HVAC PT ChartsVerified saturation data · 61 refrigerants
RefrigerantASHRAE R-1234yf

R-1234yf

A2LMildly flammableHFO (pure)
CF3CF=CH2

Pure HFO (2,3,3,3-tetrafluoropropene) — the global mobile AC standard refrigerant replacing R-134a in new vehicles. A2L mildly flammable, GWP 4 (AR4 / EPA SNAP basis; <1 per strict AR5), no temperature glide. Trade names Honeywell Solstice yf and Chemours Opteon YF.

Saturation @ 70°F
73.9PSIG
GWP (IPCC AR5)
—
Temperature glide
≈0°F
Boiling point
-21.1°F
Sourced facts
ASHRAE safety class
A2L[src]
Chemical formula
CF₃CF=CH₂[src]
GWP (100-yr)
4IPCC AR4 / EPA SNAP basis[src]
ODP
0[src]
Normal boiling point
−21.1°F (−29.5°C)[src]
Temperature glide
0°F[src]
Required lubricant
PAG / POE[src]
R-1234yf PT calculator Operating pressures Superheat
A2L
Mildly flammable

Lower toxicity. Flame propagates in air at 60°C, but with a low burning velocity (≤ 10 cm/s) and a heat of combustion < 19,000 kJ/kg. Requires A2L-rated equipment, leak detection, and charge limits per UL 60335-2-40 and ASHRAE 15. R-32, R-454B, R-1234yf, R-1234ze(E), R-452B, R-454C, R-455A, R-516A are A2L.

Flammability
Low (burning velocity ≤ 10 cm/s)
Toxicity
Lower (OEL ≥ 400 ppm)

Classification per ANSI/ASHRAE Standard 34-2022. See full reference.

01

Saturation pressure-temperature curve

Pressure
Temperature
°F
70°F: 73.9 PSIG
Quick lookup — R-1234yf
73.9PSIG(510 kPa)
Range: -40 to 150°FOpen full PT calculator →
Common service temperatures
32°F
31PSIG
Freezing
45°F
43PSIG
Heat-pump heat
70°F
74PSIG
Standard
75°F
81PSIG
Test ref
80°F
89PSIG
Warm
95°F
115PSIG
Summer peak

Saturation values from CoolProp 7.2.0 R1234yf. Operating pressure on a running system differs — see what R-1234yf operating pressures should be.

02

R-1234yf PT chart PDF — printable saturation table

Looking for the R-1234yf 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-1234yf PT Chart — Pressure-Temperature Saturation Table

1° increments · Source: CoolProp 7.2.0 / manufacturer datasheet · hvacptcharts.com

