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Safety precautions when working on cars with air conditioners and when handling refrigerant
Safety precautions when working on cars with air conditioners and when handling refrigerant
The assemblies and pipes in the air conditioner are filled with refrigerant
1.1.1.2 Tetrafluorethane (CF3-CH2F or CH2F-CF3)
This refrigerant is currently known in Germany by the trade names R134a, H-FKW 134a, SUVA 134a and KLEA 134a (other trade names may be used in other countries).
Safety precautions
The following precautions should be observed with this refrigerant in Germany (additional regulations may be applicable in other countries).
If it is necessary to open the refrigerant circuit during repair work, first drain the refrigerant circuit (), making sure to avoid all contact with liquid refrigerant or refrigerant vapours. If, despite the observance of the safety precautions, refrigerant should escape, the refrigerant/air mixture must not be inhaled.
For this reason, always switch on the extractor systems, and protect hands with gloves and eyes with safety goggles.
Reason:
The intensive action of refrigerants will cause frostbite on unprotected parts of the body.
Warning!
It is recommended that an eye bath be kept to hand.
If liquid refrigerant comes into contact with the eyes, the eyes should be thoroughly rinsed for about 15 minutes.
Then apply eye drops and consult a doctor , even if the eyes are not painful.
The doctor should be informed of the type of refrigerant which caused the frostbite.
If, despite observance of all the security precautions, refrigerant should come into contact with other parts of the body, they should also bethoroughly rinsed immediately for at least 15 minutes in cold water.
Although refrigerants do not represent a fire hazard, smoking, welding, soldering and brazing are not permitted in areas exposed to refrigerant.
Reason:
The high temperature of a naked flame or hot objects causes refrigerant gas to undergo chemical decomposition. The inhalation of the toxic decomposition products results in dry coughing and nausea.
Draining the refrigerant circuit
Refrigerant must not be allowed to escape into the environment, it should be extracted from the refrigerant circuit by means of a suction unit or service station. The extracted refrigerant is then reprocessed on site or returned to the manufacturer for environmentally friendly disposal (in other countries, different or additional regulations may apply). For these reasons, vehicles should be sent to Audi and VW air-conditioning servicing centres (these workshops have the relevant equipment and tools).
Reason:
Escaped refrigerant R134a in the earth's atmosphere aggravates the greenhouse effect.
Notes:
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◆ The greenhouse effect of refrigerant R134a is much less than that of refrigerant R12.
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◆ The refrigerant R134a does not affect the ozone layer in the earth's atmosphere (R134a is an H-FC with no chlorine atoms). The depletion of the ozone in the upper atmosphere is only caused by the splitting of carbon-chlorine bonds (as is the case, for example, with the refrigerant R12).
When the air conditioner has been drained, disconnect the power supply to the air conditioner magnetic clutch -N25 (e.g. detach the connector from the AC pressure switch -F129 or from high pressure sender -G65).
Reason:
Disconnecting the voltage supply or the pressure signal ensures that the compressor cannot be activated by mistake while the refrigerant circuit is empty.
Working on the refrigerant circuit
Work on the refrigerant circuit must only be performed in well ventilated rooms. Care should be taken to ensure that there are no inspection pits, shafts or cellar entrances within a radius of 5 metres. Switch on the extraction systems.
Reason:
Escaping refrigerant is not only colourless and odourless, but also heavier than air and therefore displaces oxygen. If, despite the observance of all the safety precautions, refrigerant gas is emitted, there may be a negligible risk of asphyxiation in poorly ventilated rooms and workshop pits.
Note:
The mixture of gas and air which forms when refrigerant gas escapes must not be inhaled; it must be extracted using suitable extraction systems (workshop extractor).
Welding, brazing and soldering must not be performed on parts of the filled air conditioner. The same applies to welding and soldering work on the vehicle if there is a risk that parts of the air conditioner could become warm.
Reason:
The application of heat creates a severe build-up of pressure in the system which could cause it to burst.
Remedy:
Drain the refrigerant circuit ().
Note:
Damaged or leaking parts of the air conditioner may not be repaired by welding or soldering; they should be renewed instead.
During repair work on the air conditioner, all open components and pipe connections in the air conditioner should be re-sealed immediately.
Reason:
Air conditioner components left open for a lengthy period present a risk of moisture penetration. Air conditioners which have been left open for a lengthy period cannot, therefore, be re-filled without replacing parts of the system.
Painting work on vehicles with air conditioner
When carrying out paintwork repairs, ensure that the vehicle is not exposed to temperatures of more than 80 °C in the drying ovens or their preheating zones.
Reason:
The application of heat creates a severe build-up of pressure in the system which could cause it to burst.
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