How does a car heater work? Installing autonomous heaters Controlling the car heater

The heating system of a car for many models is arranged and works on a similar principle. Understanding the principle of turning on and adjusting the speed of the interior heater fan will be very helpful when looking for a malfunction on your own (for example, if you have one).

General air circulation pattern

The intake of air into the passenger compartment is carried out by a fan, which can be installed in the passenger compartment or behind the motor shield. Above the electric motor is located. If heating is required, the air flow passes through the heater core. The stove radiator is connected to the car's cooling system, so when the engine heats up, the circulating liquid from the engine cooling system heats the stove radiator cells. Therefore, passing through the honeycomb, the air flow also becomes warm.

Air flaps

The redirection of air flows for temperature control is carried out by a special damper. Damper control types:

• mechanical. The damper drive is connected directly to the switch in the passenger compartment by means of rods and cables. In this case, the driver, moving the regulator, manually doses the temperature of the incoming air;
• electronic. The damper is equipped with a servo drive. The electric motor changes the position of the damper, receiving commands from the control unit. This scheme is used on cars with air conditioning. It is enough for the driver to set the desired temperature in the cabin in the on-board computer, after which the electronic control unit, focusing on temperature sensors, will control the air damper servo.

Channels leave the stove fan into the cabin, through which air can be supplied to the windshield, to the legs or through the central deflectors. Depending on the scheme of operation, the modes can be either combined or single, when all the intake air is supplied to only one zone. Mode switching can be carried out mechanically or with the help of a servo drive and a control unit. The mechanical method involves the direct connection of the air dampers to the switch on the dashboard. The electric damper drive allows you to control them by pressing a button, as well as to realize automatic control of the electronic unit of the interior air conditioning system.

recycling

In recirculation mode, the main air damper closes, after which the stove fan begins to take air from the passenger compartment. This mode of operation allows you to block the access of unpleasant odors and polluted air from the street, if, for example, you are driving behind a car on a dusty gravel road.

In winter, the recirculation mode allows you to warm up the car interior faster, since not frosty, but warm cabin air passes through the heater radiator. Accordingly, in the summer, recirculation simplifies the cooling process for the air conditioner.

Types of recirculation drive:

How does a stove fan work?

The car interior heating fan is a conventional AC motor. It can be either a simple axial fan or a diametrical version, which is most often installed on modern cars. The device of the inside of the stove fan is no different from the device of a conventional AC motor with excitation from permanent magnets.

Of greater interest to us is the operation of the electric motor at different speeds. This possibility is realized by including additional resistance in the circuit. Resistors increase resistance, which reduces the amount of current flowing in the circuit. Therefore, the fan starts to rotate more slowly. The value of the resistor determines how much current will drop in the circuit. The last fan speed is direct as no resistance is included in the circuit. This allows the heater fan to remain operational even if the resistor fails.

Wiring diagram

The figure shows the simplest circuit diagram for connecting a stove fan. When the positive terminal of the fused switch is closed to terminal H, current flows directly to the motor, causing it to rotate at maximum speed. When the positive contact is closed with the V pin, current flows through the resistance, which reduces the fan speed.

The heater motor of the VAZ 2108, 21099 models already has 3 fan speeds. When the positive output of the mode switch is closed to 1 contact, 2 resistances are connected in series in the circuit, so the rotation speed of the electric motor will be minimal. When power is applied to the second pin of the mode switch, current will flow through one resistor, which will correspond to the average rotation speed. Accordingly, pin 3 is designed to supply power bypassing the additional resistor and corresponds to the fastest rotation speed.

This is the principle of turning on the heater electric motor on most cars. For a better understanding of the scheme, we suggest watching the video.

Automated control system

In the diagram, we still see an additional resistor, only now all commands are transmitted to the electric fan not directly from the speed switch knob, but through the heating system control unit (No. 3). The unit also controls the saloon recirculation solenoid valve and the damper drive micromotor. This scheme uses only one temperature sensor in the cabin, but in more advanced versions there are also intake air temperature sensors, as well as sensors that measure the temperature of the air supplied to the passenger compartment at several points.

Ventilation and heating system VAZ 2109

As you know, on the VAZ 2109, interior heating is provided by air heated by a radiator. On the VAZ 2109, heating and ventilation of the cabin are interconnected and represent a kind of special system.
In this article, we will consider the general principles of the VAZ 2109 heating and ventilation system.

