R1150 RefrigerantEthylene · ultra-low-temperature hydrocarbon · cascade and industrial cryogenic-adjacent duty
R1150 is refrigerant-grade ethylene, also called ethene. It is one of the key natural refrigerants used for very low temperature and cascade refrigeration systems because its boiling point is even lower than that of R170 ethane. This gives R1150 a strong niche in ultra-low-temperature industrial and laboratory applications, but the refrigerant is A3 and therefore demands careful hydrocarbon safety engineering.
What is R1150 refrigerant?
R1150 is a specialized refrigerant for very low temperature work. Search interest may be lower than for common comfort-cooling gases, but user intent is often more technical and higher value. A strong R1150 page helps refrigerants.net cover the complete low-temperature refrigerant chain instead of stopping at mainstream HVAC or supermarket refrigerants.
R1150 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 | R1150 | ASHRAE designation for ethylene / ethene |
| Chemical name | Ethylene / ethene | Natural hydrocarbon |
| Formula | C₂H₄ | Industrial gas data |
| Molecular weight | 28.05 g/mol | Industrial gas data |
| Normal boiling point | ≈ −103.7°C | Industrial gas data |
| ODP | 0 | No ozone depletion |
| 100-year GWP | 3.7 | EPA Technology Transitions |
| Safety classification | A3 | Higher flammability |
| Temperature glide | None | Pure compound |
| Primary role | Very low / ultra-low temperature refrigeration | Cascade and specialty systems |
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 R1150 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.
Very low temperature refrigeration
Covered under EPA SNAP’s dedicated VLT category.
Cascade refrigeration systems
Often used on the lowest-temperature stage.
Laboratory / scientific cooling
Relevant for ultra-low-temperature equipment subject to applicable use conditions.
Industrial gas and process cooling
Useful where extremely low process temperatures are required.
LNG / cryogenic-adjacent cooling contexts
Industrial suppliers note its relevance in very low temperature applications.
Natural refrigerant technology study
Important when comparing hydrocarbon options in ultra-low-temperature systems.
Continue through the Refrigerant Replacements and Low-GWP Refrigerants hubs for broader selection context.
Why R1150 is different from 'ordinary' refrigerants
R1150 serves a temperature range that many mainstream refrigerants simply cannot reach effectively.
That makes it especially relevant in cascade and ultra-low-temperature systems rather than everyday commercial refrigeration.
A good profile should therefore orient the reader around the application niche first, then the chemistry.
R1150 vs R170: lower boiling point, deeper low-temperature reach
R1150 ethylene has a lower normal boiling point than R170 ethane, which is one reason it is chosen for more extreme low-temperature duties.
This does not automatically make R1150 'better.' The system choice still depends on the required temperature range, safety strategy, compressor architecture and overall cascade design.
Still, the R170/R1150 comparison is one of the most useful educational angles for searchers.
A3 safety becomes even more important in ultra-low-temperature systems
Ultra-low-temperature systems can involve complex enclosures, staged compression or cascade arrangements. Introducing an A3 refrigerant into that context raises the importance of hazard analysis, ventilation and ignition source control.
R1150 should therefore be discussed as an engineering refrigerant, not just a green alternative with a low GWP number.
This is also why fixed hydrocarbon detection may be relevant in larger installations.
Specialized SNAP context improves content quality
EPA addresses R1150 in the very low temperature refrigeration category rather than as a general-purpose refrigerant.
That specialized regulatory placement helps explain where the refrigerant fits and prevents readers from assuming it belongs in normal AC or supermarket equipment.
Content that makes this distinction clearly tends to be more useful for GEO than pages that simply repeat physical properties.
R1150 vs R170
The table highlights engineering differences rather than implying direct interchangeability.
| Characteristic | R1150 | R170 |
|---|---|---|
| Chemical | Ethylene / ethene (C2H4) | Ethane (C2H6) |
| EPA GWP | 3.7 | 5.5 |
| Safety class | A3 | A3 |
| Boiling point | ≈ −103.7°C | ≈ −88.6°C |
| Typical role | Ultra-low-temperature / deeper cascade stage | Very low temperature / cascade |
| Phase behavior | Pure | Pure |
| Selection angle | Lower boiling point, deeper temperature capability | Broader VLT hydrocarbon reference |
R1150 safety: ultra-low-temperature performance comes with A3 hydrocarbon risk
R1150 is A3. Its main acute hazard is flammability, and the very low temperature context can make enclosure, release and ventilation behavior more complex. Safe use requires refrigerant-specific component suitability, ignition source control, ventilation planning and validated hydrocarbon detection where appropriate.
A3 hydrocarbon
Flammability controls are fundamental.
Ultra-low-temperature context
System complexity increases the need for disciplined hazard assessment.
Detection and mitigation
Fixed and portable detection strategies should match the actual equipment risk.
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.
R1150 refrigerant leak detection
Validate detector response to the finished blend
Use combustible-gas detectors validated for ethylene / R1150. Detector technology, placement and alarm strategy should be based on the actual enclosure, airflow and release scenario. In larger industrial systems, a fixed detection and mitigation strategy may be more relevant than handheld leak tracing alone.
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 R1150 in 2026
United States
EPA Technology Transitions uses GWP 3.7 for R1150. EPA addresses R1150 through the very low temperature refrigeration category, including the applicable use conditions and narrowed use limits for specialized equipment. That narrow regulatory context is central to understanding the refrigerant correctly.
European Union
R1150 is a natural hydrocarbon and not part of the HFC phasedown quota structure. In Europe, its adoption depends mainly on safe A3 system design, low-temperature equipment strategy and relevant standards.
Is R1150 being phased out?
R1150 is not being phased out on climate grounds. Its limits are primarily driven by flammability management and the highly specialized nature of ultra-low-temperature systems.
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 R1150?
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 R1150
“R1150 is just another name for R170.”
No. R1150 is ethylene; R170 is ethane.
“Because the GWP is low, the refrigerant is easy to use.”
R1150 is A3 and is used in demanding ultra-low-temperature systems.
“Any low-temperature refrigerant can substitute for R1150.”
Selection depends on temperature target, safety, compressor design and cascade architecture.
“R1150 belongs in normal HVAC discussions.”
Its strongest role is specialized very low temperature refrigeration.
R1150 refrigerant FAQ
Concise answers to common composition, retrofit, glide, safety and regulation questions.
What is R1150?
What is the EPA GWP of R1150?
Is R1150 flammable?
What is R1150 used for?
Is R1150 a blend?
What is the boiling point of R1150?
How is R1150 different from R170?
Is R1150 common in normal air conditioning?
How should R1150 leaks be detected?
Is R1150 being phased out?
R1150 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 R1150 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.