Scheme of the movement of air flows in the ventilation, heating and air conditioning system: 1 - windshield air deflectors; 2 - dampers for the distribution of air flows to the windshield deflectors and instrument panel deflectors; 3 - instrument panel deflectors; 4 - air ducts for heating the foot area of the driver and passengers; 5 - damper for distributing air flows to the instrument panel deflectors and to the air ducts for heating the driver's and passengers' feet area; 6 - heater radiator; 7 - damper of the recirculation system; 8 - air intake box; 9 - air intake in the passenger compartment; 10 - fan impeller; 11 - fan motor; 12 - air conditioner evaporator; 13 - drainage hole for draining condensate; 14 - damper of the temperature controller; 15 - housing block of the heating and air conditioning system
Schematic diagram of the movement of the refrigerant in the air conditioning system: 1 - combined pressure sensor; 2 - section of the high pressure pipeline; 3 - receiver-drier; 4 - service valve of the high pressure line; 5 - condenser (air conditioning radiator); 6 - fan of the condenser and radiator of the cooling system; 7 - air conditioner compressor; 8 - section of the low pressure pipeline; 9 - service valve of the low pressure line; 10 - thermal bulb; 11 - heater fan; 12 - evaporator; 13 - thermostatic valve
Technical data
heater | Maximum heating power, kcal/h | 4 500 ±10% |
Cooling | Maximum cooling capacity, kcal/h | 4100±410 |
Compressor | Type | 10RA15C |
Performance, cm3 | 155,3 | |
Condenser | Cooling power, kcal/h | 11000 |
Electromagnetic clutch | Friction at rest, N·m | 5,4 |
Triple pressure sensor | High pressure, kg/cm2 | OFF:32 |
Average pressure, kg/cm2 | OFF:14 | |
Low pressure, kg/cm2 | OFF:2 | |
Evaporator | Air conditioner on/off | OFF:1,5±0,6°C |
refrigerant | Type | R134a |
Quantity, g | 500±25 |
General information
The compressor driven by the car engine compresses the gaseous refrigerant to a high pressure, while the temperature of the refrigerant rises significantly. Then the compressed and heated refrigerant is fed into a condenser mounted on the radiator of the cooling system. The condenser cools the gaseous refrigerant, which turns into a liquid. The liquid refrigerant enters the receiver/dryer, where it is separated from the water, then it supplies the liquid to the evaporator located in the heater unit in the vehicle interior. In the evaporator, the liquid refrigerant evaporates, turning into a gaseous state, and reduces the temperature of the air entering the passenger compartment. Next, the gaseous refrigerant enters the compressor and the cycle repeats again.
The A/C relay controls the condenser fan and A/C compressor circuits. The relay is controlled by the engine control unit. If the coolant exceeds a certain temperature, the engine control unit turns off the relay, which turns off the air conditioning system. When the engine is started or the vehicle accelerates, the engine control unit turns off the relay, as a result of which the air conditioning system is turned off within 5 seconds.
The fan blows air through the evaporator core, which increases the flow of cool air into the vehicle interior. The fan speed is determined by the position of the fan switch and the resistor pack.
The air conditioning compressor is the primary element of the air conditioning system. If the air conditioning compressor fails, there is no compression and no movement of the refrigerant through the air conditioning circuit. The air conditioning compressor is driven by a belt from the crankshaft pulley.
The A/C compressor clutch engages the compressor. The clutch is electromagnetically controlled.
The condenser is installed in front of the radiator. The condenser fan increases the air flow through the condenser.
The fan/evaporator assembly contains the fan motor, A/C relay, evaporator core and expansion valve.
The evaporator core performs the functions of cooling and dehumidifying the air. When the air is cooled, moisture from the air is deposited on the evaporator and cooled dry air enters the car interior.
The expansion valve allows high pressure liquid refrigerant to expand into the evaporator. The valve passes a certain amount of liquid refrigerant to prevent flooding of the evaporator.
The dehumidified air can be reheated by passing through the heater core. The heater core is heated by the hot coolant passing through it.
The receiver/dryer receives liquid refrigerant from the condenser, where water is removed from it and then the refrigerant enters the evaporator.
The air conditioning system is charged with R-134a refrigerant.