Heating system

As a rule, the heating system of a VAZ 2109 car consists of several main elements and assemblies, shown below.

heater

The heater or stove itself is the main link in the heating system. It is fastened with 4 nuts in the passenger compartment under the bolts.
There are air ducts installed on the stove, which are fixed to the instrument panel from below. Sealing gaskets are required in their design.

What is the oven made of?

The heater of the VAZ 2109 system consists of:

• 2 plastic casings interconnected by brackets (fastening brackets are connected along the perimeter);
• Special harness, laid in the grooves for sealing;
• An electric fan that forces air into the passenger compartment and is screwed on top of the stove;

Note. The motor is mounted on the stove so that its dismantling is convenient and does not cause any difficulties.

• Heating radiator, which is installed in the heater casings;
• faucet;
• The cooling system pump, which circulates fluid through the radiator;
• Stove handles that allow you to control the heater.

Furnace handle control

You can achieve the most comfortable conditions in the cabin if you move the stove control knobs and adjust the position of the nozzles in the following way:

• The upper right knob regulates the air supply to the legs of the driver and front passenger (if the position is extreme left - the supply is maximum, if the knob is in the extreme position on the right - the supply is blocked).

• The top left knob controls the airflow to .
• The lower knob regulates the temperature of the air that enters the passenger compartment (leftmost position - cold air, rightmost position - hot).
• The left rotary button, visible in the photo above, connects the stove fan. It will increase the air supply.
  The button has 4 positions: 0 - off, 1 - initial speed, 2 - average speed, 3 - maximum speed.

If the air temperature outside is minus 20 degrees Celsius, the stove starts to provide the maximum heating mode automatically.
The indicators in this case are as follows:

• +20 degrees Celsius is provided in the vehicle interior;
• +25 degrees Celsius is provided in the area of ​​\u200b\u200bthe legs of the passenger and driver.

Radiator

This is one of the most important parts of the car heating system. Unfortunately, during the passage of a certain amount of time begins to flow.
Traces of antifreeze on the passenger mat or under the mat are a symptom of a heater radiator leak. In this case, on the VAZ 21093, the interior heating will be completely broken and the radiator will have to be replaced.

Types of radiators

For the VAZ 2109, there are several main types of radiator.
The most popular are:

• Aluminum original;
• Aluminum aftermarket;
• Copper.

Of all this trinity, the most expensive is a copper radiator, which can be soldered in case of emergency and which is largely more reliable than the others.
less reliable, but cheaper. The original one costs about 700 Russian rubles, while the non-original one can be bought for 400 rubles.
The design of both types of aluminum radiators is different:

• The plates in the original radiator are much denser than in the non-original version.
• The heat exchange area in a non-original radiator is less than in the original one.
• The construction of the aluminum original radiator is much stronger.
• On the original radiator, the air begins to warm up already at a coolant temperature of 60 degrees, and in a non-original one only at 90 degrees and above.
• Inside the original radiators there are special coolant swirlers made in the form of spiral ribbons. They significantly increase work efficiency, because the coolant does not “fly” through the radiator, but circulates slowly, giving off heat more efficiently.

Radiator replacement

It is needed if the old one is no longer functioning efficiently enough.
The replacement is carried out in the following way:

• The front panel is unscrewed.
• The radiator is dismantled and removed carefully from its place.
• A new one is being installed.

Note. Self-taught masters recommend removing the radiator from the bottom of the instrument panel, where the lower shelf prevents this from being done. This shelf is sawn off, and after installing a new radiator, it is mounted on self-tapping screws, and in the future its removal will be an easy task.

On the VAZ 2109, the interior heating system is notable for exhaust ventilation, which provides air exhaust from the passenger compartment. This ventilation is located on the back of the VAZ 2109.
In addition to providing air suction, exhaust ventilation is also carried out through the vacuum that occurs at the deflectors when the vehicle is moving.

valve

Exhaust ventilation on some versions of the VAZ 2109 is equipped with valves on a regular basis, which serve to increase the amount of fresh flowing air in the cabin.
In wet weather, these same valves help reduce fogging of the windows. Basically, the VAZ 2109 models are not endowed with these valves, and most owners install them on their cars on their own.
What needs to be done in order to install the valve:

• It is enough to make technological holes in the body.
• Remove the rear bumper.
• Mark seats for valves.
• Insert valves.

