Operation CHARM: Car repair manuals for everyone.

Refrigerant




Temperature/Pressure Relationship

In a partially charged refrigerant container, refrigerant gas comes to the surface, which under particle formation becomes fluid. This occurs under pressure and is known as gas pressure. Similar to R-12 refrigerant, the gas pressure of R-134a is temperature dependent.

Temperature in °C ( °F) Pressure in bar (psi)
-30 (-22) 0.0 (0.0)
-20 (-4) 0.3 (4.4)
-10 (14) 1.0 (14.5)
0 (32) 1.9 (27.5)
10 (50) 3.1 (45.0)
20 (68) 4.7 (68.2)
30 (86) 6.7 (97.2)
40 (104) 9.1 (132.0)
50 (122) 12.2 (177.0)
60 (140) 15.8 (229.2)
70 (158) 20.2 (293.0)


WARNING!
Paint repairs on vehicles with A/C:
- While performing body/paint repairs involving the use of preheating or drying ovens, do not expose any component of the A/C system to temperatures above 80 °C/176 °F.
- Excessive heat will cause a pressure increase which could burst the system.