R134A Refrigerant 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
- CH2F CF3
- H-KW 134a
- SUVA (R) 134a
- ARCTON (R) 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 °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)

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. See safety measures for Warnings and Cautions 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 H1400A-TEL or equivalent to check for R-134a system leaks. This tool can also be used to detect leaks in R12 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.