R-404A (HFC, commercial refrigeration)

R-404A PT Chart

The full R-404A pressure-temperature reference table, from -20 to 130°F. R-404A is a near-azeotropic blend read on a single saturation column, the format used on manufacturer charts. Checked cell by cell against one other published table, a separate publisher: Arkema. It has a full column on file here, so this chart prints where that table and ours disagree at every pressure instead of quietly picking one. The widest gap anywhere on it is 0.67 degrees F, at 48.2 psig. Print it or save it as a PDF for the truck.

Open the calculator
Quick answer: R-404A saturates at 40°F at about 84 psig and 100°F at about 234 psig (about 353 psig at 130°F). It is a near-azeotropic blend with a very small glide, so one saturation column serves both superheat and subcooling.

Read the R-404A chart at your gauge pressure

The chart below is the reference. This reads it at the pressure you actually have, including between the published rows, and works out superheat or subcooling once you add the line temperature.

the big insulated line, for superheat

Saturation temperature one saturation column40.0°F

At 84.4 psig, this is a published row of the table below, not an interpolated value.

Add the suction line temperature to get superheat from this reading.

R-404A Pressure-Temperature Table

R-404A saturation temperature at gauge pressure (psig). Single column (near-azeotropic).
R-404A
Pressure (psig)Sat. Temp (°F)Publisher spread (°F)
15.7-20°F0.43
19.3-15°F0.50
23.2-10°F0.50
27.5-5°F0.44
32.10°F0.50
375°F0.64
42.410°F0.64
48.215°F0.67
54.520°F0.62
61.225°F0.64
68.430°F0.60
76.135°F0.63
84.440°F0.59
93.245°F0.56
10350°F0.32
11355°F0.30
12360°F0.57
13565°F0.22
14770°F0.17
15975°F0.42
17380°F0.15
18785°F0.18
20290°F0.13
21895°F0.03
234100°F0.18
252105°F0.03
270110°F0.11
289115°F0.15
310120°F0.02
331125°F0.05
353130°F0.11

About the spread column. It is the widest gap in saturation temperature between the published tables we hold, at that pressure, on the saturation column. Across this chart the widest is 0.67°F, at 48.2 psig. Our table and 1 other published table are compared here: 1 is a separate publisher. A narrow spread means the charts agree, which is not the same as the charts being right: they are all computed from equations of state fitted to lab data, and no field measurement settles it.

Where this table comes from. Hudson Technologies R-404A vapor chart.
  • Checked against Arkema Forane R-404A, 29 of 31 shipped cells within 1.0 psig on its vapor column, widest gap 1.2 psig at 60F; its liquid column runs 1.1 to 3.0 psig higher, which is the bubble-versus-dew glide; re-derived in DEGREES against the vapor column, the column our base tracks, it differs by at most 0.67 F at every one of the 31 pressures we ship [separate publisher]

A separate publisher can catch a transcription, edition or rounding error. A cross-check marked same model resolves to the same equation of state as the base table, so it is a consistency check rather than independent confirmation. One marked same printing prints numbers identical to another table listed here, so the two are one witness and we do not count them twice. Sources last re-verified 2026-08-25.

Read the low-side (suction) pressure and find its saturation temperature for superheat, and read the high-side (liquid) pressure and its saturation temperature for subcooling. The chart is in psig (gauge) and °F. To convert: kPa gauge = psig × 6.895; °C = (°F − 32) / 1.8.

These are the same locked R-404A data the Intry calculator interpolates. The published tables they were checked against, and how closely each agrees, are named in the citation that prints with the chart above. Free reference from intrysys.com, updated August 25, 2026.


R-404A PT Chart FAQs

What is the R-404A pressure at 40F and 100F?

On the R-404A PT chart, 40F saturation is about 84 psig and 100F is about 234 psig. Read the low-side (suction) pressure and its saturation temperature for superheat, and the high-side (liquid) pressure and its saturation temperature for subcooling. R-404A is used mostly in low-temperature and commercial refrigeration (reach-in freezers, walk-ins, ice machines), where the evaporator normally runs well below the comfort-cooling range.

Does the R-404A PT chart have glide (bubble and dew)?

R-404A is a near-azeotropic HFC blend with a very small temperature glide, so field pressure-temperature charts, including this one, list a single saturation column rather than separate bubble and dew points. That is standard practice for R-404A. The larger-glide zeotropic blends that need two columns are R-407C, R-448A, and R-449A.

Is R-404A being phased out?

R-404A has a high global warming potential, so under the AIM Act its production and import are being stepped down and new equipment is moving to lower-GWP alternatives such as R-448A, R-449A, R-454C, and CO2. The large installed base of R-404A reach-in coolers, walk-ins, ice machines, and transport units still needs service, so the PT chart stays in daily use.

What units is this R-404A PT chart in, and how do I convert to kPa or Celsius?

The table is in psig (gauge pressure) and degrees Fahrenheit, the field-standard units in North America. To convert pressure to kPa (gauge), multiply psig by 6.895. To convert temperature to Celsius, use C = (F - 32) / 1.8. For example, 100F is about 37.8C.


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Intry Verified. The R-404A pressure-temperature table and its saturation anchors on this page are the locked, second-sourced R-404A PT data, and every build re-checks the page against those locked values. Those figures are computed by a locked engine straight from the source it cites, not hand-typed, and that computation re-runs inside a deterministic test on every deploy. Source-checked. Locked. This is our own deterministic gate, not a third-party audit. What Intry Verified means