The shift to new refrigerants is one of the biggest changes the Australian HVAC industry has seen in decades. For tradies in Queensland, the move from R410A to lower-GWP options like R32 and R290 isn’t just a paperwork exercise — it directly affects how systems perform in winter, especially when heating demand peaks. Understanding these refrigerant changes winter heating dynamics is critical for both installation and service work. Whether you’re retrofitting an old split or commissioning a new multi-head, the refrigerant you choose influences efficiency, pressure profiles, and even the tools you carry in your van.
Why Refrigerant Choice Matters for Winter Heating
Winter in Queensland might not hit the lows of Victoria, but we still see mornings below 10°C in the southeast, and coastal humidity makes that cold bite harder. A heat pump’s heating performance depends on the refrigerant’s thermodynamic properties at low outdoor temperatures. R32 and R290 operate at different pressures and temperatures than R410A, which changes how the system extracts heat from the outdoor air.
R32 and Heating Efficiency
R32 has a lower boiling point than R410A, which means it can absorb heat more effectively in cooler conditions. In practice, a well-designed R32 split system often maintains higher COP (coefficient of performance) below 7°C compared to its R410A equivalent. But that advantage only holds if the system is properly charged — undercharging or overcharging by even 10% can drop heating capacity by 15-20%. Tradies need to use accurate scales and follow manufacturer charge charts, not just rely on superheat rules of thumb.
R290 (Propane) – Different Beast Altogether
R290 is flammable (A3 classification) and requires strict handling procedures under AS/NZS 5149. For heating, R290 offers excellent thermodynamic efficiency — often better than R32 at very low ambients — but the system design is completely different. Most R290 units use smaller charge sizes (typically under 150 grams) and specialised compressors. If you’re servicing one, never guess the charge. Use a certified recovery unit rated for flammable refrigerants. And yes, you need the right ARC tick for hydrocarbon work.
Service Practice Changes You Can’t Ignore
Refrigerant changes winter heating performance isn’t just about the chemistry; it’s about how you approach the job. Here’s what changes in your daily routine:
- Recovery equipment: Your old recovery machine might not be rated for R32 or R290. Check the manufacturer’s specs. Using the wrong unit can recieve damage or safety issues.
- Leak detection: R32 requires electronic leak detectors that are sensitive to that specific refrigerant. R290 requires detectors rated for flammable gas.
- Pressure testing: Both R32 and R290 systems often run at higher discharge pressures in heating mode. Always use nitrogen with a regulator — no shortcuts.
- Brazing: If you’re repairing a leak on an existing R32 system, purge the lines with nitrogen and avoid open flames near any residual refrigerant. For R290, you should be purging and verifying zero combustibles before brazing.
One thing I see a lot is blokes pulling out their gauges and connecting them to a new R32 unit without checking if the hoses are rated for the higher pressure. That’s like a cat in a room full of rocking chairs — something’s gonna go wrong eventually. Don’t be that person.
Winter Heating Performance: Real-World Numbers
Let’s look at a typical 3.5kW split system in Brisbane winter. An R410A unit might deliver around 3.2kW heating capacity at 7°C outdoor ambient with COP of 3.1. An equivalent R32 unit under the same conditions often achieves 3.5kW capacity and COP of 3.5 — that’s roughly 13% more heat for the same input. For R290, the numbers can be even better, but the units are less common in standard residential installations here due to safety requirements.
However, these figures rely on the system being clean and properly maintained. Blocked filters, dirty outdoor coils, or low refrigerant levels kill heating performance regardless of refrigerant type. I’ve seen plenty of call-outs where the homeowner complains about poor heating, and it turns out they’ve got a filter that looks like a possum’s nest. Basic maintenance still rules.
Regulatory Updates for Queensland Tradies
The refrigerant transition is driven by the federal Ozone Protection and Synthetic Greenhouse Gas Management Act, enforced through the ARC. As of 2025, new split systems under 4.5kg charge must use a refrigerant with GWP below 750. In practice, that means R32 or R290 for most residential gear. R410A is still allowed for service of existing systems, but you can’t install it in new equipment.
Queensland also follows AS/NZS 5149 for refrigeration safety, which includes requirements for ventilation, room size, and signage when using flammable refrigerants. If you’re installing a multi-head R32 unit, you need to check the total charge against the room volume to stay compliant. The Australian Refrigeration Council (ARC) is doing random audits now, and they will fine you if you can’t show the paperwork.
Practical Tips for Better Winter Heating with New Refrigerants
If you’re a tradie or a homeowner wanting to get the most out of your system this winter, here’s what works:
- Set the fan speed higher during heating — it helps circulate warm air away from the ceiling.
- Don’t let the outdoor unit get blocked by leaves, mulch, or winter debris. Clear at least 300mm around it.
- Check the defrost cycle on R32 units — some need a manual reset if the board loses power.
- Educate homeowners that modern inverters are designed to run longer at lower speeds. Turning it off and on actually wastes energy.
For tradies servicing older units, remember that if you need to top up R410A, you can still do so — but if the leak is significant, the best advice is to recommend a replacement with an R32 or R290 system. The performance improvement alone often justifies the upgrade, and you’ll be future-proofing the customer’s home.
If you’re in Brisbane and need a qualified technician, get a free quote through the site. (We don’t do the work ourselves, but we can connect you with licensed tradies who know their refrigerant changes winter heating backwards.)
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