R13 PT Chart
Updated October 12, 2026
R-13
Pure CFC, chlorotrifluoromethane (CClF₃). Normal boiling point −114°F — one of the lowest of any commercial refrigerant. Critical temperature only 83.7°F, so the PT chart is limited to ultra-low-temperature operating ranges. Used as cascade low-stage refrigerant for environmental test chambers and cryogenic systems. Production banned in 1996; ODP 1.0, GWP 14,400.
R-13 saturation pressure is 123.1 PSIG at −15°F, 225.7 PSIG at 20°F, and 402.0 PSIG at 60°F. These are the gauge readings on a static, fully-saturated system; a running system's high side sits well above them. The full table below runs from −40°F to 83°F in 1°F steps.
Not yet checked against an independent source.
R-13 PT chart — printable saturation table
Looking for the R-13 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).
R-13 PT Chart — Pressure-Temperature Saturation Table
Computed with CoolProp 7.2.0 in 1°F steps · hvacptcharts.com
| Temp (°F) | Pressure (PSIG) |
|---|---|
| −40°F | 72.7 |
| −39°F | 74.4 |
| −38°F | 76.2 |
| −37°F | 77.9 |
| −36°F | 79.7 |
| −35°F | 81.5 |
| −34°F | 83.3 |
| −33°F | 85.2 |
| −32°F | 87.1 |
| −31°F | 89.0 |
| −30°F | 90.9 |
| −29°F | 92.8 |
| −28°F | 94.8 |
| −27°F | 96.8 |
| −26°F | 98.9 |
| −25°F | 100.9 |
| −24°F | 103.0 |
| −23°F | 105.1 |
| −22°F | 107.3 |
| −21°F | 109.5 |
| −20°F | 111.7 |
| −19°F | 113.9 |
| −18°F | 116.2 |
| −17°F | 118.5 |
| −16°F | 120.8 |
| −15°F | 123.1 |
| −14°F | 125.5 |
| −13°F | 127.9 |
| −12°F | 130.3 |
| −11°F | 132.8 |
| −10°F | 135.3 |
| −9°F | 137.8 |
| −8°F | 140.4 |
| −7°F | 143.0 |
| −6°F | 145.6 |
| −5°F | 148.3 |
| −4°F | 151.0 |
| −3°F | 153.7 |
| −2°F | 156.4 |
| −1°F | 159.2 |
| 0°F | 162.0 |
| 1°F | 164.9 |
| 2°F | 167.8 |
| 3°F | 170.7 |
| 4°F | 173.6 |
| 5°F | 176.6 |
| 6°F | 179.6 |
| 7°F | 182.7 |
| 8°F | 185.8 |
| 9°F | 188.9 |
| 10°F | 192.1 |
| 11°F | 195.3 |
| 12°F | 198.5 |
| 13°F | 201.8 |
| 14°F | 205.1 |
| 15°F | 208.4 |
| 16°F | 211.8 |
| 17°F | 215.2 |
| 18°F | 218.7 |
| 19°F | 222.2 |
| 20°F | 225.7 |
| 21°F | 229.3 |
| 22°F | 232.9 |
| 23°F | 236.5 |
| 24°F | 240.2 |
| 25°F | 244.0 |
| 26°F | 247.7 |
| 27°F | 251.5 |
| 28°F | 255.4 |
| 29°F | 259.3 |
| 30°F | 263.2 |
| 31°F | 267.2 |
| 32°F H₂O freeze | 271.2 |
| 33°F | 275.2 |
| 34°F | 279.3 |
| 35°F | 283.5 |
| 36°F | 287.7 |
| 37°F | 291.9 |
