Abstract:
A multiple zoned air conditioning system for providing air conditioning to the interior of an automotive vehicle. The air conditioning system includes a main air conditioning module with a first heat exchanger for cooling and with a second heat exchanger for heating, as well as a multiple zone module. The main air conditioning module creates, in cooperation with the multiple zone module, at least one first air flow conditioned for temperature. The multiple zone module is interchangeably disposed in the main air conditioning module, with the second heat exchanger engaging the multiple zone module so as to allow air flow therethrough, when the multiple zone module is disposed on the main air conditioning module.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention is directed to an air conditioning system for providing separate, zoned air-conditioning in different areas of the interior of a vehicle. 
     2. Related Technology 
     With a view to the rising demands for comfort placed by users on modern automotive vehicles, it has become the standard, as a matter of fact, to equip passenger cars with an air conditioning system. High demands for comfort are met by air-conditioning systems by means of which the different areas or zones of the interior of the automotive vehicle can be set to different temperatures. Air conditioning systems with separate temperature setting in the right and the left half of the passenger compartment are already available in vehicles of the lower middle class for example. 
     Further improvement may be achieved by air conditioning the rear zone of the passenger compartment independently of the first row of seats. Separate temperature setting in the right and the left half of this rear zone has also already been realized. Due to the very high construction expense associated hereto before with such type three or four zone air conditioning systems, these are to be found only in vehicles of the upper middle class or in the upper class. 
     A multiple zoned air conditioning system comprising a modular structure is known from DE 103 282 75A1. A one to four zone air conditioning system may be realized with one unitary base member by interchanging one single module. The modular structure therefore permits to equip a plurality of vehicles with one and the same base member of an air conditioning system and to then turn the air conditioning system into a one or multiple zoned air conditioning system adapted to the standard of the automotive vehicle by selecting the appropriate module. Such standardized construction translates into a profound savings in cost. The disadvantage of the air conditioning system known from DE 103 282 75A1, however, is that the partial flows of cool and warm air that are to be mixed in the multiple zone module have to cover a quite long distance and, what is more, not in a straight line, which presents considerable disadvantages in terms of fluid flow. 
     It is therefore the object of the present invention to indicate a multiple zoned air conditioning system that is simpler in design and still more efficient. 
     SUMMARY 
     The multiple zoned air conditioning system of the invention includes a main conditioning module with a first and a second heat exchanger. The first heat exchanger may thereby, for example, be connected to a refrigerant circuit of the vehicle and the second heat exchanger, with a coolant circuit of the automotive vehicle&#39;s drive system. The first heat exchanger serves to cool down to a defined temperature incoming ambient air and to dry it as needed. The second heat exchanger serves to heat the air that has been cooled down to low temperature and dried by the first heat exchanger. 
     Moreover, the multiple zoned air conditioning system of the invention includes a multiple zoned module that is interchangeably disposed on the main air conditioning module. The main air conditioning module is designed to create, in cooperation with the multiple zone module, at least one air flow that may be conditioned with regard to temperature so as to conform to the wishes of the passenger. However, the main air conditioning system may also be designed to create a plurality, more specifically two, independently air conditionable air flows for providing air conditioning to a plurality of separate zones of the interior of the vehicle. As used herein, cooperation between main air conditioning module and multiple zone module means that the main air conditioning module cannot be operated in accordance with its purpose of utilization without the multiple zone module. 
     In accordance with the invention, the multiple zone module is configured in such a manner that, if the multiple zone module is disposed on the main air conditioning module, the second heat exchanger, which is part of the main air conditioning module, engages the multiple zone module so that the air may flow therethrough. More specifically, the main air conditioning module and the multiple zone module can be configured in such a manner that a first flow path (provided in addition to the flow path already formed within the air conditioning module) forms if the multiple zone module is disposed on the main air conditioning module. Advantageously, the main air conditioning module and the multiple zone module are now configured in such a manner that at least the second heat exchanger engages into said first flow path so that the air may flow therethrough. 
     This makes it possible to operate but one second heat exchanger (provided for heating a supplied partial air flow) even if a genuine multiple zoned air conditioning system providing the possibility of independently air conditioning the front seat row area and the rear area is being realized. The structure of the air conditioning system of the invention is thus considerably simplified as compared to the generic air conditioning system known from prior art. 
