Are heat pumps and reverse cycle air conditioners the same thing?

Yes. Both use an identical vapour compression cycle to move heat from one place to another. The only difference is application — reverse cycle air conditioners heat and cool indoor air, while heat pump hot water systems heat water. The core technology, refrigerant cycle, and efficiency principles are the same.

Why does Australia use different names for the same technology?

Marketing and product history. Air conditioners were originally sold as cooling-only devices. When manufacturers added heating capability by reversing the refrigerant flow, they called it 'reverse cycle' to distinguish it. Hot water systems using the same technology were marketed as 'heat pumps' to differentiate from electric element and gas systems. Most other countries just call both 'heat pumps'.

Can I get a rebate for a reverse cycle air conditioner?

Generally no. Federal STCs only apply to heat pump hot water systems, not space heating or cooling. However, some state programs like Victoria's VEU scheme provide certificates for upgrading to high-efficiency reverse cycle systems. There is no federal rebate for reverse cycle air conditioners.

What is COP and why does it matter?

COP (Coefficient of Performance) measures how many kilowatt-hours of heating or cooling a heat pump delivers per kilowatt-hour of electricity consumed. A COP of 4 means 4 kWh of heat output for every 1 kWh of electricity. Both reverse cycle ACs and heat pump hot water systems typically achieve COP 3-5, making them 3-5 times more efficient than direct electric heating.

Is a heat pump more efficient than a gas heater?

Yes. A gas heater converts about 80-90% of gas energy into heat. A heat pump delivers COP 3-5, meaning 3-5 times more heat energy than the electricity it consumes. Even though electricity costs more per kWh than gas, heat pumps are cheaper to run in most Australian climates and produce zero direct emissions.

Do heat pumps work in cold climates?

Yes. Modern reverse cycle ACs with inverter compressors maintain effective heating down to -15°C or below. Heat pump hot water systems using CO2 refrigerant maintain strong performance in cold conditions. Efficiency drops in cold weather but heat pumps remain more efficient than resistive electric or gas heating at any temperature where they operate.

Heat Pump vs Reverse Cycle Air Con Australia

If you have searched for “heat pump vs reverse cycle air conditioner” expecting to find two different technologies, here is the answer: they are the same technology. The same refrigeration cycle, the same physics, the same type of compressor. The only difference is what they are heating or cooling.

This is not a simplification. It is the literal engineering reality, and it is one of the most common points of confusion in Australian energy discussions.

The vapour compression cycle — one technology, many names

Every heat pump — whether it is a split system air conditioner, a ducted reverse cycle system, a hot water heat pump, a pool heater, or a heat pump clothes dryer — uses the vapour compression cycle. The cycle has four stages and four components:

Compressor — compresses refrigerant gas, raising its temperature and pressure
Condenser — the hot, high-pressure refrigerant releases heat to the target (indoor air, water, or a pool)
Expansion valve — drops the pressure, cooling the refrigerant rapidly
Evaporator — the cold refrigerant absorbs heat from the source (outdoor air, in most residential applications)

That is it. The refrigerant moves in a loop. It absorbs heat in one place and releases it in another. The compressor is the engine that drives the cycle. The electricity you pay for runs the compressor — not a heating element.

Heating mode vs cooling mode

A reverse cycle air conditioner can run the cycle in both directions:

Heating mode: Absorbs heat from outdoor air → releases it indoors (the evaporator is outside, the condenser is inside)
Cooling mode: Absorbs heat from indoor air → dumps it outside (the evaporator is inside, the condenser is outside)

A heat pump hot water system only runs in one direction — absorbing heat from outdoor air and releasing it into a water tank. It is a heat pump that only heats.

A reverse cycle air conditioner is a heat pump that can both heat and cool.

That is the entire difference.

Why Australia uses different names

In most of the world — Europe, the UK, North America, Japan — the term “heat pump” covers all applications: space heating, space cooling, hot water, and pool heating. An air conditioner that can heat is called a heat pump. A hot water system that uses the same technology is called a heat pump water heater.

Australia took a different path, for entirely historical and marketing reasons:

Air conditioners were originally sold as cooling-only devices. When manufacturers added heating by reversing the refrigerant flow, they called this “reverse cycle” to distinguish from cooling-only models. The term stuck.
Hot water systems using the same technology were marketed as “heat pumps” to distinguish from the dominant technologies of the time: electric element and gas storage. Calling them “air conditioners for water” would not have sold units.

The result is that many Australians think of “heat pump” and “reverse cycle air conditioner” as fundamentally different products. They are not. They are the same technology applied to different tasks — heating water versus heating and cooling air.

