Control unit for the heating, ventilation, and air conditioning system

The car, regardless of the type of body and configuration of the instrument panel, can be equipped with a heating, ventilation and air conditioning system with manual activation of the air conditioner or with automatic control of the air temperature in the cabin (climate control system). Control of any of the heating, ventilation and air conditioning systems is possible only when the engine is running. It is not recommended to use the system devices with the ignition on and the engine off, as this can lead to battery discharge.

On a car with manual air conditioning, the fan operation mode switch changes the airflow strength from the lowest (position 1) to the greatest (position 4). If you turn off the ignition while the fan is on, it will also turn off, and after turning on the ignition, it will turn on in the previously set mode.


The flow distribution regulator sets the following air flow directions in the passenger compartment:

- to the area where the head is located. The air flow through the deflectors in the instrument panel enters the upper part of the vehicle interior. This mode is recommended to be used in clear and dry weather - it allows you to quickly warm up or cool down the interior;

- in the areas of the legs and head. Air flows through the deflectors into the upper part of the car and through the lower ventilation openings into the driver's and front passenger's footwells. This mode is recommended for use in clear and dry, but very cold or hot weather;

- to the leg area. Air flows through the lower vents to the driver's and front passenger's footwells only. This mode is recommended for use in clear and dry, but moderately cold or hot weather. In this case, in cold weather, the air in the upper part of the cabin (in the area of the driver's head) will remain relatively cool - this will keep the driver in good shape and prevent relaxation and falling asleep on a long journey;

- in the foot area and on blowing the windshield and front door windows. Air flows through the lower vents to the footwell area, as well as to the windshield and front door windows. It is recommended to use in cold and damp weather, when the glasses fog up quickly;

- for blowing the windshield and front door windows. The air flow enters the grilles for blowing the windshield and the windows of the front doors.

Recommended for use in wet weather and for quick windshield cleaning if fogged up before driving (see below).






Air flows will be distributed in this way even when the fan is off - when the car is moving due to natural air intake. If the natural air supply is not strong enough to ventilate or heat the interior, turn on the fan.

By turning the air temperature control knob, you can change the temperature of the air entering the passenger compartment. To increase the air temperature, turn the regulator knob clockwise, to the red sector of the scale, to decrease it, counterclockwise, to the blue sector.

When the recirculation mode is off, air enters the ventilation and heating system from outside the car. It makes sense to turn on the recirculation mode in the following cases:

• for the fastest possible warming up of the interior of a stationary car in winter (when driving, the air flow from the outside is more efficient);
• when driving in a highly polluted atmosphere (e.g. in long tunnels);
• when driving in dusty areas.

Before turning on the recirculation mode, close all door windows.


It is not recommended to use the recirculation mode for a long time, as this can lead to an increase in air humidity in the cabin and fogging of the windows.

Deflectors of the heating and ventilation system allow you to change the direction of the air flow. To do this, use the handle located in the center of the deflector. Moving it left-right or up-down, we change the direction of the air flow. The regulator at the bottom of the deflector allows you to open the air flow from this deflector or block it. The photo shows the deflectors on the instrument panel of cars with hatchback and station wagon bodies. On a sedan car, the ventilation, heating and air conditioning vents have a different shape, but function in the same way.

When fogging up the windshield in the warm season, you can send cold air to it. For this:

• using the flow distribution regulator, we direct the air to blow the windshield in ;
• turn on the recirculation mode;
• we transfer the handle of the temperature regulator to the blue sector;
• turn on the fan at maximum speed. When the condensate evaporates, reduce the fan speed so that the cabin is not noisy.

To clean the windshield from ice and snow, as well as to free the wiper brushes frozen to it, direct the air flow onto the glass, turn the air temperature control knob to the red sector and turn on one of the high fan speeds. With this mode of operation of the heating system, the temperature of the air directed to the windshield will increase gradually, which will avoid the formation of cracks on the windshield. After thawing the glass, use the air flow distribution regulator to select the desired direction of air flow in the cabin.

Air conditioning is also only available when the engine is running. It is not recommended to turn on the air conditioner with the ignition on and the engine not running - this can lead to battery discharge.


Before turning on the air conditioner, close the windows of all doors. To turn on the air conditioner, press the A / C button (at the same time, the orange indicator lights up in it) and turn on the fan at whatever speed you think is appropriate. Turn off the air conditioner by pressing the button again (the indicator goes out).

