R-454C pressure–temperature table and P–h diagram

Opteon XL20 (R-32/1234yf) — a zeotropic blend of R-32 and R-1234yf, 21.5 / 78.5 % by mass. Bubble and dew pressures from −70 to 78 °C, every 2 K, and a pressure–enthalpy diagram to read any state from, computed with CoolProp. Also written R454C.

Safety class A2LGWP 145 (AR4), 166 (AR6)ODP 0Sources

Pressure–enthalpy diagram

log P · h

Pressure (kPa abs)

Specific enthalpy (kJ/kg)

Point anywhere on the diagram to read the state there

Pressure: —
Temperature: —
Specific enthalpy: —
Specific entropy: —
Density: —
Specific volume: —
Saturation: —
Superheat or subcooling: —

Values come from a CoolProp 7.2.1dev tabulation of R-454C (71 pressures, each with states across its liquid, two-phase and vapour spans), interpolated between the points of that grid, and must be verified by a qualified professional before they're relied on.

Enthalpy and entropy are on the IIR datum: h = 200 kJ/kg and s = 1 kJ/(kg·K) for saturated liquid at 0 °C, the bubble-point liquid for a blend.

CoolProp has no pressure–enthalpy solution for a blend it models as a mixture, so each state here is its pressure–temperature or pressure–quality solution at the enthalpy the grid needed. It gives no critical point for this blend either, so the diagram stops at 3,554 kPa, the dew-point pressure at the top of the table above.

CoolProp didn't solve the saturation lines between 3,315 and 3,554 kPa, so the diagram shades that band and draws nothing across it.

Where CoolProp gives no state — outside its equation's range of −84.5 to 146.2 °C, for one — the diagram is shaded, the readout says "Not solved here" and nothing is filled in.

Points

CoolProp

R-454C critical and boiling points
Reading	Value	Basis
Critical pointNot published for a mixture: CoolProp can't solve most blends' critical points	—	Not published for a mixture: CoolProp can't solve most blends' critical points
Bubble pointAt 101.325 kPa, solved by CoolProp	−45.56°C	At 101.325 kPa, solved by CoolProp
Dew pointAt 101.325 kPa, solved by CoolProp	−37.75°C	At 101.325 kPa, solved by CoolProp
GlideDew point less bubble point, at 101.325 kPa	7.81K	Dew point less bubble point, at 101.325 kPa

Saturation pressure

kPa abs · bar g

R-454C saturation bubble and dew pressures by temperature, in kPa absolute and bar gauge
T (°C)	Bubble (kPa abs)	Dew (kPa abs)	Bubble (bar g)	Dew (bar g)
−70	27.1	16.8	−0.74	−0.85
−68	30.6	19.1	−0.71	−0.82
−66	34.5	21.7	−0.67	−0.80
−64	38.7	24.6	−0.63	−0.77
−62	43.4	27.8	−0.58	−0.74
−60	48.5	31.4	−0.53	−0.70
−58	54.1	35.3	−0.47	−0.66
−56	60.2	39.5	−0.41	−0.62
−54	66.8	44.2	−0.35	−0.57
−52	74.0	49.3	−0.27	−0.52
−50	81.7	54.9	−0.20	−0.46
−48	90.2	61.0	−0.11	−0.40
−46	99.2	67.7	−0.02	−0.34
−44	109.0	74.9	0.08	−0.26
−42	119.5	82.6	0.18	−0.19
−40	130.8	91.1	0.29	−0.10
−38	142.9	100.2	0.42	−0.01
−36	155.9	109.9	0.55	0.09
−34	169.8	120.5	0.68	0.19
−32	184.6	131.8	0.83	0.30
−30	200.3	143.9	0.99	0.43
−28	217.1	156.9	1.16	0.56
−26	235.0	170.8	1.34	0.69
−24	253.9	185.6	1.53	0.84
−22	274.0	201.4	1.73	1.00
−20	295.3	218.3	1.94	1.17
−18	317.8	236.2	2.16	1.35
−16	341.6	255.3	2.40	1.54
−14	366.8	275.5	2.65	1.74
−12	393.3	296.9	2.92	1.96
−10	421.2	319.6	3.20	2.18
−8	450.6	343.6	3.49	2.42
−6	481.5	368.9	3.80	2.68
−4	513.9	395.7	4.13	2.94
−2	548.0	423.9	4.47	3.23
0	583.7	453.7	4.82	3.52
2	621.2	485.0	5.20	3.84
4	660.4	518.0	5.59	4.17
6	701.4	552.6	6.00	4.51
8	744.2	589.0	6.43	4.88
10	789.0	627.1	6.88	5.26
12	835.7	667.2	7.34	5.66
14	884.4	709.1	7.83	6.08
16	935.2	753.0	8.34	6.52
18	988.1	799.0	8.87	6.98
20	1,043.1	847.1	9.42	7.46
22	1,100.4	897.3	9.99	7.96
24	1,159.9	949.8	10.59	8.48
26	1,221.7	1,004.6	11.20	9.03
28	1,285.9	1,061.7	11.85	9.60
30	1,352.5	1,121.3	12.51	10.20
32	1,421.7	1,183.5	13.20	10.82
34	1,493.3	1,248.2	13.92	11.47
36	1,567.5	1,315.6	14.66	12.14
38	1,644.4	1,385.8	15.43	12.84
40	1,723.9	1,458.9	16.23	13.58
42	1,806.2	1,534.9	17.05	14.34
44	1,891.3	1,613.9	17.90	15.13
46	1,979.3	1,696.1	18.78	15.95
48	2,070.2	1,781.5	19.69	16.80
50	2,164.0	1,870.2	20.63	17.69
52	2,260.9	1,962.4	21.60	18.61
54	2,360.8	2,058.2	22.59	19.57
56	2,463.9	2,157.7	23.63	20.56
58	2,570.1	2,261.1	24.69	21.60
60	2,679.6	2,368.4	25.78	22.67
62	2,792.3	2,480.0	26.91	23.79
64	2,908.4	2,595.9	28.07	24.95
66	3,027.8	2,716.4	29.26	26.15
68	3,150.6	2,841.7	30.49	27.40
70	3,276.8	2,972.2	31.75	28.71
72	3,406.3	3,108.1	33.05	30.07
74	3,539.3	3,250.0	34.38	31.49
76	3,675.4	3,398.5	35.74	32.97
78	3,814.5	3,554.3	37.13	34.53

