R-365mfc
Pure HFC, 1,1,1,3,3-pentafluorobutane (CF₃CH₂CF₂CH₃). Solvay Solkane 365mfc. ASHRAE A2 (flammable, not the milder A2L). GWP 794. Normal boiling +104°F — very high for a refrigerant. Primarily a foam blowing agent for polyurethane insulation; limited refrigeration use.
Lower toxicity. Flame propagates in air at 60°C with a burning velocity between 10 and 100 cm/s. Less common in HVAC. R-152a and R-365mfc are A2.
- Flammability
- Yes (10 ≤ burning velocity ≤ 100 cm/s)
- Toxicity
- Lower
Classification per ANSI/ASHRAE Standard 34-2022. See full reference.
Saturation pressure-temperature curve
Saturation values from CoolProp 7.2.0 R365MFC. Operating pressure on a running system differs — see the operating-pressure references for in-use values.
R-365mfc PT chart PDF — printable saturation table
Looking for the R-365mfc PT chart PDF for shop reference? The complete pressure-temperature saturation table is below — every 1° increment from −40°F to 150°F (or to the refrigerant's critical temperature). Use the Print / Save as PDF button in the table header to download a clean, table-only PDF (the rest of the page is hidden from the print output). Important service temperatures (normal boiling point, freezing point of water, residential AC evap and condenser targets) are tinted and tagged in the table for at-a-glance shop reference.
R-365mfc PT Chart — Pressure-Temperature Saturation Table
1° increments · Source: CoolProp 7.2.0 / manufacturer datasheet · hvacptcharts.com
| Temp (°F) | Pressure (PSIG) |
|---|---|
| -29°F | -14.3 |
| -28°F | -14.3 |
| -27°F | -14.3 |
| -26°F | -14.3 |
| -25°F | -14.3 |
| -24°F | -14.3 |
| -23°F | -14.2 |
| -22°F | -14.2 |
| -21°F | -14.2 |
| -20°F | -14.2 |
| -19°F | -14.2 |
| -18°F | -14.2 |
| -17°F | -14.1 |
| -16°F | -14.1 |
| -15°F | -14.1 |
| -14°F | -14.1 |
| -13°F | -14.0 |
| -12°F | -14.0 |
| -11°F | -14.0 |
| -10°F | -14.0 |
| -9°F | -13.9 |
| -8°F | -13.9 |
| -7°F | -13.9 |
| -6°F | -13.9 |
| -5°F | -13.8 |
| -4°F | -13.8 |
| -3°F | -13.8 |
| -2°F | -13.7 |
| -1°F | -13.7 |
| 0°F | -13.7 |
| 1°F | -13.6 |
| 2°F | -13.6 |
| 3°F | -13.6 |
| 4°F | -13.5 |
| 5°F | -13.5 |
| 6°F | -13.5 |
| 7°F | -13.4 |
| 8°F | -13.4 |
| 9°F | -13.3 |
| 10°F | -13.3 |
| 11°F | -13.3 |
| 12°F | -13.2 |
| 13°F | -13.2 |
| 14°F | -13.1 |
| 15°F | -13.1 |
| 16°F | -13.0 |
| 17°F | -13.0 |
| 18°F | -12.9 |
| 19°F | -12.8 |
| 20°F | -12.8 |
| 21°F | -12.7 |
| 22°F | -12.7 |
| 23°F | -12.6 |
| 24°F | -12.6 |
| 25°F | -12.5 |
| 26°F | -12.4 |
| 27°F | -12.4 |
| 28°F | -12.3 |
| 29°F | -12.2 |
| 30°F | -12.2 |
| 31°F | -12.1 |
| 32°FH₂O freeze | -12.0 |
| 33°F | -11.9 |
| 34°F | -11.9 |
