R-502 pressure–temperature table and P–h diagram
R-502 (R-22/115 azeotrope) — an azeotropic blend of R-22 and R-115, 48.8 / 51.2 % by mass. Bubble and dew pressures from −70 to 70 °C, every 2 K, and a pressure–enthalpy diagram to read any state from, computed with CoolProp. Also written R502.
Safety class A1GWP 4,657 (AR4), 5,872 (AR6)ODP 0.334Sources
Pressure–enthalpy diagram
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-502 (70 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 3,166 kPa, the dew-point pressure at the top of the table above.
CoolProp didn't solve the saturation lines between 2,954 and 3,166 kPa, so the diagram shades that band and draws nothing across it.
Points
| Reading | Value |
|---|---|
| Critical pointNot published for a mixture: CoolProp can't solve most blends' critical points | — |
| Bubble pointAt 101.325 kPa, solved by CoolProp | −44.78°C |
| Dew pointAt 101.325 kPa, solved by CoolProp | −44.31°C |
| GlideDew point less bubble point, at 101.325 kPa | 0.47K |
Saturation pressure
| T (°C) | Bubble (kPa abs) | Dew (kPa abs) | Bubble (bar g) | Dew (bar g) |
|---|---|---|---|---|
| −70 | 26.5 | 25.3 | −0.75 | −0.76 |
| −68 | 29.8 | 28.6 | −0.71 | −0.73 |
| −66 | 33.6 | 32.2 | −0.68 | −0.69 |
| −64 | 37.7 | 36.3 | −0.64 | −0.65 |
| −62 | 42.2 | 40.7 | −0.59 | −0.61 |
| −60 | 47.1 | 45.5 | −0.54 | −0.56 |
| −58 | 52.4 | 50.8 | −0.49 | −0.51 |
| −56 | 58.3 | 56.5 | −0.43 | −0.45 |
| −54 | 64.6 | 62.8 | −0.37 | −0.39 |
| −52 | 71.5 | 69.6 | −0.30 | −0.32 |
| −50 | 79.0 | 77.0 | −0.22 | −0.24 |
| −48 | 87.0 | 84.9 | −0.14 | −0.16 |
| −46 | 95.7 | 93.5 | −0.06 | −0.08 |
| −44 | 105.1 | 102.8 | 0.04 | 0.01 |
| −42 | 115.1 | 112.8 | 0.14 | 0.11 |
| −40 | 125.9 | 123.5 | 0.25 | 0.22 |
| −38 | 137.5 | 135.0 | 0.36 | 0.34 |
| −36 | 149.9 | 147.3 | 0.49 | 0.46 |
| −34 | 163.1 | 160.5 | 0.62 | 0.59 |
| −32 | 177.2 | 174.6 | 0.76 | 0.73 |
| −30 | 192.2 | 189.5 | 0.91 | 0.88 |
| −28 | 208.2 | 205.5 | 1.07 | 1.04 |
| −26 | 225.2 | 222.5 | 1.24 | 1.21 |
| −24 | 243.3 | 240.5 | 1.42 | 1.39 |
| −22 | 262.4 | 259.6 | 1.61 | 1.58 |
| −20 | 282.7 | 279.8 | 1.81 | 1.78 |
| −18 | 304.1 | 301.2 | 2.03 | 2.00 |
| −16 | 326.8 | 323.9 | 2.25 | 2.23 |
| −14 | 350.7 | 347.8 | 2.49 | 2.46 |
| −12 | 375.9 | 373.0 | 2.75 | 2.72 |
| −10 | 402.5 | 399.6 | 3.01 | 2.98 |
| −8 | 430.5 | 427.5 | 3.29 | 3.26 |
| −6 | 459.9 | 456.9 | 3.59 | 3.56 |
| −4 | 490.7 | 487.8 | 3.89 | 3.87 |
| −2 | 523.2 | 520.3 | 4.22 | 4.19 |
| 0 | 557.1 | 554.3 | 4.56 | 4.53 |
| 2 | 592.8 | 590.0 | 4.91 | 4.89 |
| 4 | 630.1 | 627.3 | 5.29 | 5.26 |
| 6 | 669.1 | 666.3 | 5.68 | 5.65 |
| 8 | 709.9 | 707.2 | 6.09 | 6.06 |
| 10 | 752.5 | 749.8 | 6.51 | 6.49 |
| 12 | 797.0 | 794.4 | 6.96 | 6.93 |
| 14 | 843.4 | 840.9 | 7.42 | 7.40 |
| 16 | 891.7 | 889.3 | 7.90 | 7.88 |
| 18 | 942.2 | 939.8 | 8.41 | 8.38 |
| 20 | 994.6 | 992.3 | 8.93 | 8.91 |
| 22 | 1,049.3 | 1,047.0 | 9.48 | 9.46 |