     In a particularly advantageous developed implementation of the air conditioning system of the invention, both the main air conditioning module and the multiple zone module are configured in such a manner that, if the multiple zone module is disposed on the main air conditioning module, a first flow path forms, which passes within the main air conditioning module, and a second flow path forms which passes within the multiple zone module. In terms of fluid flow, particular advantages are obtained if the second heat exchanger engages both the first and the second flow path so that the air may flow therethrough. 
     This implementation of the first and of the second flow path in accordance with the invention permits to provide, with but one second heat exchanger (suited for example for heating), an additional air-conditioned (e.g., warm) partial air flow in addition to the cool partial air flow generated by the first heat exchanger. Said partial air flows may be used for controlled mixing in mixing chambers provided both in the main air conditioning module and in the multiple zone module. If, in addition to the first mixing chamber formed in the main air conditioning module, another mixing chamber is provided in the multiple zone module for mixing air conditioned cool and warm partial air flows, the flow paths of the air-conditioned partial air flows into said second mixing chamber may be kept extremely short and with few windings thanks to the configuration of the main air conditioning module and of the multiple zone module in accordance with the invention, so that considerable advantages in terms of fluid flow are obtained. 
     As a result, the air conditioning system of the invention permits to realize an adequate single to four zone air conditioning system with but one first and one second heat exchanger. The modular structure permits in the simplest manner to adapt the air conditioning system to the standard required for the automotive vehicle. In spite of the simple construction of the two modules, short flow paths with but few windings may be realized for the partial air flows to be mixed by common use of the first and the second heat exchanger both in the main air conditioning module and in the multiple zone module, which results in advantages in terms of fluid flow, more specifically in a low internal flow resistance and low noise level. These advantages are more specifically based on the fact that, as contrasted with the air conditioning system previously know from DE 103 282 75 A1, only a cool air flow is supplied to the multiple zone module. It is only within the multiple zone module that a cool and a warm partial air flow are generated for controlled mixing. 
     In a particularly advantageous developed implementation of the multiple zoned air conditioning system the multiple zone module is designed to create, in cooperation with the main air conditioning module, at least one additional air conditionable air flow. More specifically, the multiple zone module may also be simply configured to create two additional independently air conditionable air flows for conditioning the air in two additional zones of the vehicle interior. 
     In a particularly preferred implementation, the main air conditioning module of the multiple zoned air conditioning system of the invention is designed to create two independently air conditionable air flows for separate air conditioning of the right and of the left front seat of the automotive vehicle. This may be realized for example by inserting a central partition wall into the multiple zone module so that the mixing chamber formed in the main conditioning module is divided into two halves that are functionally independent from each other with the number of air inlet and outlet ports being doubled. Servo flaps, which may be provided inside or outside of the mixing chamber, can then be mounted onto shafts which, although coaxially aligned, are separately drivable. 
     In this manner, the structure of the single zone air conditioning module and of the dual main air conditioning module (e.g., for the first row of seats) and of the single zone multiple zone module and of the dual zone multiple zone module (e.g., for the rear zone) may be largely uniformed. For the single zone module, the central partition wall is simply excluded and the servo flaps are disposed on common shafts. 
     The multiple zone module may be configured to create an air flow that is adapted to be air conditioned independently of the air conditionable air flows created by the main air conditioning module for separately conditioning the air in an additional zone of the vehicle interior, in the rear zone for example. Further, the multiple zone module can also be designed to create two air flows that are adapted to be air conditioned independently of one another and of the main air conditioning module, though, for example for providing separate air conditioning to the right and to the left half of the rear zone of the vehicle interior. In this case as well, this enlarged functionality can be realized as described herein above by inserting a central partition wall into the multiple zone module. 
     It is particularly advantageous if each of the air flows are adapted to be independently air conditioned in conformity with the present invention indeed consists of two partial flows that are not adapted to be air conditioned independently of one another, but only to be commonly air conditioned. This means for example that there are two partial flows having different temperatures, the temperature difference or the relationship between the temperatures, the temperature difference or the relationship between the temperatures being substantially constant. The temperature and/or the intensity of the partial flows may then be commonly adjusted i.e., the partial flows may be commonly air conditioned. This may for example be realized by a particular design of the mixing chamber in which the air flow adapted to be commonly air conditioned are created. 
