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. |
|
|
|
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:
Legal Requirements
The manufacturer is granted general type approval for the
whole vehicle including all parts and for specific retrofitting
(general type approval according to § 20 StVZO (Motor Vehicle
Construction and Use Regulations or EU type approval).
...
Seat heating
Fig. 43 In the centre console: buttons
for the front seat heating
First read and observe the introductory information
and safety warnings
The seat cushions on the front seats can be heated electrically when the ignition
is switched on. In some versions, the backrests may also be heated.
D ...
Introduction
This chapter contains information on the following subjects:
→ Socket in the vehicle
Electrical equipment can be connected to the socket in the vehicle.
The devices connected must be in good condition and fault-free.
Additional information and warnings:
Cigarette lighter
Acce ...
© 2016-2026 Copyright www.vwpolo.net
Refrigerant R134a Physical Data
Refrigerant R134a Environmental Information