Air flow distribution
Air conditioning 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 vented to the outside; c - Uncooled air passing through the fan; d - Cooled air going into 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
Airflow control and air conditioning filters
Fresh air supplied by the ventilation system to the car 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 air conditioning is located in the passenger compartment, in a 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.
The fan speed is controlled by an electronic device. 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 regulated by mixing a certain ratio of cold and hot air using a mixing damper with a servomotor.
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 no outside air enters the passenger compartment.
Switching the system to the circulation mode is confirmed by the ignition of the control lamp.
If the vehicle is equipped with a diesel engine, then there is an additional electric heater built into the engine cooling circuit and switched on at low outside temperatures. If the outside temperature drops below +8°C and at the same time the temperature of the coolant is less than 70°C, the additional heater turns on, depending on the position of the interior temperature regulator, and automatically raises the temperature of the coolant, which ensures heating of the vehicle interior.
The auxiliary heater is located on the cylinder block, to the left above the starter, looking forward.
Work on the air conditioning system must be carried out by specialists.
The air conditioner is capable of both heating and cooling, and dehumidifying the air entering the passenger compartment. In wet weather, the incoming fresh air is pre-cooled and then reheated to the set temperature. In this case, condensation of excess moisture in the air occurs, i.e. his drying up. This prevents fogging of the glass.
The dehumidification mode, depending on air humidity, has three steps of management.
The air conditioner consists of a heater and a refrigerator. Refrigerator air conditioner - from the compressor, condenser, throttle, evaporator, refrigerant tank and pipelines. Refrigerant circulates in the system (type R134a), which, depending on temperature and pressure, can be in a liquid or gaseous state.
The air conditioning compressor is driven by the engine crankshaft using a ribbed belt. It creates pressure up to 30 atm. in the unit's refrigeration circuit, whereby the refrigerant, which is a gas, is heated. In the condenser, the refrigerant is cooled by outside air (not entering the salon). 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, while being strongly cooled. In the evaporator, the refrigerant removes heat from the air blown through it. The air is cooling. 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.
On request, the car can be equipped with automatic air conditioning (air conditioner). Two installation options are possible, differing in touch control and comfort automatics.
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, in compliance with depressurization procedures, and who are familiar with the methods of collecting and storing 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 and is odorless. Its accumulation leads to a decrease in oxygen supply and difficulty breathing.
The gaseous refrigerant is heavier than air and must collect relatively quickly at the bottom, such as 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 cause system pressure to rise and ignite.
Cleaning the condenser or evaporator with steam is not permitted. Use only cold water or compressed air.