| 35°F | -11.8 |
| 36°F | -11.7 |
| 37°F | -11.6 |
| 38°F | -11.5 |
| 39°F | -11.5 |
| 40°F | -11.4 |
| 41°F | -11.3 |
| 42°F | -11.2 |
| 43°F | -11.1 |
| 44°F | -11.0 |
| 45°F | -10.9 |
| 46°F | -10.8 |
| 47°F | -10.7 |
| 48°F | -10.6 |
| 49°F | -10.5 |
| 50°F | -10.4 |
| 51°F | -10.3 |
| 52°F | -10.2 |
| 53°F | -10.0 |
| 54°F | -9.9 |
| 55°F | -9.8 |
| 56°F | -9.7 |
| 57°F | -9.6 |
| 58°F | -9.4 |
| 59°F | -9.3 |
| 60°F | -9.2 |
| 61°F | -9.0 |
| 62°F | -8.9 |
| 63°F | -8.8 |
| 64°F | -8.6 |
| 65°F | -8.5 |
| 66°F | -8.3 |
| 67°F | -8.2 |
| 68°F | -8.0 |
| 69°F | -7.8 |
| 70°F | -7.7 |
| 71°F | -7.5 |
| 72°F | -7.3 |
| 73°F | -7.2 |
| 74°F | -7.0 |
| 75°F | -6.8 |
| 76°F | -6.7 |
| 77°F | -6.5 |
| 78°F | -6.3 |
| 79°F | -6.1 |
| 80°F | -5.9 |
| 81°F | -5.7 |
| 82°F | -5.5 |
| 83°F | -5.3 |
| 84°F | -5.1 |
| 85°F | -4.9 |
| 86°F | -4.7 |
| 87°F | -4.4 |
| 88°F | -4.2 |
| 89°F | -4.0 |
| 90°F | -3.8 |
| 91°F | -3.5 |
| 92°F | -3.3 |
| 93°F | -3.0 |
| 94°F | -2.8 |
| 95°F | -2.5 |
| 96°F | -2.3 |
| 97°F | -2.0 |
| 98°F | -1.8 |
| 99°F | -1.5 |
| 100°F | -1.2 |
| 101°F | -1.0 |
| 102°F | -0.7 |
| 103°F | -0.4 |
| 104°F | -0.1 |
| 105°FNBP (atmospheric) | 0.2 |
| 106°F | 0.5 |
| 107°F | 0.8 |
| 108°F | 1.1 |
| 109°F | 1.4 |
| 110°F | 1.7 |
| 111°F | 2.1 |
| 112°F | 2.4 |
| 113°F | 2.7 |
| 114°F | 3.1 |
| 115°F | 3.4 |
| 116°F | 3.8 |
| 117°F | 4.1 |
| 118°F | 4.5 |
| 119°F | 4.8 |
| 120°F | 5.2 |
| 121°F | 5.6 |
| 122°F | 6.0 |
| 123°F | 6.3 |
| 124°F | 6.7 |
| 125°F | 7.1 |
| 126°F | 7.5 |
| 127°F | 7.9 |
| 128°F | 8.3 |
| 129°F | 8.8 |
| 130°F | 9.2 |
| 131°F | 9.6 |
| 132°F | 10.1 |
| 133°F | 10.5 |
| 134°F | 11.0 |
| 135°F | 11.4 |
| 136°F | 11.9 |
| 137°F | 12.4 |
| 138°F | 12.8 |
| 139°F | 13.3 |
| 140°F | 13.8 |
| 141°F | 14.3 |
| 142°F | 14.8 |
| 143°F | 15.3 |
| 144°F | 15.8 |
| 145°F | 16.4 |
| 146°F | 16.9 |
| 147°F | 17.4 |
| 148°F | 18.0 |
| 149°F | 18.5 |
| 150°F | 19.1 |
| Temp (°C) | Pressure (kPa) |
|---|---|
| -33°C | -99 |
| -32°C | -98 |
| -31°C | -98 |
| -30°C | -98 |
| -29°C | -98 |
| -28°C | -98 |
| -27°C | -97 |
| -26°C | -97 |
| -25°C | -97 |
| -24°C | -97 |
| -23°C | -96 |
| -22°C | -96 |
| -21°C | -96 |
| -20°C | -95 |
| -19°C | -95 |
| -18°C | -94 |
| -17°C | -94 |
| -16°C | -94 |
| -15°C | -93 |
| -14°C | -93 |
| -13°C | -92 |
| -12°C | -91 |
| -11°C | -91 |
| -10°C | -90 |
| -9°C | -90 |
| -8°C | -89 |
| -7°C | -88 |
| -6°C | -88 |
| -5°C | -87 |
| -4°C | -86 |
| -3°C | -85 |
| -2°C | -85 |
| -1°C | -84 |
| 0°CH₂O freeze | -83 |
| 1°C | -82 |
| 2°C | -81 |
| 3°C | -80 |
| 4°C | -79 |
| 5°C | -78 |
| 6°C | -77 |
| 7°C | -75 |
| 8°C | -74 |
| 9°C | -73 |
| 10°C | -72 |