R-1234yf · 1° increments · °F / PSIG
Tinted rows: NBP atmospheric crossover · 32°F H₂O freeze · 35°F MAC evap target · 100°F Cabin ambient · 140°F Engine bay cond
R-1234yf pressure-temperature saturation table in Fahrenheit and PSIG
Temp (°F)Pressure (PSIG)
-40°F-5.7
-39°F-5.4
-38°F-5.2
-37°F-4.9
-36°F-4.6
-35°F-4.4
-34°F-4.1
-33°F-3.8
-32°F-3.5
-31°F-3.2
-30°F-2.9
-29°F-2.6
-28°F-2.3
-27°F-2.0
-26°F-1.7
-25°F-1.4
-24°F-1.0
-23°F-0.7
-22°F-0.3
-21°FNBP (atmospheric)0.0
-20°F0.4
-19°F0.8
-18°F1.1
-17°F1.5
-16°F1.9
-15°F2.3
-14°F2.7
-13°F3.1
-12°F3.5
-11°F4.0
-10°F4.4
-9°F4.8
-8°F5.3
-7°F5.8
-6°F6.2
-5°F6.7
-4°F7.2
-3°F7.7
-2°F8.2
-1°F8.7
0°F9.2
1°F9.8
2°F10.3
3°F10.8
4°F11.4
5°F11.9
6°F12.5
7°F13.1
8°F13.7
9°F14.3
10°F14.9
11°F15.5
12°F16.2
13°F16.8
14°F17.5
15°F18.1
16°F18.8
17°F19.5
18°F20.2
19°F20.9
20°F21.6
21°F22.3
22°F23.1
23°F23.8
24°F24.6
25°F25.4
26°F26.1
27°F26.9
28°F27.8
29°F28.6
30°F29.4
31°F30.3
32°FH₂O freeze31.1
33°F32.0
34°F32.9
35°FMAC evap target33.8
36°F34.7
37°F35.6
38°F36.5
39°F37.5
40°F38.4
41°F39.4
42°F40.4
43°F41.4
44°F42.4
45°F43.4
46°F44.5
47°F45.5
48°F46.6
49°F47.7
50°F48.8
51°F49.9
52°F51.0
53°F52.1
54°F53.3
55°F54.5
56°F55.7
57°F56.9
58°F58.1
59°F59.3
60°F60.6
61°F61.8
62°F63.1
63°F64.4
64°F65.7
65°F67.0
66°F68.4
67°F69.8
68°F71.1
69°F72.5
70°F73.9
71°F75.4
72°F76.8
73°F78.3
74°F79.8
75°F81.3
76°F82.8
77°F84.3
78°F85.9
79°F87.4
80°F89.0
81°F90.6
82°F92.3
83°F93.9
84°F95.6
85°F97.2
86°F98.9
87°F100.7
88°F102.4
89°F104.2
90°F105.9
91°F107.7
92°F109.6
93°F111.4
94°F113.3
95°F115.1
96°F117.0
97°F119.0
98°F120.9
99°F122.9
100°FCabin ambient124.9
101°F126.9
102°F128.9
103°F130.9
104°F133.0
105°F135.1
106°F137.2
107°F139.3
108°F141.5
109°F143.7
110°F145.9
111°F148.1
112°F150.4
113°F152.7
114°F154.9
115°F157.3
116°F159.6
117°F162.0
118°F164.4
119°F166.8
120°F169.2
121°F171.7
122°F174.2
123°F176.7
124°F179.3
125°F181.8
126°F184.4
127°F187.0
128°F189.7
129°F192.3
130°F195.0
131°F197.7
132°F200.5
133°F203.3
134°F206.1
135°F208.9
136°F211.7
137°F214.6
138°F217.5
139°F220.5
140°FEngine bay cond223.4
141°F226.4
142°F229.4
143°F232.5
144°F235.6
145°F238.7
146°F241.8
147°F245.0
148°F248.2
149°F251.4
150°F254.7
CoolProp 7.2.0 · PSIG/kPa = gauge · PSIA = PSIG + 14.696 · kPa(abs) = kPa(gauge) + 101.325

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-1234yf PT chart data: CoolProp 7.2.0 (REFPROP-compatible Helmholtz EOS) or manufacturer datasheet, validated against AHRI Standard 700-2019.

03

At a glance

Chemistry

CF3CF=CH2
2,3,3,3-Tetrafluoropropene

Lubricant compatibility

POEPAGMO

Industry standard for mobile AC since the 2010s as a low-GWP R-134a replacement. PAG is the OEM mobile-AC standard; POE used in stationary applications.

Trade names

  • Opteon YFChemours
  • Solstice yfHoneywell

Common applications

  • Mobile air conditioning (passenger vehicles, most OEMs since 2014)
  • Light commercial refrigeration
  • Industrial chiller alternative
04

Properties

  • Boiling point (1 atm)
    -29.5°C / -21.1°F
  • Critical point
    202.5°F at 476 PSIG
  • Molar mass
    114.04 g/mol
  • Temperature glide
    Negligible (0.00°F)
  • ODP
    0
  • GWP (AR5, 100-yr)
    —
  • GWP (AR6, 100-yr)
    0.501
  • Atmospheric lifetime
    0.029 years
05

What is R-1234yf?

R-1234yf is pure 2,3,3,3-tetrafluoropropene (CF₃CF=CH₂), a single-molecule hydrofluoroolefin (HFO) with a carbon-carbon double bond [ashrae34]. The double bond is what gives R-1234yf its very short atmospheric lifetime (~11 days) — atmospheric OH radicals attack the double bond rapidly, breaking down the molecule before it can contribute meaningful warming.

R-1234yf was developed jointly by Honeywell and Chemours in the late 2000s specifically as the mobile AC replacement for R-134a under the EU MAC Directive 2006/40/EC [eumac]. The 150-GWP threshold for new MAC vehicle types from 1 January 2017 made R-134a (GWP 1430) non-compliant; R-1234yf — cited as GWP 4 under the IPCC AR4 basis EPA SNAP uses, and below 1 under the strict IPCC AR5/AR6 100-year window — was the chosen industry-standard replacement.

