Refrigerant Types in CRAC Systems: R410A, R134a, R513A, and R32 Under Australia's Phase-Down

Australia's obligations under the Kigali Amendment to the Montreal Protocol are now producing real procurement consequences for data centre operators. The phase-down of hydrofluorocarbons (HFCs) with high global warming potential (GWP) is no longer a distant compliance exercise. It is affecting refrigerant availability, equipment pricing, and the long-term viability of CRAC units already installed in Australian facilities.

For data centre managers, mechanical contractors, and sustainability officers making purchasing or maintenance decisions today, understanding the four refrigerants most commonly found in precision cooling equipment is not optional. R410A, R134a, R513A, and R32 each carry different GWP ratings, safety classifications, charge restrictions, and efficiency profiles. Choosing the wrong refrigerant pathway now can mean stranded assets within five years.

Australia's HFC Phase-Down: The Timeline That Matters

Australia ratified the Kigali Amendment in 2020. Under the schedule administered through the Ozone Protection and Synthetic Greenhouse Gas Management Act 1989, Australia's HFC consumption baseline was set using 2011 to 2013 average consumption data. The phase-down trajectory requires:

• 2024 to 2028: Freeze at baseline, then reduction to 90% of baseline
• 2029 to 2034: Reduction to 70% of baseline
• 2035 to 2039: Reduction to 50% of baseline
• 2040 onwards: Reduction to 15% of baseline by 2047

The practical effect is that bulk HFC imports are already being constrained. Refrigerants with GWP above 2,500 face the steepest restrictions first, but the quota pressure on all high-GWP HFCs is tightening. R410A, with a GWP of 2,088, sits directly in the crosshairs of the mid-phase-down reductions. Pricing for R410A cylinders in Australia has already risen materially since 2022, and that trajectory is expected to continue.

The Department of Climate Change, Energy, the Environment and Water (DCCEEW) publishes annual quota data, and the trend is unambiguous.

R410A (GWP 2,088): The Incumbent Under Pressure

R410A has been the dominant refrigerant in precision air conditioning for roughly two decades. Vertiv Liebert, Schneider Electric Uniflair, and Stulz all built large product ranges around R410A, and the majority of CRAC units currently operating in Australian data centres use it.

From a thermodynamic standpoint, R410A operates at higher pressures than its predecessors, which allowed manufacturers to design more compact, efficient systems. Coefficient of performance (COP) figures for R410A-based precision cooling units are well established and generally favourable for the DX cooling applications typical in edge and mid-tier data centres.

The problem is not performance. It is supply trajectory. R410A is a blend of R32 and R125 (50/50 by weight). Because R125 has a GWP of 3,500, the blend's overall GWP of 2,088 places it firmly in the category facing the most sustained quota pressure over the next decade. Servicing existing R410A equipment will become progressively more expensive as refrigerant costs rise. For units with significant remaining service life, operators should factor in a refrigerant cost premium of 20 to 40% by the early 2030s based on current import quota trajectories.

New R410A equipment purchases are increasingly difficult to justify unless the unit is replacing an emergency failure and no alternative is available on short lead time.

R134a (GWP 1,430): Common in Chilled Water Plant, Less So in CRAC

R134a is a single-component refrigerant used extensively in centrifugal chillers and some larger precision cooling systems, particularly chilled water plant serving data centres at scale. In direct expansion CRAC units, R134a is less common, but it does appear in certain Vertiv CW configurations and legacy Liebert PCW units.

With a GWP of 1,430, R134a is lower than R410A but still well above the thresholds that will be targeted in the 2035 to 2040 phase-down period. It is classified A1 under AS/NZS ISO 817, meaning it is non-flammable and low toxicity. That safety profile has made it a default choice for large-charge applications where flammability restrictions would otherwise apply.

The longer-term replacement pathway for R134a in chiller applications is R1234ze or R515B, both of which carry GWP values below 10. For data centre operators running chilled water infrastructure with R134a, the transition horizon is roughly 2030 to 2035 before refrigerant costs make continued operation economically marginal.

R513A (GWP 631): The Drop-In Transition Refrigerant

R513A is a blend of R1234yf (56%) and R134a (44%), developed specifically as a lower-GWP replacement for R134a. With a GWP of 631, it sits at less than half the impact of R134a and less than a third of R410A.

The key advantage of R513A in a data centre context is its A1 safety classification. It is non-flammable and low toxicity, which means it does not trigger the charge limits or ventilation requirements associated with A2L or A3 refrigerants. This matters considerably in enclosed data centre environments where refrigerant safety codes under AS/NZS 1677 and AS/NZS 3666 govern system design.

