DE10019103C1 - Device for determining the temperature and the speed of the air flowing into the interior of a vehicle from an air outlet opening - Google Patents

Abstract

The device (76) for determining the temperature and the speed of the air flowing into the interior of a vehicle from an air outlet opening is provided with at least one measuring element (52, 54) with temperature-dependent resistance behavior. The at least one measuring element (52, 54) can be heated by the supply of electrical power for the duration of a heating interval (72) and can be cooled by the air for the duration of a subsequent cooling interval (74) after termination or after reduction of the electrical power. The device (76) also has an energy source (64) for supplying the at least one measuring element (52, 54) with electrical energy and a control and evaluation unit (62) for switching on and off or controlling the energy source (64) and for Measuring the voltage dropping across the at least one measuring element (52, 54) and / or the current flowing through the at least one measuring element (52, 54) at least at a first measuring time (t¶1¶) before or after a cooling interval (74) Start and at least a second measurement time (t¶2¶) after a cooling interval (74) or at the end of it. The control and evaluation unit (62) uses the values for the voltage and / or the current measured at the at least two measuring times (t¶1¶, t¶2¶) to determine the temperature and the speed of the at least one measuring element (52 , 54) air flowing past.

Description

The invention relates to a device for determining the temperature and the speed of an air outlet opening into the interior of a vehicle's flowing air.

Conventionally, vehicle air conditioning systems work in such a way that Controller depending on the difference between the set target temperature and the actual temperature for the interior of the vehicle controls various actuators, the throughput, the distribution and the Influences temperature of the air flowing into the vehicle interior sen. These actuators are mostly flaps that are in the Air flow duct system of the air conditioning system are arranged. A problem here is that the actuators must have a position control, which requires a feedback potentiometer with appropriate wiring do it. In addition to these feedback potentiometers, you also need to In addition, various maps to specify the damper position in Depends on the desired changes in air flow and Air temperature. All of this could be eliminated if the throughput and the temperature of the air flowing out of the air outlet openings and Air entering the vehicle interior can be measured. Then namely without the position control and feedback potentiometer Interior temperature control loop closed.

It is known to improve the response time of an indoor room temperature control loop in this one subordinate discharge temperature Control loop. Such a blow-out temperature control circuit makes  a so-called blow-out temperature sensor is required, which in at least one of the air outlet openings is arranged (see, for example, DE 199 01 319 C1). Preferably, there are air outlet openings per group (Defrost, Mannanström and footwell outlet) each one Air outlet opening with such a discharge temperature sensor is provided. Now it is only necessary in those concerned Air outlet openings also to arrange a flow meter. However, this requires additional wiring, which the Savings in terms of the elimination of the final control and the Feedback potentiometer of the actuators partially consumed again.

The invention is therefore based on the object, a device for Er averaging the temperature and speed of an air to create air flowing into the interior of a vehicle fen, which is designed as a two-pole sensor unit and thus no counter via air conditioners with outlet temperature sensors increased wiring effort.

To solve this problem, a device is provided with the invention, which is provided with

• - At least one measuring element with temperature-dependent resistance stability, the at least one measuring element for the Duration of a heating interval, by supplying electrical power heatable and for the duration of a subsequent cooling interval Termination or after reduction of electrical power through the air is cool,
• - An energy source for supplying the at least one Messele with electrical energy and
• - a control and evaluation unit for switching on and off or Control the energy source and measure the above the minimum a measuring element dropping voltage and / or by the at least one measuring element flowing current to at least one first measurement point before a cooling interval or at the beginning of it  and at least a second measurement time after cooling interval or at its end,
• - The control and evaluation unit based on the at least values for the voltage measured at least two measuring times and / or the current the temperature and the speed of the the air flowing past at least one measuring element is determined.