Features of the operation of the stove and its refinement

Owners of a VAZ 2109 car are often worried that over time the stove starts to heat up badly. Needless to say, driving in such a car will already be uncomfortable.
In such cases, only upgrading the stove can solve the problem.

Improvement methods

Lots of ways. Below are a few of them.

Throttle lever

So:

• You can simply tighten the stove damper control cable to solve the problem. 1-2 turns of the cable are made, located on the damper control lever (the lever itself is located on the stove body, near the gas pedal).

Note. The joints of the air ducts and the edges of the heater damper are pasted over with foam rubber, which is not completely compressed.
In this regard, a gap of several millimeters is formed, and the damper does not close completely. The above method will help you set the lever properly.

• You can get to the control lever in another way. There is a place on the driver's side and you need to try to reach out with your hand and tighten the lever, be sure to turn on the heater fan.
  During the adjustment process, the left ear will be in the area of ​​​​the air duct nozzle and thus it will be possible to hear how the sound of the outgoing air changes.

Heater faucet

The reason for the inefficient operation of the heating system may also be the incomplete opening of the stove faucet. Such a problem, by the way, is found in almost all front-wheel drive cars of the Vaz family.

• The solution to the problem can be the tension of the valve control cable and the subsequent fine-tuning of the control lever to the maximum open position.

Note. In this case, it is possible that the valve will now not fully close. But this is not the problem, but that after adjusting the lever, the damper may lose its tightness and begin to leak (seen in the photo).
In this case, it can be advised to wrap the leak with a cloth that has been soaked in sealant and fix it all with cold welding.

air ducts

The reason for the poor functioning of the heating system may be leakage of air ducts. The air that is blown by the heater fan partially goes into the cracks, and the air flow, thereby weakens and cools down.

• The solution can be complete sealing and gluing of the joints that are located in the places where air follows from the stove to the exit.

Air locks

In addition, the reason for the poor operation of the stove can be air pockets formed in the heater radiator.

• The solution would be to stop the car with the front part on some hill. Then you should open the heater tap completely and press the accelerator pedal several times.

Above were some ways to fix problems with the heating and ventilation system of the VAZ 2109. The instructions and advice given by experts is a chance to “cure” your car with your own hands, thereby saving a lot on repairs.
As you know, the price of technical procedures in the service station is not low, and if they are carried out regularly, the family budget will noticeably become scarce. It is recommended to use photo and video materials in the process of independent work.

The heater is necessary for the high-quality operation of the car's stove in the winter. Only under the condition of the normal functioning of the heating system will the driver and passenger be as comfortable as possible. Even in the most modern models of domestic cars, the heating system is one of the most vulnerable parts. Component failure is very common. In summer, drivers usually turn a blind eye to malfunctions, but with the onset of the first cold weather, corrective measures must be taken.

Before proceeding with the repair, it is necessary to carry out diagnostics in order to understand which particular component in the heating system has broken down. The easiest way is to go to a service station where an experienced car mechanic will help you troubleshoot. Of course, you will have to pay a tidy sum for diagnostics. But on domestic cars, all repairs can be done independently so that the autonomous heater works as expected.

Features of the control unit

Very often, when the stove is not working, it turns out that the malfunction lies in the control unit. VAZ-2110 injection cars, for example, come from the factory with microcontroller automatic heating control systems. If one or more fan modes suddenly refuse to work, then the malfunction lies in the control unit.

With the help of an electronic system inside the cabin, the temperature that the driver sets will always be maintained. Of course, the air will not be cooled in summer. But in winter, the stove will perfectly warm the air in the cabin. On VAZ-2110 vehicles manufactured before 2003, an old-style stove is installed. On them, the heater control unit (2110) has a different design and is not replaced by new devices.

Right control handle

The electronic unit consists of a microcontroller, which receives signals from the handles on the front panel. The right switch is needed in order to set the desired fan speed. A resistor is installed in the stove, with the help of which the engine speed is adjusted. If an old-style stove is installed on your car, then there are several resistances that are designed to adjust the rotation speed. But the stoves of the new model are equipped with modified resistances.

