HVAC PT Data

Pressure-temperature charts, field calculators and refrigerant data for HVAC/R technicians

PT data: CoolProp 8.0 equations of state, US units

Data Sources and Method: How the PT Charts Are Computed

Every pressure and property on this site is calculated with CoolProp 8.0.0 (HEOS backend), then compared with the manufacturer's or NIST's published values. This page lists the method, the models and every check.

The equation of state

A PT chart is a table of saturation pressures: the pressure at which a refrigerant boils or condenses at each temperature. The most accurate way to produce one is from an equation of state, a fitted model of the fluid's thermodynamic behaviour built from laboratory measurements. NIST's REFPROP program and the open-source CoolProp library both implement the reference equations of state published for refrigerants. This site uses CoolProp because its code and fluid files are public, so anyone can reproduce every number.

Pure refrigerants such as R-22, R-134a, R-32 and R-290 use the reference equation for that fluid. Blends are modelled as mixtures of their components at the nominal mass composition in ASHRAE Standard 34, using CoolProp's mixture model with fitted interaction parameters. For a zeotropic blend the script computes two curves: the bubble point (saturated liquid, first bubble of vapor) and the dew point (saturated vapor, last drop of liquid). The difference between them at one pressure is the temperature glide.

Units and conventions

  • Pressures are gauge pressure at sea level: absolute pressure minus 14.696 psia. Below 0 psig, charts show inches of mercury vacuum (in Hg).
  • The CSV downloads also give kPa absolute, which is how most metric and engineering tables are published.
  • Temperatures are in °F, in 1°F steps (2°F for a few refrigerants with very wide ranges), with °C alongside.
  • Gauges read relative to local air pressure, which drops with elevation. The lookups and calculators accept an elevation and convert using the standard atmosphere: at 5,000 ft a gauge reads about 2.5 psi higher than at sea level for the same refrigerant state.
  • Charts end 2°F below the critical temperature, where liquid and vapor stop being distinct.

Validation against published charts

Each refrigerant's computed chart was compared with the manufacturer's PT chart or the NIST Chemistry WebBook at several temperatures, using the matching column (liquid or vapor) for blends. For 55 of the 62 refrigerants the largest difference is 3.5 psi, and for most it is under 0.5 psi. Small differences are normal: manufacturers round, some use older equations of state, and blends are made to a composition tolerance of about ±0.5 to 2% per component. Each profile page shows its own checks.

Known deviations. For R-416A, R-434A, R-454A, R-454C, R-455A, R-500 and R-502 the computed values differ from the manufacturer's chart by 2 to 3%, mostly in the vapor (dew) column. Both manufacturer sources for R-454C agree with each other, so the gap comes from the published mixing parameters in the open model (for the R-32/R-1234yf pair in R-454A, R-454C and R-455A, and R-22/R-115 in R-502). Refitting one parameter set could not bring all the R-32/R-1234yf blends within tolerance together, so the values are published unadjusted, with an accuracy note on each page. Use the manufacturer's chart when charging those refrigerants.

For R-438A, R-453A, R-401A and R-409A the open model has no fitted parameters for some component pairs (isopentane with the HFCs, R-124 with R-22 and R-152a). Those pairs use documented estimates, the matching n-butane pair or a linear mixing rule, not values tuned to the charts. The resulting charts still agree with the published ones within 1.5 psi.