Such a device having a vehicle air conditioning system is provided according to the invention with

• - A flow channel system that a fan and at least one Air inlet opening for sucking in air as well as several air outlets openings for blowing air into the interior of the vehicle having,
• - An air and temperature control unit with a first actuator flow of the temperature flowing through the flow channel system breathing air,
• - An air distribution device with at least a second actuator to influence the distribution of the flow channel system flowing air to at least one group of air outlet openings gene, each group having at least one air outlet opening,
• - A temperature sensor to determine the temperature in the interior of the vehicle,
• - A control unit that works with the interior temperature sensor and Position feedback free with the first and second actuators connected is,
• - A device for determining the temperature and speed speed of the air flowing out of the outlet openings, wherein
• - The device for each group of outlet openings at least one Measuring element with temperature-dependent resistance behavior has the electri for the duration of a heating interval by supply power and can be heated for the duration of a subsequent ab cooling interval after termination or after reduction of electrical  Power can be cooled by the air, and the device further is provided with
• - An energy source for supplying the at least one Messele with electrical energy and
• - a control and evaluation unit for switching on and off or Control the energy source and measure the above the minimum a measuring element dropping voltage and / or by the at least one measuring element flowing current to at least one first measurement point before a cooling interval or at the beginning of it and at least a second measurement time after cooling interval or at its end,
• - The control and evaluation unit based on the at least values for the voltage measured at least two measuring times and / or the current the temperature and the speed of the the air flowing past at least one measuring element is determined.

In the device according to the invention, the temperature and the Ge speed of the air flowing out of an air outlet opening with the help of a single measuring element with temperature-dependent resistance ver hold determined. This measuring element is alternately divided into two operated modes. In the first operating mode, the measuring element is a electrical power supplied so that it heats up. This electrical Heating power is known because of the one electrical quantity (namely the current or the voltage) determined by the energy source and thus known while the other electrical quantity (the voltage drop across which or the current through the measuring element) is measured. After the first operating mode (heating phase) has ended, the measurement element operated according to the invention in a second operating mode, at which it is cooled by the air flowing past. During this second operating mode, the measuring element has a lower electrical Power supplied than in the first operating mode. "Lower electrical Performance "in the sense of the invention also means that the measuring element  no electrical power in the cooling phase (second operating mode) is supplied, so the measuring element is decoupled from the energy source.

The measuring element in the above is via a control and evaluation unit Way supplied with electrical power. During at least two measurements times, one of which is before a cooling interval or with which The beginning of a cooling interval coincides and a second measurement time after a cooling interval or at the end of the cooling interval coincides, the variable not determined by the energy source of the two electrical variables voltage and current measured. Is considered Energy source a current source with constant current is used, so is the two measurement times, the one above the measuring element voltage drop measured. On the other hand, becomes an energy source Voltage source with constant voltage is used, so it becomes the electrical current flowing through the measuring element at both measuring times measured. Based on the values measured at the two measurement times then the temperature and the speed of the on the measuring element air flowing past is determined.

In the device according to the invention, the fact that the ohmic resistance of the measuring element during the cooling phase depending on the air temperature and flow rate the air changes if the measuring element has been electri power has been heated. By appropriately offsetting the measured electrical quantities at the two measurement times, d. H. the electrical quantities before and after a cooling process, can under Ver application of the electri supplied during the previous heating process performance, both the temperature and the speed of the air be determined.

The advantage of the device according to the invention is on the one hand that, as with today's blow-out temperature sensors, everyone with such a sensor provided air outlet opening only two lines  have to lead. Simply by supplying electrical power a cooling phase and by measuring an electrical Size (current or voltage) at the two measurement times mentioned above score succeeds in making statements about the temperature and the speed to reach the air.

In an advantageous development of the invention, the Luftge speed based on the temperature difference of the measuring element to the two measurement times and based on the electrical power for the first To determine the time of measurement. The temperature difference is determined by that based on the ohmic resistance of the measuring element to the two Measurement times the respective temperatures of the at least one measurement elements can be determined.

It is then expedient, based on the determined air speed to infer the temperature of the air. This is done with an advantageous Further development of the invention such that the measuring element supplied electrical power and the temperature of the measuring element each Weil determined at the first time of measurement and together with the Luftge speed can be used to determine the air temperature.

The procedure described above uses temperature values, which the measuring element has at the two measuring times. The tempe rature determination is not done physically but arithmetically, and about the intermediate size of the ohmic resistance of the Messele ment, which in turn consists of the two electrical quantities current and Voltage can be calculated. Since the dependence of the electrical resistance which is known from the temperature, can ultimately from the electrical The current and voltage variables determine the temperature of the measuring element become. As a measuring element with temperature-dependent resistance behavior expediently an NTC or a PTC resistance element (also Called thermistor). Such elements are used as sensors for  the measurement / determination of temperatures in vehicle air conditioning systems basically known.