Left control stick

The handle located on the left is necessary to select the temperature in the car. Depending on the position of the handle, a signal is sent to the damper electric actuator about what temperature it is necessary to set. The microcontroller adjusts the valve position. The regulator allows you to set the temperature from 16 to 30 degrees Celsius.

On cars until 2003, stoves were installed, which had controllers with four and five positions. At the moment, you are unlikely to find them on sale, as the products have been discontinued. Before buying spare parts needed for repairs, check which particular heater control system is installed on your car.

How to diagnose the system

The control system module is located in the center console. It is possible to repair the heater's electronic control unit, but only if you have at least general knowledge of electrical engineering. The easiest way to check the health of the device is to replace it with a known-good one (borrowed from a car with the same heater). Before replacing the blocks, be sure to disconnect the negative terminal from the battery - this will avoid a short circuit in the power circuits.

Other diagnostic methods are not provided, you can only visually assess the condition. If there is damage to the case or board, then the device will not be able to work normally. The slightest damage to the printed circuit leads to the fact that the entire control system stops working, the set temperature is not maintained at the desired level.

Dismantling the device

To remove the device, do the following:

1. Remove the buttons located on the sides of the stove.
2. Move both knobs to the positions corresponding to "0" (fully counterclockwise).
3. Now you need to carefully pull out the module.
4. As soon as the wire connection pads appear, carefully disconnect them.

Try not to damage the wires during work, otherwise even a new, fully functional heater control unit will not be able to function normally. Installation is carried out in the reverse order.

Moreover, you can only connect the wires and check the performance of the entire system with a new device. If the heater still does not work, then you will have to look for a malfunction in other components of the car's stove.

How to disassemble the device

If during the diagnosis it turned out that the VAZ-2110 heater control unit is faulty, then you can try to repair it. Of course, it is best to install a new element. But its cost is quite high, and malfunctions in the device circuit are usually very simple. You only need to have basic knowledge of electrical engineering, as well as be able to use a soldering iron and a multimeter. Before starting work, be sure to disassemble the control unit.

Since the block has already been dismantled, it remains only to disconnect the front cover, on which the regulators are located. After that, it is necessary to detach a special glass lining. Next, use a screwdriver to unscrew the two screws that are on the front panel. Another one is located at the back. Then carefully remove the top cover of the control box. Be careful not to damage the contacts and parts inside the device.

Checking schema elements

Inside the case you will find a printed circuit board on which jumpers, contacts, resistors, a microcontroller, capacitors are located. They are responsible for the normal operation of all heating systems. The GAZ-3110 heater control unit consists of the same elements. There may be such breakdowns:

1. Carefully examine all the elements to detect damage. Very often, under the action of high temperature, the printed circuit board heats up, because of this, the contacts are disconnected.
2. It is possible that for repair it will be enough only to solder the joints.
3. Take a close look at the tracks that supply power to the electrical circuit. If it has damage that is visible to the naked eye, then this problem should be corrected.
4. In the event that there is damage to capacitors or resistors, new ones must be installed in their place. To find out their parameters, you need to use the literature, which describes in more detail the scheme of the heater control unit.
5. If there is no visible damage, then it is necessary to use a multimeter to check the performance of all resistors in the circuit, as well as the connection of the elements. In other words, you just need to ring all the tracks.
6. After eliminating all the breakdowns that have been identified, it is necessary to connect the product to the power supply. Then put the multimeter into voltage measurement mode. Check the test points on the board for power.

After repairing the unit, it is necessary to assemble it in the reverse order and install it in place. After connecting power to the battery, check the operation of the entire system. If it does not recover, then you will have to replace the heater control unit.

How to adjust the microcontroller

It is provided that he must warm up the interior to the temperature that the driver sets, no more than 15 minutes. Moreover, the permissible deviation is less than 2 degrees Celsius. The driver sets the desired temperature using the knob. To check the correct operation of the heating system, you must use a mercury or digital room thermometer. Set the desired temperature, then turn on the heating.

Keep track of what readings it gives. If after 15 minutes the set temperature is not reached in the cabin, it will be necessary to adjust the controller. The procedure is quite simple: you just need to pull out the entire module, then turn the temperature control knob to the maximum, then in the opposite direction. After this simple manipulation, it is necessary to install the device in place. Check if the interior heater control unit is working properly.

