A/C Refrigerant R-134a, Properties

A/C Refrigerant R-134a, Properties

Commercial designation

The following designations are used and appear on component labels and factor tags:
- R-134a
- Tetrafluoroethane
- CH(2) FCF(3)
- H-KW134a
- SUVA 134a
- ARCTON 134a

Color
Refrigerant R-134a is colorless and is invisible as a gas. R-134a when viewed through the sight glass may appear milky due to the mixture of refrigerant and lubricating oil (PAG oil).

Temperature/pressure relationship
R-134a in an enclosed container will have a specific temperature/pressure relationship.

Temperature in degrees C (degrees 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)


Refrigerant oil
A special Polyalkylene Glycol (PAG) synthetic oil is used in R-134a systems. This oil is NOT compatible with mineral based oils used in R-12 systems. Refer to Cautions and Warnings regarding proper oil usage.

Airborne properties
Escaped refrigerant gases are heavier than air and will gather first in low places, like under the car. R-134a refrigerant gas displaces oxygen and may cause suffocation in low areas of poor air circulation.

Refrigerant R-134a is not poisonous in any state (liquid or gas) and is safe when used properly.

Affects on plastic
Refrigerant R-134a will deteriorate some plastics. Therefore, when making system repairs, use only genuine VW replacement parts which are specified for use with R-134a refrigerant.

Affects on metal
In its pure state, refrigerant R-134a is chemically stable and will not attack iron, copper, brass or aluminum. However, the mixture of R-134a and PAG oil may deteriorate certain metals (copper). Therefore, when making system repairs, use only genuine VW replacement parts which are specified for use with R-134a refrigerant.

Water solubility
Liquid R-134a refrigerant will absorb only very minute quantities of moisture. However, R-134a vapor can absorb large amounts of moisture.

Flammability
R-134a refrigerant is not flammable.

Refrigerant containers
DO NOT exceed maximum rated capacity of refrigerant container.

Leak detection
Use halogen leak detector Hitec HI400A-TEL or equivalent to check for R-134a system leaks. This tool can also be used to detect leaks in R-12 systems. Many currently available R-12 leak detectors cannot detect R-134a refrigerant leaks.

R-134a refrigerant oil
A special Polyalkylene Glycol (PAG) synthetic oil is used in R-134a systems. This oil is NOT compatible with mineral based oils used in R-12 systems.