To with air currents with relatively strong speed and / or Temperature gradients make a statement about the mean temperature and the to be able to make medium flow velocity, it is an advantage if you distribute several in one air outlet opening over the opening provides arranged measuring elements, which are in series (in the case of NTC re stand elements or in parallel (in the case of PTC resistance elements) are switched.

To speed in a vehicle air conditioning system with the help of the invention and the temperature of the air flowing into the vehicle interior This device or at least needs to be able to determine air a measuring element of this device is not necessarily in every off inlet opening or the channel leading to this opening his. Because normally the air distribution devices comprise a driver Air conditioning unit several groups of outlet openings (for example Defroster openings, male inflow openings and footwell openings), which, Depending on the setting of the air distribution, differently strong air flows flows through. So it is sufficient to the invention direction or the at least one measuring element of the invention Device per group of outlet openings in one outlet opening or to be arranged in the channel leading to this outlet opening. At a The left / right climate system doubles the number. Groups against over a simple air conditioning system, so the number accordingly to begin with the device according to the invention controlling measuring elements increases.

When using multiple measuring elements for multiple outlet openings it required that the electrical quantity "current or voltage" for each Measuring element at the at least two measuring times by the control and evaluation unit can be measured. This querying the individual  Measuring elements can either be serial or parallel, whereby in the latter case, the control and evaluation unit via an ent speaking number of measuring channels must have. The hardware effort Serial polling of the individual measuring elements is therefore cheaper.

The invention is explained in more detail below with reference to the drawing. in the single show:

Fig. 1 in side elevational view of the front part of a vehicle location with ACU,

Fig. 2 shows schematically the wiring of the measuring element with temperature-dependent resistance and

Fig. 3 to 5
Time profiles of the electrical quantities shown in FIG. 2, namely the drive current I _G for the ON / OFF switch for switching the current source on and off, the current I _S flowing through the temperature-dependent resistor R and the voltage U dropping across the resistor R. _S.

According to Fig. 1 10, an air conditioner for an automobile 12, a Ge blower 14 which in dependence on the position a fresh air / recirculated air flap 16 fresh air from a fresh-air intake channel 18, or draws recirculated air from an ending in the interior 20 of circulating air passage 21. Viewed in the flow direction behind the blower 14 is a Kühlvorrich device 22 which has a (not shown) compressor and an evaporator 23 for cooling the intake air. Behind the evaporator 23 is a (in this example controlled on the air side) heater 24 angeord net. Depending on the position of a mixing flap 26 forming the actuator of the heating device 24, the cooled air flows through one of two channels 28 , 30 of the heating device 24 connected in parallel to one another. One of these two channels (channel 30 in the exemplary embodiment) has a heat exchanger 32 through which a partial flow of the engine cooling water flows to heat the previously cooled air. After the heat exchanger 32 , the two channels 28 , 30 are brought together again. In the direction of flow behind the mixing flap 26 is an Luftver dividing device 34 , which has two flaps 36 , 38 , the air selectively via the man inflow openings 40 , the defroster openings 42 and / or the footwell outflow openings 44 in the interior 20 .

The entire air conditioning system 10 is controlled in such a way that a predeterminable target temperature for the interior 20 is reached and maintained. For this purpose, the air conditioning system 10 has an interior temperature sensor 46 which measures the actual value of the interior temperature and z. B. is housed in the control unit 48 . The control unit 48 has an adjusting device 50 for manually specifying the setpoint for the interior temperature.

In the air conditioning system 10 to be described here, the flaps 26 , 36 and 38 are driven by actuators, the respective adjustment positions of which are not queried by measurement on the actuator or the flap itself. The actuators or flaps therefore do not have a travel sensor that reports the respective adjustment position. As a result, the wiring effort can be reduced. Instead of the feedback of the flap pen positions a device is used in the air conditioning system to be described here, which determines the temperature and the speed of the air flowing through the channels leading to the outlet openings 40 and 44 of the air distribution device 34 . In one or more of these channels there are measuring elements in the form of NTC thermistors 52 , 54 , which can be operated in different modes and whose output signals are evaluated in the manner described below.