Air conditioning is a very efficient device that provides high comfort in the car. However, they should be used with some caution. So, for example, in the heat, too intensive use of air conditioning can provoke colds for the driver or passengers, especially children. It is undesirable to turn on the air conditioner when the air distribution control is in the or positions.

It is better to choose the position . Try not to use the air conditioner when the recirculation mode is on - this will greatly lower the air temperature in the car. It is recommended to maintain in the cabin not a low, but a moderate, comfortable temperature.

It is undesirable to turn on the air conditioner immediately after driving a car that has been standing in the hot sun for a long time. This can cause a hot windshield to cool rapidly and crack. Pre-ventilate the interior by opening all windows or blowing air onto the glass with a fan (not including air conditioning).

The air conditioner increases the load on the engine when driving. This is especially noticeable when starting from a standstill, during acceleration, as well as when driving uphill: engine power decreases, the car's throttle response worsens. In some conditions, this can even lead to engine overheating. Therefore, it is recommended to turn off the air conditioner in difficult driving conditions, and also follow the arrow of the coolant temperature gauge.

The air conditioner allows you to quickly eliminate the fogging of glasses in wet weather. To do this, turn on the air conditioner and move the air distribution regulator to the position, while setting the air temperature regulator to the border of the blue and white zones.

It is recommended to turn on the air conditioner at least once a week for a few minutes, even in cases where there is no need for it (e.g. in winter). This extends the life of the A/C system by helping to retain lubricant on the A/C compressor parts and their seals.

On some cars, a system for automatically controlling the temperature of the air in the cabin can be installed (climate control system). The driver only needs to set the desired air temperature and direction of air flow, after which this system will automatically turn on heating and ventilation devices, or air conditioning (except for the recirculation system) and will maintain the set temperature in the cabin or until the driver changes the system operation mode manually (see below), or until the system is turned off, or until the ignition is turned off. If you then turn on the ignition and the climate control system, it will start working when the previously set temperature is reached.



To turn on the climate control system, press the AUTO button (3), or the A/C button (10), or turn the temperature control knob (2) until the system's LCD displays the desired interior temperature. In this case, the AUTO symbol will appear on the display, and the system will automatically set the required fan speed, which will gradually decrease as the set temperature is reached. If necessary, you can set a higher or lower fan speed to speed up or slow down the heating / cooling of the air in the cabin, but the AUTO mode will turn off.

Using the temperature controller, you can set the desired air temperature in the cabin from 18 to 32°C with an accuracy of 0.5 degrees. Optionally, you can set the temperature measurement to Fahrenheit. To do this, set the temperature controller to the position 26°C and, while holding down the AUTO button, press the MODE button three times within 3 seconds (6) - the display will change to 79°F. To return to the Celsius scale, repeat the procedure.

If using this regulator the values \u200b\u200bof the maximum (Hi) or minimum (Lo) temperature, the climate control fan will start at maximum speed and will not change even after reaching this temperature.

The temperature regulator allows, in addition to setting the required temperature inside the cabin, to determine the temperature of the outside air. To do this, press the center of the temperature control knob. In this case, the display will show the air temperature outside the car and above it - the OUTSIDE symbol. The outdoor temperature display will change to the indoor temperature display by pressing the center of the knob again or automatically after approx. 5 s. Please note that the air temperature outside the car, shown on the display, is usually slightly higher than the actual temperature (It has to do with the location of the temperature sensor).

By successively pressing the MODE button, you can change the modes of distribution of air flows in the cabin in the following order (round):

- air supply to the head area. The air flow through the deflectors in the instrument panel enters the upper part of the car;

- in the areas of the legs and head. Air flows through the deflectors into the upper part of the car interior and through the lower ventilation openings into the area where the driver's and front passenger's feet are located;

- to the leg area. The air flow enters through the lower ventilation openings only in the area of \u200b\u200bthe location of the legs of the driver and front passenger;

- in the foot area and on blowing the windshield and front door windows. Air flows through the lower vents to the footwell area, as well as to the windshield and front door windows.

All modes of distribution of air flows are displayed on the display of the climate control system.







Also, the display will show the inclusion of the recirculation mode, blowing the windshield and air conditioning.





The windshield blower mode is activated by pressing the button with the icon, while the corresponding indicator turns on on the display, the recirculation mode automatically turns off and the air conditioner turns on. If you want to free the glass from condensation (fogging) without turning on the air conditioner, just press the button to turn off the air conditioner - it will turn off, but the glass blowing mode will remain on.

To turn off the windscreen blowing mode, press the button to turn it on again, or turn on the air conditioner, or turn on the air recirculation mode.