| 11°C | -70 |
| 12°C | -69 |
| 13°C | -67 |
| 14°C | -66 |
| 15°C | -64 |
| 16°C | -62 |
| 17°C | -61 |
| 18°C | -59 |
| 19°C | -57 |
| 20°C | -55 |
| 21°C | -53 |
| 22°C | -51 |
| 23°C | -49 |
| 24°C | -47 |
| 25°C | -45 |
| 26°C | -42 |
| 27°C | -40 |
| 28°C | -37 |
| 29°C | -35 |
| 30°C | -32 |
| 31°C | -29 |
| 32°C | -27 |
| 33°C | -24 |
| 34°C | -21 |
| 35°C | -18 |
| 36°C | -14 |
| 37°C | -11 |
| 38°C | -8 |
| 39°C | -4 |
| 40°C | -1 |
| 41°CNBP (atmospheric) | 3 |
| 42°C | 7 |
| 43°C | 11 |
| 44°C | 15 |
| 45°C | 19 |
| 46°C | 23 |
| 47°C | 27 |
| 48°C | 32 |
| 49°C | 36 |
| 50°C | 41 |
| 51°C | 46 |
| 52°C | 51 |
| 53°C | 56 |
| 54°C | 61 |
| 55°C | 66 |
| 56°C | 72 |
| 57°C | 78 |
| 58°C | 83 |
| 59°C | 89 |
| 60°C | 95 |
| 61°C | 101 |
| 62°C | 108 |
| 63°C | 114 |
| 64°C | 121 |
| 65°C | 128 |
Full saturation values at 1° increments — toggle between °F / PSIG and °C / kPa. Use Print / Save as PDF for laminated shop reference, or download the CSV / JSON below for use in other tools. R-365mfc PT chart data: CoolProp 7.2.0 (REFPROP-compatible Helmholtz EOS) or manufacturer datasheet, validated against AHRI Standard 700-2019.
At a glance
Chemistry
Lubricant compatibility
Class A2 (flammable). Primarily used as a foam blowing agent for polyurethane insulation. Limited refrigeration use.
Trade names
- Solkane 365mfcSolvay
Common applications
- Foam blowing agent (polyurethane insulation)
- Solvent applications
- Limited refrigeration use
Properties
- Boiling point (1 atm)40.2°C / 104.3°F
- Critical point368.3°F at 459 PSIG
- Molar mass148.07 g/mol
- Temperature glideNegligible (0.00°F)
- ODP0
- GWP (AR5, 100-yr)794
- GWP (AR6, 100-yr)914
- Atmospheric lifetime8.7 years
What is R-365mfc?
R-365mfc is 1,1,1,3,3-pentafluorobutane — a four-carbon HFC with five fluorines. The notable physical property is the high normal boiling point of +104°F (40°C) — well above ambient temperatures, meaning the refrigerant is liquid at most operating environments. This places it in a different class than typical AC and refrigeration refrigerants (NBP -50°F to +0°F).
The A2 safety classification (flammable, not the milder A2L) reflects the saturated four-carbon backbone — like other hydrocarbons of similar size, R-365mfc supports combustion, though less aggressively than pure hydrocarbon refrigerants (R-290, R-600a). The combination of high boiling point + flammability makes R-365mfc a poor choice for typical HVAC refrigeration but useful for foam-blowing applications where the high boiling point allows liquid storage at ambient and the flammability is managed through controlled-environment manufacturing.