In addition, the air conditioning system 10 has a further plurality of sensors, not described here in detail and partially not shown in FIG. 1, for example for the outside temperature (sensor 58 ), the cooling water temperature, the pollutant concentration in the fresh air, etc. All of these sensors are connected to a central control unit 60 , which has an interior temperature controller with subordinate outlet temperature control and is in turn connected to the actuators for the cooling device 22 , the heating device 24 , the blower 14 and the flaps 16 , 26 , 36 , 38 . The control unit 60 also evaluates the measurement signals from the NTC thermistors 52 , 54 and controls them differently, which will be explained below by way of example for the thermistor with reference to FIGS. 2 to 5.

As can be seen from FIG. 2, the control unit 60 has a control and evaluation unit 62 in the form of a microcontroller for the NTC thermistors 52 , 54 , in FIG. 2 only the interconnection with one of the two NTCs -Thermistors is shown. In addition to the control and evaluation unit 62 , the control unit 60 comprises a current source 64 which, via a controllable electronic viewer in the form of a transistor 66, impresses the NTC thermistor 52 , 54 on a constant current I _S. The transistor 66 is controlled by means of the control current I _G , which is output by the control and evaluation unit 62 at the output 68 . The voltage U _S dropping across the NTC thermistor 52 , 54 becomes at the input. 70 of the control and evaluation unit 62 tapped and measured. Unless the air conditioner has multiple. Air outlet openings assigned NTC thermistors has - as in the case to be described here - a thermistor 66 , an input 70 and an output 68 are required for the connection of each NTC thermistor with the control and evaluation unit 62 . Possibly, a common current source can be provided for several NTC thermistors, which must have the necessary power to supply the several NTC thermistors with the constant current I _S.

In order to be able to use the electrical behavior of the NTC thermistor 52 , 54 with temperature-dependent resistor R to extract the information relating to the temperature and the speed of the air flowing past, the control and evaluation unit 62 controls the NTC thermistor 52 , 54 in two different modes , In a first mode during a switch-on interval 72 (see FIG. 3), the transistor 66 is activated, so that the current I _S flows through the NTC thermistor 52 , 54 (first operating mode). During this switch-on interval 72 , the NTC thermistor 52 , 54 heats up, which is why its resistance value decreases. This makes it enter in the Einschaltintervallen 72, the transistor 66 is open in Figs. 4 and time courses 5 shown for the decreasing voltage U _S and the resistance value R. In a subsequent to the switch-on interval 72 stop interval 74, so that the NTC Thermistor 52 , 54 is de-energized. As a result, the NTC thermistor 52 , 54 cools down in this second operating mode, which is why its resistance value R increases (see FIG. 5). Both intervals 72 , 74 determine the period with which the sequence of the two operating modes is repeated.

The voltage drop U _S is measured at a first measuring time t ₁ immediately before the switch-off or cooling interval 74 and at a measuring time t ₂ immediately after this interval. Is thereby obtained at the time t _1, the voltage measurement U ₁ and the measuring time t _2, the measurement voltage U. ₂ Using the known current I _S , the resistance value R ₁ at time t ₁ and R ₂ at time t _{2 can be} calculated. Due to the stored in the control and evaluation unit 62 characteristic line of the NTC thermistor 52 , 54 , which describes the dependence of the resistance value R on the temperature of the thermistor 52 , 54 , the temperatures T ₁ and T _{2 of} the NTC thermistor can now 52 , 54 can be determined at the measurement times t ₁ and t ₂ . The time derivative of the temperature of the NTC thermistor 52 , 54 can thus be approximately calculated on the basis of the temperature difference and the duration of the switch-off or cooling interval 74 . The ratio of this derivative and the heating power impressed on the NTC thermistor 52 , 54 at time t ₁ (product of the measured voltage U ₁ and the impressed constant current I _S ) is a measure of the current flow velocity V _air . The first value to be determined is thus calculated.

This parameter for the air speed is now used for the calculation of the temperature of the air. The air speed results namely on the basis of the determined flow speed and the heating power impressed on the NTC thermistor 52 , 54 and the temperature of the NTC thermistor 52 , 54, for example at the measurement time t ₁ (the corresponding values for the measurement time t ₂ can alternatively be he be drawn). The second value to be calculated is therefore also present, namely the temperature T _{air of} the flowing air.

