the heat moved in from outside.

A standard electric heater turns one unit of electricity into about one unit of heat. According to the Australian Government's Energy Rating website, a reverse cycle air conditioner can move three to five units of heat into the room for every unit of electricity it uses, within the normal operating range in Australia. The example label in our energy label guide shows a heating COP of 4.1.

No combustion in your home

• Reverse cycle systems can run on renewable energy such as solar and batteries, which can reduce running costs.
• No mining, fracking, refining, transporting or burning of fossil fuels such as LPG or natural gas is needed to heat your home.
• Nothing is burnt inside the home, so a reverse cycle system carries no risk of carbon monoxide poisoning. Carbon monoxide is a tasteless, odourless gas that can kill people and animals.

Reverse cycle options for your home

EZYAIR installs reverse cycle split systems, multi-split systems, bulkhead systems and ducted reverse cycle systems, including ducted systems over 25kW and VRF. If you are replacing gas ducted heating, see ducted heating.

You may also be eligible for a discount under the Victorian Energy Upgrades (VEU) program. Eligibility depends on what you are replacing and the system you install. EZYAIR is an accredited provider under the VEU program (accreditation A2261).

Further reading

• Melbourne Energy Institute: Switching off gas, an examination of declining gas demand in Eastern Australia
• VEU accredited provider and air conditioning licences in Victoria

Frequently asked questions

Is a reverse cycle air conditioner the same as a heat pump?

Yes. A reverse cycle air conditioner is an air source heat pump. It moves heat into your home in winter and out of your home in summer.

Can reverse cycle heating work in a Melbourne winter?

Yes. A reverse cycle system can absorb heat from the outside air even when it is below zero. Heating output falls as it gets colder, so the system needs to be sized correctly for your home.

Does reverse cycle cost much more than cooling only?

Usually not. The refrigeration process is the same and the main difference is a reversing valve, so the price difference is usually small.

Can I get a VEU discount on reverse cycle air conditioning?

You may be eligible under the Victorian Energy Upgrades program, depending on what you are replacing and the system you install. EZYAIR is an accredited provider (accreditation A2261) and can check eligibility before any work starts.

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 an Inverter Air Conditioner?
• How to Read a Split System Energy Label
• VEU Accredited Provider and Air Conditioning Licences in Victoria

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 reverse cycle heating and cooling 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.