Heater flaps

Check how the dampers in the stove work. If there are extraneous sounds during the switching of the temperature mode, then be sure to check whether the dampers work correctly. In the case when cold air enters the cabin from the outside without problems, but hot air does not pass, then most likely the problem lies in the lower damper.

If hot air enters the passenger compartment normally, but cold air does not pass, then the malfunction is in the upper damper. On all cars of the tenth model, dampers very often fail, as they are made of plastic. Under the influence of temperature, this plastic is deformed, as a result of which the flaps stop moving. It would be much better to install aluminum dampers instead of regular dampers, they are resistant to temperature changes.

Conclusion

You can independently perform minor repairs to the electronic unit, but if you have the slightest knowledge of electrical engineering. It is also desirable to diagnose all electric drives and the condition of the dampers. It often turns out that hot air does not enter the car interior heater due to a faulty filter: leaves or other objects got inside. Carefully monitor the condition of your car and try to change all filter elements in a timely manner. Only in this case will the heater be completely autonomous, your intervention during operation will not be required.

If you decide to repair your car yourself, you need to know the structure of its components well and be able to read the drawings. Of course, such skills come with experience in operating and maintaining the VAZ 2110. This time we will study in detail the operation of the heater. If the heating system is functioning properly, then inside the "ten" it will be comfortable for both the driver and his companions. This material contains schemes of the stove and a description for them. This information is also present in the instruction manual, but we try to describe complex processes in simple language. Our task is to convey important information to beginners and already experienced motorists.

Stove device

The device of this node includes several devices. The radiator is the main element of the stove - it heats the air entering the cabin. It is located under the hood. The next component is an air distributor equipped with special pipes that run through the 2110 cabin.

If we compare the "top ten" with previous models, an important innovation has appeared in its heating system - an evaporator (the scheme includes it in the list). The device is installed in the air conditioner. Not all owners are aware of its existence, as it rarely fails.

To control the operation of the heater, a SUAO unit is installed in the VAZ 2110 car, which is called a controller in the technical instruction manual. The unit works together with the temperature sensor in the cabin, it is also called the ceiling. The sensor reports the temperature to the block, then this indicator is compared with the temperature set on the handle. If the indicators differ by more than 2 °, warm or cool air is supplied to the VAZ 2110 cabin.

It is worth dwelling on the handle in more detail, or rather, on its extreme positions - MAX and MIN. If the stove knob is set to one of these indicators, heat is supplied without the operation of the temperature sensor in the cabin. The scheme includes all of the above elements.

The “tens” heater device includes another unit - a gearmotor, which is responsible for opening and closing the damper. A miniature electric motor performs an important task in the operation of the heating system, as indicated by the diagram. If the gearmotor is faulty, the system will only produce cold or hot air. In the event that the gearmotor fails with the damper closed, the system will cease to function. We have described the main components of the VAZ 2110 heater, the diagram contains a more detailed list.

Let's single out the main components of the system:

• Radiator.
• Air distributor.
• Block SUAO.
• ceiling sensor.
• Lever.
• damper.
• Motor reducer.

Radiator

In the heater system, a radiator is installed for heating, which enters the VAZ 2110. It is also called a heat exchanger. Heating is performed by the heat of the antifreeze. This component is connected to the engine cooling system by pipes and hoses. Antifreeze constantly circulates through the heat exchanger of the stove. The damper, based on the commands of the unit, directs the incoming air to the radiator or directly to the passenger compartment. If the heater damper is in an intermediate position, then one part passes through the heat exchanger, and the second bypasses the radiator. If we compare this part of the stove with previous generations of the VAZ, then it has a number of useful improvements, and the diagram demonstrates this.

SUAO and ceiling sensor

These components of the VAZ 2110 heater are connected and work according to the following principle:

1. The sensor detects the temperature inside the car;
2. This data is sent to the SUAO block;
3. The block compares the temperature with the position set on the handle of the VAZ 2110 stove;
4. After comparison, the damper position changes or remains the same - it depends on the indicator;
5. Thus, the temperature in the cabin is controlled;
6. If the stove handle is set to MAX or MIN, then the data from the ceiling sensor is not taken into account.

