Refrigerant Designation Decoder
Type a common R-number and read the ASHRAE designation pattern, then review local property rows, GWP-basis caveats, safety-class notes, and source boundaries.
Refrigerant numbers are not arbitrary labels. For a single compound the digits count the carbon, hydrogen, and fluorine atoms in the molecule, which is how R-22 reads as one chlorine, one hydrogen, two fluorines (an HCFC) and R-32 reads as an HFC. For blends, a 400-series number is zeotropic and a 500-series number is azeotropic, with a trailing letter that distinguishes composition rows. The 700 series uses the molar mass cue, so 744 is CO2. This decoder reads those rules and, for common refrigerants, adds local source-gap rows for safety class, ODP, GWP, glide, and transition context. Verify those rows against current ASHRAE 34, SDS/product data, EPA SNAP/Section 608, program GWP basis, and equipment documentation before regulated or safety use.
Once you know the refrigerant, look up saturation pressure-temperature on the
Refrigerant P-T Chart →Check the charge with superheat and subcooling using the
Superheat / Subcooling Calculator →Estimate additional line-set charge with the
Refrigerant Charge Worksheet →Estimate the CO2-equivalent of a leak from the selected GWP basis with the
Refrigerant Leak CO2 Equivalent Calculator →How It Works
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Enter the R-number
Type the designation from the nameplate or cylinder (R-410A, R-32, R-1234yf). Shorthand like CO2 works too.
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Read the number breakdown
The decoder shows how the digits resolve under the ASHRAE 34 rules: the atom counts for a compound, or the blend series and composition letter for a blend.
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Check the local property rows
For common refrigerants you get source-gap display rows for family, composition, safety class, ODP, GWP, and glide. These are prompts, not current standard-table certification.
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Read the source warnings
Notes cover zeotrope fractionation, A2L/A3 flammability, CO2 pressure, high-GWP phase-down context, and where SDS, EPA, code, AHJ, and manufacturer review control.
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Verify before a regulated decision
Confirm GWP basis, safety class, blend composition, SNAP/end-use status, Section 608 duties, and equipment compatibility against current sources before safety or compliance use.
Built For
- An HVAC tech who finds an unfamiliar R-number on a nameplate and needs the safety class and pressure behavior before connecting gauges.
- A contractor reviewing an R-22 nameplate before pulling current retrofit, SDS, SNAP, and manufacturer documents.
- A facility manager flagging which GWP basis must be checked before CO2e or reporting work.
- An apprentice learning why R-454B is mildly flammable but R-410A is not.
- Anyone confused by why R-410A and R-32 have such different numbers despite both being used in AC.
Features & Capabilities
Parses common R-number patterns
The designation rules resolve atom-count or blend-series prompts even when detailed property rows are not in the local dataset.
Safety class broken out
The class is split into toxicity (A/B) and flammability (1/2L/2/3) with plain-English meaning.
Visible source boundaries
GWP, ODP, and composition rows are labeled as local source-gap values so cross-tool consistency does not look like regulatory approval.
Transition and phasedown context
For common refrigerants the tool shows local transition notes and HFC phasedown prompts without approving a substitute, retrofit, or purchase decision.
Comparison
| R-number | Family | Safety class | GWP | Glide | Note |
|---|---|---|---|---|---|
| R-22 | HCFC | A1 | 1810 | None | Legacy; production phased out 2020 |
| R-410A | HFC blend | A1 | 2088 | Negligible | Residential AC; being phased down |
| R-32 | HFC | A2L | 675 | None | Low-GWP A2L, mildly flammable |
| R-454B | HFO/HFC blend | A2L | 466 | ~1 F | R-410A replacement, A2L |
| R-1234yf | HFO | A2L | 1 | None | Automotive R-134a replacement |
| R-744 | Inorganic (CO2) | A1 | 1 | None | Natural; very high pressure |
References
- ANSI/ASHRAE Standard 34, Designation and Safety Classification of Refrigerants
- ISO 817, Refrigerants, Designation and Safety Classification
- US EPA Significant New Alternatives Policy (SNAP) substitute refrigerant lists
- IPCC Fifth Assessment Report (AR5) 100-year GWP values
- ToolGrit shared refrigerant dataset (consistent with the P-T chart and charge/leak tools)