Superheat Calculator

R-22 (Legacy HCFC)

R-22 PT Chart

The full R-22 pressure-temperature reference table, from -40 to 120°F. R-22 is a pure single-component refrigerant, so the chart is one saturation column with zero glide. Checked cell by cell against one other published table, a separate publisher: iGas/Arkema, printing NIST REFPROP 9.0. 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 1.00 degrees F, at 1 psig. This table is stored in whole psig, the resolution its two sources agree to. Near -40°F the curve is flat enough that one psig is worth about 2.5°F of saturation temperature, so read the cold end as a guide and take the reading itself off your gauge.

Field brief
40°F / 100°FR-22 saturates at about 69 psig at 40°F and 196 psig at 100°F (84 psig at 50°F, 260 psig at 120°F).69/196 psig
GlideZero. One saturation column serves both superheat and subcooling; there is no separate bubble and dew point.single column
SupplyReclaimed only since the January 1, 2020 production phase-out; weigh repair against replacing with an A2L system.reclaimed

Read the R-22 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 69.0 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-22 Pressure-Temperature Table

R-22 saturation temperature at gauge pressure (psig). Single column, zero glide.
R-22
Pressure (psig)Sat. Temp (°F)Publisher spread (°F)
1-40°F1.00
3-35°F0.87
5-30°F0.20
7-25°F0.80
10-20°F0.36
13-15°F0.33
17-10°F0.69
20-5°F0.14
240°F0
285°F0.35
3310°F0.20
3815°F0.19
4320°F0.09
4925°F0.16
5530°F0
6235°F0.35
6940°F0.27
7645°F0.07
8450°F0.06
9355°F0.22
10260°F0.21
11165°F0.15
12170°F0.20
13275°F0.09
14480°F0.17
15685°F0.12
16890°F0.16
18295°F0.07
196100°F0.03
211105°F0.06
226110°F0.13
243115°F0.06
260120°F0

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 1.00°F, at 1 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-22 PT chart.
  • Checked against NIST REFPROP 9.0, as printed by iGas and Arkema, agrees to the whole psig at all 33 shipped points, raw spread at most 0.4 psig [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.

R-22 PT Chart FAQs

What is the R-22 pressure at 40F and 100F?

On the R-22 PT chart, 40F saturation is about 69 psig and 100F is about 196 psig; 50F is about 84 psig and 120F is about 260 psig. R-22 is a single-component refrigerant with zero glide, so the same saturation temperature serves both superheat (suction) and subcooling (liquid); there is no bubble and dew split.

Is R-22 still available, and can I still buy it?

R-22 production and import ended January 1, 2020 under the EPA Clean Air Act, so only reclaimed R-22 is available and its price is high. Existing R-22 systems can still be serviced with reclaimed refrigerant, but for a failed compressor or a major leak the economics usually favor replacement with an A2L system on R-454B or R-32.

What refrigerant replaces R-22?

For new equipment, R-454B (ducted) and R-32 (mini splits) are the A2L successors. For servicing an existing R-22 system without replacing it, common retrofit blends include R-407C, R-421A, and R-422B, but a retrofit changes the oil and the target pressures, so always follow the blend manufacturer's retrofit guide rather than reading the system on the R-22 column afterward.

What units is this R-22 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.

Related R-22 Tools

R-22 Superheat & Subcooling Calculator

Enter your readings; the calculator interpolates this PT chart and returns the verdict.

R-407C PT Chart

The common R-22 retrofit blend, read on bubble and dew columns for its glide.

Line Set Calculator

Size the line set and get the reuse, flush, or replace verdict when converting an old system.

Keep going

Don’t stop at the number.

The calculatorRun your own numbersThe number above is the general case. Open the R-22 Superheat Calculator and put your own figures in.Your AIAsk it in plain EnglishConnect Intry to your AI once (ChatGPT, Claude, Cursor), then just ask. It runs the numbers and hands back the verdict and the source.The appKeep the whole jobSave your readings into one job in the free app, ready for the next step.