DE19902050A1 - Heating or air conditioning for vehicles - Google Patents

Description

The invention relates to a heating or air conditioning system for a passenger compartment of a motor vehicle according to the preamble of claim 1.

In motor vehicles, their internal combustion engine or motor is constructed in a way that is optimized for consumption lower heat loss, which is due to the engine cooling provided heating energy for heating the Passenger cell is sometimes too small. The remedy is here an additional electric heater, which if necessary the Air flow through the heat exchanger heats up more.

In a known heating system of the type mentioned (DE 37 15 194 A1) is the flow of cooling water Heat exchanger in an outside air leading to the passenger compartment Channel arranged. Next to it is also the outside air leading duct provided an additional electric heater that for heating the air during the warm-up phase of the Internal combustion engine ensures. To be as intense as possible To achieve warming of the air with the additional heating points this a large area, to a low temperature of  less than 150 ° C adjustable heating conductor and is as flat, box-shaped structure formed in Direction of air flow immediately behind the Heat exchanger is arranged and attached to it, wherein the heat exchanger supports the additional electrical heating forms.

In a known heating system of the type mentioned (DE 42 38 364 A1) is also the electric auxiliary heater downstream of the heat exchanger, so that of a blower generated air flow first flows through the heat exchanger, only is partially heated and then by the electric Additional heating flows through and here to a higher one Temperature is heated. The preheated air flows in the passenger compartment. One located in the passenger compartment Interior temperature sensor, which together with a Setpoint generator determines the heating requirement and in the Airflow flowing into the passenger compartment is controlled the cooling water flow through the control unit Heat exchanger and the duty cycle of the additional heating.

In a heating system also known for Motor vehicles (DE 44 33 814 A1) also set themselves there existing electrical auxiliary heating from a plurality of so-called PTC elements (Positive Temperature Coefficient) together, the electrically heated and from which the Air flow exiting or flowing through the heat exchanger become.

In all known heating systems, the arrangement of the additional electrical heater in the air flow leading Air duct behind the heat exchanger and makes a special,  interpretation of the electric auxiliary heating Air duct necessary because of the additional electrical heating additional space must be created.

The invention has for its object a heating or Air conditioning of the type mentioned in such a way that no separate one for the installation of the additional electrical heating Space in the air duct is required.

The task is characterized by the features in the label part of the Claim 1 solved.

The heating or air conditioning system according to the invention Advantage that through the direct involvement of electric auxiliary heater in the heat exchanger of it Dimensions remains unchanged, so that in one Air conditioning box trained air duct without constructive Changes either a normal one, only from Cooling water flow through the cooling water circuit Heat exchanger or a heat exchanger with integrated additional electric heater can be used. Thereby there is the additional possibility of already installed Heating or air conditioning systems later with a to provide additional electrical heating, which by simple Heat exchanger change can be done in the climate box. Through the Integration of the additional electric heater in the The heat exchanger also makes the air volume flow less strong reduced as with the known heating systems. A Fan adjustment when installing the additional electric heater therefore not necessary.  

Appropriate embodiments of the heating or Air conditioning with advantageous training and Improvements to the invention are in the further Claims specified.

According to a preferred embodiment of the invention the heat exchanger a plurality of cooling water flowed through water channels, which are in parallel distance from each other via the air passage surface of the heat exchanger extend and end each in a water collection box flow out, as well as heat-conducting fins, with the water channels are connected. The additional electric heater has one Majority of electric heating elements located between the Water channels and parallel to it in preferably more uniform Spread over the air passage area. Preferably, a run alternately with Water channel provided with heat-conducting elements and an electrical one Heating element parallel next to each other.

According to an advantageous embodiment of the invention each heating element has two parallel ones Busbars and a plurality of PTC elements that spaced apart between the two busbars arranged and with these mechanically and electrically conductive are connected.

To avoid electrical short circuits, is between everyone Heating element and an adjacent water channel an electrical Insulating plate arranged on the one hand with the Water duct connected heat-conducting elements and on the other hand by Support thermal conductors protruding from the busbars.  