     In simplified embodiments of the air conditioning system of the invention the multiple zone module is configured so as to direct at least one of the air conditionable air flows provided by the main air conditioning module to the rear zone of the vehicle interior without subjecting it to further air conditioning processes. 
     Both the main air conditioning module and the multiple zone module generally comprise their own mixing chambers, at any rate if they are designed to create at least one independently air conditionable air flow each. In said chambers, the independently air conditionable air flows are produced by mixing the warm and cool partial air flows in a controlled manner. To mix the warm and cool partial air flows in the mixing chambers in a controlled manner, various concepts in fluid dynamics are provided. Particular advantages are obtained if the concept in fluid dynamics respectively used is individually adjusted to the flow conditions within the main air conditioning module and within the multiple zone module respectively, or to the space available there. It may thereby be particularly advantageous to mix the hot and cool partial air flows in the mixing chamber of the main air conditioning module according to a principle in fluid dynamics different from that in the mixing chamber of the multiple zone module. The various concepts in fluid dynamics available will still be discussed in closer detail in the description of the exemplary embodiments. 
     The present invention is further directed to an air conditioning system consisting of both a multiple zoned air conditioning system and a plurality of interchangeable multiple zone modules. By providing such an air conditioning system, a manufacturer of original equipment for automotive vehicles will be able to meet in the simplest manner the client&#39;s various requirements using one and the same air conditioning base member, viz., the main air conditioning module, and a uniformed control logic unit. The manufacturer of the air conditioning system may thus realize enormous benefits of cost which may be passed on to the automotive vehicle manufacturer and finally to the end user. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further advantages and features of the multiple zoned air conditioning system of the invention and the air conditioning system configuration of the invention will become apparent from the subordinate claims and from the following non-restrictive description of embodiments, given by way of example only with reference to the drawings. The Figures show: 
         FIG. 1   a  is a perspective view of the main air conditioning module of a multiple zoned air conditioning system of the invention; 
         FIG. 1   b  is a perspective view of a first multiple zone module of a multiple zoned air conditioning system of the invention; 
         FIG. 1   c  is a perspective illustration of a second multiple zone module; 
         FIG. 2  is a sectional view of a multiple zoned air conditioning system of the invention with the first zone module mounted to the main air conditioning module; 
         FIG. 3  is a perspective sectional illustration of the mixing chamber of the first multiple zone module; and 
         FIG. 4  is another perspective sectional view of the mixing chamber of the multiple zone module seen in  FIG. 3 . 
     
    
    
     DETAILED DESCRIPTION 
     The  FIGS. 1   a ,  1   b  and  1   c  taken together show an air conditioning system configuration in accordance with the invention.  FIG. 1   a  thereby shows the main air conditioning module  2  of a multiple zoned air conditioning system  1  (see  FIG. 2 ) of the invention, with  FIGS. 1   b  and  1   c  illustrating a first multiple zone module  10 ′ and a second multiple zone  10  for use with the main air conditioning module  2  shown. 
     The air conditioning system  1  in accordance with this exemplary embodiment is divided into various modules that are readily interchangeable and are tightly connected together when the air conditioning system  1  is operable. The air conditioning system  1  comprises a main air conditioning module  2  with a base member  34 . On the inlet side, an air supply module  3 , in which a fan  26  is disposed, is connected to the base member  34 . The fan  26  serves to take ambient air in. The base member  34  of the main air conditioning module  2  and the air supply module  3  are configured in such a manner that the air supply module  26  may alternatively be disposed on the right or on the left side of the main air conditioning module  2  (as viewed in the direction of travel of the automotive vehicle). The multiple zone air conditioning system  1  of the invention is thus suited to being mounted both in right hand drive and in left had drive automotive vehicles. The ambient air taken from by the fan  26  into the air supply module  3  is directed through an (optional) filter  32  (not shown in  FIG. 1   a , but seen in  FIG. 2 ) disposed in the air supply module into the interior of the base member  34  of the main air conditioning module  2 . 