Thus, the device 76 , which has the control and evaluation unit 62 , the energy source in the form of the current source 64 and the measuring element with temperature-dependent resistance behavior in the form of the NTC thermistor 52 , 54 , succeeded in measuring data from a single measuring element obtained, which make it possible to obtain two parameters, namely the temperature and the speed of the air flowing into the interior 20 of the vehicle 12 . The wiring effort is identical to the wiring effort that is found in a vehicle air conditioning system with the actual interior temperature controller subordinate Ausblastem temperature control circuit.

LIST OF REFERENCE NUMBERS

10

air conditioning

12

vehicle

14

fan

16

recirculation damper

18

Fresh air intake duct

20

inner space

21

return air duct

22

cooler

23

Evaporator

24

heater

26

mixing flap

28

channel

30

channel

32

heat exchangers

34

air distribution

36

flap

38

flap

40

Mannanströmöffnung

42

defroster

44

Fußraumausströmöffnung

46

Interior temperature sensor

48

control unit

50

adjustment

52

NTC thermistor

54

NTC thermistor

58

Outside temperature sensor

60

control unit

62

Control and evaluation unit

64

power source

66

transistor

68

output

70

entrance

72

Aufheizintervalls

74

cooldown

76

Device for determining the temperature and speed of the air

Claims (16)

