Air Conditioner Refrigerant Types: What You Need to Know in Hong Kong

R22: The Discontinued Legacy Refrigerant

R22 (a hydrochlorofluorocarbon) was once the most common household refrigerant in Hong Kong. However, due to its ozone-depleting properties, the Montreal Protocol requires all countries to phase it out progressively. Hong Kong has banned the import and production of new R22; existing stocks shrink year by year and top-up costs keep rising.

Units using R22 are typically quite old. If the refrigerant system develops a leak, locate and properly repair the leak point before topping up. Skipping the repair and topping up regardless means the new refrigerant will leak out again quickly — repeated top-ups are wasteful and expensive. If the unit's overall condition has deteriorated significantly, assess whether replacement makes more sense than continuing to top up R22.

R410A: The Transitional Mainstream Refrigerant

R410A became common in Hong Kong from around the 2000s. It contains no chlorine and has minimal ozone impact. However, its Global Warming Potential (GWP) is approximately 2,088 — a high-GWP refrigerant — and the Kigali Amendment requires countries to progressively reduce its use.

A large number of R410A units remain in use and on sale; servicing and top-ups are still straightforward and less costly than R22. Supply of R410A for service should remain normal over the next 10–20 years, though it will also face replacement pressure in the longer term.

R32: The Current Default Refrigerant for New Units

R32 has a GWP of approximately 675 — substantially lower than R410A — and generally delivers better energy efficiency. Most new split-type units from major brands sold in Hong Kong now use R32. R32 is mildly flammable (A2L classification) and requires compliance with relevant installation standards, but the risk in normal residential use is extremely low.

When buying a new unit, R32 is the more mainstream and environmentally considered choice at present; supply for servicing is also adequate. If you are thinking about replacing your unit, knowing the new model's refrigerant type helps compare long-term repair costs.

Identifying and Handling a Refrigerant Leak

Under normal operation, refrigerant should not diminish. If cooling gradually declines but dust build-up and settings issues have been ruled out, a minor refrigerant leak may be involved. A technician can measure system pressure using a gauge to confirm whether refrigerant is low.

The correct procedure for a refrigerant leak: a technician locates and repairs the leak point first, confirms the system is sealed, and only then tops up the refrigerant. Skipping the repair and topping up directly means the refrigerant will leak out again quickly — an expensive habit that also harms the environment.

Do not ask or allow a technician to top up refrigerant without first checking for a leak. A responsible technician should diagnose the root cause and provide a full repair recommendation.

Know Your Unit's Refrigerant Type: Checklist

• Check the nameplate or manual for the refrigerant type (e.g. R32, R410A, R22)
• If using R22, assess the unit's overall condition and likely future repair costs
• If cooling is declining, rule out dust and settings issues before suspecting refrigerant
• If a refrigerant leak is suspected, arrange for a technician to locate the leak first, then top up
• When buying a new unit, confirm the refrigerant type and relevant installation requirements
• Keep maintenance records including the amount and date of any refrigerant top-up

Frequently asked questions

Can different refrigerant types be mixed?

No — different refrigerant types must not be mixed. If a system originally uses R410A, it cannot be topped up with R32, and vice versa. Mixing refrigerants alters system pressure and operating characteristics and can damage the compressor. Always confirm that the correct refrigerant for the unit's specification is used during servicing.