Every heat pump in your home

Once you understand that “heat pump” just means “vapour compression cycle device that moves heat,” you start noticing them everywhere:

Appliance	What it heats or cools	Typical COP	Common Australian name
Split system AC (heating mode)	Indoor air	3.5–6.0	”Reverse cycle air conditioner”
Split system AC (cooling mode)	Indoor air (removes heat)	3.0–5.5	”Air conditioner”
Ducted system (heating mode)	Whole-home air	3.0–5.0	”Ducted reverse cycle”
Hot water system	Tank of water	2.5–5.0	”Heat pump hot water”
Pool heater	Pool water	4.0–7.0	”Pool heat pump”
Clothes dryer	Removes moisture from clothes	2.5–4.0	”Heat pump dryer”
Refrigerator	Inside the fridge (removes heat)	1.5–3.0	”Fridge”

Your refrigerator is also a heat pump. It absorbs heat from inside the fridge and releases it into your kitchen (that is why the back of a fridge is warm). Nobody calls it a heat pump, but it is one.

COP — the number that matters

COP (Coefficient of Performance) is the metric that makes heat pumps worth understanding. It measures how much heat energy the device delivers compared to the electrical energy it consumes.

COP 1.0 = 1 kWh of electricity produces 1 kWh of heat. This is what an electric bar heater or resistive element achieves. 100% efficient — but only in the narrow sense of converting electricity to heat.
COP 4.0 = 1 kWh of electricity produces 4 kWh of heat. This is what a good heat pump achieves. It is not creating energy from nothing — it is moving heat from outdoor air into your home or water tank, and the compressor only needs enough energy to drive the cycle.

A heat pump with COP 4.0 is effectively 400% efficient compared to direct electric heating. This is why:

A reverse cycle air conditioner running in heating mode costs roughly one-quarter as much as a portable electric heater for the same heat output
A heat pump hot water system costs roughly one-quarter as much to run as an electric element system
Both cost less to run than gas heating in most Australian climates, even though electricity costs more per kWh than gas

COP is not fixed

COP depends on the temperature difference between the heat source (outdoor air) and the heat target (indoor air or water). The closer the temperatures, the easier the cycle works and the higher the COP.

Heating air on a 15°C day: COP 5–6 (small temperature lift, easy)
Heating air on a 0°C day: COP 2–3 (large temperature lift, harder)
Heating water to 60°C on a 25°C day: COP 4–5
Heating water to 60°C on a 5°C day: COP 2–3

This is why heat pump performance varies by climate zone and season. A heat pump in Brisbane runs at a higher average COP than the same unit in Hobart. But even at COP 2.0, a heat pump is still twice as efficient as resistive electric heating.

Where the rebates differ — and why

This is where the “same technology, different names” distinction has real financial consequences.

Heat pump hot water: STCs and state rebates

Heat pump hot water systems are eligible for Small-scale Technology Certificates (STCs) under the federal Small-scale Renewable Energy Scheme. This is the same scheme that provides the “solar rebate” — STCs are created for the system and traded as certificates, producing an upfront discount.

A typical heat pump hot water system creates 20–30 STCs, worth $760–$1,140 at current prices (~$38/STC). This discount is applied at the point of sale.

On top of STCs, most states offer additional heat pump hot water rebates:

State	Program	Typical value
VIC	Victorian Energy Upgrades (VEU)	$800–$1,000 in certificates
NSW	Energy Savings Scheme (ESS)	$600–$1,000 in certificates
SA	Retailer Energy Productivity Scheme (REPS)	$500–$900
QLD	Climate Smart Energy Savers	$300–$1,000
ACT	Home Energy Support	Up to $2,500 for low-income
WA	Limited programs	Check current availability

Combined federal and state rebates can reduce the installed cost of a heat pump hot water system by $1,500–$2,500 in most states.

For the full rebate breakdown, see our heat pump rebate guide.

Reverse cycle air conditioners: no STCs

Reverse cycle air conditioners are not eligible for STCs. The SRES covers solar panels, solar water heaters, and heat pump water heaters — not space heating or cooling equipment.

This seems inconsistent, given that both are the same technology. The distinction is legislative, not technical. When the SRES was designed, the intent was to incentivise renewable energy generation and efficient water heating (which is a large share of household energy). Space heating and cooling were addressed through building codes and appliance efficiency standards (MEPS — Minimum Energy Performance Standards) rather than certificate schemes.

Some state programs do provide incentives for efficient air conditioning:

Victoria’s VEU provides certificates for upgrading from old, inefficient split systems to high-efficiency reverse cycle units
NSW’s ESS has similar provisions for air conditioning upgrades
These are typically worth less than heat pump hot water rebates

Bottom line on rebates: If you are replacing a gas or electric element hot water system, a heat pump hot water system attracts significant rebates. If you are buying a new air conditioner, the rebates are minimal — you are mainly paying the full installed price. This is despite both products being the same fundamental technology.