Gauge pressure is absolute pressure less a standard atmosphere, 101.325 kPa; below it, gauge pressure is negative. Bubble: saturated liquid. Dew: saturated vapour.

CoolProp could not solve the dew line at 80 °C. Those rows are left out, not interpolated.

Identity

Kelvin’s refrigerant library

Designation: R-454C (also written R454C)
Name: Opteon XL20 (R-32/1234yf)
Kind: zeotropic blend of R-32 and R-1234yf
Composition: R-32 21.5 % / R-1234yf 78.5 % by mass

Environment and safety

Cited

Safety class: A2LLower toxicity, lower flammability. The class assigned in ISO 817 or ANSI/ASHRAE 34, as tabled in UNEP RTOC 2018; the Australian Government lists A2L (AS/NZS ISO 817).
GWP, 100-year (AR4): 145The mass-weighted sum of its components' figures from IPCC AR4 (2007): 21.5 % × 675 (R-32). R-1234yf has no AR4 figure and counts as zero, as in the Australian Government's figure.
GWP, 100-year (AR6): 166The mass-weighted sum of its components' figures from IPCC AR6 (2021): 21.5 % × 771 (R-32) + 78.5 % × 0.501 (R-1234yf).
ODP: 0None of its components is an ozone-depleting substance in the Montreal Protocol's annexes.

Two GWPs, both for a 100-year horizon. AR4 is the assessment that Australia's Ozone Protection and Synthetic Greenhouse Gas Management Act 1989 and the Montreal Protocol count HFCs in, so it is the figure behind Australia's HFC import phase-down (DCCEEW). The Montreal Protocol's Annexes A, C and F list the same AR4 figures for the CFCs, HCFCs and HFCs they control. AR6 is the IPCC's most recent assessment. The GHG Protocol's table of IPCC GWPs (version 2.0, August 2024) recommends using these latest values.

Sources

UNEP RTOC 2018: Annex I to Chapter 2, Tables 2.I-1 to 2.I-3: safety classes as assigned in ISO 817:2014 or ANSI/ASHRAE Standard 34-2016.
DCCEEW (Australian Government): Hydrofluorocarbon refrigerants – global warming potential values and safety classifications (last updated 13 December 2024): AR4 GWPs as used under the Ozone Protection and Synthetic Greenhouse Gas Management Act 1989, safety classes from AS/NZS ISO 817:2016.
IPCC AR4 (2007): Working Group I, Chapter 2, Table 2.14, 100-year GWP (as corrected in the Working Group I errata).
IPCC AR6 (2021): Working Group I, Chapter 7 Supplementary Material, Table 7.SM.7, GWP-100.
Montreal Protocol: Annex A, Group I (CFCs), and Annex C, Group I (HCFCs): ozone-depleting potentials.
ASHRAE refrigerant designations: Refrigerant blends (zeotropes and azeotropes): each blend's components and composition by mass.
GHG Protocol (2024): IPCC Global Warming Potential Values, version 2.0 (7 August 2024): the recommendation to use AR6.

Source

Computed with: CoolProp 7.2.1dev, HEOS backend — open-source software under the MIT licence
Fluid: A mixture of R32 and R1234yf at the composition above
Cite: Bell, I.H., Wronski, J., Quoilin, S., Lemort, V. (2014). Pure and pseudo-pure fluid thermophysical property evaluation and the open-source thermophysical property library CoolProp. Ind. Eng. Chem. Res. 53(6), 2498-2508.

Note

Not published here

The critical point. Not published for a mixture: CoolProp can't solve most blends' critical points.

Components: R-32, R-1234yf
In R-number order: Before: R-454B · After: R-455A
Every refrigerant: All refrigerant tables

Use R-454C in Kelvin

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