     In the base member  34  of the main air conditioning module  2  there are disposed a first heat exchanger  4 , as seen in  FIG. 2 , and a second heat exchanger  6 . The entire ambient air taken by the fan  26  is supplied to the first heat exchanger  4 . The first heat exchanger  4  serves to cool down and dry the ambient air that has been taken in. It is connected to a refrigerant circuit of the automotive vehicle. The condensed refrigerant supplied by a refrigerant pump is vaporized in the first heat exchanger  4  to generate cool. Typically, the ambient air intake was cooled down to a temperature of about 4° C. 
     A second heat exchanger  6  serves to heat a portion of the air that has been cooled down and dried by the first heat exchanger  4 . For this purpose, the second heat exchanger  6  is, for example, connected to the coolant circuit of the automotive vehicle drive unit. When the drive unit is operative, the coolant is heated by the heat loss of the drive unit to an increased temperature which typically is on the order of 100° C. A further heating element  26  may additionally be disposed on the main air conditioning module  2 , this heating element being electrically operated (PTC) in the exemplary embodiment shown and serving as an additional heater in the starting phase of the drive unit, at low ambient temperatures or with highly efficient drive units generating (too) little heat loss. 
     As a direct result of the shape of the main air conditioning module  2  and of the multiple zone modules  10  and  10 ′, the multiple zone modules  10  and  10 ′ respectively can be disposed singly on the main air conditioning module  2 . By disposing a respective one of the multiple zone modules  10  and  10 ′, the multiple zoned air conditioning system  1  of the invention is made operative.  FIG. 1   b  here shows a first multiple zone module  10 ′ that is designed to create two air flows  24 ,  25  of differing temperatures for unitarily supplying the entire rear zone of an automotive vehicle. On the multiple zone module  10 ′ there is formed a panel outlet  38  at which a cool air flow  24  for supplying the upper region of the rear zone is provided as well as a leg space outlet  40  at which a warm air flow  25  for supplying the leg space of the rear zone is provided. 
       FIG. 1   c , by contrast, shows a second multiple zone module  10  that is not designed to create an independently air-conditionable air flow. The second multiple zone module  10  that can be seen from  FIG. 1   c  rather serves to primarily cover the mounting aperture for the multiple zone modules  10 ,  10 ′ formed on the main air conditioning module  2  in such a manner that the air is caused to efficiently flow through the second heat exchanger  6  on the entire heat exchange surface thereof. The second multiple zone module  10 ′ therefore in particular comprises a strong flow directing function. 
       FIG. 2  shows a sectional view, in the plane of symmetry of the main air conditioning module  2  of the air conditioning system  1 , of a multiple zoned air conditioning system  1  according to the  FIGS. 1   a  and  1   b . In the mounted position in the automotive vehicle, this plane of symmetry is generally oriented in the direction of travel and in the vertical direction as well. For simplicity&#39;s sake, it is assumed in the remainder of this discussion that the main air conditioning module  2  is designed for single supply of the left and the right front seats. Accordingly, the main air conditioning module  2  differs from the embodiment shown in  FIG. 1   a  which is designed to individually air-condition the respective one of the left and the right front seats. 
     The ambient air taken by fan  26  passes through an air filter  32  before it enters the base member  34  of the main air conditioning module  2 . The first heat exchanger  4 , in which a liquefied refrigerant is vaporized, is disposed directly behind the filter  32 . The thus generated cold serves to cool down to a defined initial temperature of e.g., 4° C. the ambient air that has been taken in and to remove by condensation the humidity contained therein. 
     Upon passage through the first heat exchanger  4 , the cooled dried air is divided into a plurality of flow paths as shown by the discontinuous line in  FIG. 2 . A first flow path  29  leads a first portion of the air flow exiting the first heat exchanger  4  through the second heat exchanger  6  disposed within the base member  34  and through the electric heating element  26  disposed downstream thereof. The second heat exchanger  6  is connected to the coolant circuit of the automotive vehicle drive unit. The coolant circulating therein has a quite high temperature of typically about 100° C. The electric heating element  26 , which is mounted downstream thereof and which is optional, may be additionally connected if the heat demand in the air conditioning system can no longer be met by the heat loss of the automotive vehicle drive unit. This condition may for example occur in the warm-up phase of the drive unit. An additional heating element  26  may, however, also be permanently necessary given the operable automotive vehicle drive unit is highly efficient and, as a result thereof, comprises a low heat loss rate. An example thereof is the modern common rail diesel engine. 