According to a preferred embodiment of the invention Control of the auxiliary heating depending on the Parameters determining heat demand, such as outside temperature, Cooling water temperature, a control device is provided, the Heat exchanger is arranged so that it from the in the Air flowing into the heat exchanger is coated. The Control unit assigns power electronics and heat sinks Heat dissipation and the arrangement of the control unit is on the Air inlet side of the heat exchanger hit so that at least the heat sinks are in the air flow. Through this Housing the for the control of the electrical Additional heater required control unit on the heat exchanger you get a compact unit that is in one Assembly process by screwing, clipping or another rattle-free and play-free connection without wiring the Heating rods and the control unit among each other in the climate box can be accommodated.

According to an advantageous embodiment of the invention the control unit is arranged on a plastic frame that is on the air inlet side of the heat exchanger on this put on and connected to it, e.g. B. clipped or is screwed. The between the water channels of the Heat exchanger arranged electrical heating rods Auxiliary heating are each in one of the heat exchangers facing underside of the plastic frame in one piece protruding frame-like immersed in the heat exchanger Trough added, the longer trough walls preferably the between the heating elements and the water channels Form insulation plates.  

According to an advantageous embodiment of the invention a mechanical on / off for the additional electrical heating switch provided, the spatially in the additional heating integrated and from one placed in the dashboard manual control button via a Bowden cable and one can be actuated by this pivotable cam. By the spatial integration of the on / off switch in the additional electric heating is a concentrated design of the complete heating system with mechanical switching device achieved. It is therefore possible to use the heating variants with or only to the air conditioning box without additional electrical heating restrict without additional controls in the dashboard too change. The blower box variants with or without additional electrical heating are only immediately before Montage formed, which means that environmental boxes and electrical auxiliary heating modules are delivered separately. Through the variants formed immediately before installation Logistics costs saved and the coordination effort minimized. Manufacturing can be more flexible based on demand react. The electric auxiliary heater can both in the heat exchanger integrated as well as separately from Heat exchangers are used in the air flow.

A saving of components is obtained if according to one advantageous embodiment of the invention of the on / off switch from one in the climate box Air mixing flap for mixing the heat exchanger immediate cold air flow and one through the heat exchanger flowing hot air flow is actuated, the On / off switch is adjusted so that its electrical Circuit of the additional heating switch contact in the Swinging end position of the air mixing flap for maximum  Warm air supply is closed. The air mixing flap will be there from one which specifies the pivoting position of the air mixing flap Temperature adjuster actuated.

According to an advantageous embodiment of the invention the mechanical on / off switch for the electrical Additional heating spatially on one of the heat exchangers upstream blower for generating the heat exchanger and air flow flowing through the electric auxiliary heater be arranged, the on / off switch in turn from a manual control button placed in the dashboard can be confirmed. The advantages here are the same as when the on / off switch is housed in the Heating module of the additional electrical heater itself.

The invention is illustrated in the drawing Embodiments described in more detail below. It each show in a schematic representation:

Fig. 1 is a longitudinal section of an air conditioning system for a passenger compartment of a motor vehicle,

Fig. 2 shows a longitudinal section according to section line II-II in Fig. 3 of a heat exchanger with an integrated electric heater of the air conditioner in Fig. 1,

Fig. 3 a section of a perspective view of the heat exchanger with an integrated electric heater in Fig. 2.

Fig. 4 is a perspective view of the heat exchanger in Fig. 2 and 3 before assembling the electric auxiliary heater,

Fig. 5 is a perspective view of a can be placed on the heat exchanger of FIG. 4 the plastic frame with troughs for receiving the electrical auxiliary heater,

Fig. 6 is a perspective view of a, with the plastic frame in Fig. Connectable 5 control device for the electric auxiliary heater

Fig. 7 is a perspective view of the plastic frame in the direction of arrow VII in Fig. 5, increases with an inserted heating element of the electric auxiliary heater,

Figure 8 is shown a perspective view of a conductor rail with the contact rail of the electrical auxiliary heater in Fig. 7 enlarged.,

Fig. 9 is a bottom perspective view of a heating module of an electrical auxiliary heater according to a further embodiment,

Fig. 10 is a front view of the heating module in the direction X in Fig. 9,

FIG. 11 shows a side view of an on / off switch for the additional electrical heating in FIG. 9 according to a further exemplary embodiment.

