The air submitted 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 air submitted to salon goes for heating or cooling through the same casing. The temperature and speed of a stream of air are regulated by means of the same governing bodies.

Heat allocated at operation of the engine, is transferred by cooling liquid to a radiator of the heater located in salon. The brought stream of air from system of ventilation passes through a radiator and heats up heat of cooling liquid of the engine proceeding in a radiator.

Central air 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 the high pressure is supported, evaporates and turns into gas on a site of low pressure. At expansion of gas there is a cooling, being accompanied heat selection from the air submitted by the fan to passenger salon and fall of its temperature. Further, in process of passing via the condenser, a coolant gives absorbed heat to air. The cycle of selection of heat proceeds infinitely long — in process of coolant circulation on the closed contour. From the air submitted to salon, there is a moisture removal owing to condensation on the evaporator of the refrigerating chamber and an otekaniye.

PREVENTION At service of central air strict observance of certain rules is required. For performance of the majority of operations on repair and service of central air the special equipment and skills of work is necessary.

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

Ventilation of a body is provided at the expense of formation of a through stream of air (fig. 14.1) . Zabortny air gets in the car through a branch pipe of the air inlet attached on the right side to the mixing chamber, being directly under a cover of a motor compartment, is direct behind a windscreen. The air stream in salon is formed in such a manner that blows in an internal surface of back glass, preventing its zapotevaniye, 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 of a body and hidden under extending parts of a rear bumper.

Intensity of a stream of air is regulated by the four-high-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 zabortny air is prevented. At very hot weather it is possible to provide an air retsirkulyatsiya 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 fast response to change of air temperature in salon and reduction of pulsations of temperature of 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 air temperature which changes the mixing zaslonka defining amount of air, passing through a radiator before its hit in salon. Two more zaslonka supervise distribution of a stream of air. The distributive zaslonka 8 (see fig. 14.3 ) distributes an air stream between the air lines 6,7 and 9 (fig. 14.2) located on the dashboard, and other channels of system of heating. Zaslonka 10 (fig. 14.3) of a regulator of heating of feet and a windscreen distributes an air stream between an air pipe of heating of a windscreen both forward and back air pipes of heating of the feet, located in a salon floor. All zaslonka are executed in the form of the block which has been built in an airdistributing box and to separate service are not subject.

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–air distributor and evaporator casing; 5–control panel conditioner; 6–management cables; 7–air pipe; 8–distributive zaslonka; 9–flange of fastening of hoses of a radiator of a heater; 10-zaslonka of heating of feet and windscreen; 11-broad valve

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