Air conditioner refrigerants: what R22, R410A and R32 mean for you

Refrigerant is the working fluid that carries heat between the indoor and outdoor units. It boils at a very low temperature, so as it evaporates in one coil it soaks up heat, and when the compressor squeezes it and it condenses in the other coil, it gives that heat off. In cooling, the indoor coil absorbs heat and the outdoor coil releases it; in heating, a reverse-cycle unit runs the other way.

It travels in a sealed loop of copper pipe, coils and the compressor. It doesn't get used up or wear out, and a healthy system holds the same charge for its whole working life. A system that's short of gas has a leak somewhere.

The refrigerant type and charge are printed on the outdoor unit's nameplate, usually on the side. In Australian homes you'll mainly see the gases below.

The federal environment department says 1 kg of R410A has the same greenhouse impact as 2 tonnes of carbon dioxide. That's why letting it escape matters, and why lower-impact gases are taking over.

R22 is harder to get than it once was, and a repair that opens the refrigerant circuit on an R22 unit is more involved. A leak repair on an old R22 system can be done, but it often doesn't stack up against replacement once the gas, the labour and the unit's age are counted.

Age matters as much as the gas. The Victorian Government says a reverse-cycle system more than 15 years old will typically use more than three times the energy of a modern one. If an older system has a major leak, a failing compressor or a corroded coil, replacement usually makes more sense than another round of repairs.

R410A systems are still widely serviced and repaired. There's no reason to replace a sound R410A unit because of the gas in it.

Each system is designed around one refrigerant, with pressures, oil, valves and charge to suit. Under the federal regulations it's an offence to charge equipment with a refrigerant that has a higher global warming potential than the one it was designed for, so an R32 system can't be charged with R410A. The ban doesn't apply when charging older HCFC equipment, such as R22 systems, with an HFC, but that's a technician's call made with the manufacturer's guidance, not a routine fix.

Going the other way isn't a simple swap either. Manufacturers design and test each unit for its own gas, so an R410A unit isn't refilled with R32. When an older unit is replaced with an R32 one, the practical question is whether the existing pipework can stay, which depends on the manufacturer's rules, the pipe sizes, their condition and how they're cleaned.

Australia's HFC phase-down started on 1 January 2018 and will cut HFC imports to 15% of the baseline level by 1 January 2036. It's a big part of why the market has moved from R410A to lower-impact gases such as R32.

It doesn't ask you to do anything with equipment you already own. The federal environment department says consumers don't have to replace their existing equipment, and a working R410A system can be serviced and repaired as normal.

Where it matters is when you're buying. A new system on a current, lower-impact gas is the sensible choice, and if an older unit is near the end of its life, the gas becomes one more factor alongside efficiency and repair history.

Signs a system may be short of gas: air that isn't as cold or warm as it used to be, longer running times, ice on the pipes or coil, or a hiss or gurgle. Dirty filters and fan faults cause similar symptoms, so a technician tests before blaming the refrigerant.

No-one is allowed to top up a system with refrigerant until it has been fully tested and every identified leak repaired. A top-up without a repair puts back gas that will leak out again, so you pay twice and the escaped gas adds to emissions. Releasing regulated refrigerants into the air is illegal.

A proper repair finds the leak, recovers the remaining gas, fixes the joint or part, pressure tests the circuit with nitrogen, pulls a vacuum, then charges the system with the correct weight of the right refrigerant.

Under the national scheme run by the Australian Refrigeration Council, anyone who installs, commissions, services, maintains or decommissions air conditioning equipment needs a Refrigerant Handling Licence, which covers all fluorocarbon refrigerants, including R22 and R410A. Businesses that acquire, store or dispose of refrigerant need a Refrigerant Trading Authorisation.

The restricted split system licence covers installing and decommissioning single-head splits under 18 kW. It doesn't allow service, repair or maintenance that involves accessing or handling refrigerant, so when someone quotes a leak repair, it's fair to ask which licence they hold. When an old system is removed, its refrigerant should be recovered into a cylinder, never vented.