Volkswagen Touran Service Manual: Physical Principles

Volkswagen Touran Service Manual / Heating, Ventilation and Air Conditioning / A/C System, General Information / A/C Technology Basic Principles / Physical Principles

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

1 -	gaseous (invisible)

2 -

vapor

3 -

fluid

4 -

solid

When water is heated in a vessel (heat absorption), water vapor can be seen to rise. If the vapor is further heated through heat absorption, the visible vapor turns into invisible gas. The process is reversible. The warmth is extracted from gaseous water, vapor forms first, then water and then ice.

A -	Heat absorption

B -	Heat emission

Heat Transfer

Every substance consists of a mass of moving molecules. The fast moving molecules of a warmer substance give off some of their energy to the cooler and thus slower molecules. As a result, the molecular motion of the warmer substance slows down and that of the colder substance is accelerated. This process continues until the molecules of both substances are moving at the same speed. They are then at the same temperature and no further heat exchange takes place.

A/C Technology Basic Principles

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Pressure and Boiling Point

The boiling point given in tables for a liquid is always referenced to an atmospheric pressure of 1 bar (14.5 psi). If the pressure acting on a fluid changes, its boi ...

Other materials:

Volkswagen Touran Owners Manual. Adjusting the head restraints
Fig. 42 Adjusting front head restraint Fig. 43 Adjusting rear L-shaped head restraint. First read and observe the introductory information and safety warnings Every seat is fitted with a head restraint. Adjusting the height Push the head restraint up in the direction of the ar ...

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Fig. 162 In the dash panel: vents Fig. 163 In the rear section of the centre console: vents for rear ventilation First read and observe the introductory information and safety warnings Vents To ensure that the vehicle interior is sufficiently heated, ventilated and cooled, you should ne ...