1. Device for determining the temperature and the speed of the air flowing from an air outlet opening into the interior of a vehicle, with
at least one measuring element (52, 54) with temperaturabhängi according resistor behavior, wherein the at least one Messele ment (52, 54) can be heated for the duration of a Aufheizintervalls (72) through to driving electric power and for a period of one to closing cooldown period (74) can be cooled by the air after termination or after reduction of the electrical power,
an energy source ( 64 ) for supplying the at least one measuring element ( 52 , 54 ) with electrical energy and
a control and evaluation unit ( 62 ) for switching on and off or controlling the energy source ( 64 ) and for measuring the voltage drop across the at least one measuring element ( 52 , 54 ) and / or the voltage through the at least one measuring element ( 52 , 54 ) flowing current at at least a first measuring time (t ₁ ) before a cooling interval ( 74 ) or at the beginning and at least a second measuring time (t ₂ ) after a cooling interval ( 74 ) or at the end thereof,
The control and evaluation unit ( 62 ) uses the values for the voltage and / or the current, the temperature and the speed of the at least one measuring element ( 52 , 54 ) measured at the at least two measuring times (t ₁ , t ₂ ). air flowing past is determined. 2. Device according to claim 1, characterized in that the control and evaluation unit ( 62 ) on the basis of the ohmic resistance values of the at least one measuring element ( 52 , 54 ) at the two measuring times (t ₁ , t ₂ ) the respective temperatures of the at least a measuring element ( 52 , 54 ) at these two measuring times (t ₁ , t ₂ ) and on the basis of the difference between these temperatures and the electrical power supplied to at least one measuring element ( 52 , 54 ) at the first measuring time before the start of a cooling interval ( 74 ) determines the speed of the air. 3. Device according to claim 1 or 2, characterized in that the control and evaluation unit ( 62 ) the temperature of the air based on its speed, the at least one measuring element ( 52 ) at the first measurement time (t ₁ ) before the cooling interval ( 74 ) , 54 ) to the electrical power and the temperature of the at least one measuring element ( 52 , 54 ) determined at the first measuring time (t ₁ ). 4. Device according to one of claims 1 to 3, characterized in that the energy source is a current source ( 64 ) with a constant output current (I _S ) for the at least one measuring element ( 52 , 54 ) and that the control and evaluation unit ( 62 ) measures the voltage drop (U _S ) across the at least one measuring element ( 52 , 54 ) at at least two measuring times (t ₁ , t ₂ ). 5. Device according to one of claims 1 to 3, characterized in that the energy source is a voltage source with a constant output voltage for the at least one measuring element ( 52 , 54 ) and that the control and evaluation unit ( 62 ) at the at least two measuring times (t ₁ , t ₂ ) measures the current flowing through the at least one measuring element ( 52 , 54 ). 6. Device according to one of claims 1 to 5, characterized in that the at least one measuring element ( 52 , 54 ) is an NTC or a PTC resistance element. 7. Device according to one of claims 1 to 6, characterized in that a plurality of measuring elements ( 52 , 54 ) are provided, which are connected in series or in parallel. 8. Device according to one of claims 1 to 7, characterized in that the control and evaluation unit ( 62 ) is a microcontroller. 9. Air conditioning system for the interior of a vehicle
a flow duct system which has a blower ( 14 ) and at least one air inlet opening for sucking in air and a plurality of air outlet openings ( 40 , 42 , 44 ) for blowing out air into the interior ( 20 ) of the vehicle ( 12 ),
an air and temperature control unit ( 22 , 24 ) with a first actuator ( 26 ) for influencing the temperature of the air flowing through the flow duct system,
an air distribution device ( 34 ) with at least one second actuator ( 36 , 38 ) for influencing the distribution of the air flowing through the flow channel system to at least one group of air outlet openings ( 40 , 42 , 44 ), each group having at least one air outlet opening ( 40 , 42 , 44 ),
a temperature sensor ( 46 ) for determining the temperature in the interior ( 20 ) of the vehicle ( 12 ),
a control unit ( 60 ) which is connected to the interior temperature sensor ( 46 ) and without position feedback to the first and second actuators ( 26 , 36 , 38 ),
a device ( 76 ) for determining the temperature and the speed of the Ge from the outlet openings ( 40 , 42 , 44 ) flow the air, wherein
the device ( 76 ) for each group of outlet openings ( 40 , 42 , 44 ) has at least one measuring element ( 52 , 54 ) with temperature-dependent resistance behavior which can be heated for the duration of a heating interval ( 72 ) by supplying electrical power and for the duration a subsequent cooling interval ( 74 ) can be cooled by the air after termination or after reduction of the electrical power, and the device ( 76 ) is further provided with
an energy source ( 64 ) for supplying the at least one measuring element ( 52 , 54 ) with electrical energy and
a control and evaluation unit ( 62 ) for switching on and off or controlling the energy source ( 64 ) and for measuring the voltage drop across the at least one measuring element ( 52 , 54 ) and / or through the at least one measuring element ( 52 , 54 ) flowing current at at least a first measuring time (t ₁ ) before a cooling interval ( 74 ) or at the beginning and at least a second measuring time (t ₂ ) after a cooling interval ( 74 ) or at the end thereof,
The control and evaluation unit ( 62 ) uses the values for the voltage and / or the current, the temperature and the speed of the at least one measuring element ( 52 , 54 ) measured at the at least two measuring times (t ₁ , t ₂ ). air flowing past is determined. 10. Air conditioning system according to claim 9, characterized in that the control and evaluation unit ( 62 ) on the basis of the ohmic resistance values of the at least one measuring element ( 52 , 54 ) at the two measuring times (t ₁ , t ₂ ) the respective temperatures of the at least a measuring element ( 52 , 54 ) at these two measuring times (t ₁ , t ₂ ) and on the basis of the difference between these temperatures and the electrical power supplied to at least one measuring element ( 52 , 54 ) at the first measuring time before the start of a cooling interval ( 74 ) determines the speed of the air. 11. Air conditioning system according to claim 9 or 10, characterized in that the control and evaluation unit ( 62 ) the temperature of the air on the basis of its speed, the at least one measuring element ( 74 ) at the first measurement time (t ₁ ) before the cooling interval ( 74 ) 52 , 54 ) supplied electrical power and the temperature of the at least one measuring element ( 52 , 54 ) likewise determined at the first measurement instant (t ₁ ). 12. Air conditioning system according to one of claims 9 to 11, characterized in that the energy source is a current source ( 64 ) with a constant output current (I _S ) for the at least one measuring element ( 52 , 54 ) and that the control and evaluation unit ( 62 ) measures the voltage drop (U _S ) across the at least one measuring element ( 52 , 54 ) at the at least two measuring times (t ₁ , t ₂ ). 13. Air conditioning system according to one of claims 9 to 11, characterized in that the energy source is a voltage source with a constant output voltage for the at least one measuring element ( 52 , 54 ) and that the control and evaluation unit ( 62 ) to the at least two Measuring times (t ₁ , t ₂ ) measure the current flowing through the at least one measuring element ( 52 , 54 ). 14. Air conditioning system according to one of claims 9 to 13, characterized in that the at least one measuring element ( 52 , 54 ) is an NTC or a PTC resistance element. 15. Air conditioning system according to one of claims 9 to 14, characterized in that a plurality of measuring elements ( 52 , 54 ) are provided, which are connected in series or in parallel. 16. Air conditioning system according to one of claims 9 to 15, characterized in that the control and evaluation unit ( 62 ) is a Mikrocon troller.