The air conditioning system shown schematically in longitudinal section in FIG. 1 has a blower 11 which is connected to the entrance of an air duct box 12 , also called a climate box. In the air guide box 12 , an evaporator 13 integrated in a refrigerant circuit and a heat exchanger 14 integrated in the cooling water circuit of the internal combustion engine or the internal combustion engine of the motor vehicle are accommodated, which are arranged downstream of the fan flow in the order mentioned. An air distributor 15 is arranged immediately downstream of the heat exchanger 14 , from which three air channels 16-18 branch off. The middle air duct 16 leads to air outlet nozzles, not shown here, in the middle plane of the passenger compartment, while the air duct 17 leads to the defroster nozzles on the underside of the front window of the passenger compartment and the air duct 18 leads to footwell nozzles arranged in the footwell of the passenger compartment. The fresh air drawn in by the blower 11 either from the vehicle environment or mixed air drawn in from the passenger compartment is cooled and dehumidified in the evaporator 13 and warmed up in the heat exchanger 14 through which the hot cooling water of the internal combustion engine flows. The air conditioned in this way is distributed via the air distributor 15 to the individual air outlet nozzles in the passenger compartment. The water precipitating from the air conveyed by the blower 11 and precipitating in the air guide box 12 is discharged via a water separator 19 in the box section between the evaporator 13 and the heat exchanger 14 .

In FIGS. 2 and 3, the heat exchanger 14 is shown with all its details. The hot cooling water coming from the internal combustion engine enters a water collection box 22 via a cooling water inlet 21 and is distributed here over a multiplicity of water channels 23 which extend parallel to one another over the entire air passage area 141 of the heat exchanger 14 . The water channels 23 open into a second water collection box 24 arranged on the opposite side of the heat exchanger 14 parallel to the first water collection box 22 . The water flowing into the second water collection box 24 is led back to the internal combustion engine via a cooling water outlet 25 . As can be seen from the perspective illustration in FIG. 3, the individual water channels 23 , which are parallel to one another, are subdivided into a plurality of side-by-side channel tubes 231 with a rectangular cross section, each of which is separated from one another by a channel wall 232 . In the embodiment of FIG. 3, each water channel 23 is formed with four channel tubes 231 . On the top and bottom of each water channel 23 , heat-conducting elements 26 are arranged in the form of lamellae or ribs, which are in mechanically firm and heat-conducting connection to the walls of the water channel 23 and ensure good heat dissipation to the air flowing through them.

To cover the heating requirement when the internal combustion engine has not yet warmed up and / or to cover the maximum heating requirement in motor vehicles with consumption-optimized internal combustion engines, in which the heating requirement can no longer be covered solely by the cooling water circuit of the internal combustion engine, an additional electric heater 20 is provided, which is also provided by the Air flowed through by the blower 11 , which also flows through the heat exchanger 14 , and additionally heats it up. As can be seen from FIGS. 2 and 3, the electrical auxiliary heater 20 is structurally integrated in the heat exchanger 14 , in such a way that its dimensions do not change compared to a conventional heat exchanger 14 through which only cooling water flows and without an electrical auxiliary heater. The additional electrical heater 20 has a plurality of electric heating rods 27 which extend between the water channels 23 and parallel to it in a preferably uniform distribution over the air passage surface 141 of the heat exchanger 14 . A water channel 23 equipped with the heat-conducting elements 26 and an electric heating element 27 alternately run parallel to one another. To optimize the heat transfer to the air flow, each heating rod 27 is also provided on its two mutually facing outer sides with heat-conducting elements 28 in the form of fins or ribs. Each heating rod 27 has two busbars 30 , 31 running parallel to one another and a plurality of so-called PTC elements 29 which are spaced apart from one another between the two busbars 30 , 31 and are mechanically and electrically conductively connected to them. These PTC elements 29 have, for example, a honeycomb or hollow box profile and are made of an electrically conductive material with a positive temperature coefficient. The PTC elements 29 are connected to an electrical circuit via the two busbars 30 , 31 . The two busbars 30 , 31 are held at the ends in insulators 32 , 33 which are fastened to the mutually facing inner surfaces of the water collecting boxes 22 and 24 . To avoid electrical short circuits, an insulation plate 34 is arranged between each water channel 23 with heat-conducting elements 26 and each heating rod 27 with heat-conducting elements 28 , which extends parallel to the water channel 23 and heating rod 27 between the two water collecting boxes 22 , 24 . The heat-conducting elements 26 and 28 held by the water channel 23 and busbars 30 , 31 are supported on this insulation plate 34 on sides facing away from one another. As can be seen from FIG. 3, the water channels 23 with heat-conducting elements 26 , the busbars 30 , 31 with the PTC elements 29 , the insulation plates 34 and the insulators 32 , 33 extend over the entire depth of the heat exchanger 14 seen in the air flow direction.

