The air given by system of ventilation to salon can be warmed up or cooled depending on the conditions of comfort chosen by the passenger. Systems of heating and conditioning are separate, however units and knots of these systems are located in a passenger compartment, in the general 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 are regulated by means of the same governing bodies.

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.

Air conditioning system deletes excessive heat and moisture from salon according to the basic physical principles. The coolant circulating in the form of liquid in that part of system where high pressure is supported evaporates and turns into gas on the site of low pressure. At expansion of gas there is a cooling which is followed by selection of heat from the air given by the fan to passenger salon and decrease in its temperature. Further, in process of passing via the condenser, coolant gives the absorbed heat to air. The cycle of selection of heat proceeds infinitely long — in process of circulation of coolant on the closed contour. From the air given to salon there is a removal of moisture owing to condensation on the evaporator of the refrigerator and an otekaniye.

PREVENTION At service of air conditioning system strict observance of certain rules is required. Performance of the majority of operations on repair and service of air conditioning system requires the special equipment and skills of work.

Fig. 14.1. Scheme of ventilation of interior of the Passat car

Ventilation of a body is provided due to formation of a through stream of air (fig. 14.1) . Outboard air gets in the car through a branch pipe of the air inlet attached on the right side to the mixing camera which is directly under a cover of a motor compartment, directly behind a windshield. The air stream in salon is formed in such a way that blows in the internal surface of back glass, preventing its fogging, and passes through a decorative lattice in the panel of a luggage compartment. The stream of air comes to light via the final channels located on each side bodies and hidden under the extending parts of a rear bumper.

Intensity of a stream of air is regulated by the 4-speed fan. At switching off of the fan there is an automatic closing of a cover of airinflow owing to what hit in salon of outboard air is prevented. At very hot weather it is possible to provide recirculation of air in salon for effective cooling. The cover of airinflow moves under the influence of the vacuum servo-driver.

The system of heating of air — the mixed type — is intended for quick response to change of air temperature in salon and reduction of pulsations of temperature of the warmed-up air. Cooling liquid of the engine constantly circulates in a radiator, the stream of cooling liquid is not regulated. An adjustable factor is the air temperature which changes the mixing gate defining amount of the air passing through a radiator before its hit in salon. Two more gates control distribution of a stream of air. The distributive gate 8 (see fig. 14.3 ) distributes an air stream between the air ducts of 6,7 and 9 (fig. 14.2) located on the dashboard and other channels of system of heating. The gate 10 (fig. 14.3) of the regulator of heating of legs and a windshield distributes an air stream between the air duct of heating of a windshield both forward and back the air ducts of heating of legs located in a floor of salon. All gates are executed in the form of the block which is built in an airdistributing box and are not subject to separate service.

Fig. 14.3. System of distribution of air of a heater and conditioner: 1 – airinflow cover; 2 – vacuum drive of a cover of airinflow; 3 – fan; 4 – casing of the air distributor and evaporator; 5 – control panel of the conditioner; 6 – cables of management; 7 – air duct; 8 – distributive gate; 9 – flange of fastening of hoses of a radiator of a heater; 10 – gate of heating of legs and windshield; 11 – broad valve

Fig. 14.2. Arrangement of elements of air supply of system of heating and conditioning: 1 – vodootboyny guard; 2 – dashboard; 3 – right side nozzle; 4 – central nozzles; 5 – lower air duct; 6 – right air duct; 7 – central air duct; 8 – left side nozzle; 9 – left air duct