Where R-1234yf is used

  • Mobile air conditioning — new light-duty vehicles globally since 2017-2021
  • Component in low-GWP HFC/HFO blends — R-454B (residential AC), R-513A (chillers), R-454C / R-455A (commercial refrigeration), R-448A / R-449A (R-404A retrofits)
  • Some stationary commercial refrigeration applications
  • Heat pump applications in some EV thermal management systems

Regulatory & phase-down status

R-1234yf faces no phase-down pressure — under any reasonable GWP basis (4 per AR4 / EPA SNAP, <1 per AR5/AR6) the value sits below every regulatory threshold including the EU F-Gas 150-GWP cap for the strictest categories [aimact][eumac]. R-1234yf is structurally a long-term destination refrigerant.

Market position is dominant in mobile AC (most major OEMs transitioned 2017-2021) and substantial as a blend component in commercial refrigeration. Direct standalone use in stationary HVAC is limited because A2L flammability requires equipment-design accommodations and other HFO/HFC alternatives have better operational fit for some applications.

Service notes

Mobile AC: PAG (polyalkylene glycol) oil typically PAG 46 or 100 viscosity — same lubricant family as R-134a MAC, NOT interchangeable with stationary HVAC POE [saej639]. Service ports are different from R-134a (R-1234yf uses M14 quick-disconnect to prevent cross-contamination).

Stationary HVAC: POE oil typically. A2L safety procedures apply: nitrogen-purged brazing, A2L-rated leak detection, ignition-source isolation in the refrigerant circuit. Pressure envelope similar to R-134a; standard 500 PSI manifold gauges adequate.

07

Operating cycle

CompressorRaises pressureCondenserRejects heat to outdoorsExpansion deviceDrops pressureEvaporatorAbsorbs heat from indoorsDischarge: 146 PSIG, 180°FLiquid: 146 PSIG, 100°FEvap inlet: 38 PSIG, 40°F (two-phase)Suction: 38 PSIG, 50°FTypical residential cooling cycle for R-1234yf (40°F evap, 110°F condenser, 10°F superheat, 10°F subcooling)
08

Phase-down timeline

R-1234yf is not currently regulated by AIM Act or EU F-Gas phase-down. Its very low GWP (<1) places it below regulatory thresholds. No published phase-down milestones exist for this refrigerant — it is a forward-compatible option for the current low-GWP transition rather than a refrigerant being phased out.

Properties: GWP not published · ODP 0 · Not AIM Act-affected · type: hfo-pure
09

Global warming potential, in context

Mobile air conditioning

R-134a1.4kR-1211kEU F-Gas (150)EPA AIM Act (700)
10

Retrofit and replacement paths

R-1234yf replaces

Reading the R-1234yf PT chart

R-1234yf's PT chart is a single saturation curve — R-1234yf is pure single-component HFO with no temperature glide [ashrae34]. Service measurement: superheat = suction line temp − saturation temp at suction pressure; subcooling = saturation temp at discharge pressure − liquid line temp. No glide correction needed.

The pressure envelope is similar to R-134a — R-1234yf was engineered to deliver R-134a-comparable performance in MAC equipment. At 70°F R-1234yf saturation is approximately 74 PSIG (CoolProp 7.2.0); R-134a at 70°F is 71 PSIG. Differences are small enough that MAC equipment designed for R-134a accepts R-1234yf with appropriate safety provisions.

HFO chemistry — the carbon-carbon double bond delivers very low GWP

R-1234yf is a hydrofluoroolefin: an HFC variant with a carbon-carbon double bond (the "olefin" or "ene" part of the name). The double bond is the chemistry feature that delivers R-1234yf's very low GWP — atmospheric OH radicals attack double bonds rapidly, breaking down the molecule within days.

R-1234yf atmospheric lifetime: approximately 11 days. Compare to R-134a (HFC, no double bond): approximately 14 years. The 450× shorter lifetime translates to a GWP gap that exceeds 350× by any IPCC reckoning — R-1234yf is reported as 4 per AR4 (the EPA SNAP exchange figure) and below 1 per strict AR5/AR6, against R-134a at 1430 (AR5) [ipccar5].

HFO chemistry is the modern low-GWP solution

HFOs (R-1234yf, R-1234ze, R-1233zd) all share the carbon-carbon double bond architecture that gives them very short atmospheric lifetimes and GWP values in the single digits. The HFO chemistry is the technical solution that makes Kigali Amendment compliance achievable for the refrigeration industry — without HFOs, the only zero-GWP alternatives would be naturals (R-744, R-290, R-717) with their own constraints.

Pressure envelope matches R-134a — mobile AC drop-in compatibility

R-1234yf was engineered specifically to match R-134a's pressure envelope, enabling minimal-redesign retrofit of MAC equipment from R-134a to R-1234yf. At 70°F R-1234yf saturation is 74 PSIG vs R-134a's 71 PSIG (CoolProp 7.2.0) — within 5%. At 95°F outdoor ambient, R-1234yf is approximately 128 PSIG vs R-134a's 124 PSIG.