RefrigerantModelChecked againstLargest difference
R-11pure:R11NIST Chemistry WebBook, SRD 69, Thermophysical Properties of Fluid Systems: R11, saturation properties (temperature increments)0.4 psi
R-12pure:R12NIST Chemistry WebBook, SRD 69, Thermophysical Properties of Fluid Systems: R12, saturation properties (temperature increments)0.1 psi
R-14pure:R14NIST Chemistry WebBook, SRD 69, Thermophysical Properties of Fluid Systems: Tetrafluoromethane (R14), saturation properties (temperature increments)0.1 psi
R-22pure:R22NIST Chemistry WebBook, SRD 69, Thermophysical Properties of Fluid Systems: R22, saturation properties (temperature increments)0.0 psi
R-23pure:R23NIST Chemistry WebBook, SRD 69, Thermophysical Properties of Fluid Systems: R23, saturation properties (temperature increments)0.1 psi
R-32pure:R32NIST Chemistry WebBook, SRD 69, Thermophysical Properties of Fluid Systems: R32, saturation properties (temperature increments)0.1 psi
R-113pure:R113NIST Chemistry WebBook, SRD 69, Thermophysical Properties of Fluid Systems: R113, saturation properties (temperature increments)0.0 psi
R-123pure:R123NIST Chemistry WebBook, SRD 69, Thermophysical Properties of Fluid Systems: R123, saturation properties (temperature increments)0.0 psi
R-125pure:R125NIST Chemistry WebBook, SRD 69, Thermophysical Properties of Fluid Systems: R125, saturation properties (temperature increments)0.0 psi
R-134apure:R134aNIST Chemistry WebBook, SRD 69, Thermophysical Properties of Fluid Systems: R134a, saturation properties (temperature increments)0.1 psi
R-143apure:R143aNIST Chemistry WebBook, SRD 69, Thermophysical Properties of Fluid Systems: R143a, saturation properties (temperature increments)0.0 psi
R-152apure:R152ANIST Chemistry WebBook, SRD 69, Thermophysical Properties of Fluid Systems: R152a, saturation properties (temperature increments)0.0 psi
R-170pure:EthaneNIST Chemistry WebBook, SRD 69, Thermophysical Properties of Fluid Systems: Ethane, saturation properties (temperature increments)0.1 psi
R-245fapure:R245faNIST Chemistry WebBook, SRD 69, Thermophysical Properties of Fluid Systems: R245fa, saturation properties (temperature increments)0.0 psi
R-290pure:PropaneNIST Chemistry WebBook, SRD 69, Thermophysical Properties of Fluid Systems: Propane, saturation properties (temperature increments)0.0 psi
R-401Acustom:R22&R152A&R124:0.53,0.13,0.34Forane Refrigerants Pressure Temperature Chart (Arkema, 2020)1.4 psi
R-401Bcustom:R22&R152A&R124:0.61,0.11,0.28Forane Refrigerants Pressure Temperature Chart (Arkema, 2020)3.5 psi
R-404Amix:R404AChemours "R-22 Replacements" and "R-12 and R-502 Replacements" Pressure-Temperature Guide (C-10914, 3/19)0.0 psi
R-407Amix:R407AChemours "R-22 Replacements" and "R-12 and R-502 Replacements" Pressure-Temperature Guide (C-10914, 3/19)0.1 psi
R-407Cmix:R407CChemours "R-22 Replacements" and "R-12 and R-502 Replacements" Pressure-Temperature Guide (C-10914, 3/19)0.0 psi
R-407Fmix:R407FHoneywell PT Charts for A/C and Refrigeration, G525-710, August 2017 (Genetron Performax LT / R-407F columns)0.2 psi
R-407Hmix:R407HDaikin Chemical Europe GmbH, R407H Product information, saturation table (based on REFPROP 9.0); no document number or date printed0.0 psi
