How does car heating work?

How does car heating work on the blower side, blower side and water circuit? Indeed, the study of heating consists of studying two different circuits: one that produces heat and the other that distributes it in the interior of a car.

First, let's start with the heating circuit on the ventilation side.

See also: breakdowns associated with heating a car

Heating circuit (ventilation side)

Here is a diagram of the car's ventilation so you know how the heat intensity is regulated (see also the operation of the automatic air conditioner). If there is an air conditioner, an evaporator will be present (this is the case in the diagram of my example), otherwise the mixture will consist of ambient air (outside) and air heated through the radiator. The more the dampers are opened in front of the radiator, the more heat will be. You can read more about how the blower works here.

The air heats up more or less depending on the heat of the heating radiator, the opening of the blinds and the intensity (coldness) of the air conditioner evaporator. When the heating is turned on, the evaporator (or rather the air conditioner compressor) is turned off and the blinds open to the maximum.

The heater is also an integral part of the defrosting device. Here, through fogging under the windshield (you cannot put too many heating resistors, as, for example, on the rear window)

Heating circuit diagram (radiator water circuit)

Together with the vehicle's cooling system, the heater uses water from the engine to heat the passenger compartment. Therefore, it should be noted that heating does not cause excessive consumption, unlike air conditioning, which requires energy to compress the gas (through the crankshaft pulley). But let's take a closer look at how the circuit works and how it is controlled.

In this diagram I am showing also cooling circuit so you can see how two chains

connected

... Because you must know that the heat of the water contained in the cooling circuit is used to heat the vehicle. However, you must

focus on the top

that the heating circuit. The heating is off here, actuator / valve (top left) prevents hot water (highlighted in red) from the cooling circuit from entering the heating radiator (small one at the top, the bottom one is for cooling water in the engine).

When we turn on the heatingthen crane (top left corner) let it happen water burning to the little Radiator which will then become very hot. a FAN go then send air into the passenger compartment through the ventilation nozzles. In the end, you get hot air

On older cars, the valve was operated by a lever (cable connection between the regulator and the valve), while recent cars use solenoid valves / solenoids electrically controlled by a computer (allowing automatic air conditioning).

Engine heating and overheating?

If the engine overheats, the heater should be turned on to maximum to help the engine cool down. Indeed, your vents will then serve as additional auxiliary radiators and the water will cool faster.