Australia is experiencing a surge of heat pump sales that is expected to continue at least into the mid-2030s as heat pumps continue to replace gas appliances in both existing and new buildings.
The additional HFC usage from the surge in heat pumps is estimated to add up to 0.071 million tonnes of carbon dioxide equivalent (Mt CO2e), equating to around 4.4 per cent of the Montreal Protocol limit of 1.622 Mt CO2e in 2036.
The largest emission risk from this equipment – hermetically sealed heat pumps and split system air conditioners – will be at end of life, according to a federal government report entitled Heat pumps – emerging trends in the Australian market.
The report, which was released this week by the Department of Climate Change, Energy, the Environment and Water, was undertaken by the Expert Group.
It looks at heat pumps from a refrigerant perspective, particularly at the types of hydrofluorocarbons (HFCs) in equipment that could have an impact on Australia’s HFC phase down which began on 1 January 2018.
“There is no national legislative approach to the end-of-life disposal and recycling of heat pumps, air conditioning equipment and refrigeration equipment,” the report said.
“To date there have been few restrictions on the GWP of refrigerants in heat pump equipment however this is changing with international and Australian regulations and incentives expected to influence manufacturers’ choice of refrigerant in products sold locally.”
From 1 July 2024 the Australian government will ban the import and manufacture of small air conditioners using refrigerant with a GWP over 750.
Reverse cycle
Air conditioners that incorporate both a heating and cooling function are heat pumps, however, they are more commonly called reverse cycle air conditioners in Australia.
The most common format, comprising more than 90 per cent of installations, are wall hung split single systems.
Single split system sales in 2022 are estimated to have been 1.32 million units, comprising 1.14 million non-ducted split systems and 181,000 split ducted systems.
Ducted systems are growing steadily and were up by 14 per cent compared to the average of 159,000 from 2017 to 2020. Strong growth is expected to continue in the years ahead as heat pumps replace gas appliances.
There was a further 36,000 sales of multi split systems, excluding VRV/F systems for which detailed information is not available, and around 200,000 small self-contained AC including window/wall units and portable AC.
National sales of non-ducted gas space heaters are estimated at 50,000 with a stock of 1.3 million, and sales of gas ducted heaters are estimated at 70,000 with a stock of 1.4 million.
“Suppliers and contractors are already seeing significant declines of gas heater sales of more than 30 per cent, particularly in new dwellings,” the report said.
“It is plausible that most of these sales will transition to heat pumps over the next decade.”
Ducted splits
Split ducted systems have already commenced the transition to lower GWP refrigerants with HFC-32 accounting for more than 50 per cent of models sold in 2023.
“This trend is expected to continue until 2030 when we estimate 85 per cent of models sold will contain HFC-32,” the report said.
“The larger charge size (i.e., >3 kg of A2L refrigerant) of split ducted systems poses a significant barrier to transition to a A3 class refrigerant (i.e., HC-290) and we do not consider hydrocarbon to be an option for this product category under the existing range of technical standards and regulations.
“HFC/HFO blend R454B (GWP of 465) was being considered by some suppliers. However, given the GWP ban for refrigerants with a GWP greater than 150 proposed in 2033, suppliers are likely to step from HFC-32 to A2L class HFC/HFO refrigerant blend such as R454C (GWP of 148), HFC/HFO blend R455A (GWP of 145) or similar to satisfy this requirement.”
The report said local manufacturers are currently transitioning split ducted air conditioning models from HFC-410A to HFC-32.
Non-ducted split systems
The bank of controlled refrigerants contained in small air conditioner: non-ducted split is a significant bank, estimated at approximately 14,300 tonnes of HCFCs and HFCs in 2022, accounting for 25 per cent of the total bank.
The revised new sales mix and growth projection estimates the bank of controlled refrigerants will grow to around 22,700 tonnes (14.2 Mt CO2e) by 2036.
The bank projection estimates that around 19,300 tonnes will be HFC-32 (more than 82 per cent) in 2036.
Medium sized equipment
Medium air conditioners (excluding cooling only equipment) includes ducted split systems, roof top packaged systems, multi-split systems and VRV/VRF split systems, and excludes cooling only equipment such as close control AC (incl. chillers) and compressed air refrigerated filter/dryers.
The bank of controlled refrigerants contained in medium air conditioner is the largest bank estimated at approximately 14,600 tonnes of HCFCs and HFCs in 2022, accounting for 27 per cent of the total bank.
The report estimates the bank of controlled refrigerants will grow to over 24,600 tonnes (24.2 Mt CO2e) by 2036. This is around 1,400 tonnes greater than previous projections.
The bank projection estimates that around 15,700 tonnes will be HFC-32 (around 64 per cent) in 2036.
Commercial heat pumps
The commercial heat pump market is complex as it encompasses air-to-water, water-to-water, ground sourced and multi-function technologies.
According to the report the dominant refrigerants in use are currently HFC-410A, HFC-134a and HFC-32 which account for around 75 per cent of the market.
However, R744 (CO2), HFO-1234ze and R454B are all catching on as lower-GWP solutions and already account for around one fifth of this small specialised market.
“Although lower GWP working fluids are a sustainability priority for some customers, R744 and HFO-1234ze have real technical merit in water heating applications as they can achieve higher water temperatures than mainstream products such as HFC-410A,” the report said.
“HFO-1234ze in particular provides an excellent solution for heat pump boosters working in conjunction with multi-function chillers to provide higher water temperatures.”
A substantial volume of commercial heat pumps, especially multi-function chillers are installed in new buildings.
The report forecasts the transition away from HFC-410A and HFC-134a, initially in favour of HFC-32, HFO-1234ze, R744 and R454B.
It is projected that between 2030 and 2036, HFC-410A and HFC-134a installs will cease and that HFC-32 will also decline sharply.
HC-290 is expected to slowly grow as a refrigerant in commercial heat pumps as manufacturing standards mature, technician training increases and market confidence grows in its ability to be safely utilised.
By 2036 it is projected that the commercial heat pump market will be dominated by R744 (CO2), HFO Blends, HFO-1234ze and HC-290, the report said.
The commercial heat pump bank is one of the most diverse banks with a very diverse mix of technologies and refrigerants.
The technology transition away from gas is in its early stages and the bank of controlled refrigerants is relatively small, estimated at approximately 370 tonnes in 2022. This bank of HFCs and HFO blends is expected to grow to around 600 tonnes (0.83 Mt CO2e) by 2036.
Australia started a gradual phase down of HFC imports from 1 January 2018. Consumption is estimated to be 2.6 Mt CO2e above the Australian phase-down schedule in 2028 on present trends.
The most challenging Montreal Protocol control point will be in 2029, where usage is predicted to be 2.2 Mt CO2e (65 per cent) above the cap.