R513A is increasingly specified in new Vertiv and Schneider Electric precision cooling products targeting the Australian market. It is not a perfect drop-in for R410A systems because the operating pressures and compressor requirements differ, but for R134a-based systems, the transition to R513A can sometimes be achieved with minimal component changes, subject to manufacturer approval and full system assessment.

From an efficiency perspective, R513A performs comparably to R134a in most precision cooling applications, with some independent testing showing marginal COP improvements at typical data centre operating conditions. It is not a step backwards in performance.

R32 (GWP 675): Efficient but Mildly Flammable

R32 is a single-component refrigerant with a GWP of 675, slightly higher than R513A but with notably better thermodynamic efficiency. It has a higher latent heat of vaporisation than R410A, which means a smaller refrigerant charge can deliver equivalent cooling capacity. Charge reductions of 20 to 30% compared to R410A systems of equivalent capacity are typical.

The complication with R32 is its A2L safety classification. Under AS/NZS ISO 817, A2L refrigerants are mildly flammable. They require an ignition source to combust and have a low burning velocity, but the classification still triggers specific requirements under Australian standards. In practice, this means:

• Charge limits per occupied space apply and vary by room volume
• Leak detection systems are required in enclosed spaces
• Installer competency requirements are more stringent
• Some building types have additional restrictions under state-based building codes

For open-plan data centre floor environments with good airflow, R32 charge limits are generally manageable. For smaller edge computing rooms or enclosed plant rooms, the charge limits can become a genuine constraint on system sizing.

Stulz's CyberAir 4 range and several Vertiv units now ship with R32 as the standard refrigerant for the Australian market. Schneider Electric's Uniflair InRow products have also moved to R32 in recent product generations. The efficiency gains are real: independent testing of R32-based precision cooling systems has shown COP improvements of 5 to 10% compared to equivalent R410A equipment, which translates directly to ongoing power cost reductions in a 24/7 operating environment.

Comparing the Four Refrigerants Side by Side

| Refrigerant | GWP | Safety Class | Typical CRAC Application | Phase-Down Pressure |

|---|---|---|---|---|

| R410A | 2,088 | A1 | DX CRAC, legacy fleet | High, near-term |

| R134a | 1,430 | A1 | Chillers, some DX | Moderate, medium-term |

| R513A | 631 | A1 | New DX CRAC, R134a retrofit | Low |

| R32 | 675 | A2L | New DX CRAC, InRow | Low, with charge constraints |

What This Means for Equipment Decisions

For operators planning new CRAC installations in 2026 and beyond, specifying R410A equipment is difficult to justify on a whole-of-life basis. The refrigerant cost trajectory over a 10 to 15 year asset life will erode any short-term procurement saving.

R513A and R32 equipment are both sound choices, with the selection depending on site-specific factors. Where charge limits are not a constraint and installer competency for A2L refrigerants is available, R32 offers the better efficiency outcome. Where the site has enclosed spaces, mixed-use building integration, or legacy systems being partially retrofitted, R513A's A1 classification removes a layer of compliance complexity.

For existing R410A equipment with several years of service life remaining, the priority is minimising refrigerant loss through regular leak detection and preventive maintenance. Every kilogram of R410A that stays in the system rather than being released or topped up is a cost avoided. Proactive leak detection under AS/NZS 3666 requirements is not just a compliance obligation; it is a direct operating cost control measure as refrigerant prices rise.

Mechanical contractors quoting on data centre cooling work should be documenting refrigerant type and GWP in their scope documents. Sustainability officers preparing Scope 1 emissions reports need to account for refrigerant leakage as a direct greenhouse gas emission, calculated using the GWP of the refrigerant multiplied by kilograms leaked. Moving from R410A to R513A or R32 reduces that emissions factor by roughly 70%.

Planning the Transition

The refrigerant phase-down is not a single event. It is a decade-long shift that rewards operators who plan ahead and penalises those who defer decisions until equipment failure forces their hand. The organisations that will manage this transition well are those that audit their current refrigerant inventory now, model their replacement schedule against the phase-down timeline, and specify lower-GWP equipment in all new procurement.

CRAC Services Australia works with data centre operators across Brisbane, Sydney, and Melbourne on refrigerant management planning, leak detection programmes, and equipment specification for new installations. If you are assessing your current refrigerant exposure or planning a cooling upgrade, visit [https://crac.services](https://crac.services) to discuss your site's requirements.