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:
Overview - Tire Pressure Monitoring Sensor without Valve
1 -
Valve Cap
2 -
Nut
Individual component of -item 7-
→ Item
Tightening specification. Refer to
→ Anchor.
Always replace if removed
3 -
W ...
Trailer Socket
Connect the trailer socket to the vehicle electrical system
of the vehicle pulling the trailer according to the manufacturer
instructions.
Refer to the applicable wiring diagrams or manufacturer
installation instructions when installing ...
Odor from Evaporator or Heat Exchanger?
Fishy smell
–
From leak at cooling system of engine or of A/C system
heater core.
Note
If the fishy smell gets weaker when the temperature is set
to “cold” and stronger when i ...
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Refrigerant R134a Physical Data
Refrigerant R134a Environmental Information