Where R-365mfc is used
- Foam blowing agent for polyurethane insulation (the dominant use, marketed as Solvay Solkane 365mfc)
- Solvent applications in some precision-cleaning processes
- Some specialty high-temperature heat-pump and ORC research applications
- Not used in conventional HVAC refrigeration
Regulatory & phase-down status
R-365mfc's GWP of 794 places it within EPA AIM Act phase-down scope and EU F-Gas Regulation scope. For foam-blowing applications the regulatory pressure has been intense — the EU F-Gas Regulation specifically targeted foam-blowing HFCs as one of the highest-emission HFC use categories.
The foam-blowing industry transition has progressed substantially: R-1233zd(E) (Honeywell Solstice LBA, A1, GWP 1) is the dominant modern foam-blowing HFO for polyurethane spray and rigid foam applications. R-365mfc retains market share in some specific foam formulations where its specific volatility profile is preferred, but the trajectory is toward lower-GWP alternatives.
Service notes
R-365mfc is rarely encountered in HVAC service contexts. Foam-blowing applications involve refrigerant handling at the foam-manufacturing facility rather than in HVAC equipment service. The A2 flammability classification requires appropriate handling — flammable refrigerant storage and transfer procedures apply, with EPA Section 608 covering refrigeration applications.
POE oil is compatible for any refrigeration use; mineral oil is not.
Operating cycle
Phase-down timeline
No phase-down milestones documented for R-365mfc in this build. This may mean: (a) no regulatory phase-down currently published; (b) the refrigerant has local regulatory schedules not yet transcribed into the site dataset; or (c) it is a specialty refrigerant outside the main regulatory frameworks. For authoritative current status, consult the EPA AIM Act allocations (40 CFR Part 84), EU F-Gas Regulation 517/2014 + 2024/573, and the relevant national implementations of the Kigali Amendment.
Global warming potential, in context
No peer-comparison group is defined for R-365mfc. Its 100-year GWP per IPCC AR5 is 794 — above the EPA AIM Act 700 GWP cap.
Peer-comparison groups are defined for refrigerants that compete in the same application sector (residential AC, commercial MT/LT, chillers, mobile AC). Specialty or research-grade refrigerants without a clear peer set don't appear in any group; their GWP is shown above in absolute terms instead.
Frequently asked
›What's a foam blowing agent?
A volatile compound used to generate gas bubbles in polymer foam manufacturing. For polyurethane insulation, the blowing agent is mixed with the liquid polyurethane precursors; when the chemical reaction generates heat, the blowing agent vaporizes and creates the cellular foam structure that provides the insulating value. The agent remains trapped in the foam cells, contributing to long-term thermal performance. Foam-blowing agents are different from refrigerants in HVAC application but share volatile properties — many refrigerants (HFCs, HFOs) are also foam-blowing agents.
›Why is R-365mfc's boiling point so high?
Four-carbon molecule with five fluorines. Each carbon-fluorine bond adds molecular weight, and four-carbon chains have more intermolecular interactions than three-carbon or two-carbon chains. The combination produces a normal boiling point of +104°F (40°C). For comparison, three-carbon R-245fa boils at +59°F; two-carbon R-134a boils at -15°F; one-carbon R-32 boils at -62°F. Higher-carbon-count HFCs generally have higher boiling points.
›What does A2 flammability classification mean?
ASHRAE 34's A2 classification indicates flammability with burning velocity greater than the A2L threshold (10 cm/s). A2 refrigerants support more aggressive combustion than A2L refrigerants — flame propagation is faster and combustion is more complete. R-152a (HFC-152a) is the other commonly-discussed A2 HFC. A2 refrigerants face more restrictive equipment design requirements than A2L; widespread commercial deployment is correspondingly limited.
›What is the GWP of R-365mfc?
794 per IPCC AR5. Moderate — lower than R-134a (1,430) but well above modern low-GWP HFO alternatives like R-1233zd(E) (1). The 8.7-year atmospheric lifetime is short for an HFC.
›Why is R-365mfc being replaced in foam blowing?
GWP and regulatory pressure. The EU F-Gas Regulation has targeted foam-blowing applications specifically due to the high emissions intensity (the blowing agent vapors are not contained — they're released during foam manufacturing and gradual diffusion from the foam over decades). R-1233zd(E) provides similar foam-blowing performance with GWP 1 instead of 794 — a 99.9% GWP reduction. The transition is now well-established in most polyurethane spray-foam and rigid-foam applications.