HVAC Toolkit

Pressure-Temperature Charts

Saturation P-T data for common refrigerants

Select Refrigerant

HFC / HCFC

R-22 R-32 R-125 R-134a R-143a R-404A Z R-407C Z R-410A R-507A

Low GWP (HFO)

R-449A Z R-454B Z Low GWP R-513A R-1234yf Low GWP R-1234ze(E) Low GWP

Natural

R-290 (Propane) Low GWP R-600a (Isobutane) Low GWP R-744 (CO2) Low GWP R-717 (NH3) Low GWP

Pressure Unit

psig kPa bar kgf/cm²

R-600a

Pure
GWP: 3
ODP: 0
Safety Class: A3

Natural refrigerant common in domestic refrigerators. Lower working pressure than R-290. Charge limits apply per IEC 60335-2-89.

A3 HIGHLY FLAMMABLE - Safety Warning

  • ASHRAE 34 Classification: A3 - Non-toxic but HIGHLY FLAMMABLE
  • Maximum charge limits: 150g (sealed systems) per IEC 60335-2-89
  • Use only explosion-proof equipment and tools
  • Work in well-ventilated areas - gas is heavier than air
  • No open flames, sparks, or hot surfaces during service
  • Use hydrocarbon-rated recovery equipment and leak detectors
  • Most domestic refrigerators contain 50-100g charge
Flammability Range: LEL 1.8% - UEL 8.4% in air

Quick P-T Lookup

kgf/cm²

* Results are interpolated from the P-T table data

Pressure Units: psig = Gauge pressure (relative to atmosphere) kPa / bar / kgf/cm² = Absolute pressure

°C °F kgf/cm²
-50 -58 0.1
-45 -49 0.2
-40 -40 0.3
-35 -31 0.4
-30 -22 0.5
-25 -13 0.6
-20 -4 0.8
-15 5 1.0
-12 10 1.2
-10 14 1.3
-5 23 1.6
0 32 1.9
5 41 2.4
10 50 2.8
15 59 3.4
20 68 4.0
25 77 4.8
30 86 5.6
35 95 6.5
40 104 7.5
45 113 8.7
50 122 9.9
55 131 11.3
60 140 12.9
65 149 14.5
70 158 16.4
75 167 18.4
80 176 20.6
85 185 23.0
90 194 25.5
95 203 28.3
100 212 31.3