Audi A3 1997 Manual page 132

Audi A3 1997 ➤
Heating, Air Conditioner - Edition 06.2000
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:
◆ The greenhouse effect of refrigerant R134a is much less than that of refrigerant R12.
◆ 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 (=>Page
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.
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87 - Air conditioning
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