# R-32 PT Chart (Pressure-Temperature)

An R-32 PT chart lists the saturation pressure of R-32 (difluoromethane) at each temperature. R-32 is a single-component refrigerant, so liquid and vapor saturate at the same pressure and the chart needs only one column. At 40°F, R-32 is about 121.0 psig; at 100°F, about 325.7 psig.

## Key takeaways

- R-32 is a pure fluid: no glide, no bubble and dew columns, and a leak doesn't change the composition of what's left.
- It runs slightly above R-410A: 2.6 psi higher at 40°F and 7.2 psi higher at 100°F.
- EPA SNAP lists R-32 as acceptable with use conditions for new residential and light commercial AC and heat pumps, GWP 675.
- ASHRAE safety class A2L: lower toxicity, lower flammability. Use A2L-rated tools and follow the installation instructions.
- It's the main ingredient in both R-410A (50% by mass) and R-454B (68.9%).

## Why does an R-32 chart have only one pressure column?

Because R-32 is one molecule, not a mixture. A pure refrigerant boils and condenses at the same temperature for a given pressure, so the bubble point and the dew point are identical. There's no glide to account for, and you use the same number whether you're working out superheat on the suction line or subcooling on the liquid line.

That also makes the field side simpler than a blend. A slow leak can't fractionate R-32, so after the leak is repaired the remaining charge is still R-32. Follow the manufacturer's charging and recovery instructions all the same, since A2L handling rules apply.

> **Worked example (illustrative readings)**
>
> Superheat: suction 120 psig converts to 39.6°F. With a 49°F suction line, superheat is 49 − 39.6 = **9.4°F**.
>
> Subcooling: liquid 350 psig converts to 105.1°F. With a 96°F liquid line, subcooling is 105.1 − 96 = **9.1°F**.
>
> Wrong chart: read the same 120 psig on an R-410A chart and you'd get 40.7°F. That's about a degree off, small enough to miss and big enough to skew a tight charge. Run your own readings in the [superheat calculator](https://www.brix.so/tools/superheat-calculator).

## R-32 vs. R-410A and R-454B pressures

**Saturation pressure, psig (this site's CoolProp tables; dew column for the blends)**

| Saturation temp | R-32 | R-410A | R-454B | R-32 minus R-410A |
| --- | --- | --- | --- | --- |
| 0°F | 49.3 | 48.2 | 42.9 | +1.1 |
| 20°F | 80.0 | 78.4 | 70.6 | +1.6 |
| 40°F | 121.0 | 118.4 | 107.5 | +2.6 |
| 70°F | 205.8 | 201.1 | 183.9 | +4.7 |
| 100°F | 325.7 | 317.6 | 291.9 | +8.1 |
| 120°F | 429.3 | 418.3 | 385.5 | +11.0 |

_R-32 and R-410A are close enough that the wrong chart gives a plausible-looking answer. R-454B runs noticeably lower. Check the nameplate before you look anything up._

## Is R-32 flammable? What A2L means

Yes, mildly. R-32 carries the ASHRAE safety class A2L: A for lower toxicity, 2L for lower flammability. [ASHRAE Standard 34](https://www.ashrae.org/File%20Library/Technical%20Resources/Standards%20and%20Guidelines/Standards%20Addenda/34_2007_ak_FINAL.pdf) defines 2L as a maximum burning velocity of 10 cm/s or less, tested at 23°C and 101.3 kPa. It's harder to ignite and burns more slowly than a class 2 or 3 refrigerant, but it isn't nonflammable like R-22 or R-410A (both A1).

- **EPA status:** [EPA SNAP](https://www.epa.gov/snap/substitutes-residential-and-light-commercial-air-conditioning-and-heat-pumps) lists R-32 as acceptable with use conditions for new residential and light commercial AC and heat pumps, with a GWP of 675 and an ozone depletion potential of 0. The listings are in Federal Register rules dated April 10, 2015, May 6, 2021 and April 28, 2023.
- **New equipment only:** use R-32 in equipment designed and listed for it. Don't convert an R-410A or R-22 system to R-32, and never mix refrigerants.
- **Tools:** recovery machines, cylinders, vacuum pumps and leak detectors should be rated for A2L refrigerants. Keep ignition sources out of the work area and ventilate before brazing.
- **Install rules** such as charge limits, leak detection and mitigation come from the equipment's installation instructions and your adopted codes.

> **Verify against the manufacturer's installation instructions**
>
> This chart gives saturation pressures only. The unit's installation instructions and charging chart set the target superheat or subcooling and the charge, and they take precedence over any generic table.

## Where these numbers come from

We compute the table with [CoolProp](https://coolprop.org) 8.0.0 using its reference equation of state for pure R-32, converted to gauge pressure relative to 14.696 psia. Our tests compare 20 temperatures against the [Daikin A1 vs. A2L chart](https://www.chadwellsupply.com/globalassets/articles-pk/a2l/a2lptc-usa_04-24.pdf) and 10 against the [Arkema Forane wall chart](https://forane.arkema.com/files/live/sites/fluorogases_forane_arkema/files/downloads/literature/general-forane-literature/forane-wall-chart-americas.pdf) (NIST REFPROP 9.0); every point is within 0.1 psi. At 0°F we compute 49.3 psig; Daikin prints 49.2 and Arkema 49.3.

