Porsche P-80 2005, Руководство пользователя

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Air Conditioning Basics
Climate Control Systems Diagnosis & Repair
Page 1.15
Refrigerants
The refrigerant is the substance that is pumped by the
compressor through the closed system to transport heat
from one place to another. The refrigerant changes state
from a liquid to a gas and back again as it cycles. It does
not wear out or get used up unless it gets contaminated.
Refrigerant R-12 (Dichlorodifluoromethane, trade name
FREON) was the refrigerant used in vehicles for decades.
R-12 was considered completely inert, safe and harmless,
but it is a CFC or Chlorofluorocarbon. CFCs contains
Chlorine which is suspected of damaging the ozone layer
and contributing to global warming.
R-12 is no longer produced in this country, and
Porsche discontinued its use in 1993.
R-134a (Tetrafluoroethane, trade name SUVA) is the refrig-
erant used today. It has similar heat transfer properties
like R-12 but it does not contain Chlorine. R-134a has 84%
less global warming potential than R-12 and it does not
destroy ozone. For these reasons, R-134a has been
judged to be better for the environment. R-134a is the only
approved refrigerant and the only approved replacement
for R-12.
R-134a and R-12 refrigerants are not compatible and will
not mix. Cross-contamination must be avoided when
servicing the A/C system. To reduce the possibility of
errors, refrigerant storage containers are different colors
(white for R-12 and light blue for R-134a), and fittings are
different. Mixed refrigerants are a hazardous waste that
must be disposed of properly.
As mentioned before, the lubricating oils are different for
each refrigerant. R-12 systems use mineral oil and R-134a
systems use synthetic PAG or ester oils.
Note:
Refer to Equipment Bulletins for recomendation of a refrig-
erant tester that can analyze the refrigerant used in a
vehicle.
Notes: