Volkswagen Golf Service & Repair Manual: Physical basics

Volkswagen Golf Service & Repair Manual / Air conditioning system with refrigerant R134a / General notes on air conditioning systems / Basics of air conditioning / Physical basics

The four known physical states of water also apply to air conditioning refrigerants.

1 -	Gas (invisible)

2 -

Vapour

3 -

Liquid

4 -

Solid

Physical basics

When water is heated in a container (heat absorption), the rising water vapour is visible. If the vapour is heated by further heat absorption, the visible vapour becomes invisible gas. This process is reversible. If heat is extracted from gaseous water, it changes first to vapour, then to water and finally to ice.

A -	Heat absorption

B -	Heat dissipation

Physical basics

Basics of air conditioning

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Heat always flows from warmer to colder material

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 ...

Other materials:

Removing and installing seat depth adjustment
Special tools and workshop equipment required Removal wedge -3409- Removing – Remove front seat → Chapter. ...

Switching the front passenger front airbag on and off manually using the key-operated switch
Fig. 72 In the dash panel on the front passenger side: key-operated switch for switching the front passenger front airbag on and off First read and observe the introductory information and safety warnings The front passenger front airbag must be switched off when securing a rear-facing c ...

Leak detection in refrigerant circuit using compressed air or nitrogen
Note A leak in the refrigerant circuit can be detected, for example, by pressurising the circuit to a maximum of 15 bar using cleaned and dried compressed air or nitrogen → Chapter. If the leak is large, the leakage point ...