     The branched first partial air flow warms up as it passes via the first flow path  29  through the second heat exchanger  6  and through the optional heating element  26  and enters thereafter, from the bottom, as the first warm partial air flow  16  into the first mixing chamber  12  of the multiple zoned air conditioning system  1  of the invention, which is disposed in the main air conditioning module  2 . 
     On a second flow path  31 , a second, initially cool partial air flow also passes through the second heat exchanger  6  and through the optional heating element  26 , the second flow path  31  being separated from the first flow path  39  by barriers. On the second flow path  31 , a second warm partial air flow  20  is created which enters a second mixing chamber  14  disposed in the multiple zone module  10 ′ from the top. 
     A third flow path  28 , which again is separated from the first flow path  29  by barriers, leads a first cool partial air flow  18  into the first mixing chamber  12  from the bottom. The mix ratio between the first warm partial air flow  16  and the first cool partial airflow  18  is adjusted by means of an angled mixing valve  58 . 
     On a fourth flow path  30 , a last cool partial air flow is finally conducted from the first heat exchanger  4  to the second mixing chamber  14 , which it enters from the side, as the second cool partial air flow  22 . The mix ratio of the second warm partial air flow  20  and the second cool partial air flow  22  is adjusted by means of an adjustable mixing valve  60 . 
     The multiple zoned air conditioning system of the invention having a main air conditioning module  2  and a multiple zone module  10 ′ is thereby made operative by inserting the multiple zone module  10 ′ into the base member  34  of the main air conditioning module  2 , the two modules being jointed together. The junction  50  where the base member  34  of the main air conditioning module  2  is connected to the multiple zone module  10 ′ forming on the superimposed joint surfaces of the two modules is shown by a dash-dot line in  FIG. 2 . The connection between the main air conditioning module  2  and the multiple zone module  10 ′ is thereby configured to be overpressure proof. Once the multiple zone module  10 ′ is inserted into the main air conditioning module  2 , it is preferably secured in place on the main air conditioning module  2  by screwing. The multiple zone module  10 ′ is thereby configured such that the first flow path  29  described herein above, which leads into the first mixing chamber  12  disposed in the main air conditioning module  2 , does not form until the multiple zone module  10 ′ is disposed on the main air conditioning module  2 . Further, the second flow path  31 , which extends through the main air conditioning module  2  and the multiple zone module  10 ′, does not form until the multiple zone module  10 ′ is disposed on the main air conditioning module  2 . 
     Both the first flow path  29  and the second flow path  31  extend through the second heat exchanger  6  and through the optional heating element  26 . In this manner, a space-saving configuration of the multiple zoned air conditioning system may be realized. Substantial constructional features may be realized by having the multiple zone module  10 ′ and the main air conditioning module  2  share both the second heat exchanger  6  and the optional heating element  26  and by having both the first flow path  29  leading to the first mixing chamber  12  of the main air conditioning module  2  and the second flow path  31  leading to the second mixing chamber of the multiple zone module  10 ′ passing through one and the same second heat exchanger  6  and through one and the same additional heating element  26 . The multiple zone module  10 ′ may thus dispense with an additional (second) heat exchanger or with a second optional heating element. This allows a particularly compact construction of the multiple zoned air conditioning system of the invention. 
     The first mixing chamber  12 , which is formed in the main air conditioning module  2 , functions in the same way as the often realized mixing chambers formed in prior art air conditioning systems. The concept behind the mixer in accordance with the present invention is termed a “stratified air flow mixer”. The first warm partial air flow  16  and the first cool partial air flow  18  are supplied to the first mixing chamber  12  from the bottom. In the first mixing chamber  12 , the first and the second partial air flow  16 ,  18  are mixed in such a manner that a shear layer with a fixed temperature profile forms in the vertical direction within the first mixing chamber  12 . This means that, depending on the location of the outlet, an air-conditionable air flow  8 ,  9  exits the first mixing chamber  12  the temperature of which depends on the exact position of the outlet in the vertical direction. This principle of construction is regularly made use of in prior art. It permits to create a plurality of air-conditionable air flows of different temperatures using one mixing chamber supplied with one warm and one cool partial air flow. As a rule however, the air flows of different temperatures thus created will not be adapted to be air-conditioned independently of one another. Usually, there is rather a temperature difference between the created air-conditionable air flows. By the appropriate design of the air conditioning system this difference may be kept constant over the widest possible temperature and ventilation range. 
