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At vehicle introduction, the 2019 A8 will uses refrigerant
R1234yf in the climate control refrigerant system. Audi has
been using R1234yf since model year 2017.
Properties of the R744:
The essential difference between the new air conditioning
system and previous air conditioning systems is the high
working pressures in the system. These are required in
order to use CO
2
as a refrigerant.
Components of the R744 refrigerant circuit
System pressure
›
Up to 1348.8 psi (93 bar) on the low pressure side.
›
The maximum system pressure on the high pressure side
is 2030.5 psi (140 bar).
662_120
AC compressor with pres-
sure relief valve,
high pressure side
Gas cooler
Pressure relief valve,
low pressure side
Service connection,
low pressure side
Expansion valve
Accumulator
Coaxial refrigerant line
Service connection,
high pressure side
Low Pressure Side A/C Pres-
sure/Temperature Sensor
G1052
High Pressure Side A/C
Pressure/Temperature
Sensor G1053
Connection to air conditioner
with evaporator
A new refrigerant is known as R744 will be introduced at a
later date. It is C0
2
and contains neither fluorine nor chlo-
rine and is produced in a series of natural processes without
depleting the earth’s ozone layer.
Climate control
