Volkswagen Golf Service & Repair Manual: Water content

Volkswagen Golf Service & Repair Manual / Air conditioning system with refrigerant R134a / General notes on air conditioning systems / Characteristics of refrigerant R134a / Water content

Only very small amounts of water are soluble in liquid refrigerant. On the other hand, refrigerant vapour and water vapour mix in any proportion.

Any water present in the refrigerant circuit will be carried along as droplets. The dessicant, dessicant bag or dessicant cartridge in the receiver or reservoir are capable of holding approx. 7 grams of water before they are full and cannot absorb any more water. If there is further water in the circuit, it will flow to the expansion valve jet or to the restrictor and becomes ice.

The air conditioning system will stop cooling.

Water destroys the air conditioner because at high pressures and temperatures it combines with other impurities to form acids.

Combustibility

Refrigerant is non-flammable. On the contrary, it has a fire-inhibiting or fire-extinguishing effect. Refrigerant decomposes when exposed to flames or incandescent surfaces. UV light can also decompose refrigerants (UV is emitted by electric arc welding). Products of this decomposition are poisonous and must not be inhaled. However, these chemicals irritate the mucous membranes, giving adequate warning of their presence.

Effects on metal

In its pure state, refrigerant R134a is chemically stable and does not attack iron or aluminium. However, impurities such as chlorine compounds in th ...

Charge factor

There must be space both for liquid and vapour in a container. As the temperature rises, the liquid expands. The space occupied by the vapour becomes smaller. Eventua ...

Other materials:

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