Four-zone air conditioning on the BMW X6

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Nowadays, driving a car on hot summer days without air conditioning seems to be a medieval skirmish of a knight equipped with a sword against a fire-breathing dragon. It’s almost gone travels with windows open just to feel the hot blast of air whipping us, which minimally compensates for the heat inside the car. Nowdays, every car is equipped with air conditioning and does not actually need opening windows at all, not counting a few situations, such as ordering food in drive-through, payment at the highway gates.

Today’s air conditioning in premium cars is not only the button with the snowflake symbol printed on it, but a computer-controlled, sophisticated panel for heating and cooling management as well as distribution of power and temperature of the blow. Today we will look at this behemoth on the example of four-zone air conditioning in a BMW X6 car, but at the beginning a little about the air conditioning itself.


Air conditioning structure

Air conditioning system diagram

All air conditioning, both manual and automatic, consists of basic elements. The compressor (1) that compresses and feeds the factor walking under high pressure and high temperature to the condenser (2). Commonly known as the A / C walkway, the condenser converts from gas to liquid by the refrigerant going down. Then it goes to the dryer (3). Here, the entire refrigerating agent is cleaned of impurities and moisture. Often in the summer you can see a puddle under the car. If it is water, it comes from the air conditioning system. The next stage is the expansion valve (4). Its task is to expand the medium by changing the liquid state to gas, which drastically reduces its temperature. A similar reaction occurs when using compressed gas in an aerosol can (placed and compressed contents of the can are in a liquid state, and when the trigger is pressed, very cold gas is released). The evaporator (5), reminiscent of a heater, is the last stop of this journey. Here, the coolant releases the low temperature in the ventilation duct, and the fan feeds it inside the car. After rendering the temperature, the refrigerant is sucked in by the compressor and the whole cycle begins again.


Below is a gallery with several elements of the cooling system of the four-zone air conditioning in the BMW X6

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Car air conditioning is a complex system operating under high loads in the form of low and high temperatures and different pressures throughout the system, so it should be properly used to ensure its long-term and trouble-free operation.

How should air conditioning be used? As often as possible. Rarely used air conditioning can be damaged faster because the coolant mixture also includes oil that lubricates the entire system during operation, in particular the compressor. It is a kind of gas pump, not liquid, therefore lubrication is a very important element of proper functioning. Compressor components can quickly corrode or seize without proper lubrication. Therefore, it is so important to regularly service the system, but more on that later.

Car air conditioning is intended to reduce the air temperature inside the car, but it does not stop working. Thanks to her work, we get a pleasant cool breeze on hot summer days but also dry, moisture-free air. We can successfully use this advantage in winter. By increasing the heating temperature to maximum and turning on the air conditioning, we will get rid of fogged windows much faster than just the air supply.



If the performance of our air conditioning drops and the windows evaporate, the air conditioning system must be cleaned and the refrigerant added / replaced to the correct level. It must be remembered that the factor decreases with time and therefore this treatment should be performed at least every two years.

When an unpleasant smell comes out of our vents, it’s the last bell to arrange a visit to the site. These signs indicate that the air conditioning is molding, which can lead to allergies and irritation of the upper respiratory tract. Therefore, remember to replace the cabin filter at least once a year, clean the ventilation ducts and external air intakes, as well as fume the evaporator and check the patency of the moisture removal ducts. These activities should also include ozonation of the interior of the car, which kills fungi, molds, mites and various types of bacteria and viruses.

The dryer, i.e. the air conditioning system filter, should be replaced immediately if it is unsealed, e.g. after a collision or if it is opened during service work on the air conditioning. Its absorption properties are so high that after opening in a vacuum packed it completely loses its properties within three days. Standard replacement of such a filter should be done once every 3 years.


Below is a video presenting the control panels for heating and air conditioning and the function of climate control from the level of the i-Drive system in the BMW X6 (E71).