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R-407C PT Chart

A1 GWP 1774

Zeotropic blend (R-32/R-125/R-134a). HFC Blend.

Boiling Point
-46.5°F
-43.6°C
Critical Temp
187.2°F
86.2°C
Critical Pressure
671.8 psia
46.32 bar

About R-407C

R-407C was designed to match R-22's capacity in air conditioning and became the most common R-22 retrofit for split systems. It is a three-part blend of R-32, R-125 and R-134a with about 10°F of glide. That means the vapor (dew) and liquid (bubble) pressures below differ a lot, and using the wrong column is the most common charging mistake with this refrigerant.

Saturation pressures at typical operating points, taken from the table below:

The table covers -80°F to 180°F in 5°F steps. Below about -47°F the liquid saturation pressure is below atmospheric, so gauges read in vacuum (shown in blue in the table).

R-407C Pressure-Temperature Graph (Bubble & Dew)

R-407C Saturation Pressure Table

R-407C is a zeotropic blend with temperature glide, so it has two saturation pressures at each temperature. Use Vapor (dew) PSIG to find evaporator saturation for superheat, and Liquid (bubble) PSIG to find condenser saturation for subcooling. PSIA, kPa and bar columns are liquid (bubble) pressures. Blue values indicate vacuum.

°F °C Liquid PSIG
(bubble)
Vapor PSIG
(dew)
PSIA kPa bar
-80-62.2-9.2-11.25.4837.80.378
-75-59.4-8.3-10.56.4344.40.444
-70-56.7-7.2-9.87.5151.80.518
-65-53.9-6.0-8.98.7360.20.602
-60-51.1-4.6-7.910.1169.70.697
-55-48.3-3.0-6.711.6580.40.804
-50-45.6-1.3-5.413.3892.30.923
-45-42.80.6-3.915.31105.51.055
-40-40.02.7-2.317.44120.31.203
-35-37.25.1-0.419.81136.61.366
-30-34.47.71.622.41154.51.545
-25-31.710.63.925.29174.31.743
-20-28.913.76.528.44196.11.961
-15-26.117.29.331.88219.82.198
-10-23.320.912.335.64245.82.458
-5-20.625.015.739.74274.02.74
0-17.829.519.444.19304.73.047
5-15.034.323.549.01337.93.379
10-12.239.527.954.23373.93.739
15-9.445.232.759.86412.74.127
20-6.751.237.965.92454.54.545
25-3.957.743.572.44499.44.994
30-1.164.749.679.43547.65.476
351.772.256.186.92599.35.993
404.480.263.294.93654.56.545
457.288.870.7103.49713.57.135
5010.097.978.8112.61776.47.764
5512.8107.687.5122.32843.48.434
6015.6117.996.8132.64914.59.145
6518.3128.9106.7143.6990.19.901
7021.1140.5117.3155.211070.110.701
7523.9152.8128.5167.511155.011.55
8026.7165.8140.5180.521244.712.447
8529.4179.6153.2194.271339.413.394
9032.2194.1166.7208.771439.414.394
9535.0209.4181.0224.061544.815.448
10037.8225.5196.1240.161655.916.559
10540.6242.4212.1257.111772.717.727
11043.3260.2229.0274.921895.518.955
11546.1278.9246.9293.632024.520.245
12048.9298.6265.8313.272159.921.599
12551.7319.2285.7333.862301.923.019
13054.4340.7306.6355.432450.624.506
13557.2363.3329.4378.032606.426.064
14060.0387.0352.1401.672769.427.694
14562.8411.7376.7426.42939.929.399
15065.6437.5402.6452.243118.131.181
15568.3464.5429.9479.233304.233.042
16071.1492.7458.7507.393498.334.983
16573.9522.0489.1536.743700.737.007
17076.7552.6521.4567.293911.339.113
17579.4584.3555.6598.984129.841.298
18082.2616.9—631.584354.643.546

Properties

ASHRAE Designation407C
Safety ClassificationA1 (non-flammable, low toxicity)
GWP (AR4, 100-yr)1774
ODP0
Molecular Weight86.2 g/mol
Boiling Point (1 atm)-46.5°F / -43.6°C
Critical Temperature187.2°F / 86.2°C
Critical Pressure671.8 psia / 46.32 bar
CategoryHFC Blend

Common Applications

Frequently Asked Questions

What pressure should R-407C be at 70°F?

At 70°F, R-407C has a saturation pressure of 140.5 PSIG (155.2 PSIA), compared to R-22's 121.4 PSIG. R-407C operates at moderately higher pressures than R-22 across the temperature range.

Is R-407C a drop-in replacement for R-22?

R-407C is a near-drop-in retrofit for R-22 in split AC systems. It requires charging as a liquid to maintain blend composition, may need a Schrader valve change, and may require POE oil addition. Check manufacturer guidance before converting.

What is the temperature glide of R-407C?

R-407C has a temperature glide of about 10–12°F at typical evaporator conditions. Unlike a pure refrigerant, the liquid and vapor have different compositions during phase change. This means bubble and dew point temperatures differ — important for system analysis and leak repair.