To control the electric auxiliary heater 20 depending on the heat determining variables such as outside temperature, cooling water temperature and. Like., A control unit 35 is provided, which is combined with the heat exchanger 14 to form a structural unit. The control unit 35 has power electronics and heat sinks for dissipating the heat generated in the power electronics, which are symbolized in their entirety in FIG. 6 by the box 36 . Power electronics and heat sink 36 are arranged on a circuit board 37 which is equipped with sockets 38 for electrical connectors 39 . In addition, the circuit board 37 also has a contact strip (not shown here), via which the power electronics can be connected to the heating rods 27 of the additional electrical heater 20 . The contact strip is arranged on the component side of the circuit board 37 facing away from the connecting plugs 39 , which also carries the power electronics with the heat sink 36 .

The control unit 35 is now arranged on the air inlet side of the heat exchanger 14 in such a way that the power electronics with the heat sink 36 lie in the air flow entering the heat exchanger 14 . For this purpose, a plastic frame 40 is provided, which is placed flush and screwed on the upper side of the heat exchanger 14, which is shown in perspective in FIG. 4, in the two water collection boxes 22 , 24 , and rigidly connecting cross members 142 . For this purpose, threaded screws are inserted through through holes 41 in the plastic frame 40 and screwed into threaded holes 42 in the cross member 142 . The plastic frame 40 carries on its front facing the water inlet and outlet 21 , 25 a rectangular frame part 401 projecting in one piece from the frame 40 , on which the circuit board 37 is placed flush and by means of screws which are inserted through through holes 43 in the circuit board 37 and in Threaded holes 44 are screwed into the frame part 401 , is fastened. Instead of a screw connection, a clip can also be provided, which also applies to the fastening of the plastic frame 40 to the heat exchanger 14 .

After the circuit board 37 has been attached to the frame part 401 , the power electronics with the cooling body 36 protrude beyond the air passage surface 141 of the heat exchanger 14 , so that it is swept by the air entering the heat exchanger 14 . The contact strip on the circuit board 37 is inserted into a further contact strip 46 , which is fastened on the frame leg of the frame part 401 lying in one plane with the plastic frame 40 . The electrical connection to the additional electrical heater 20 is made from this contact strip 46 .

In the heat exchanger 14 shown in FIG. 4, the additional electrical heater 20 shown in FIGS. 2 and 3 has not yet been installed. Rather, it is preassembled in the plastic frame 40 , as can be seen in FIG. 7, and when the plastic frame 40 is placed on the top of the heat exchanger 14 in FIG. 4, it is inserted into the free spaces 45 held in the heat exchanger 14 , so that the total in Fig. 2 and 3 completed heat exchanger 14 is obtained. For receiving the electrical auxiliary heater 20 27 of the electrical auxiliary heater 20 is attached to the plastic frame 40 for each heating element forming a frame-like tray 47 which in the the heat exchanger 14 facing underside of the plastic frame 40 protrudes and placement of the plastic frame 40 to the heat exchanger 14 into the pre-preserved Free space 45 is immersed in the heat exchanger 14 . In the embodiment of FIGS. 6 and 7, two spaced-apart, parallel troughs 47 are provided in the plastic frame 40 , which are arranged at a distance from one another due to the water channel 23 with heat-conducting elements 26 of the heat exchanger 14 . A heating rod 27 of the additional heater 20 is accommodated in each trough 47 . In Fig. 7, a trough is by way of example 47, equipped with a heating element 27, as has been described in detail above. The same heating rod 27 is also used in the other trough 47 which is still free in FIG. 7. Between these two troughs 47 there is a free space 48 in the plastic frame 40 , which after the plastic frame 40 has been placed on the heat exchanger 14 is filled by the water channel 23 with heat-conducting elements 26 of the heat exchanger 14 in FIG. 4. The inner, longer trough walls 471 are at the between the water channel 23 and the heating elements 27 of the one water collecting tank 22 to the other water collecting case 24 extending insulation plates 34 or assume when saving of the insulation plates 34 whose insulating performance against the heat-conducting elements 26 at the water channel 23rd

