Note. See also Section Comfort Chapters Manual
The air supplied by the ventilation system to the passenger compartment through the filter can be heated or cooled, depending on the choice of the driver and passengers. The heater or air conditioner is located in the cabin, in the housing under the instrument panel. The entire flow of air supplied to the passenger compartment is directed for heating or cooling through the same casing. The temperature and air flow rate are regulated by means of the controls located on the control panel.
Cooling System Diagram
1 - Expansion tank; 2 - Cover; 3 - Built-in silica gel tank; 4 - Intake pipe; 5 - Radiator; 6 - Thermostat; 7 - Ventilation tube; 8 - Flow from the engine to the radiator; 9 - Flow from the radiator to the engine; 10 - Pump of the cooling system; 11 - Oil cooler; 12 - Cylinder block; 13 - Cylinder head; 14 - Heater delivery pipeline; 15 - Windshield washer heater; 16 - Heater radiator; 17 - Double pulsation valve; 18 - Circulation pump; 19 - Heater return pipe
The heat generated during engine operation is transferred by the coolant to the heater radiator located in the passenger compartment. The intake airflow from the ventilation system passes through the radiator and is heated by the heat of the engine coolant flowing inside the radiator. The degree of heating is controlled by mixing in a certain ratio of cold and hot air using a mixing damper with a servo.
Used air is removed from the passenger compartment through vents with non-return valves.
The increase in air flow through the heat exchanger is provided by a fresh air fan.
If it is necessary to turn off the fresh air supply, for example in case of a bad smell, the system switches to circulation mode, in which only the air available there circulates in the passenger compartment.
Switching the system to circulation mode is confirmed by the activation of the control lamp (see chapter Manual).
Cabin air conditioning system
Functional diagram of a typical air conditioning system
Working path of the front circuit of the A/C system
A - Coolant inlet; B - Reverse flow of coolant; 1 - Engine; 2 - Block of pumping of interior heating; 3 - Heat exchanger for interior heater; 6 - Windshield heating radiator (wiper); 7 - Thermal valve, heated windshield (wiper); 8 - Thermal valve, windshield washer fluid heater
The working path of the rear circuit of the A/C system
A - Coolant inlet; B - Reverse flow of coolant; 1 - Engine; 2 - Block of pumping of interior heating; 3 - Heat exchanger, heating system; 4 - Bleeding unit, rear climate control; 5 - Heater heat exchanger, rear climate control; 6 - Windshield heating radiator (wiper); 7 - Thermal valve, heated windshield (wiper); 8 - Thermal valve, windshield washer fluid heater
Work on the air conditioning system must be carried out by a specialist workshop. Never open the refrigerant circuit, as the refrigerant may cause frostbite if it comes into contact with the skin.
The air conditioning system can lower the interior temperature below the outside temperature.
When the system is operating, the humidity in the passenger compartment decreases. In wet weather, the incoming fresh air is pre-cooled and then reheated to the set temperature. Thus, it is dried. With this procedure, the fogging of the glasses is removed.
The air conditioning system consists of a compressor, condenser, throttle, evaporator, refrigerant tank and piping. Refrigerant circulates in the system (type R134a), which, depending on temperature and pressure, can be in a liquid or gaseous state.
The air conditioner compressor is driven by the engine crankshaft through a ribbed belt. It creates a pressure of up to 30 bar in the cooling circuit of the plant, as a result of which the refrigerant, which is a gas, is heated. In the condenser, the refrigerant is cooled by the air flowing from outside (cooling air remains in the outside environment). As a result, the heated refrigerant condenses, turning into a liquid. Having a lot of pressure, it is passed through the throttle, as a result of which its pressure drops. After that, the refrigerant evaporates in the circuit, while being strongly cooled. In the evaporator, the refrigerant removes heat from the air blown through it. As a result, the air is cooled. Cooled air enters the car interior. As a result of heating in the evaporator, the refrigerant turns into a gas and enters the compressor under low pressure, after which the circulation process is repeated.
Air Conditioner Maintenance Safety Precautions
The air conditioning system must only be serviced by trained technicians who are trained in safe work practices using the proper equipment, following depressurization procedures, and who are familiar with the collection and storage of automotive refrigerant.
- Avoid skin contact with refrigerant;
- Wear protective goggles when working near the air conditioning system;
- If refrigerant comes into contact with skin or eyes, do not rub the affected area. Rinse immediately with cold water for at least 15 minutes. Contact a doctor or health facility immediately. Self-medication is not allowed;
- In a new cylinder, the refrigerant is stored under pressure. Store the cylinder at a temperature not exceeding 50°C. Take measures to prevent the cylinder from falling from a height or other situations that may lead to its damage;
- Work should be carried out in a well-ventilated area. The refrigerant evaporates quickly, leading to a decrease in oxygen supply and difficulty breathing;
- The gaseous refrigerant is heavier than air and must collect relatively quickly at the bottom, for example, under a car;
- When the refrigerant burns, poisonous gas is produced. Keep refrigerant away from open flames. Do not smoke. When using a flame leak detector, avoid breathing smoke;
- When carrying out welding work near the air conditioning system, exposure to high temperature or an open flame. Overheating can lead to an increase in pressure in the system and ignition;
- Cleaning the condenser or evaporator with steam is not permitted. Use only cold water or compressed air.