Volkswagen Polo Service & Repair Manual: Critical Point
| Vehicle air conditioning systems make use of the
vaporization and condensation process. In this case, one works
with a substance which boils easily, designated as refrigerant. |
| The refrigerant employed is tetrafluoroethane R134a, which
boils at -26.5 °C (-15.7 °F) at a vapor pressure of 1 bar (14.5
psi). |
| The critical point (critical temperature and critical
pressure) is that above which there is no longer a boundary
between liquid and gas. |
| A substance above its critical point is always in the
gaseous state. |
| At temperatures below the critical point, all types of
refrigerant in pressure vessels exhibit both a liquid and a gas
phase, i.e. there is a layer of gas above the liquid. |
| As long as there is still gas present in the container next
to the fluid, pressure is dependent on ambient temperature.
Refer to
→ Chapter „Refrigerant R134a Vapor Pressure Table“. |
 Note
| Different types of refrigerant are never to be mixed. Only
the refrigerant designated for the corresponding A/C system may
be used. |
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Vehicle air conditioning systems make use of the
vaporization and condensation process. In this case, one works
with a substance which boils easily, designated as ref ...
Vehicle air conditioning systems make use of the
vaporization and condensation process. In this case, one works
with a substance which boils easily, designated as ref ...
Other materials:
Ultrasound A/C Cleaner -VAS6189B
The Ultrasonic HVAC Cleaning System -VAS6189A- is placed in
the front passenger footwell and sprays Aero-Clean. Aero-Clean
neutralizes microbes and bacteria inside the heater and A/C
unit.
The unit comes with Operating Instructions.
...
Manual gearbox: selecting a gear
Fig. 110 Gear shift pattern of a 5 or 6-speed
manual gearbox
First read and observe the introductory information
and safety warnings The positions of the individual driving
gears are shown on the gearshift lever .
Fully depress and hold the clutch pedal.
Move the gear lever t ...
Information stored in the control units
First read and observe the introductory information
and safety warningsYour vehicle is factory fitted with electronic control
units which are responsible for engine and gearbox management. The control units
also monitor the function of the exhaust system and the airbags.
These electronic con ...
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Refrigerant R134a Physical Data
Refrigerant R134a Environmental Information