| 38°F | 296.2 |
| 39°F | 300.5 |
| 40°F | 304.8 |
| 41°F | 309.2 |
| 42°F | 313.7 |
| 43°F | 318.2 |
| 44°F | 322.7 |
| 45°F | 327.3 |
| 46°F | 332.0 |
| 47°F | 336.6 |
| 48°F | 341.4 |
| 49°F | 346.1 |
| 50°F | 351.0 |
| 51°F | 355.9 |
| 52°F | 360.8 |
| 53°F | 365.8 |
| 54°F | 370.8 |
| 55°F | 375.9 |
| 56°F | 381.0 |
| 57°F | 386.2 |
| 58°F | 391.4 |
| 59°F | 396.7 |
| 60°F | 402.0 |
| 61°F | 407.4 |
| 62°F | 412.9 |
| 63°F | 418.4 |
| 64°F | 424.0 |
| 65°F | 429.6 |
| 66°F | 435.3 |
| 67°F | 441.0 |
| 68°F | 446.8 |
| 69°F | 452.7 |
| 70°F | 458.6 |
| 71°F | 464.6 |
| 72°F | 470.6 |
| 73°F | 476.7 |
| 74°F | 482.9 |
| 75°F | 489.2 |
| 76°F | 495.5 |
| 77°F | 501.9 |
| 78°F | 508.3 |
| 79°F | 514.8 |
| 80°F | 521.4 |
| 81°F | 528.1 |
| 82°F | 534.9 |
| 83°F | 541.7 |
| Temp (°C) | Pressure (kPa) |
|---|---|
| −40°C | 502 |
| −39°C | 523 |
| −38°C | 545 |
| −37°C | 567 |
| −36°C | 590 |
| −35°C | 613 |
| −34°C | 637 |
| −33°C | 662 |
| −32°C | 687 |
| −31°C | 713 |
| −30°C | 740 |
| −29°C | 767 |
| −28°C | 795 |
| −27°C | 823 |
| −26°C | 852 |
| −25°C | 882 |
| −24°C | 912 |
| −23°C | 943 |
| −22°C | 975 |
| −21°C | 1,008 |
| −20°C | 1,041 |
| −19°C | 1,075 |
| −18°C | 1,109 |
| −17°C | 1,145 |
| −16°C | 1,181 |
| −15°C | 1,218 |
| −14°C | 1,255 |
| −13°C | 1,294 |
| −12°C | 1,333 |
| −11°C | 1,373 |
| −10°C | 1,414 |
| −9°C | 1,456 |
| −8°C | 1,498 |
| −7°C | 1,542 |
| −6°C | 1,586 |
| −5°C | 1,631 |
| −4°C | 1,677 |
| −3°C | 1,724 |
| −2°C | 1,771 |
| −1°C | 1,820 |
| 0°C H₂O freeze | 1,870 |
| 1°C | 1,920 |
| 2°C | 1,972 |
| 3°C | 2,024 |
| 4°C | 2,078 |
| 5°C | 2,132 |
| 6°C | 2,188 |
| 7°C | 2,244 |
| 8°C | 2,302 |
| 9°C | 2,360 |
| 10°C | 2,420 |
| 11°C | 2,481 |
| 12°C | 2,543 |
| 13°C | 2,606 |
| 14°C | 2,670 |
| 15°C | 2,735 |
| 16°C | 2,802 |
| 17°C | 2,870 |
| 18°C | 2,939 |
| 19°C | 3,009 |
| 20°C | 3,081 |
| 21°C | 3,154 |
| 22°C | 3,228 |
| 23°C | 3,304 |
| 24°C | 3,381 |
| 25°C | 3,460 |
| 26°C | 3,541 |
| 27°C | 3,623 |
| 28°C | 3,707 |
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-13 PT chart data: CoolProp 7.2.0 (published Helmholtz equations of state / mixture models — see the source citations above).
Lower toxicity (Occupational Exposure Limit ≥ 400 ppm). No flame propagation in air at standard atmospheric pressure and 60°C. R-134a, R-22, R-410A, R-404A, R-744 (CO2) are A1.
