R1224yd(Z) RefrigerantAMOLEA 1224yd · ultra-low-GWP A1 low-pressure refrigerant
R1224yd(Z) is a next-generation HCFO refrigerant developed mainly for low-pressure centrifugal chillers and related heat-driven or waste-heat applications. It stands out because it combines A1 nonflammability with an ultra-low EPA GWP of 1 and only trace ozone-depletion potential. In practice, it is part of the same low-pressure engineering conversation as R1233zd(E), R123 and R514A, but with its own thermodynamic and regulatory profile.
What is R1224yd(Z) refrigerant?
R1224yd(Z) is not a mass-market AC refrigerant. Its importance comes from high-value engineered applications: low-pressure centrifugal chillers, waste-heat recovery heat pumps and organic Rankine cycle systems. For refrigerants.net, that makes it a strong high-quality topic because it expands the site beyond common comfort-cooling refrigerants into advanced low-pressure machinery and industrial efficiency topics.
R1224yd(Z) refrigerant properties
Use these values for research and screening. For equipment design, charging and compliance, use the exact supplier PT data, SDS, OEM documentation and regulation that governs the project.
| Property | Reference | Engineering / source note |
|---|---|---|
| Designation | R1224yd(Z) | ASHRAE designation |
| Chemical family | HCFO | Hydrochlorofluoroolefin |
| Refrigerant type | Pure refrigerant | No blend glide |
| ODP | 0.00012 | EPA SNAP chiller tables |
| 100-year GWP | 1 | EPA Technology Transitions / SNAP tables |
| Safety classification | A1 | Nonflammable |
| Primary pressure class | Low-pressure refrigerant | Chiller / ORC relevance |
| Relative application family | R123 / R1233zd(E) / R514A class | Low-pressure systems |
| Typical uses | Centrifugal chillers, ORC, waste heat recovery | AGC literature |
| Key strength | A1 + ultra-low GWP + low-pressure suitability | Strong chiller narrative |
EPA Technology Transitions uses the values shown on this page. Older product literature may use IPCC AR4/AR5 or another assessment, so a different number is not automatically an error.
Where is R1224yd(Z) used?
Applications must be evaluated by system type, charge, compressor, heat exchanger, safety class and current regulation. The examples below describe recognized use contexts, not automatic approval for every installation.
Centrifugal chillers
Key target application in EPA SNAP and AGC technical materials.
Waste heat recovery heat pumps
Highlighted by AGC as a use case.
Organic Rankine cycle systems
Relevant because of low-pressure thermophysical behavior.
Industrial thermal systems
Suitable where low-pressure A1 fluids are valued.
Next-generation low-pressure chiller development
Strong comparison topic against R1233zd(E), R123 and R514A.
Sustainability-driven upgrades
Useful in projects seeking ultra-low-GWP refrigerants without A2L flammability.
Continue through the Refrigerant Replacements and Low-GWP Refrigerants hubs for broader selection context.
Why R1224yd(Z) is strategically important even if volumes are smaller
Many refrigerant websites focus almost entirely on R410A, R32, R134a and supermarket blends. R1224yd(Z) adds depth because it serves high-value engineered systems rather than mass-market split AC.
That makes it a good GEO topic: the searcher often has specialized intent and is looking for reliable, non-generic content on chillers, ORC or low-pressure fluids.
Adding R1224yd(Z) also helps create a richer internal content cluster around R123, R1233zd(E), R514A and other low-pressure alternatives.
R1224yd(Z) vs R1233zd(E): why both matter
Both refrigerants are low-pressure, very-low-GWP alternatives used in advanced chillers and heat recovery systems. Both are commonly positioned against legacy R123 or R245fa-class duties depending on the application.
The most important difference for content strategy is that these are not commodity drop-ins. Designers select them based on compressor/chiller architecture, efficiency window, material compatibility and lifecycle considerations.
A profile that explains this relationship is much more useful than listing only GWP and safety class.
Ultra-low GWP does not mean exactly zero environmental tradeoff
R1224yd(Z) is often marketed as 'almost zero ODP' and 'GWP 1.' That is directionally true and environmentally impressive, but the page should still state the published ODP figure instead of rounding everything to zero.
That nuance is good technical practice and also strengthens SEO/GEO trust because the content reads like it came from an actual engineering review rather than a generic marketing summary.
Using the exact SNAP value of ODP 0.00012 keeps the page fact-based.
Why A1 nonflammability is still valuable in advanced chillers
In some facilities, nonflammability can simplify site approval, machinery-room planning or owner acceptance compared with A2L designs.
That is one reason A1 low-pressure fluids such as R1224yd(Z) remain attractive even when ultra-low-GWP A2L options also exist.
However, A1 status does not remove the need to evaluate toxicity, decomposition behavior, vacuum integrity, purge requirements and machinery-specific design details.