R-408Acustom:R125&R143a&R22:0.07,0.46,0.47Forane Refrigerants Pressure Temperature Chart (Arkema, 2020)1.9 psi
R-409Acustom:R22&R124&R142b:0.60,0.25,0.15Forane Refrigerants Pressure Temperature Chart (Arkema, 2020)0.8 psi
R-410Amix:R410AChemours "R-22 Replacements" and "R-12 and R-502 Replacements" Pressure-Temperature Guide (C-10914, 3/19)0.1 psi
R-416Acustom:R134a&R124&n-Butane:0.59,0.395,0.015Hudson Technologies R-416A Pressure Temperature Chart2.8 psi
R-417Amix:R417AThermodynamic Properties of Freon MO59 (R-417A), Eng Units, C-11111 (2/17)0.4 psi
R-421Amix:R421AChoice Refrigerants R-421A PT Chart (liquid / vapor phase pressure)0.0 psi
R-422Amix:R422ADuPont Technical Information: Thermodynamic Properties of ISCEON MO79 (R-422A), ENG Units, Table 1 Saturation Properties, K-15286 (1/06)1.6 psi
R-422Bmix:R422BChemours "R-22 Replacements" and "R-12 and R-502 Replacements" Pressure-Temperature Guide (C-10914, 3/19)0.7 psi
R-422Dmix:R422DChemours "R-22 Replacements" and "R-12 and R-502 Replacements" Pressure-Temperature Guide (C-10914, 3/19)1.0 psi
R-424Acustom:R125&R134a&IsoButane&n-Butane&Isopentane:0.505,0.47,0.009,0.01,0.006RS-44 (R424A) Pressure & Temperature Table: Absolute, Refrigerant Solutions Ltd (undated)0.6 psi
R-427Amix:R427AForane Refrigerants Pressure Temperature Chart (Arkema, 2020)0.4 psi
R-434Amix:R434ARS-45 (R434A) Pressure & Temperature Table: Absolute, Refrigerant Solutions Ltd (undated)7.8 psi
R-437Acustom:R125&R134a&n-Butane&n-Pentane:0.195,0.785,0.014,0.006Chemours "R-22 Replacements" and "R-12 and R-502 Replacements" Pressure-Temperature Guide (C-10914, 3/19)0.1 psi
R-438Acustom:R32&R125&R134a&n-Butane&Isopentane:0.085,0.45,0.442,0.017,0.006Chemours "R-22 Replacements" and "R-12 and R-502 Replacements" Pressure-Temperature Guide (C-10914, 3/19)0.7 psi
R-448Amix:R448AHoneywell PT Chart for Solstice N40 (R-448A), G525-711, August 20171.7 psi
R-449Amix:R449AChemours "R-22 Replacements" and "R-12 and R-502 Replacements" Pressure-Temperature Guide (C-10914, 3/19)0.4 psi
R-450Amix:R450ANational Refrigerants Refrigerant Reference Guide, 7th Edition 2020: R-450A1.0 psi
R-452Amix:R452AOpteon XP44 Pressure-Temperature Data (Eng), C-10305 (9/15)1.7 psi
R-452Bmix:R452BHoneywell Solstice L41y (R-452B) brochure, FPR-031-2018-01-EN (2018), "Pressure and temperature" table2.5 psi
R-453Acustom:R32&R125&R134a&R227EA&n-Butane&Isopentane:0.20,0.20,0.538,0.05,0.006,0.006RS-70 (R453A) Pressure & Temperature Table, Refrigerant Solutions Ltd (undated)0.9 psi
R-454Amix:R454AOpteon XL40 (R-454A) Pressure-Temperature Data (Eng), C-XL40PT-ENG (5/24)6.5 psi
R-454Bmix:R454BOpteon XL41 Pressure-Temperature Data (Eng), C-XL41PT-ENG (7/23)2.5 psi
R-454Cmix:R454CThermodynamic Properties of Opteon XL20 (R-454C), Engineering (I/P) Units, C-XL20THP-ENG (12/23)5.5 psi
R-455Amix:R455AHoneywell Solstice L40X (R-455A) Technical Data Sheet TCS-23-06-EN (06/23), PT table p.3 (same values in PT Chart TCS-24-10-EN 05/24)5.0 psi
R-458Acustom:R32&R125&R134a&R227EA&R236FA:0.205,0.04,0.614,0.135,0.006Bluon TdX 20 (R-458A) PT Chart / Refrigerant Properties - Imperial; no document number or date printed0.7 psi
R-500mix:R500National Refrigerants Refrigerant Reference Guide, 7th Edition 2020: R-5001.7 psi