### Related

- [All refrigerant PT charts](https://www.brix.so/reference/refrigerant-pt-chart): Compare R-32 with R-410A, R-454B and R-22.
- [R-454B PT chart](https://www.brix.so/reference/refrigerant-pt-chart/r-454b): The other common A2L, a blend with glide.
- [Refrigerant PT calculator](https://www.brix.so/tools/refrigerant-pt-calculator): Convert pressure and temperature for R-32.
- [Superheat and subcooling lesson](https://www.brix.so/academy/hvac/refrigeration/superheat-subcooling): Read a charge from gauge pressures.

## Frequently asked questions

### What is the pressure of R-32 at 40°F?

About 121.0 psig at sea level. Because R-32 is a pure refrigerant, that's both the liquid and the vapor saturation pressure. A running system's suction pressure depends on load and airflow, so check the charge with superheat or subcooling against the manufacturer's chart.

### Does R-32 have temperature glide?

No. R-32 is a single-component refrigerant, so it boils and condenses at one temperature for each pressure. That's why its PT chart has one pressure column, unlike R-454B or R-410A.

### Is R-32 higher pressure than R-410A?

Slightly. At 40°F R-32 is 121.0 psig against 118.4 for R-410A, and at 100°F it's 325.7 against 318.5. Use the R-32 chart and gauges rated for R-32 rather than reading an R-410A chart.

### What is the GWP of R-32?

EPA's SNAP listing for residential and light commercial AC and heat pumps gives R-32 a GWP of 675, under the 700 limit for new systems, and an ozone depletion potential of 0.

### Can R-32 replace R-410A in an existing system?

No. R-32 is an A2L refrigerant approved for new equipment designed for it. Converting an R-410A system isn't an approved retrofit, and mixing refrigerants is never acceptable. Use the refrigerant on the nameplate.

### Is R-32 the same as R-454B?

No. R-454B is a blend that's 68.9% R-32 by mass, with R-1234yf making up the rest. It runs lower pressures than R-32 and has about 2.5–2.7°F of glide, so the two charts aren't interchangeable.

## Related

- [Refrigerant PT Charts (Pressure-Temperature)](https://www.brix.so/reference/refrigerant-pt-chart)
- [R-454B PT Chart (Pressure-Temperature)](https://www.brix.so/reference/refrigerant-pt-chart/r-454b)
- [R-410A PT Chart (Pressure-Temperature)](https://www.brix.so/reference/refrigerant-pt-chart/r-410a)
- [R-22 PT Chart (Pressure-Temperature)](https://www.brix.so/reference/refrigerant-pt-chart/r-22)
- [Refrigerant PT Calculator (Pressure ↔ Temperature)](https://www.brix.so/tools/refrigerant-pt-calculator)
- [Superheat Calculator](https://www.brix.so/tools/superheat-calculator)
- [Subcooling Calculator](https://www.brix.so/tools/subcooling-calculator)
- [Superheat and Subcooling, Explained with Worked Examples](https://www.brix.so/academy/hvac/refrigeration/superheat-subcooling)
- [Free EPA 608 Core Practice Test](https://www.brix.so/practice/epa-608/core)
- [HVAC Software That Answers the Phone, Books the Tech and Keeps the Books](https://www.brix.so/for/hvac)

## Sources

- [CoolProp 8.0.0: thermophysical property library (HEOS backend), used to compute this table](https://coolprop.org/coolprop/HighLevelAPI.html) (checked 2026-10-24)
- [Daikin Comfort Technologies: A1 vs. A2L Pressure Temperature Chart, USA (PM-A2LPTC-USA_04-24)](https://www.chadwellsupply.com/globalassets/articles-pk/a2l/a2lptc-usa_04-24.pdf) (checked 2026-10-24)
- [Arkema Forane: refrigerant pressure-temperature wall chart, Americas (2019, NIST REFPROP 9.0)](https://forane.arkema.com/files/live/sites/fluorogases_forane_arkema/files/downloads/literature/general-forane-literature/forane-wall-chart-americas.pdf) (checked 2026-10-24)
- [U.S. EPA SNAP: Substitutes in residential and light commercial AC and heat pumps (R-32: acceptable with use conditions, GWP 675)](https://www.epa.gov/snap/substitutes-residential-and-light-commercial-air-conditioning-and-heat-pumps) (checked 2026-10-24)
- [ANSI/ASHRAE Addendum ak to Standard 34-2007: A2L / 2L burning velocity ≤ 10 cm/s](https://www.ashrae.org/File%20Library/Technical%20Resources/Standards%20and%20Guidelines/Standards%20Addenda/34_2007_ak_FINAL.pdf) (checked 2026-10-24)

Last verified against [CoolProp 8.0.0 (computed 2026-10-24), cross-checked against the Daikin A1 vs. A2L PT chart (04-24) and the Arkema Forane wall chart (2019)](https://www.chadwellsupply.com/globalassets/articles-pk/a2l/a2lptc-usa_04-24.pdf) on 2026-10-24.

Talk to BRIX: call or text (518) 588-1122, email eeharris2004@gmail.com, or book a 15-minute call at https://cal.com/ethanharris/15min.

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Written by BRIX Editorial Team. Last updated 2026-10-24.
Canonical: https://www.brix.so/reference/refrigerant-pt-chart/r-32