R-134A Properties

Commercial Designation:
Obtain R-134a refrigerant from a local A/C supplier under one of the following names:
- R-134a
- Tetra fluoroethane
- CH2FCF3
- H-FKW 134a
- SUVA(R) TRANS A/C
- ARCTON(R) 134a

NOTE: R-134a refrigerant is packaged in different containers. One variation is SUVA(R) COLD MP used only for commercial applications. This type of R-134a is sold in cylinders using a 1/4 flare fitting which will not connect to the 1/2"- 16 ACME fittings used on the vehicle and servicing equipment. Use only R-134a which comes in containers having the correct type of service fitting.

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

Temperature/Pressure Relationship:
Similar to R-12 refrigerant, R-134a in an enclosed container will have a specific temperature/pressure relationship as follows:

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 Service Precautions for Warnings and Cautions regarding proper oil usage.

CAUTION:
- Refrigerant oils used for the R-134a system and R-12 system are not compatible. Use only the specified synthetic oil for the R-134a refrigerant system. Do not use R-12 system oil in an R-134a system or R-134a system oil in an R-12 system. If the refrigerant oils are mixed, system contamination will occur and compressor failure may result.
- R-134a refrigerant system oil (PAG 0IL) absorbs moisture very rapidly. Moisture combines with the refrigerant to form acids which will damage the system. Use only the specified oil from a sealed container and always reseal oil container immediately after use. Do not use oil if it has become contaminated with moisture or if container has been left open
- Do not allow refrigerant oil to come in contact with engine oil or transmission fluid (for example when disposing). Dispose of used PAG refrigerant oil separately following laws governing hazardous waste disposal.

Airborne Properties:
Escaped refrigerants are heavier than air and will gather first in low places, such as under a car. R-134a refrigerant displaces oxygen and may cause suffocation in low areas of poor air circulation.

Effects On The Environment:
Because R-134a does not contain chlorine atoms, the major catalyst in ozone depletion, R-134a has no ozone depletion potential.
R-134a does not cause smog and has a considerably lower global warming potential (greenhouse effect) than R-12 refrigerant. Nonetheless, do not release R-134a into the environment and always recover/recycle using approved service equipment

Effects On Plastics:
Refrigerant R-134a will deteriorate some plastics. When system temperature drops, these plastics can be deposited at the expansion valve or restrictor causing blockage. Therefore, when making system repairs, use only genuine Audi replacement parts which are specified for use with R-134a refrigerant.

Effects On Metal:
In its pure state, refrigerant R-134a is chemically stable and will not attack iron or aluminum. However, the mixture of R-134a and PAG oil may deteriorate certain metals (copper), which could lead to blockage, leaks, or deposits on the compressor piston. When making system repairs, use only genuine Audi replacement parts 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.
Water in the system forms ice in the expansion valve or restrictor causing the system to stop cooling. In addition, moisture combines with the refrigerant to form acids that will damage the system.

Toxicity:
Refrigerant R-134a is non-toxic up to a temperature of 101 °C (214 °F) and is safe when handled and used properly.
Above 101 °C (214 °F), gas pressure is above 39.5 bar (573 psi) and R-134a begins to decompose into poisonous gases (hydrogen fluoride, carbonyl fluoride and fluorine). These gases give adequate warning of their presence since they cause irritation of the mucous membrane (throat).
Refrigerant R-134a gas has no effect on foodstuffs; it does not poison food or make it inedible.

Flammability:
R-134a refrigerant is not flammable. In fact, it tends to inhibit combustion and has a fire extinguishing effect. However, a flame or glowing hot surface, as well as ultraviolet light (from electric welding), will decompose the refrigerant into poisonous gases (hydrogen fluoride, carbonyl fluoride and fluorine). These gases give adequate warning of their presence since they cause irritation of the mucous membrane (throat).
R-134a can become flammable at pressures above ambient pressure in conjunction with air concentrations greater than 60% by volume.

Refrigerant Containers:
Do not exceed maximum rated capacity of refrigerant containers. NEVER fill a container to more than 60% of its gross weight rating (for example, 18 lb in a 30 lb container.)
Without sufficient room for expansion of R-134a (gas cushion), the container could explode when the temperature rises causing serious injury.

Leak Detection:
Use halogen leak detector Hitec H1400A-TEL, or equivalent, to check for R-134a system leaks. Many currently available R-12 leak detectors cannot detect R-134a refrigerant leaks.