As shown in FIG. 7, the busbars 30 , 31 of the two heating rods 27 , between which the PTC elements 29 are clamped, are arranged such that the busbar connections of the same polarity are located on one of the two long sides of the plastic frame 40 . In the exemplary embodiment in FIG. 7, the connecting lugs 301 (positive pole) of the busbars 30 are arranged on the right frame leg and the connecting lugs 311 (negative pole) of the busbars 31 are arranged on the left frame leg of the plastic frame 40 . The electrical connecting lines (not shown in FIG. 7) from the heating rods 27 to the contact strip 46 on the frame leg of the frame part 401 run on these frame legs of the plastic frame 40 . The electrical connecting lines are preferably designed as contact rails 49 , which are laid in the frame legs of the plastic frame 40 and z. B. are pinched or melted and can wear contact tongues at the ends, which together form the second contact strip 46 . In this case, the first contact strip on the circuit board 37 is composed of contact shoes, each of which overlaps one of the contact tongues formed on the contact rails 49 . In FIG. 8, a conductor rail 30 is shown a heating rod 27 which is laid in contact with a lateral frame leg of the plastic frame 40 contact rail 49. The terminal lug 301 of the busbar 30 can be soldered to the contact rail 49 or can be formed in one piece with it.

FIG. 9 shows an electrical auxiliary heater 20 designed as an independent heating module 50 , which, unlike in FIGS. 1-8, is not integrated in the heat exchanger 14 itself, but rather separately from a conventional heat exchanger in the air flow flowing through the heat exchanger 14 , closely adjacent to the heat exchanger is arranged. A spatial integration of the heating module 15 in the heat exchanger, as in Fig. 1-8, is easily possible. The heating module 50 is equipped with three heating elements 27 , each heating element 27 in turn consisting of two busbars 30 , 31 with PTC elements 29 arranged therebetween. The heating rods 27 are connected at the end to connecting plugs 51 which are arranged next to one another in a plug-in strip 52 on the end face of the heating module 50 . A mechanical on / off switch 53 for the additional electrical heater 20 is spatially integrated in the heating module 50 and can be actuated by a manual control button (not shown) placed in the dashboard or in another place in the cockpit of the vehicle. The on / off switch 53 is fastened, preferably adjustable, to a support bracket 54 formed in one piece on the connector strip 52 and projects with an actuating plunger 55 into the pivoting path of a pivotably fixed cam 56 , which in the exemplary embodiment in FIG. 10 is connected to an air mixing flap 57 ( Fig. 10) is formed. The air mixing flap 57 mixes in a known manner a cold air stream bypassing the heat exchanger 14 ( FIG. 1) with a warm air stream heated by the heat exchanger 14 , the mixed air temperature being determined by the pivoting position of the air mixing flap 57 . The air mixing flap 57 is formed via a Bowden cable 58 ( FIG. 10) by a temperature control that is manually operated and is arranged in the dashboard (not shown here). The actuating plunger 55 acts directly on a switching contact (not shown here) which is arranged in the circuit of the electrical auxiliary heater 20 and which is open in the rest position and, when acted upon by the cam 56, changes into its working position which closes the circuit of the electrical auxiliary heater 20 . The on / off switch 53 is fixed to the bracket 54 in such a way that its switching contact is closed in the pivoting end position of the air mixing flap 57 for maximum warm air supply. The on / off switch 53 can be clipped, attached or screwed to the mounting bracket 54 .