The pressure-envelope match is the engineering reason the MAC industry transition from R-134a to R-1234yf was operationally smooth. Compressor designs, expansion-valve setpoints, condenser sizing all carried over with minor calibration. The major engineering changes were on the safety side (A2L flammability accommodations) and the supply side (R-1234yf availability and pricing).

GWP — among the lowest commercial refrigerants, with two numbers to know

R-1234yf's GWP is reported as 4 under the IPCC AR4 100-yr basis — the figure EPA SNAP, the AIM Act exchange-value table, and every manufacturer datasheet (Honeywell Solstice yf, Chemours Opteon YF) use. Under the strict IPCC AR5 / AR6 100-yr basis the value is less than 1, because R-1234yf's ~11-day atmospheric lifetime is well below the integration window AR5 and AR6 use for a precise figure. Both readings agree on the substance: R-1234yf belongs to the lowest-impact tier alongside R-744 (CO₂, GWP 1) and R-290 (propane, AR5 GWP 3). For compliance and reporting use 4; for honest climate-impact discussion use the AR5 value.

The very low GWP eliminates phase-down risk under EPA AIM Act, EU F-Gas Regulation, Kigali Amendment, and any reasonably-foreseeable future climate policy. R-1234yf is structurally a long-term destination refrigerant for applications where its A2L flammability can be managed and its pressure envelope fits the application.

A2L flammability — managed in MAC, accommodated in stationary HVAC

R-1234yf is ASHRAE class A2L — mildly flammable with low burning velocity. The flammability classification was the major industry debate during R-1234yf MAC adoption (2010-2017). Concerns focused on potential vehicle-fire scenarios from crash-induced refrigerant release into the engine compartment.

Industry response: vehicle-level safety design (refrigerant routing away from high-temperature engine components, crash-resistant refrigerant lines, refrigerant detection in some applications, sealed electrical components in the refrigerant circuit). Post-adoption real-world data through 2017-2026 has not shown elevated vehicle-fire incidents from R-1234yf MAC systems.

For stationary HVAC applications using R-1234yf as a standalone refrigerant or component, A2L safety procedures apply: sealed motor compressors, A2L-rated leak detection where appropriate, charge limits per ASHRAE 15.

PAG for mobile AC, POE for stationary — different chemistries for different applications

R-1234yf uses different lubricants depending on application. Mobile AC: PAG oil (polyalkylene glycol), typically PAG 46 or PAG 100 viscosity. Stationary HVAC: POE oil (polyolester), typical viscosity per equipment OEM specification.

The PAG / POE split mirrors R-134a's split. PAG was chosen for MAC because the variable-displacement automotive compressors common in modern vehicles benefit from PAG's specific oil-return characteristics. POE serves stationary applications where the compressor designs are different.

Never mix PAG and POE in a single system — the two lubricant chemistries are incompatible and produce oil-return failures and accelerated component wear. Verify lubricant grade against equipment OEM service literature before adding oil.

How to think about R-1234yf in 2026 and beyond

R-1234yf is the dominant mobile AC refrigerant globally in 2026 and the structural long-term destination for that application. New vehicle MAC installations since 2017 (EU) / 2021 (US) use R-1234yf; the installed base is growing rapidly as R-134a vehicles age out and are replaced.

For stationary HVAC, R-1234yf serves primarily as a blend component in low-GWP HFC/HFO blends (R-454B, R-454C, R-455A, R-513A, R-448A, R-449A) rather than as a standalone refrigerant. The blend role is significant — R-1234yf provides the GWP-diluting component in most modern low-GWP blends across residential AC, chillers, and commercial refrigeration applications.

Service supply economics are favorable. R-1234yf production capacity has scaled significantly since 2017 to meet global MAC demand; pricing has come down from initial premium levels. The pricing gap vs R-134a has narrowed considerably through 2020-2026.

11

Frequently asked

›What is R-1234yf used for?

Dominantly mobile air conditioning in light-duty vehicles. EU mandated R-1234yf in new MAC vehicle types from 1 January 2017 under Directive 2006/40/EC [eumac]; major US OEMs transitioned 2017-2021. R-1234yf is also a component in low-GWP HFC/HFO blends used in stationary commercial refrigeration (R-454C, R-455A, R-448A, R-449A, R-513A).

›What's the GWP of R-1234yf?