     In the case of the present multiple zoned air conditioning system  1 , three outlets  42 ,  44  and  46  are provided in the region of the first mixing chamber  12 . In the upper region of the mixing chamber  12  there is disposed a defrost outlet  42  and a front panel outlet  44 . Air-conditionable air flows  7  and  8  of slightly different temperatures exit the defrost outlet  42  and the front panel outlet  44 . 
     A front leg space outlet  46  through which much warmer air is caused to exit the first mixing chamber  12  is disposed much lower in the vertical direction in the first mixing chamber  12 . In this manner, (cooler) first air-conditionable air flows  7  and  8  exiting the outlets  42  and  44  and one (warmer) second air-conditionable air flow  9  exiting the leg space outlet  46  are created using but one first mixing chamber  12 . The absolute and relative intensity of the air flows  8  and  9  exiting the outlets  42 ,  44  and  46  is controlled by means of the fan  26  and of mixing valves which are disposed in the region of the outlets. The mixing valves, the first mixing chamber  12  and possibly the control unit of the air conditioning system are advantageously designed such that intensity and temperature of the air flows  7 ,  8  and  9  exiting the outlets  42 ,  44  and  46  hardly change upon adjustment of but one single mixing valve. 
     By contrast, the second mixing chamber  14 , which is formed in the multiple zone module  10 ′, is based on a new fluid mechanical mixer concept, said concept being termed herein a “crossflow mixer”. As can be seen from  FIG. 2 , the second warm partial air flow  20  of the second mixing chamber  14  is supplied from the top. The also supplied second cool partial air flow  22  however is supplied to the second mixing chamber  14  from the side. As a result, the flow paths  70 ,  72  of the warm and the cool partial air flows  20 ,  22  intersect in the second mixing chamber  14  at an angle of about 135°. More specifically, the two partial air flows are partially caused to run counterflow in the forming mixing zone  66 . With regard to the “crossflow mixer” concept of the invention, this counterflow pattern may have a positive effect in certain cases. However the crossflow mixer is not limited to such a flow pattern. It may instead be advantageously realized over a wide range of angles of intersection that may readily extend from 35° to 155°. By optimizing, in terms of fluid flow, the second mixing chamber  14  and in particular the chimney  68  provided there that will be discussed in further detail herein after, this angular range may still be widened if necessary. 
     A leg space outlet  40  of mixing chamber  14  provided to supply the leg space in the rear zone with a warmer air-conditionable air flow  25  is disposed opposite the entrance site where the warm partial air flow  20  enters the second mixing chamber  14 . The leg space outlet  40  for the rear zone is thereby disposed substantially underneath the second mixing chamber  14 . A panel outlet  38  for the rear zone is disposed laterally from the second mixing chamber opposite the entrance site of the second cool partial air flow  22 , though. A second air-conditionable air flow  24 , which is slightly cooler than the one exiting the leg space outlet  40 , exits said panel outlet  38 . The precise ratio between the temperatures of the air-conditionable air flows  24  and  25  can be adjusted by the mix ratios in the “crossflow mixer”. These mix ratios are substantially determined by the properties of the second mixing chamber  14  in terms of fluid mechanics. This is the reason why the air flows  24  and  25  are not adapted to be air-conditioned independently from one another with regard to temperature. The relative intensity of the air flows  24  and  25  exiting the ports  38  and  40  can be varied by means of another angled mixing valve  64 , though. 