Refrigerants — the shared evolution

Both reverse cycle ACs and heat pump hot water systems use refrigerants, and both are undergoing a transition to lower Global Warming Potential (GWP) options.

Refrigerant	GWP	Used in	Status
R410A	2,088	Older ACs and heat pumps	Being phased out
R32	675	Most new reverse cycle ACs	Current mainstream
R134a	1,430	Some heat pump HW systems	Being replaced
R290 (propane)	3	Newer heat pump HW (iStore, Reclaim)	Growing adoption
R744 (CO2)	1	Premium heat pump HW (Sanden, Reclaim)	Best for cold climates

The heat pump hot water industry has moved faster to ultra-low GWP refrigerants (R290 and CO2) than the air conditioning industry. R290 and CO2 heat pump hot water systems are widely available, while most residential ACs still use R32.

CO2 (R744) refrigerant is notable because it maintains better COP at low ambient temperatures than other refrigerants, making CO2 heat pump hot water systems the best choice for cold climates. For details, see our cold climate heat pump guide.

What to look for when buying

Since both products are heat pumps, many of the same principles apply.

Buying a reverse cycle air conditioner

Check the COP/EER rating on the energy label. Higher stars = higher COP = lower running costs.
Inverter compressor is essential. All modern quality units are inverter-driven, which varies compressor speed to match demand. Non-inverter (on/off) units are far less efficient.
Size correctly. An oversized unit short-cycles (turns on and off frequently), reducing efficiency and lifespan. An undersized unit runs constantly without reaching temperature. Get a proper heat load calculation.
Consider ducted vs split. Split systems are cheaper for individual rooms. Ducted serves the whole home but costs significantly more to install and run.
Brands: Daikin, Mitsubishi Electric, Fujitsu, and Panasonic dominate the Australian market for quality and support.

Buying a heat pump hot water system

Check the COP — anything above 3.5 is good for most Australian climates.
Integrated vs split. Integrated units have the compressor on top of the tank (simpler installation, fewer parts). Split units have the compressor separate from the tank (quieter, more flexible placement).
Tank size. 250L suits 2–3 people, 315L suits 3–4, 400L+ for 5+. See our heat pump sizing calculator.
Refrigerant type. CO2 or R290 for cold climates. R134a or R290 for mild-to-warm climates.
Noise. The compressor runs for 4–8 hours per day. Check the dB rating and consider placement relative to bedrooms and neighbours.
Claim your rebates. STCs and state rebates can save $1,500–$2,500. Your installer should handle the STCs.

For our ranked recommendations, see the best heat pump hot water systems in Australia. For cost analysis, see the heat pump hot water cost guide or run the numbers on our payback calculator.

Heat pump vs gas — the efficiency comparison

Since both reverse cycle ACs and heat pump hot water systems compete with gas alternatives, here is why heat pumps win on running costs in most situations.

Heating method	Effective efficiency	Typical cost per kWh of heat delivered
Gas ducted heating	70–90% (losses in flue and ducts)	5–8 c/kWh
Gas storage hot water	65–80% (standby losses)	6–10 c/kWh
Gas instantaneous hot water	80–90%	5–7 c/kWh
Electric element (resistive)	~100%	25–35 c/kWh
Reverse cycle AC (COP 4)	~400%	6–9 c/kWh
Heat pump hot water (COP 3.5)	~350%	7–10 c/kWh

Gas appears competitive on cost per kWh of heat — and in some states with cheap gas (WA, parts of VIC) it still is. But the trend is clear: gas prices are rising, electricity prices are stabilising (especially with solar), and the gap is closing.

The decisive advantage is that a heat pump with rooftop solar produces hot water or heating for near-zero marginal cost during daylight hours. Gas cannot do this. If you already have or plan to install solar panels, a heat pump of any type (AC or hot water) pairs far better than gas.

The bottom line

“Heat pump” and “reverse cycle air conditioner” are marketing terms for the same underlying technology. Both use a vapour compression cycle to move heat. Both achieve COP 3–5, delivering 3–5 times more heat energy than the electricity they consume.

The main practical difference is rebates: heat pump hot water systems attract federal STCs and state rebates worth $1,500–$2,500. Reverse cycle air conditioners generally do not receive comparable rebates, despite using identical technology.

If you are replacing a gas or electric hot water system, a heat pump is the most efficient replacement — and the rebates make the economics even stronger. See our complete heat pump hot water guide or compare systems on our heat pump comparison page.

If you are buying an air conditioner, buy a reverse cycle unit with an inverter compressor and high star rating. It is a heat pump by another name, and it will cost a fraction of gas or resistive electric heating to run.

Heat Pump vs Reverse Cycle Air Conditioner: They're the Same Technology