The widely-cited figure is **4** — but that's the IPCC AR4 100-yr GWP, which the EPA AIM Act and SNAP exchange-value framework use, and which Honeywell, Chemours and every manufacturer datasheet cite [ipccar5]. The strict IPCC AR5 / AR6 100-yr GWP is **less than 1**. The disagreement is real: R-1234yf's atmospheric lifetime is only ~11 days, which is far below the integration window IPCC's later assessments use for a precise 100-yr figure. Practically, both numbers are below every regulatory threshold, so the operational answer is "negligible". For compliance and reporting, cite 4 (the standardized exchange value). For the underlying climate impact, the figure is essentially zero.

›Is R-1234yf flammable?

Yes — ASHRAE class A2L (mildly flammable with low burning velocity, ≤10 cm/s). The flammability concern triggered substantial debate before MAC industry adoption; Daimler initially resisted R-1234yf adoption (citing crash-fire concerns) but ultimately conformed. Vehicle MAC system design accommodates the A2L classification through component design and routing.

›What lubricant does R-1234yf use?

Mobile AC: PAG oil (polyalkylene glycol), typically PAG 46 or PAG 100 viscosity grades [saej639]. The same lubricant family used with R-134a MAC; the lubricant choice was preserved to simplify the MAC industry transition. Stationary HVAC applications use POE oil.

›Why did MAC industry choose R-1234yf instead of R-152a or R-744?

R-152a (GWP 124) was an alternative but classified A2 (more flammable than A2L); harder to mitigate in confined vehicle cabin space. R-744 (CO₂, GWP 1) was an alternative but requires transcritical operation at very high pressures incompatible with existing MAC equipment designs. R-1234yf at AR4-basis GWP 4 (and AR5 basis <1), A2L (manageable flammability), and pressure envelope close to R-134a was the best balance for industry transition.

›Can I retrofit an R-134a vehicle to R-1234yf?

Not as a refrigerant swap. R-1234yf service ports are different from R-134a (specifically designed to prevent cross-contamination), the A1-to-A2L safety class change requires vehicle-level safety design, and the PAG oil grade differs. Mobile AC retrofit is rare and economically unjustified — service existing R-134a vehicles with R-134a or replace the vehicle.

›What is R-1234yf trade name?

Two primary manufacturer brands: Honeywell Solstice yf and Chemours Opteon YF [honeywellsolstice][chemoursopteon]. Both meet ASHRAE Standard 34 R-1234yf specification and AHRI Standard 700 purity requirements — they're functionally interchangeable.

Download this dataset

Full PT chart for R-1234yf · CC BY 4.0 · attribute the source

CSV JSON
13

Sources & citations

  1. [1]
    ASHRAE Standard 34-2022 — Designation and Safety Classification of Refrigerants
    2022https://www.ashrae.org/technical-resources/standards-and-guidelines
  2. [2]
    IPCC AR5 (2014) Working Group I, Chapter 8, Table 8.A.1
    2014https://www.ipcc.ch/report/ar5/wg1/
  3. [3]
    EU Mobile Air Conditioning Directive 2006/40/EC — Mandated sub-150 GWP refrigerants in new MAC from 1 Jan 2017
    2006 (full ban 2017)https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=celex%3A32006L0040
  4. [4]
    SAE J639 — Safety standards for motor vehicle refrigerant vapor compression systems
    https://www.sae.org/standards/content/j639_201407/
  5. [5]
    CoolProp 7.2.0 (Bell, Wronski, Quoilin, Lemort 2014)
    2014 (continually updated)http://www.coolprop.org/doi:10.1021/ie4033999
  6. [6]
    EPA AIM Act — 40 CFR Part 84 Subpart B
    Final Rule Oct 2021https://www.epa.gov/climate-hfcs-reduction
  7. [7]
    AHRI Standard 700-2019
    2019https://www.ahrinet.org/search-standards
  8. [8]
    Honeywell Solstice yf (R-1234yf) Technical Information
    https://www.honeywell-refrigerants.com/americas/
  9. [9]
    Chemours Opteon YF (R-1234yf) Product Data Sheet
    https://www.chemours.com/en/products/refrigerants

Data sources & provenance

PT chart
CoolProp 7.2.0 R1234yf
Cross-checked against
CoolProp 7.2.0 (R1234yf); Chemours Opteon YF datasheet
Properties
CoolProp 7.2.0 + ASHRAE Standard 34-2022
GWP
IPCC AR5 Table 8.A.1
Generated
2026-06-12

Reference material. Always verify pressure values against the equipment data plate and manufacturer service literature before charging or troubleshooting a specific system. Saturation pressure differs from operating pressure — see superheat & subcooling fundamentals.