All these actions are shown in the diagram. The block is a set of chips, the normal operation of the stove depends on its serviceability. Both the sensor and the SUAO can be replaced.

damper and gearmotor

The motor reducer of the stove changes the position of the damper, due to which air is supplied to the passenger compartment. This component is controlled by the SUAO block. If the device is faulty, the damper will not move. The unit is a miniature electric motor. When it breaks, it is usually changed, since it will be problematic to repair it. This also applies to shutters. The diagram shows the connections between the reducer and the block.

Scheme and explanations for it

Below is a diagram of the parts that make up the heater system of a VAZ 2110 car.

It is worth saying that recirculation operates in the “tens” heater system, which is also reported to us by the circuit. In simple words: air circulates inside the VAZ 2110, and is not taken from the street. The main advantage is that dust and unpleasant odors do not get into the cabin from the street. There are more disadvantages to such a stove system - the glasses quickly fog up. It is recommended to open windows more often if the temperature outside allows it. Stagnation of air adversely affects the health of the driver and his companions. The heater motor gearbox is rarely repairable, so it should be changed immediately.

For owners of the VAZ 2110 who want to modify the heater system or carry out electrical repairs, an automatic control scheme will be useful.

The thin metal body of a passenger car or truck cab instantly reacts to fluctuations in atmospheric temperature. In summer, the temperature in the cabin can rise to 40 - 50 degrees. In winter, the temperature in the cabin or cabin differs from the outside frost by 2-3 degrees. Drivers and passengers of vehicles are saved from summer overheating by turning on the air conditioner or opening windows. In winter, only the car's heating system can provide a normal temperature in the cabin. In the climatic conditions of Russia, the normal operation of a car heater is relevant for two-thirds of the year.

The principle of operation of the car heater

In the history of the car, there were even such types of interior heating as compact coal and wood stoves, gas lamps. Later, exhaust gases were used for heating. Automakers have practically abandoned the water interior heating, which was used in some models of passenger buses. Heated water circulating through pipelines under the seats and on the walls of the cabin was quickly cooled, the heating system was characterized by low efficiency.

Modern heating systems mainly use engine coolant to heat the cabin, with its help, heated and filtered atmospheric air. A fan is used for forced air intake. The air is heated by the heat transfer of a running car engine, the intensity of its supply is regulated manually or automatically.

A normally functioning car heater, which drivers simply call a "stove", in winter heats the air in the cabin up to 20 - 25 degrees Celsius. An additional function of the car stove is to warm up the foggy or icy windows of the car, thawing the frozen windshield wipers.

Types of heating systems

In general, car stoves are divided into regular ones (installed by the automaker) and additional ones that car owners install on their own. For most foreign cars, the car heater is assembled in a single unit with air conditioning, making up the climate system.

Design of regular heating systems

The stationary heating system of a car with an internal combustion engine (diesel or gasoline) uses the working heating of the motor as a heat source.

For most heating systems, an air intake fan and a heat exchanger (stove radiator) are installed in front of the partition of the engine compartment. The heat exchanger is connected by the outlet and inlet pipelines to the cooling system of the automobile engine. Atmospheric air blown by the fan heats up when passing through the radiator cells. After that, the heated air passes through the cabin filter and is fed through pipelines to the cabin ventilation deflectors.

Engine cooling system

For various models of cars, the deflectors are located in the center console, in the center and on the sides of the dashboard, under the windshield, and can exit at the feet of the rear passengers. The normal temperature of a running engine of 90 degrees provides heating of the air supplied to the cabin, up to 30 - 35 degrees.

An important quality of the heating system is the regulation of the supply of warm air. The strength of the air supply is regulated by turning the knob or pressing the button with the fan icon (for air conditioning systems).

Manual adjustments of the direction of air to the sides of the deflector dampers are very approximate. Climate control is much more accurate. After the driver sets the desired temperature in the on-board computer, the climate control unit automatically adjusts the opening or closing position of the dampers using temperature sensors through servomotors.

The device of a modern interior heater with air conditioning

Heating systems of many car models can use direct and recirculation modes of heated air supply. The recirculation mode works with the main air intake damper closed. In this position, the exhaust fan of the heating system uses only the volume of air from the passenger compartment. At the same time, the air temperature rises, unpleasant smells of road dust and automobile exhausts disappear in the cabin.

