Mercedes S-Class W-220

since 1998 release

Repair and operation of the car

Mercedes W220
+ Mercedes-Benz cars of the class S (W220)
+ Operation manual
+ Routine maintenance
+ Engine
- Cooling system and heating
   + Cooling system
   - Systems of ventilation, heating and air conditioning
      The air conditioning system - the general information and precautionary measures
      Arrangement of the basic electric elements of the air conditioning system
+ Power supply system and release
+ Engine electric equipment
+ Automatic transmission
+ Power shafts
+ Brake system
+ Suspension bracket and steering
+ Body
+ Onboard electric equipment
+ Schemes of electric equipment

Systems of ventilation, heating and air conditioning

General information and security measures

Function chart of the refrigerator of the conditioner of air


1 — the K/V Compressor 2 — the Condenser 3 — the Receiver dehumidifier 4 — the Broad valve 5 — the Evaporator 6 — the Evaporator of the back conditioner of air 7 — the Valve of cutoff of coolant of the back conditioner of air	8 — the Valve of injection of coolant of the back conditioner of air And — the High pressure (a gaseous phase) In — the High pressure (a liquid phase) With — the Low pressure (a liquid phase) D — the Low pressure (a gaseous phase)

Additional heater. Diesel models


1 — the thermolysis module Control unit 2 — the torch Case 3 — the Exit of cooling liquid 4 — the burning air purge Module 5 — burning Air supply 6 — the Socket 7 — the thermolysis Module 8 — the Torch	9 — an exhaust Exit 10 — Supply of cooling liquid 11 — fuel Supply A6m2 — a burning air Purge A6n1 — the Control unit additional heater A6r2 — the Heater

Ventilating streams

The air given by system of ventilation to interior of the car via the filter can be warmed up or cooled depending on the choice of the driver and passengers. The heater or the conditioner settle down in salon, in the case under the dashboard. All stream of the air given to salon goes for heating or cooling through the same casing. Temperature and speed of a stream of air is regulated by means of the governing bodies located on the control panel.

Heat generated during the operation of the engine is transferred by cooling liquid to the heater radiator located in salon. The brought air stream from system of ventilation passes through a radiator and heats up heat of the cooling liquid of the engine proceeding in a radiator. Extent of heating is regulated by means of mixing in a certain ratio of cold and hot air by means of the mixing gate with the servo-driver.

The used air is removed from salon through air vents with backpressure valves.

Increase in a consumption of air via the heat exchanger provides the fan of fresh air.

If it is necessary to turn off supply of fresh air, for example, at a bad smell, the system switches in the circulation mode at which in salon only the air which is available there circulates.

Switching of system in the mode of circulation is confirmed by fire of a control lamp.

Air conditioning system of salon

Works with air conditioning system have to be performed by a specialized workshop. Do not open at all a coolant circulation contour as at contact with skin coolant can cause a frostbite.

By means of air conditioning system air temperature in salon can go down below external temperature. During the work of system humidity in salon decreases. During wet weather, the arriving fresh air previously it is cooled then again heats up to the set temperature. Thus its drainage is made. By means of this procedure fogging of glasses is removed.

Air conditioning system consists of a heater and the refrigerator. The KV refrigerator consists of the compressor, the condenser, a throttle, the evaporator, container with coolant and pipelines. In system coolant (R134a type) which depending on temperature and pressure can be in liquid or gaseous state circulates.

The conditioner compressor through a ridge belt is given to rotation from a bent shaft of the engine. He creates pressure to 30 atm. in an installation cooling contour owing to what the coolant representing gas heats up. In the condenser coolant is cooled with the air proceeding outside (the cooling air remains in the external environment). Thereof the warmed coolant is condensed, turning into liquid.

Having big pressure, it is passed through a throttle therefore its pressure falls. After that coolant evaporates in a contour, at the same time strongly being cooled. In the evaporator coolant selects heat from the air blown through it. Thereof air is cooled. The cooled air comes to interior of the car. As a result of heating in the evaporator coolant turns into gas and under low pressure comes to the compressor then process of circulation repeats.

Additional heater

The additional heater on fuel is established on model with diesel engines. At start of the engine it automatically begins to work depending on temperatures of cooling liquid and the environment. Manual control is not provided. It can only be included or switched off the switch on the central console.

Besides a heater on fuel also additional electric heater is established.