- Flammability
- None (no flame propagation)
- Toxicity
- Lower (OEL ≥ 400 ppm)
Classification per ANSI/ASHRAE Standard 34-2022. See full reference.
Saturation pressure-temperature curve
Saturation values from CoolProp 7.2.0[3]. Operating pressure on a running system differs — see the operating-pressure references for in-use values.
At a glance
Chemistry
Lubricant compatibility
Ultra-low temperature refrigerant (NBP −81.4°C). Used historically as the low-stage refrigerant in cascade systems for environmental test chambers and cryogenic applications. Critical point at 28.7°C (83.7°F) — chart is partial.
Common applications
- Cascade low-stage refrigerant (legacy)
- Environmental test chambers (low-temperature)
- Cryogenic applications (legacy)
Properties
- Boiling point (1 atm)−114.5°F (−81.4°C)
- Critical point83.7°F (28.7°C) at 548 PSIG
- Molar mass104.46 g/mol
- ODP1
- GWP (100-yr)14,400 IPCC AR4 IPCC: AR4 14,400 · AR5 13,900 · AR6 16,200
- Atmospheric lifetime640 years
- New-equipment status (US)Class I ODS (CFC) — US production/import ended January 1, 1996.
What is R-13?
R-13 is pure chlorotrifluoromethane (CClF₃), a single-molecule CFC. Its remarkable property is the very low normal boiling point — −114°F (−81°C) — which made it the workhorse low-stage refrigerant in cascade systems designed to reach evaporator temperatures of −100°F to −200°F. Single-stage refrigeration with conventional refrigerants can't reach those temperatures because the pressure ratio across the compressor becomes unmanageable; cascade systems with R-13 as the low-stage and R-22 or R-502 as the high-stage solve that.
The critical temperature is only 28.7°C (83.7°F) — meaning at any ambient temperature above ~84°F, R-13 cannot condense at any pressure. This is why R-13 was always the low-stage refrigerant — its condenser was internal to the cascade system, exchanging heat with the high-stage refrigerant at temperatures well below ambient.
R-13 is a CFC — ODP 1.0 (reference value, equivalent to R-11). Banned for production in the US on January 1, 1996 under the Montreal Protocol.
Where R-13 is used
- Cascade low-stage refrigerant for environmental test chambers (−100°F to −200°F operating range) — legacy equipment only
- Cryogenic refrigeration for medical, scientific, and industrial cooling (legacy)
- Aerospace component testing chambers (legacy)
- No new equipment since 1996; reclaimed R-13 supports any remaining systems
Regulatory & phase-down status
R-13 production has been banned for almost three decades. Atmospheric lifetime of 640 years means molecules released even decades ago continue to deplete ozone — R-13 was a particularly damaging CFC because of its very long lifetime combined with full chlorine reactivity in the stratosphere.
For remaining cascade low-temperature equipment, R-23 (HFC, GWP 14,800 still high but lower than R-13) is the modern replacement low-stage refrigerant. Newer systems use R-744 (CO₂, GWP 1) in cascade — CO₂ has a high triple-point pressure that complicates ultra-low-temp use but works well for the −40°F to −100°F range many cascade systems target. Autocascade systems with mixed-refrigerant blends are another modern approach.
Service notes
Mineral oil (MO) is compatible. POE is not. EPA Section 608 Type II certification covers R-13. Recovery is required; venting was illegal under Clean Air Act §608 from 1990.
R-13's combination of low critical temperature and very low boiling point makes service work distinct from typical HVAC: the high side of the cascade may operate at moderate pressures while the low side reaches deep into negative °F territory. Equipment design accommodates this; field service requires understanding the cascade architecture.
Operating cycle
R-13 is used in: Cascade low-stage refrigerant (legacy), Environmental test chambers (low-temperature), Cryogenic applications (legacy) — applications with much lower condensing temperatures than residential AC.
Phase-down timeline
R-13 is an ozone-depleting substance controlled under the US Clean Air Act (class I — CFC). Milestones below are US production/import limits.