R1224yd(Z) vs R1233zd(E)
The table highlights engineering differences rather than implying direct interchangeability.
| Characteristic | R1224yd(Z) | R1233zd(E) |
|---|---|---|
| EPA GWP | 1 | 4 |
| Safety class | A1 | A1 |
| ODP | 0.00012 | Very low / effectively near zero but not mathematically zero |
| Primary role | Low-pressure chillers / ORC / heat recovery | Low-pressure chillers / heat pumps / industrial use |
| Flammability | Nonflammable | Nonflammable |
| Category strength | Ultra-low-GWP chiller fluid | Widely discussed low-pressure replacement |
| Selection logic | Application-specific | Application-specific |
R1224yd(Z) safety: A1 simplifies flammability, but low-pressure system engineering still matters
R1224yd(Z) is A1, so it avoids lower-flammability system design issues. But low-pressure refrigerants introduce their own engineering priorities, including vacuum integrity, possible air/moisture ingress, machinery-room design, and fluid compatibility. In chiller practice, these factors can be as important as the refrigerant’s climate metrics.
A1 classification
No flame-propagation issues under ASHRAE classification.
Low-pressure behavior
System tightness and non-condensable management remain important.
Specialized use
Selection should be based on chiller / thermal-system design, not only refrigerant name.
Actual risk depends on charge, release rate, pressure, room volume, ventilation, ignition sources, equipment construction, alarm logic and service condition.
See the Refrigerant Safety Guide for classification context.
R1224yd(Z) refrigerant leak detection
Validate detector response to the finished blend
R1224yd(Z) is not primarily discussed as a mass-market service-refrigerant leak-detection topic, but fixed refrigerant monitoring may still be used in machinery rooms depending on site policy and system size. For detection strategy, distinguish between concentration monitoring, maintenance leak finding and process safety requirements.
Portable service leak detectors, fixed area monitors, A2L mitigation sensors and refrigerant identifiers perform different functions. Define the alarm action and concentration range before selecting the technology.
Regulatory position of R1224yd(Z) in 2026
United States
EPA chiller tables and refrigerant reference materials show R1224yd(Z) as an A1 low-pressure refrigerant with GWP 1 and ODP 0.00012. Its strongest U.S. relevance is in centrifugal-chiller and advanced thermal-system discussions rather than mainstream comfort-cooling retrofits.
European Union
R1224yd(Z)’s ultra-low GWP and A1 classification align well with decarbonization goals in advanced thermal systems. As with other fluorinated/chlorinated fluids, actual equipment use still depends on the relevant standards and product-specific approvals.
Is R1224yd(Z) being phased out?
R1224yd(Z) is not currently a classic phaseout target. Its future is shaped more by technical adoption in low-pressure chiller and energy-recovery equipment than by near-term GWP restrictions.
U.S. refrigeration limits differ by cold storage, supermarket, remote condensing, stand-alone product, industrial process and chiller category. A refrigerant may fit one pathway and fail another.
Use the Refrigerant Regulations Hub for regional research.
What should be compared with R1224yd(Z)?
Compare the real equipment pathway: retrofit vs new system, A1 vs A2L capability, GWP threshold, glide, compressor envelope, energy efficiency and service ecosystem.
Practical misconceptions about R1224yd(Z)
“R1224yd(Z) is just another common AC refrigerant.”
Its strongest role is in low-pressure chillers, ORC and waste-heat systems.
“Because it is very low GWP, all its values should be rounded to zero.”
Published SNAP tables list GWP 1 and ODP 0.00012.
“A1 means there are no engineering concerns.”
Low-pressure system design, purge strategy and compatibility still matter.
“R1224yd(Z) and R1233zd(E) are the same refrigerant.”
They are related low-pressure alternatives, but not the same fluid.
R1224yd(Z) refrigerant FAQ
Concise answers to common composition, retrofit, glide, safety and regulation questions.
What is R1224yd(Z)?
What is the EPA GWP of R1224yd(Z)?
Is R1224yd(Z) flammable?
What is the ODP of R1224yd(Z)?
Is R1224yd(Z) a blend?
Where is R1224yd(Z) used?
Is R1224yd(Z) the same as R1233zd(E)?
Why is R1224yd(Z) worth adding to the site?
Does R1224yd(Z) have glide?
How should R1224yd(Z) be selected?
R1224yd(Z) sources and further reading
This profile uses current EPA regulatory references plus refrigerant supplier, NIST, scientific and GasNose resources. Re-check the latest edition before design or compliance decisions.
Working with R1224yd(Z) or planning a refrigerant transition?
Compare GWP, safety class, temperature glide, equipment compatibility and regulatory lifetime before selecting a refrigerant.
Technical Notice: This page is for refrigerant research and general technical reference. Refrigerant suitability, permitted charge, equipment approval, leak mitigation, servicing procedures and regulatory compliance depend on the exact equipment, installation and jurisdiction. Always verify current manufacturer documentation, SDS, applicable standards and local regulations before selecting, replacing, charging or servicing a refrigerant.