CalcSpec

Refrigerant Pressure–Temperature (PT) Charts

Saturation pressure-temperature for the seven refrigerants you actually see on a job — from −40 °F to +140 °F. Pull it up on your phone, check your superheat, move on.

Refrigerants
7
Temp range
−40 to +140°F
Step size
10°F
Source
NISTREFPROP
Field use Superheat = suction-line temp − saturation temp at suction pressure. Subcooling = saturation temp at discharge pressure − liquid-line temp. For zeotropic blends (R-407C, R-404A, R-454B) use bubble-point for subcool, dew-point for superheat. Bubble-point shown (R-454B lists bubble + dew).

R-410A — A1, residential / light commercial AC

Pentafluoroethane / difluoromethane (50/50). Near-azeotropic, glide ~0.2 °F. Phasing down under the AIM Act; R-454B is the OEM replacement.

Temp (°F)Pressure (psig)
−4010.8
−3017.8
−2026.3
−1036.5
048.4
1062.4
2078.7
3097.4
40118.8
50143.1
60170.7
70201.7
80236.5
90275.3
100318.5
110366.5
120419.5
130478.0
140542.6

R-22 — A1, legacy service only

Chlorodifluoromethane (HCFC-22). Production phased out Jan 2020 under the Montreal Protocol. Service / reclaimed stock only.

Temp (°F)Pressure (psig)
−400.6
−304.9
−2010.2
−1016.5
024.0
1032.8
2043.1
3055.0
4068.6
5084.1
60101.6
70121.4
80143.6
90168.4
100195.9
110226.4
120260.0
130296.9
140337.4

R-134a — A1, auto AC & chillers

1,1,1,2-Tetrafluoroethane. Normal boiling point −15.3 °F — below that, gauge pressure is subatmospheric (marked "vac" in the table).

Temp (°F)Pressure (psig)
−40−7.3 vac
−30−5.4 vac
−20−2.9 vac
−101.9
06.5
1011.9
2018.4
3026.1
4035.0
5045.4
6057.4
7071.1
8086.7
90104.3
100124.2
110146.4
120171.2
130198.7
140229.2

R-404A — A1, low-temp commercial refrigeration

R-125 / R-143a / R-134a (44/52/4). Near-azeotropic, glide ~0.9 °F. Bubble-point shown. Being phased down under AIM Act.

Temp (°F)Pressure (psig)
−404.9
−3010.3
−2016.8
−1024.6
033.7
1044.3
2056.6
3070.7
4086.9
50105.3
60126.0
70149.3
80175.4
90204.5
100236.8
110272.6
120312.1
130355.7
140403.7

R-32 — A2L, AC & heat pumps

Difluoromethane. Dominant R-410A replacement in Asia/EU, growing share in North America. Mildly flammable (A2L).

Temp (°F)Pressure (psig)
−4011.0
−3018.2
−2026.8
−1037.1
049.3
1063.5
2080.0
3099.1
40121.0
50145.8
60174.0
70205.8
80241.5
90281.3
100325.7
110374.9
120429.3
130489.5
140555.8

R-407C — A1, R-22 retrofit

R-32 / R-125 / R-134a (23/25/52). Zeotropic, large glide ~9–10 °F. Bubble-point shown; dew-point runs 6–10 psig lower at the same temperature.

Temp (°F)Pressure (psig, bubble)
−402.7
−307.7
−2013.7
−1020.9
029.5
1039.5
2051.2
3064.7
4080.2
5097.9
60117.9
70140.5
80165.8
90194.1
100225.5
110260.2
120298.6
130340.7
140387.0

R-454B — A2L, R-410A replacement (2025+)

R-32 / R-1234yf (68.9/31.1). Low-GWP (~466). Glide ~2 °F (use dew for superheat, bubble for subcool). Runs ~15–26 psig below R-410A at AC conditions — a system redesign, not a field drop-in.

Temp (°F)Pressure (psig, bubble)Pressure (psig, dew)
−409.88.5
−3016.614.9
−2024.722.7
−1034.532.0
045.942.9
1059.355.7
2074.870.6
3092.787.8
40113.2107.5
50136.4129.9
60162.7155.3
70192.3183.9
80225.4216.0
90262.3251.9
100303.3291.9
110348.6336.3
120398.6385.5
130453.6440.0
140514.1500.2
Warn R-454B values come from Chemours and Honeywell manufacturer data (REFPROP 10 mixture models), not the NIST Webbook standalone database — treat as ±1 psig accuracy until the blend gets its own NIST entry.

Sources

NIST Webbook fluid properties NIST REFPROP 10 Chemours Opteon XL41 (R-454B) Honeywell Solstice 454B

FAQ

What is the saturation pressure of R-410A at 40 °F for setting suction pressure?

Per the CalcSpec PT chart (NIST REFPROP data), R-410A saturates at 118.8 psig at 40 °F. R-410A is a near-azeotropic A1 blend (R-125/R-32, 50/50) with roughly 0.2 °F glide, so bubble and dew are effectively the same point.

For R-454B, do I use the bubble or dew pressure to calculate superheat, and what's the value at 40 °F?

Use the dew-point column for superheat and the bubble-point for subcooling. Per the CalcSpec R-454B PT chart, at 40 °F bubble is 113.2 psig and dew is 107.5 psig. R-454B (R-32/R-1234yf, 68.9/31.1) has about 2 °F glide.

How much lower does R-454B run than R-410A, and can I drop it into an R-410A system?

R-454B runs roughly 15 to 26 psig below R-410A at AC conditions per CalcSpec. At 80 °F, R-410A is 236.5 psig versus R-454B bubble 225.4 psig. It is a system redesign, not a field drop-in, and is the OEM R-410A replacement under the AIM Act.

Where do the refrigerant PT values come from and how accurate is R-454B?

CalcSpec sources values from NIST REFPROP 10 and the NIST Webbook, rounded to 0.1 psig, covering −40 °F to +140 °F in 10 °F steps. R-454B uses Chemours and Honeywell manufacturer REFPROP 10 mixture models; treat as ±1 psig until the blend gets its own NIST entry.

No LTE on the roof, none in the crawlspace

The web page won't load where you charge the unit

HVAC Toolkit keeps R-410A/R-454B PT curves on the phone, logs each check, and exports the run for the ticket. No signal, no login. Pay once.

Related

Values rounded to 0.1 psig for field use. Cross-reference against the printed PT chart on your refrigerant cylinder and follow EPA 608 procedures. Reference only — not engineering advice for equipment design or service signoff.