       FIG. 3  illustrates the fluid mechanical conditions within the second mixing chamber  14  of the air conditioning system, which is configured to be a “crossflow mixer”. A second warm partial air flow  20  is supplied to the second mixing chamber  14  via a second flow path  31 . This one enters the second mixing chamber from the top. The intensity of this second warm partial air flow  20  is regulated by means of a closing valve  62 . Further, a second cool partial air flow  22  enters the second mixing chamber  14  through a laterally disposed entrance port that is disposed well beneath the entrance port for the second warm partial air flow  20 . After the second warm partial air flow  20  has entered the second mixing chamber  14 , it traverses a mixing zone  66  and is conducted toward a leg space outlet  40  for the rear zone. The second cool partial air flow  22 , which has entered the second mixing chamber  14  in a horizontal flow direction, strikes an impingement baffle  56  and is redirected upward toward mixing zone  66  through said impingement baffle. Before reaching the mixing zone  66 , it is thereby circulated around the leg space outlet  40  for the rear zone which projects into the second mixing chamber  14  in the form of a chimney  68 . Said chimney  68  ends only upon reaching the mixing zone  66  located in the center of the second mixing chamber  14 . 
     In accordance with the invention, a portion of the second warm partial airflow  20  supplied to the mixing chamber  14  is conducted out of the second mixing chamber  14  through chimney  68  after having traversed the mixing zone  66 . The aperture cross section of the upper aperture of chimney  68 , which is proximate to the mixing zone  66 , is thereby smaller than the cross-sectional area of the entrance port  54  of the second warm partial air flow  20  into the second mixing chamber  14 . In accordance with the invention, a fraction of the second warm partial air flow  20 , which is substantially determined by the area ratios, enters the chimney  68 . This fraction of the second warm partial air flow  20  is therefore caused to exit the second mixing chamber  14  immediately upon entrance into mixing zone  66  without having been mixed with the second cool partial air flow  22 . Here no relevant blending with the second cool air flow  22  occurred so that the air-conditionable air flow  25  exiting the leg space outlet  40  for the rear zone was only cooled down to a certain extent as compared to the incoming second warm partial air flow  20 . 
     That fraction of the second warm partial air flow  20  that has not been captured by the entrance port  52  of the chimney  68  is mixed with the second cool partial air flow  22  passing by the chimney  68  in the mixing zone  66 . This results in a considerable cooling effect. For this reason, a substantially cooler second air-conditionable air flow  24  exits the laterally disposed rear panel outlet  42 . It is evident that the flow path  70  of the warm partial air flow  20  extends almost in a straight line through the second mixing chamber  14 . It can also be seen that the flow path  72  of the cool partial air flow  22  does not extend in a straight line through the second mixing chamber  14 . After having entered the second mixing chamber  14 , the horizontally incoming second cool partial air flow  22  strikes a sloped surface that is configured to be an impingement baffle  56 . The impingement baffle  56  redirects the cool partial air flow  22  in the vertical direction so that, in the region of the mixing zone  66 , it flows in a direction counter to the direction of the warm partial air flow  20 . In the mixing zone  66 , the flow paths  70  and  72  of the warm and of the cool partial air flow are inclined to one another at an angle α which, in the exemplary embodiment shown, is on the order of 135°. As already mentioned, such a counterflow pattern may have an advantageous effect, but it is not absolutely necessary for the “crossflow mixer” concept of the invention. More specifically, a flow pattern with an intersection angle of 90° and less, i.e., completely dispensing with counterflow, may also be advantageous. Those skilled in the art will recognize various possibilities to adapt the supply of the partial air flows to be mixed in the “crossflow mixer” to the construction conditions of the air conditioning system which is being designed. 
     In the exemplary embodiment shown the size of the mixing zone  66  in which the warm and cool partial air flows  20 ,  22  partially blend is substantially determined by the distance the chimney  68  projects into the center of the second mixing chamber  14 . Accordingly, the temperature difference between the generated air flows  24  and  25  may be determined in particular by dimensioning the chimney  68  accordingly. 