| 24 | 1,106.1 | 1,103.9 | 10.05 | 10.03 |
| 26 | 1,165.2 | 1,163.1 | 10.64 | 10.62 |
| 28 | 1,226.5 | 1,224.5 | 11.25 | 11.23 |
| 30 | 1,290.3 | 1,288.3 | 11.89 | 11.87 |
| 32 | 1,356.4 | 1,354.5 | 12.55 | 12.53 |
| 34 | 1,425.0 | 1,423.2 | 13.24 | 13.22 |
| 36 | 1,496.2 | 1,494.5 | 13.95 | 13.93 |
| 38 | 1,570.0 | 1,568.3 | 14.69 | 14.67 |
| 40 | 1,646.4 | 1,644.8 | 15.45 | 15.44 |
| 42 | 1,725.6 | 1,724.1 | 16.24 | 16.23 |
| 44 | 1,807.6 | 1,806.2 | 17.06 | 17.05 |
| 46 | 1,892.4 | 1,891.1 | 17.91 | 17.90 |
| 48 | 1,980.2 | 1,979.0 | 18.79 | 18.78 |
| 50 | 2,071.1 | 2,069.9 | 19.70 | 19.69 |
| 52 | 2,165.0 | 2,163.9 | 20.64 | 20.63 |
| 54 | 2,262.2 | 2,261.1 | 21.61 | 21.60 |
| 56 | 2,362.6 | 2,361.6 | 22.61 | 22.60 |
| 58 | 2,466.5 | 2,465.5 | 23.65 | 23.64 |
| 60 | 2,573.8 | 2,572.8 | 24.72 | 24.71 |
| 62 | 2,684.7 | 2,683.8 | 25.83 | 25.82 |
| 64 | 2,799.4 | 2,798.5 | 26.98 | 26.97 |
| 66 | 2,917.9 | 2,917.0 | 28.17 | 28.16 |
| 68 | 3,040.4 | 3,039.5 | 29.39 | 29.38 |
| 70 | 3,167.0 | 3,166.2 | 30.66 | 30.65 |
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 bubble line at 74–80 °C, or the dew line at 72 °C. Those rows are left out, not interpolated.
Identity
- Designation
- R-502 (also written R502)
- Name
- R-502 (R-22/115 azeotrope)
- Kind
- azeotropic blend of R-22 and R-115
- Composition
- R-22 48.8 % / R-115 51.2 % by mass
Environment and safety
- Safety class
- A1Lower toxicity, no flame propagation. The class assigned in ISO 817 or ANSI/ASHRAE 34, as tabled in UNEP RTOC 2018.
- GWP, 100-year (AR4)
- 4,657The mass-weighted sum of its components' figures from IPCC AR4 (2007): 48.8 % × 1,810 (R-22) + 51.2 % × 7,370 (R-115).
- GWP, 100-year (AR6)
- 5,872The mass-weighted sum of its components' figures from IPCC AR6 (2021): 48.8 % × 1,960 (R-22) + 51.2 % × 9,600 (R-115).
- ODP
- 0.334The mass-weighted sum of its components' figures in the Montreal Protocol's annexes: 48.8 % × 0.055 (R-22) + 51.2 % × 0.6 (R-115).
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.
- 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
- R502.mix, CoolProp's predefined mixture of R22 and R115 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.
Not published here
The critical point. Not published for a mixture: CoolProp can't solve most blends' critical points.
Related
- Components
- R-22, R-115
- Every refrigerant
- All refrigerant tables
Use R-502 in Kelvin
Kelvin’s Free plan includes the refrigerant library, P–h diagrams, single-stage cycles and draft reports. Paid plans carry a system on through pipework, equipment, charge, energy and cost to issued reports.
Verify before relying on these figures
The property figures are computed with CoolProp from published equations of state. The GWP, ODP and safety class are the named sources’ figures, a blend’s GWP and ODP summed from its composition. They must be verified by a qualified professional before they’re relied on.