Heater cycle using hot water generated by the vehicle engine heat heater. Even at very low temperatures, automotive engine produces too much heat. Heat escapes from the engine block, running a mixture of water and glycol through the engine, cylinder head. In water-glycol mixture is supplied from the engine through a belt drive the engine water pump. Hot water is sent to the car's radiator, where heat is transferred to the air. Radiator transfers the heat to the engine in combination with RAM air being forced against the sink with the forward movement of the vehicle, when the vehicle is moving. When the car is not moving very quickly, or it is stopped, the air flowing through the radiator with engine or electric radiator fan. Radiator placement and volume depends on engine design and size, figure 28-1.
When the car engine's temperature rose up to a certain point, the water valve automatically sends some water-glycol mixture for heater. Heater is installed inside the vehicle heating and cooling module, which is usually located inside the dashboard of a car.
This warm water flows through the heater. Heater with heat exchanger is used to distribute heat the passenger compartment. Fig. 28-2 illustrates one type of aluminum heater. Air is supplied to heating and cooling module, either inside or outside the car, and went through the heater system blower, warm air is then sent through the ducts of the passenger compartment.
The heating system is also used to provide warm air vehicle windows for cleansing and demisting in cold weather. Warm air is supplied to the front and side Windows using a series of small ducts and vents. Warm air heats the windows to clear the fog inside or ice on the outside of the window. Heating system control is achieved by using a series of shock absorbers inside the module to distract the air or on the floor ducts, dashboard channels, or only to the windshield and side Windows to defrost and defog conditions.
Air-Conditioning 
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