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

...

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:

Checking systems with an expansion valve, receiver and air conditioner compressor regulating valve -N280- (with externally regulated air conditioner compressor)
Note Connecting air conditioner service station → Chapter. Observe the test prerequisites → Chapter. – Raise engine speed to 2,000 rpm. ...

General notes
Cleanliness specifications for working on the auxiliary heater and fuel system When working on the fuel supply and injection system, pay careful attention to the following “rules”: Thoroughly clean all unions a ...

Assembly overview - belt pulley, Denso air conditioner compressor
1 - Bolt Qty. 3. 4.5 Nm 2 - Sealing cap 3 - Nut 25 Nm – To unfasten and tighten the hexagon nut, hold the pulley in position with ...