Refrigerant R134A

Vehicle air conditioning systems make use of the vaporization and condensation process. In this case, one works with a substance which boils easily, designated as refrigerant.

The refrigerant employed is tetrafluoroethane R134a, which boils at - 26.5 °C (-15.7 °F) at a vapor pressure of 1 bar.

Refrigerant R134a Environmental Information 

• R134a is a fluorocarbon and contains no chlorine.
• R134a has a shorter atmospheric life span than refrigerant R12.
• R134a does not damage the ozone layer. The ozone depletion potential is zero.
• The greenhouse potential of R134a (Global Warming Potential (GWP)) is approximately 1300 (the GWP of carbon dioxide is 1).
• The global warming effect of R134a is ten times less than that of refrigerant R12.

Vehicles manufactured after 1992 have air conditioning systems that use refrigerant R134a. This refrigerant does not contain chlorine and does not deplete the ozone layer.

Refrigerant R12 was used through 1992. Due to its chlorine atoms, this CFC has a high potential for depleting the ozone layer as well as a tendency to increase the greenhouse effect.

Conversions are offered for existing systems filled with the ozone-depleting substance R12.

Refer to Repair Information for A/C systems with refrigerant R12. This repair information is only available in hard copy.

For environmental protection reasons, refrigerants must not be released into the atmosphere. For laws and regulations, refer to LAWS AND REGULATIONS .

Refrigerant R134a Physical Data 

Chemical formula	CH2F-CF3 or CF3-CH2F
Chemical designation	Tetrafluoroethane
Boiling point at 1 bar	- 26.5 °C (-15.7 °F)
Solidification point	-101.6 °C (-150.88 °F)
Critical temperature	100.6 °C (213 °F)
Critical pressure	40.56 bar (absolute)

Critical Point 

The critical point (critical temperature and critical pressure) is that above which there is no longer a boundary between liquid and gas.

A substance above its critical point is always in the gaseous state.

At temperatures below the critical point, all types of refrigerant in pressure vessels exhibit both a liquid and a gas phase, for example, there is a layer of gas above the liquid.

As long as there is still gas present in the container next to the fluid, pressure is dependent on ambient temperature. Refer to REFRIGERANT R134A VAPOR PRESSURE TABLE .