R-502mix:R502National Refrigerants Refrigerant Reference Guide, 7th Edition 2020: R-5024.9 psi
R-507Amix:R507AChemours "R-22 Replacements" and "R-12 and R-502 Replacements" Pressure-Temperature Guide (C-10914, 3/19)0.0 psi
R-508Bmix:R508BNational Refrigerants Refrigerant Reference Guide, 7th Edition 2020: R-508B1.5 psi
R-513Amix:R513AChemours "R-22 Replacements" and "R-12 and R-502 Replacements" Pressure-Temperature Guide (C-10914, 3/19)0.2 psi
R-514Acustom:R1336mzz(Z)&R1130(E):0.747,0.253Opteon XP30 and Freon 123 Pressure-Temperature Data (Eng), C-10867 (6/16), Temperature-Pressure pages0.5 psi
R-515Bcustom:R1234ze(E)&R227EA:0.911,0.089Honeywell Solstice N15 (R-515B) P-T Chart (document 90350, US/metric)1.8 psi
R-600apure:IsoButaneNIST Chemistry WebBook, SRD 69, Thermophysical Properties of Fluid Systems: Isobutane, saturation properties (temperature increments)0.0 psi
R-717pure:AmmoniaNIST Chemistry WebBook, SRD 69, Thermophysical Properties of Fluid Systems: Ammonia, saturation properties (temperature increments)0.0 psi
R-744pure:CarbonDioxideNIST Chemistry WebBook, SRD 69, Thermophysical Properties of Fluid Systems: Carbon dioxide, saturation properties (temperature increments)0.1 psi
R-1233zd(E)pure:R1233zd(E)Honeywell "A Better Environment with Next-Generation Solstice zd" brochure (6846 Ref A4 EU v1, 05/2020), vapor pressure table0.1 psi
R-1234yfpure:R1234yfThermodynamic Properties of Opteon YF, Engineering (I/P) Units, C-10256 (5/23)0.0 psi
R-1234ze(E)pure:R1234ze(E)Honeywell Solstice ze (R-1234ze(E)) brochure BRO-22-40-EN (07/22), PT chart0.1 psi
R-1270pure:PropyleneNIST Chemistry WebBook, SRD 69, Thermophysical Properties of Fluid Systems: Propene, saturation properties (temperature increments)0.0 psi
R-1336mzz(Z)pure:R1336mzz(Z)McLinden and Akasaka, "Thermodynamic Properties of cis-1,1,1,4,4,4-Hexafluorobutene [R-1336mzz(Z)]: Vapor Pressure, (p, rho, T) Behavior, and Speed of Sound Measurements and Equation of State", J. Chem. Eng. Data 65 (2020), doi:10.1021/acs.jced.9b01198, Tables 2-3 (measured vapor pressures)0.1 psi

Other data

  • Safety classes follow ASHRAE Standard 34 as listed by ASHRAE and reproduced in the 2024 International Mechanical Code.
  • GWP values are 100-year values from the IPCC Fourth Assessment Report (AR4). These are the exchange values EPA uses under the AIM Act (40 CFR Part 84, Appendix A); blend values are mass-weighted sums of the components.
  • Target superheat comes from Table RA3.2-2 of the California Energy Commission's Title 24 Reference Appendices (CEC-400-2025-010-AP), transcribed in full and checked against the 2022 edition.
  • Regulatory statements cite the Federal Register, the eCFR and EPA pages directly, with the date each was checked.

Updates and corrections

The tables were generated on 2026-10-21 with CoolProp 8.0.0 (HEOS backend). They are regenerated when CoolProp publishes a release that changes a fluid or mixture model, and the checks are re-run each time. Any change of more than 0.1 psi to a published value will be listed here with its date.

No corrections have been made since the tables were first published. To report a problem, contact the editors.