Audi A4, S4

since 2000 release

Repair and operation of the car

Systems of ventilation, heating and air conditioning

General information and security measures

Scheme of a contour of the conditioner of air

1 — the Fan 2 — the Evaporator 3 — the Broad valve 4 — the Tank 5 — the condenser Fan 6 — the Condenser 7 — the Compressor and — External air for cooling of the condenser	b — the Warm air which is taken away outside with — not cooled air going via the fan d — the Cooled air going to salon And — the High pressure, gaseous In — the High pressure, liquid With — Low pressure, liquid D — Low pressure, gaseous

The heater case with the heat exchanger and the additional heater

Elements of the air conditioning system of salon

1 — the air extract Fan 2 — the K/V Compressor 3 — the K/V Coupling 4 — the Condenser 5 — the air temperature Sensor 6 — pressure Sensor To/in 7 — the Accumulator	8 — Spuskna the valve of assembly of the evaporator 9 — the Limiter 10 — the Valve of a high pressure 11 — the Valve of low pressure 12 — the giving/air circulation Gate 13 — the air temperature Sensor in an inlet air duct 14 — the Filter

Removal of the evaporator of the conditioner of air

1 — the Latch 2 — a heater Casing To/in 3 — the Latch 4 — the giving/air circulation Gate 5 — the Grid of an inlet air duct	6 — a heater Radiator 7 — the Central gate 8 — the Gate of heating of a foot well 9 — the Gate of adjustment of temperature

Address also to the Section Heater, ventilation and the conditioner of air.

Works with central air have to be performed by experts.

Fresh air for system of heating and ventilation is sucked in by the electric fan. Before receipt in salon air is cleared by filters of rough and thin cleaning.

The conditioner of air is capable as to warm up (in a heater radiator) and to cool (in the conditioner evaporator), and to drain the air coming to salon. During wet weather, the arriving fresh air previously it is cooled then again heats up to the set temperature. Thus there is a condensation of excessive moisture of air, i.e. its drainage. Thus fogging of glasses is eliminated.

Then air is distributed on ventilating nozzles in salon of the car.

Through a heater radiator constantly there passes hot cooling liquid of the cooling system of the engine. For regulation of a consumption of air in salon of the car the built-in fan of fresh air can work at several steps.

If fresh air outside does not be sucked in, for example, at poor quality of air, the system can be switched to the circulation mode. In this mode in salon only internal air circulates. If it proceeds rather long time, glasses in salon mist over.

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

The compressor of the conditioner is given to rotation from a cranked shaft of the engine by means of a ridge belt. 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 external air (which is not coming to salon). Thus 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, at the same time strongly being cooled. In the evaporator coolant selects heat from the air blown through it. Air is cooled. The cooled air comes to salon 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.

If at work works with electric equipment are in addition carried out, it is necessary to disconnect surely a negative cable (-) of the battery. For this purpose surely observe indications of the Section Replacement of the Battery.

On models with the diesel engine the additional heating element which is coming into effect at a low external temperature is established. The heating element is directly behind the heat exchanger. After start of the engine, depending on external temperature, it within several seconds heats the cold air coming to the car.

If in a heater or climatic installation there is a malfunction, it is fixed in memory of malfunctions. The schitana information from memory can be the device for reading of malfunctions.

To order the car can be equipped with the automatic, electronically controlled conditioner at which air temperature of the driver and forward passenger are regulated separately. In addition, through the connecting hose going from the conditioner to a ware box the refrigerating box if it is available in a ware box can be cooled.

The mode of automatic work provides automatic maintenance of temperature in salon and deletes moisture from air. Besides, the air temperature, its quantity and distribution are automatically regulated and fluctuations of external temperature are compensated. In economy mode of work the conditioner is switched off, but the heater and system of ventilation continue to work. By shutdown of the conditioner the compressor of the conditioner does not work therefore fuel is saved. At diesel engines, besides, additional heating is switched off. It also brings economy of fuel.

Security measures at service of the air conditioner

Central air has to be served by exclusively prepared technicians trained in safe working methods with use of the appropriate equipment with observance of rules of depressurization, acquainted with methods of collecting and order of storage of automobile coolant.

• Do not allow contact of coolant with skin.
• During the work near central air put on goggles.
• At hit of coolant on skin or eyes do not pound the struck place. Immediately wash out cold water within not less than 15 minutes. Immediately address to the doctor or in medical institution. Self-treatment is not allowed.
• Coolant is stored in a new cylinder under pressure. Store a cylinder at a temperature not above 50 °C. Take the measures excluding falling of a cylinder about heights or other situations which can lead to its damage.
• Works should be carried out in well aired room. Coolant quickly evaporates, has no smell. Its accumulation leads to reduction of access of oxygen and difficulty of breath.
• Gaseous coolant is heavier than air and rather quickly has to gather below, for example, under the car.
• At combustion of coolant poisonous gas is formed. Store coolant far from open sources of fire. Do not smoke. When using an ardent techeiskatel avoid inhalation of a smoke.
• When carrying out welding works near central air to influence of high temperature or an open flame. The overheat can lead to increase of pressure in system and to ignition.
• Cleaning of the condenser or evaporator by means of water vapor is not allowed. It is necessary to use only cold water or compressed air.