PT Charts & Reference Tools

The verified refrigerant dataset is the foundation under every page on this site. Each of the 60 refrigerants is represented by a single JSON record containing: ASHRAE 34 safety classification, refrigerant type, composition (mass fractions for blends), physical properties (boiling point, critical point, glide), environmental data (GWP on the US EPA basis plus IPCC AR4/AR5/AR6, ODP, atmospheric lifetime), lubricant compatibility, applications, replacement options, regulatory status, and a 191-row PT chart (−40°F to 150°F in 1°F increments).

The PT chart is generated from CoolProp, a REFPROP-compatible Helmholtz EOS implementation: 51 fluids on CoolProp 7.2.0 (Bell, Wronski, Quoilin, Lemort 2014, doi:10.1021/ie4033999) and 5 newer low-GWP fluids (R-450A, R-515A/B, R-1224yd(Z), R-1336mzz(Z)) on CoolProp 8.0.0. For the 3 fluids CoolProp does not model — R-438A, R-448A and R-514A — PT values come directly from the named manufacturer datasheets (Chemours ISCEON MO99, Honeywell Solstice N40).

Every value is checked against reference values before each update. Safety class is stored as a fixed value — it's structurally impossible to render the wrong class for a refrigerant. PT values below the critical pressure are guaranteed to be non-negative; values above the critical temperature truncate rather than extrapolate.

Three-layer verification:

(1) Source-level: CoolProp values are REFPROP-compatible (NIST Standard Reference Database 23, the canonical thermodynamic property database for refrigerants). Manufacturer-blend values are transcribed from named manufacturer datasheets with the publication date and URL recorded per refrigerant.

(2) Structure-level: every refrigerant record is validated before each update. PT values must be numbers (not text or blank). Safety class must be one of the ASHRAE 34 classes (A1, A2L, A2, A3, B1, B2L, B2, B3). GWP must be a non-negative number or blank (blank indicates no published value). Type must match a known refrigerant family.

(3) Cross-check: manufacturer-blend PT tables are checked against the published datasheet they were transcribed from; several CoolProp fluids are additionally cross-checked against the NIST WebBook and the ASHRAE Handbook—Refrigeration (each refrigerant record lists what its chart was verified against). Critical-point values cross-checked against NIST REFPROP 10.0. GWP headline values on the US EPA basis (40 CFR 84 / IPCC AR4), with IPCC AR4/AR5/AR6 shown alongside.

The previous WordPress version of this site shipped with approximately 25,000 fabricated quantitative errors. The current rebuild was structured to make those failure modes impossible: data comes from primary sources, validation runs at every build, and any value outside the chart range returns "out of range" rather than an extrapolated number.

Each refrigerant detail page provides download links for the underlying PT data in CSV and JSON formats, plus the full refrigerant record in JSON. Our CoolProp-computed downloads are licensed CC BY 4.0 — free to use, redistribute, or build upon with attribution to hvacptcharts.com; the manufacturer-published tables (R-438A, R-448A, R-514A) keep their publisher's terms, so attribute the underlying source (CoolProp / manufacturer datasheet) for the specific values.

Common use cases for the downloads: integrating refrigerant data into custom HVAC software, building training materials, populating equipment-OEM-specific charging tables, academic research on refrigerant transitions, and verifying calculations against the verified dataset.

Every PT chart page has CSV and JSON downloads at /data/refrigerant/<slug>/json and /csv (computed tables CC BY 4.0; manufacturer-published tables under their publisher's terms).

The 60 refrigerants in this dataset span several chemical families with characteristic property and regulatory profiles:

HCFCs (R-22, R-123) — ozone-depleting, phased out under Montreal Protocol. R-22 production stopped in developed countries 2020; service from reclaimed stock. R-123 production ends 2030.

HFCs (R-410A, R-134a, R-404A, R-32, R-407C, R-507A, etc.) — zero-ODP but high-GWP. Subject to AIM Act phase-down (40 CFR Part 84) in US and EU F-Gas Regulation. R-32 (GWP 675) is the lower-GWP HFC; R-404A (GWP 3,922) is among the highest.

HFC/HFO blends (R-454B, R-454C, R-455A, R-448A, R-449A, R-513A) — designed to achieve sub-700 or sub-150 GWP via HFO content. The AIM Act-compliant replacement family for HFCs.

HFOs (R-1234yf, R-1234ze, R-1233zd, R-1336mzz) — synthetic refrigerants with very low GWP (1-9) via short atmospheric lifetime. Used in mobile AC, chillers, and high-temperature process refrigeration.

Natural refrigerants (R-744 CO2, R-717 ammonia, R-290 propane, R-600a isobutane, R-1270 propylene) — zero or near-zero GWP. Used in commercial refrigeration (R-744), industrial refrigeration (R-717), small appliances (R-290, R-600a). Safety classes range from A1 (R-744) to A3 (hydrocarbons) to B2L (ammonia) — each with distinct equipment and handling requirements.

Use the homepage A-Z list and filters to browse the full set, or jump to the most popular refrigerants from the sections above.

ASHRAE Standard 34 assigns refrigerant numbers using a chemical-composition encoding that lets you decode a refrigerant's structure from its number alone.

For pure refrigerants in the methane / ethane / propane series, the R-number indicates: hundreds digit = (carbon atoms − 1), tens digit = (hydrogen atoms + 1), units digit = fluorine atoms; the remaining halogens fill out the molecular structure. R-22 (CHClF₂) = 0 carbons − 1 = 0 hundreds (skipped), 1 hydrogen + 1 = 2 tens, 2 fluorines = 2 units → 22. R-134a (CH₂FCF₃) is a 1-carbon ethane derivative: 1 carbon, the digit before the suffix tells you which isomer.

For zeotropic blends (400-series), the number is assigned sequentially as ASHRAE certifies new blends; the lowercase suffix (a, b, c) distinguishes different mass-fraction recipes of the same components. R-407A, R-407B, R-407C are all blends of R-32 + R-125 + R-134a in different ratios.

For azeotropic blends (500-series), same convention. R-507A is R-125 + R-143a in a near-azeotropic ratio.

For hydrocarbons (600-series), R-600 is butane (n-C₄H₁₀), R-600a is isobutane, R-601 is pentane. For inorganics (700-series), the number after 7 is the molecular weight: R-717 is ammonia (MW 17), R-744 is CO₂ (MW 44), R-718 is water (MW 18). For unsaturated compounds with double bonds (1000+ series — HFOs), the four-digit number encodes a more elaborate structure.

This isn't trivia — knowing how to decode an ASHRAE number tells you the refrigerant's rough chemistry without looking it up, which speeds field-service work when encountering an unfamiliar refrigerant.