The recirculation mode works most effectively in automatic climate control installations. The climate control unit, guided by the readings of gas analyzers, automatically switches on the recirculation mode when harmful substances are detected in the atmospheric air. Also, the recirculation mode is automatically turned off if the percentage of carbon dioxide in the cabin from the breath of passengers rises.

Autonomous interior heaters

In addition to the heating functions when the engine is on, in some cases it is necessary to provide pre-heating of the passenger compartment and engine warm-up. To do this, autonomous heaters and preheaters are installed on trucks and passenger cars. Among the quality manufacturers of autonomous heaters, the brands Webasto, Eberspacher, the Russian brand Planar stand out.

Despite the distrust of car owners to autonomous heaters, the benefits of such a device are obvious. When using it, an idle warm-up of the engine is not needed, which brings significant fuel savings. Using the remote activation of the autonomous heater, the driver gets behind the wheel into a warm cabin with clean windows and “wipers” ready for work. Reduces engine wear by eliminating cold starts with cooled oil.

For trucks in a number of EU countries, autonomous heaters are legally recognized as mandatory equipment. Without them, drivers of long-distance trucks are prohibited from spending the night or resting in cabins at roadside parking lots and cargo parking lots. Thus, the European authorities are struggling with additional emissions of harmful exhaust gases from working engines into the atmosphere, and reduce the noise level.

Most often, autonomous heaters operate on the main fuel of the engine. Therefore, their models are divided into gasoline, diesel, gas. By design, these heaters are similar.

All models, assembled in a separate compact case, use:

• sealed combustion chamber;
• fuel supply pipeline from a regular fuel tank;
• air blower;
• circulation pump;
• heat exchanger;
• spark plug or glow plug;
• overheating sensor;
• Control block.

Gasoline air heaters for passenger cars are more compact. With a power of up to 46 kW, they can be installed under the hood of a car. Diesel heaters and pre-start liquid engine heaters for trucks are characterized by greater power (up to 82 kW) and dimensions.

The electric autonomous heater does not use automobile fuel, it works on the principle of a fan heater. The heating device is often called an auto-hair dryer. In a hermetically sealed ceramic housing, there are suction and exhaust fans, an electric coil or ceramic elements that heat the air. An autonomous electric hair dryer, powered by a battery through the cigarette lighter, does not have enough power to fully heat the interior, so it is used as an additional source of heating.

A stationary electric heater of a similar design, powered by an on-board electrical network, has become the basis of the heating system of electric vehicles. It is he who provides thermal comfort in the cabin, built into the climate system unit and supplemented by heating all the seats in the car.

Maintenance and repair of heating systems of passenger vehicles

Self-maintenance of the heating systems of passenger cars usually comes down to replacing the cabin filter, which must be changed after 7000 - 15000 kilometers (depending on the dustiness of the area, the gas content of the urban atmosphere). The replacement procedure can be quite complicated, as it requires disassembly of the glove box or control pedals.

Replacing the cabin as well as air filters is recommended to be changed at less than once every 15 thousand km.

Typical stove malfunctions usually appear simultaneously with a deterioration in engine cooling and are associated with clogging of radiators with dirt, dust, and poplar fluff. Self-cleaning of radiators by rough mechanical methods is not recommended, since the thin metal of the heat exchanger is easily damaged. When contacting a car service, mechanics clean the radiators with compressed air or a water jet, observing the maximum possible pressure. In case of more complex breakdowns of a regular or autonomous heater, it is better to use the help of qualified specialists.

Repair of the heating system may require replacement of:

• radiator (with mechanical wear of cells, antifreeze leaks);
• impeller or fan motor;
• branch pipes and tees;
• elements of the electrical control circuit (resistors, controllers, temperature sensors);
• damper drive microreducers;
• heater taps;
• air damper servo drives;
• recirculation valves;
• operating mode switches.

All dismantling and installation work with the heating system must be carried out according to the manufacturer's technological maps. Repair requires accurate diagnosis, knowledge of the location of the system nodes, methods of disassembly and assembly. Qualified car services, simultaneously with the repair of the stove, disinfect the interior and air ventilation ducts, and wash the radiator.