       FIG. 4  finally shows a partial perspective sectional view of the second mixing chamber  14  when viewed from the main air conditioning module  2  from the direction of the defrost outlet  42  for the rear zone. It can be readily seen that the chimney  68  is disposed in the center of the second mixing chamber  14  and that the second cool partial air flow  22  is passing by three sides thereof. The flow paths  72  laterally passing by the chimney  68  on the right and on the left side thereof lead a substantial portion of the incoming cool partial air flow  22  to the defrost outlet  42  for the rear zone. They thereby only slightly blend with those fractions of the warm partial air flow  22  that are not being received by the aperture cross section  52  of the chimney  68 . By contrast, the fraction of the cool partial air flow  22  flowing along the flow path  72  running in the center is brought into intimate contact with the fraction of the warm partial air flow  22  that has been captured by the aperture cross section  52  of the chimney  68 . It is thereby intimately blended with the latter and conducted to the leg space outlet  40  for the rear zone. From  FIG. 4  it can be seen that the chimney  68  acts as a flow divider both for the second cool partial air flow  22  and for the second warm partial air flow  20 . 
     To conclude it should be noted that, to practically realize a mixing chamber relying for operation on the “crossflow mixer” concept, it is readily possible to vary, more specifically also to interchange, the supply of warm and cool partial air flows to the mixing chamber with regard to the exemplary embodiment discussed since gravitational influences or a lift are practically negligible with the mixing chamber dimensions of the “crossflow mixer” in question. 
       FIG. 1   a  shows the various outlets for air-conditionable air flows formed on the air conditioning module  2 . The main air conditioning module  2  is centrally symmetrically divided so that two separately controllable first mixing chambers  12   a  and  12   b  are obtained. One right and one left defrost outlet  42   a ,  42   b , one right and one left front console outlet  44   a ,  44   b  and one right and one left front leg space outlet  46   a ,  46   b  are provided in said mixing chambers  12   a  and  12   b  which are provided for separately supplying the respective one of the right and the left front seats. Substantially equally conditioned “first air-conditionable air flows  8  (“first front right  8   a ” and “first front left  8   b ”) exit the outlets  42   a ,  42   b ,  44   a ,  44   b . Further substantially equally conditioned air-conditionable air flows (“second front right  9   a ” and “second front left  9   b ”) the temperature of which is correlated with the “first air-conditionable air flows  8 ” exit the outlets  46   a ,  46   b.    
     Additionally, further rear zone connecting outlets  76   a ,  76   b  that are disposed in the region of the two mixing chambers  12   a ,  12   b  may be provided on the base member  34  of the main air conditioning module  2 . They permit to directly connect the supply lines for the rear zone (not shown) given individual adjustment is not desired in the rear zone (one- or two-zoned air conditioning system). If a three- or four-zoned air conditioning system is realized, these additional outlets  76   a ,  76   b  provided on the main air conditioning module  2  remain closed as shown in  FIG. 1   a.    
       FIG. 1   b  shows the various outlets for air-conditionable air flows that are formed on the multiple zone module  10 ′. By providing a centrally disposed parting plane, the single-zone multiple zone module  10 ′ shown may be developed in a simple manner to achieve a two-zone multiple zone module (not shown) which forms two separately controllable second mixing chambers. A rear panel outlet  38  and a rear leg space outlet  40  for the rear zone are provided in the second mixing chamber  14 . A second cooler air flow  24  adapted to be air-conditioned (independently of the first air-conditionable air flow  8 ) exits the outlet  38 . Another warmer air-conditionable air flow  25  the temperature of which is correlated with the temperature of the second air-conditionable air flow  24  exits the outlet  40 . 
     It should be further noted that all of the outlet associations described herein above for the air conditioning system  1  of the invention are given by way of example only. As a matter of course, it is also possible to freely supply to the various vent ports of the automotive vehicle the various differently air-conditioned air flows provided by the air conditioning system  1 . More specifically, the temperature differences between the leg space outlets on the one side and the panel and defrost outlets on the other side have been indicated by way of example only and can be selectively adapted to the requirements of the automotive vehicle manufacturer. 
     The fluid mechanical active actuator elements such as the closing and mixing valves that have been illustrated herein may for example be mounted on shafts and actuated by means of current servomotors, more specifically by a stepper motor. The drive of these active actuator elements is preferably achieved by a central air-conditioning control unit that receives the commands of the user of the automotive vehicle and adjusts the actuator elements so as to carry into effect the user&#39;s inputs. 
     The foregoing discussion discloses and describes a preferred embodiment of the invention. One skilled in the art will readily recognize from such discussion, and from the accompanying drawings and claims, that changes and modifications can be made to the invention without departing from the true spirit and fair scope of the invention as defined in the following claims.