- January 1, 1996 — US ban on production and import took effect[1].
Global warming potential, in context
Industrial refrigeration & cascade systems
Retrofit and replacement paths
Replacements for R-13
R-13 vs R-744: saturation pressure
| Temp | R-13 | R-744 |
|---|---|---|
| 0°F | 162.0 | 291.0(+80%) |
| 40°F | 304.8 | 552.9(+81%) |
| 70°F | 458.6 | 838.1(+83%) |
Frequently asked
›Why was R-13 used in cascade systems instead of just a single-stage refrigerant?
No single-stage refrigerant can practically reach −100°F to −200°F evaporator temperatures. The pressure ratio across the compressor becomes excessive, and at very low temperatures the suction pressure approaches vacuum, which complicates leak-tightness and lubrication. A cascade system uses two separate refrigeration loops: a high-stage loop with a conventional refrigerant (R-22, R-404A historically) that condenses against ambient, and a low-stage loop with an ultra-low-temperature refrigerant (R-13, R-23, R-503) that condenses against the cold side of the high-stage evaporator. The two loops are coupled thermally but not refrigerant-wise. R-13's low boiling point made it ideal for the low-stage role.
›What's an environmental test chamber?
A controlled-temperature enclosure used for testing electronic components, aerospace materials, and biomedical samples at extreme temperatures. Common test ranges: −100°F to +250°F for aerospace component qualification, −40°F to +185°F for automotive electronics, −150°F to +200°F for some biomedical work. The cold side of these chambers historically used R-13 cascade systems; modern designs use R-23 cascades, autocascade with HFC blends, or mechanical cryocoolers.
›Why is R-13's critical temperature so low?
Small molecular size and high vapor pressure. The chlorotrifluoromethane molecule is small and the molecular interactions in the liquid phase are weak — the critical point (where liquid and vapor phases become indistinguishable) occurs at relatively low temperature. Low critical temperatures make these refrigerants unsuitable for air-cooled condensing at normal ambient.
›What replaced R-13 in cascade low-stage applications?
R-23 (HFC-23, trifluoromethane, CHF₃) was the immediate replacement when CFCs were phased out in the 1990s. R-23 has similar physical properties to R-13 (NBP −116°F, Tcrit 78.6°F) but is HFC rather than CFC — zero ODP, though still high GWP (14,800). For modern low-GWP cascade systems, R-744 (CO₂) is used as the low-stage refrigerant despite its higher triple-point pressure complicating very-low-temperature operation. Autocascade systems with mixed refrigerants are another modern approach.
›What is the ODP and GWP of R-13?
ODP 1.0 (the reference value, same as R-11). GWP 14,400. Atmospheric lifetime 640 years — among the longest of any commercial refrigerant. R-13 was a worst-case CFC for environmental damage: high ODP, very high GWP, extremely persistent.
Sources & citations
- [1]Phaseout of Class I Ozone-Depleting Substances. US EPA. last updated March 10, 2026. https://www.epa.gov/ods-phaseout/phaseout-class-i-ozone-depleting-substances (accessed October 5, 2026)
- [2]2017 Guideline for Assignment of Refrigerant Container Colors (AHRI Guideline N-2017). AHRI. 2017. https://www.ahrinet.org/system/files/2023-06/AHRI_Guideline_N_2017.pdf (accessed October 2, 2026)
- [3]CoolProp 7.2.0. CoolProp (I. H. Bell, J. Wronski, S. Quoilin, V. Lemort). https://coolprop.org/ (accessed October 2, 2026). Bell, I. H.; Wronski, J.; Quoilin, S.; Lemort, V. Pure and Pseudo-pure Fluid Thermophysical Property Evaluation and the Open-Source Thermophysical Property Library CoolProp. Ind. Eng. Chem. Res. 53, 2498–2508 (2014). https://doi.org/10.1021/ie4033999