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:
Various securing systems
Fig. 62 On the rear seats: figure Ⓐ illustrates
the main securing points for the child restraint system on the lower retaining rings
and top tether. Figure Ⓑ shows how to secure a child restraint system using the
vehicle's seat belt
First read and observe the introductory information
a ...
First aid kit and warning triangle
Fig. 153 In the luggage
compartment: holder for the first aid kit
Fig. 154 In the luggage
compartment. A: Warning triangle under the loading edge, B: Warning triangle in
the vehicle tools
First read and observe the introductory
information and safety warnings
First aid kit
A first-ai ...
Infrared Dryer -VAS6877
Definition:
Infrared Dryer -VAS6877-
Product Description:
The infrared dryer is used to dry paste, filler, base paint,
top coats and clear coats on vertical and horizontal surfaces.
...
© 2016-2026 Copyright www.vwpolo.net
Refrigerant R134a Physical Data
Refrigerant R134a Environmental Information