The refrigerant transition that reshaped the industry when R-22 was phased out is happening again, faster than many expected. R-410A production and import caps took effect January 1, 2025 under the AIM Act, and equipment manufacturers are already shipping residential and light commercial units charged with R-454B. If you manage a portfolio of rooftop units or split systems, or if you service them, the decisions you make in the next two to three years will affect operating costs and equipment longevity for a decade.
This post covers the refrigerant transition in practical terms: what changed, what R-454B actually is, which components are affected, and what retrofit paths exist for existing R-410A equipment.
Why R-410A is being phased out
R-410A has a global warming potential (GWP) of 2,088, roughly 2,088 times the warming effect of CO2 over a 100-year period. The AIM Act directed the EPA to implement an HFC phasedown, targeting an 85% reduction in HFC production and consumption by 2036. R-410A, as the dominant residential refrigerant in the U.S., is the primary target.
Production and import allowances for high-GWP HFCs were cut significantly in 2024 and 2025. New residential equipment sold after January 1, 2025 cannot be charged with R-410A. The result is straightforward: R-454B is the industry's chosen replacement for new equipment, and R-410A will become progressively more expensive and harder to source as the decade continues.
The R-22 phaseout took roughly 15 years from the original Clean Air Act amendments to the final production ban. The R-410A timeline is compressed. Contractors and property managers who waited out the R-22 transition and got lucky may not have the same runway this time.
What R-454B actually is
R-454B is a blend of R-32 (68.9%) and R-1234yf (31.1%). Its GWP is 466, about 78% lower than R-410A. That satisfies the EPA's A2L classification criteria, which also introduces a mildly flammable designation.
Key physical and performance differences compared to R-410A:
- Operating pressures: R-454B runs at slightly lower pressures than R-410A. High-side pressures at typical summer operating conditions are roughly 10-15 psi lower. This is close enough that retrofitting an R-410A system with R-454B is not straightforward, and not approved for field retrofit.
- Discharge temperature: R-454B runs hotter discharge temperatures than R-410A under equivalent load conditions, which matters for compressor oil selection and compressor wear.
- Flammability (A2L): R-454B is classified A2L, meaning mildly flammable. It requires a minimum concentration to ignite, and its burning velocity is low, but building codes and equipment certifications now require specific installation and service practices. Leak detection, refrigerant sensors in confined spaces, and technician certification updates are not optional.
- Lubricant compatibility: R-454B requires POE oil, as does R-410A, so lubricant compatibility is less of a disruption than the R-22 to R-410A transition (which required switching from mineral oil to POE).
What happens to existing R-410A equipment
This is the question property managers with large portfolios are asking most. The short answer: existing R-410A equipment continues to operate legally. There is no ban on using R-410A in equipment that was designed for it. What changes is supply and cost.
As production caps tighten, R-410A refrigerant prices will follow the pattern R-22 set: gradual increases, then sharp spikes as supplies thin. Industry surveys suggest R-22 cylinder prices rose by more than 400% in the years following production cutoffs. Whether R-410A follows the same curve depends on how aggressively manufacturers convert capacity to R-454B alternatives, but the direction is not in question.
For a property manager with 200 split systems, the math is worth running now:
- Units installed in 2018-2022 may have 8-12 years of service life remaining.
- A system that loses 2 lbs of refrigerant per year to a slow leak now costs more to recharge each year as R-410A prices climb.
- Deferred maintenance on those units compounds the problem.
There is no approved drop-in retrofit refrigerant for R-410A equipment. R-452B has been marketed as a near-drop-in in some contexts, but it carries its own efficiency and pressure tradeoffs and is not a permanent solution. Equipment manufacturers are explicit: R-410A equipment should run on R-410A until it is replaced.
Component-level impacts of the transition
For technicians, the move to R-454B changes what you are measuring and what you are looking for on a service call.
Compressors
New R-454B compressors are designed for higher discharge temperatures. Discharge temps on R-454B equipment under high-load conditions can run 20-30°F higher than comparable R-410A equipment. If you see discharge temps above 220-230°F on an R-454B system, that warrants investigation before it becomes a compressor failure. Compressor manufacturers are updating their POE oil specifications for R-454B; using the wrong viscosity grade will accelerate wear.
Metering devices and TXVs
TXVs calibrated for R-410A are not interchangeable with R-454B. The refrigerant properties are close but not identical, and oversized or undersized TXVs affect superheat control and efficiency. On new R-454B equipment, verify superheat and subcooling during commissioning rather than assuming factory calibration is correct after shipping.
Leak detection equipment
Most electronic refrigerant leak detectors currently in the field are calibrated for HFCs. R-454B's A2L classification means a flammable refrigerant leak in a confined mechanical room or crawlspace is a safety issue, not just an efficiency issue. Verify that your leak detection equipment is rated for A2L refrigerants and that you are following ASHRAE 15 requirements for refrigerant sensor placement in occupied and semi-occupied spaces.
Electrical components and monitoring
One of the underappreciated consequences of the refrigerant transition is what it does to the baseline electrical signature of HVAC equipment. Compressors running R-454B have different current draw profiles than R-410A equipment under similar load. This is the kind of shift that matters for condition monitoring: as fleets include a mix of R-410A and R-454B equipment, tools that track compressor current, capacitor microfarad readings, and suction/discharge pressure relationships need to account for refrigerant type. The kind of early-warning monitoring Phase Sight AI is being built to provide, specifically tracking the seven signals that precede common failure modes, will need to establish separate baselines for R-454B equipment as it enters the field.
What to do now, by audience
For HVAC contractors
- Get A2L-certified now. Several HVAC training organizations offer A2L certification courses. Waiting until R-454B equipment is the majority of your service calls is waiting too long.
- Update your manifold gauges and hoses. A2L refrigerants require equipment rated for the flammability classification. Check manufacturer specs before using legacy gauge sets on R-454B systems.
- Document refrigerant type on every unit in your service software. Mixed fleets will be the norm for at least 10 years.
- Start tracking R-410A costs in your service agreements. Fixed-price maintenance contracts written in 2023 may not have anticipated refrigerant cost increases by 2027.
For property managers
- Audit your fleet by equipment age and refrigerant type. Units over 12 years old on R-410A are candidates for proactive replacement on a schedule you control, rather than emergency replacement when they fail during a heat event.
- Ask your service contractors what their plan is for R-410A cost increases. If they do not have one, that is a gap in your maintenance planning.
- Budget for refrigerant cost increases in your operating projections. R-410A will not stay at current pricing as production caps tighten.
- When replacing units, verify that new equipment is R-454B-rated and that your service team is A2L-trained before the first service call.
Tracking refrigerant transition impacts at the equipment level is exactly the kind of long-range maintenance problem that benefits from continuous monitoring rather than annual service visits. Irvin's two clip-on sensors are designed to watch the electrical and pressure signals that shift before a component fails, whether the system is running R-410A or R-454B. Pre-orders are open now at $199 (50% off the $398 retail price), and Irvin ships Early 2027.