| The boiling points given in the table below are always based
on an atmospheric pressure of 1 bar. If the pressure on a liquid
is changed, its boiling point changes also. |
| It is well known that, for example, the lower the pressure,
the lower the temperature at which water boils. |
| The vapour pressure curves for water and for refrigerant
R134a show that at constant pressure and falling temperature the
vapour becomes liquid (in the condenser), and that when pressure
drops, the refrigerant changes from liquid into the vapour state
(evaporator). |
|
|
|
| Vapour pressure curve for water |
| C - |
Vapour pressure curve for water |
| 1 - |
Pressure on the liquid in bar (absolute) |
|
|
|
| Vapour pressure curve for refrigerant R134a |
| D - |
Vapour pressure curve for refrigerant R134a |
| 1 - |
Pressure on the liquid in bar (absolute) |
|
|
 |
Questions & answers
Pressure and boiling point — Volkswagen Golf Mk7
How does pressure affect the Golf Mk7 AC refrigerant?
Higher pressure raises the boiling point; lower pressure lowers it. The AC system uses this principle to make the refrigerant evaporate (absorb heat) and condense (release heat) at controlled temperatures.
Every material consists of a mass of moving molecules. The fast moving
molecules of a warmer material loose part of their energy to slower molecules
possessing less heat. This slows down the molec ...
The vapour pressure table for each refrigerant is published
in the literature for refrigeration engineers. This table shows
the vapour pressure exerted on the liquid ...
