Air flow distribution
Air Conditioner Circuit Diagram
1 - Fan; 2 - Evaporator; 3 - Expansion valve; 4 - Reservoir; 5 - Condenser fan; 6 - Capacitor; 7 - Compressor; a - Outside air for cooling the condenser; b - Warm air exhausted to the outside; c - Uncooled air passing through the fan; d - Cooled air entering the cabin; A - High pressure, gaseous; B - High pressure, liquid; C - Low pressure, liquid; D - Low pressure, gaseous
Additional electric heater. Diesel engine
1 — Electric heater block
2 - Sealing gasket
3 - Heating element
Air Flow Control and Air Conditioning Filters
Fresh air supplied by the ventilation system to the car's interior through coarse and fine filters can be heated or cooled depending on the choice of the driver and passengers. The heater, on models without air conditioning, or the air conditioner is located in the interior, in a housing under the instrument panel. The entire flow of air supplied to the interior is directed for heating or cooling through the same casing. The temperature and speed of the air flow are regulated using controls located on the control panel.
The fan speed is controlled by an electronic device. The heat generated by the engine is transferred by the coolant to the heater radiator located in the passenger compartment. The air flow supplied by 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 regulated by mixing cold and hot air in a certain ratio using a servo-driven mixing flap.
Used air is removed from the passenger compartment through ventilation openings with check valves.
The fresh air fan increases the air flow through the heat exchanger.
If it is necessary to turn off the fresh air supply, for example, due to a bad smell, the system switches to recirculation mode, in which outside air does not enter the cabin.
Switching the system to circulation mode is confirmed by the control lamp lighting up.
If the vehicle is equipped with a diesel engine, there is an additional electric heater built into the engine cooling circuit that is switched on at low outside air temperatures. If the outside temperature drops below +8°C and at the same time the coolant temperature is below 70°C, the additional heater switches on, depending on the position of the interior temperature regulator, and automatically raises the coolant temperature, which ensures heating of the vehicle interior.
The additional heater is located on the cylinder block, to the left above the starter, looking forward.
Work on the air conditioning system must be performed by specialists.
The air conditioner is capable of both heating and cooling, as well as dehumidifying the air entering the cabin. In damp weather, the incoming fresh air is pre-cooled, after which it is heated again to the set temperature. At the same time, condensation of excess moisture in the air occurs, i.e. its dehumidification. This eliminates fogging of the windows.
The dehumidification mode, depending on the air humidity, has three control stages.
The air conditioner consists of a heater and a refrigerator. The air conditioner refrigerator consists of a compressor, condenser, throttle, evaporator, refrigerant tank and pipelines. The system circulates a refrigerant (type R134a), which, depending on the temperature and pressure, can be in a liquid or gaseous state.
The air conditioner compressor is driven by the engine crankshaft using a ribbed belt. It creates a pressure of up to 30 atm. in the cooling circuit of the unit, as a result of which the refrigerant, which is a gas, heats up. In the condenser, the refrigerant is cooled by outside air (not coming to the salon). As a result, the heated refrigerant condenses, turning into a liquid. Having high pressure, it passes through the throttle, as a result of which its pressure drops. After this, the refrigerant evaporates, simultaneously cooling down greatly. In the evaporator, the refrigerant takes heat from the air blown through it. The air cools. The cooled air enters the car's interior. As a result of heating in the evaporator, the refrigerant turns into gas and enters the compressor under low pressure, after which the circulation process is repeated.
The car can be equipped with automatic air conditioning upon request (air conditioning system). In this case, two installation options are possible, differing in touch control and comfort automation.
Safety precautions when servicing an air conditioner
The air conditioning system must be serviced only by trained technical personnel who are trained in safe operating practices using the proper equipment, observing depressurization rules, and are familiar with the methods of collecting and storing automotive refrigerant.
Avoid contact of refrigerant with skin.
Wear safety glasses when working near the air conditioning system.
If refrigerant gets on your skin or eyes, do not rub the affected area. Rinse immediately with cold water for at least 15 minutes. Seek immediate medical attention or medical attention. Self-medication is not allowed.
The refrigerant in a new cylinder 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 cause damage to it.
Work should be carried out in a well-ventilated area. The refrigerant evaporates quickly and is odorless. Its accumulation leads to a decrease in oxygen access and difficulty breathing.
The gaseous refrigerant is heavier than air and should collect relatively quickly at a low level, such as under a car.
When refrigerant burns, it produces toxic gas. Keep refrigerant away from open flames. Do not smoke. Avoid inhaling smoke when using a flame leak detector.
When welding near an air conditioning system, exposure to high temperatures or open flames may occur. Overheating may cause pressure in the system to increase and cause a fire.
Cleaning the condenser or evaporator with water vapor is not permitted. Only cold water or compressed air should be used.