In the exemplary embodiment in FIG. 10, the on / off switch 53 is screwed onto the mounting bracket 54 , with the possibility of adjusting the on / off switch 53 with respect to the pivoting path of the cam 56 on the air mixing flap 57 being provided during assembly. For this purpose, the on / off switch 53 is pivotally attached to the mounting bracket 54 by means of a first screw 59 and carries an arcuate elongated hole 61 which is arranged concentrically with the screw 59 and through which the screw shaft of a screw 60 screwed into the mounting bracket 54 passes. With loose screws 59 and 60 , the on / off switch 53 can be pivoted on the support bracket 54 until it is correctly adjusted, that is, so that the cam 56 in the pivoting end position of the air mixing flap 57 via the actuating plunger 55 the switching contact of the on / off switch 51 closes securely. After this setting, the two screws 59 , 60 are tightened so that the on / off switch 53 is fixed in this position.

In Fig. 11 it is indicated schematically that the on / off switch 53 for the heating module 50 can also be accommodated separately from the latter in the air conditioning system, an arrangement at a suitable location of the blower 11 ( Fig. 1) being preferred. The on / off switch 53 is fastened at a location prepared on the blower housing 52 . The on / off switch 53 is fixedly mounted on a plate 63 which can be adjusted by means of a round hole 64 and an elongated hole 65 with respect to the swivel path of a swivel lever 66 fixed on the blower housing 52 . On the plate 63 , a spring tongue 67 is clamped at the end, which rests on the actuating plunger 55 of the on / off switch 53 and projects into the pivoting path of the pivoting lever 66 . The swivel lever 66 can be swiveled via a Bowden cable 68 from the cockpit of the vehicle, the on / off switch 53 again being adjusted so that in the swiveled position of the swivel lever 66 shown in broken lines in FIG. 11, the switch contact of the on / off switch 53 via the Spring tongue 67 is transferred into its working position closing the circuit of the additional electrical heater 20 .

Claims (24)

1. Heating or air conditioning system for a passenger compartment of a motor vehicle with a heat exchanger arranged in the cooling water circuit of an internal combustion engine, through which an air stream can pass and with an electric auxiliary heater through which the same air stream flows, characterized in that the electric auxiliary heater ( 20 ) is structurally located in the heat exchanger ( 14 ) is integrated. 2. Installation according to claim 1, characterized in that the heat exchanger ( 14 ) has a plurality of water channels ( 23 ) through which the cooling water can flow, which extend at a parallel distance from one another via the air passage surface ( 141 ) of the heat exchanger ( 14 ) and in each case at the end in a water collection box ( 22 , 24 ) open, and with the water channels ( 23 ) connected heat conducting fins ( 26 ) and that the additional electrical heater ( 20 ) has a plurality of electric heating elements ( 27 ) which are located between the water channels ( 23 ) and parallel to it preferably uniform distribution over the air passage surface ( 141 ) of the heat exchanger. 3. Plant according to claim 2, characterized in that alternately a with heat-conducting elements ( 26 ) occupied water channel ( 23 ) and an electric heating element ( 27 ) run parallel next to each other. 4. Installation according to claim 2 or 3, characterized in that each heating element ( 27 ) has two mutually parallel busbars ( 30 , 31 ) and a plurality of PTC elements ( 29 ) spaced apart from one another between the two busbars ( 30 , 31 ) are arranged and mechanically and electrically conductively connected to them. 5. Installation according to claim 4, characterized in that between each heating element ( 27 ) and an adjacent water channel ( 23 ) at least one electrical insulation plate ( 34 ) is arranged, on the one hand with the water channel ( 23 ) connected to the heat-conducting elements ( 28 ) and, on the other hand, support heat-conducting elements ( 28 ) protruding from the busbars ( 30 , 31 ). 6. Installation according to claim 5, characterized in that the water channels ( 23 ) end in each case in a water collection box ( 22 , 24 ) and in that the busbars ( 30 , 31 ) end in in each water collection box ( 22 , 24 ) insulators ( 32 , 33 ) are held. 7. Plant according to claim 6, characterized in that the water channels ( 23 ) with heat-conducting elements ( 26 ), the busbars ( 30 , 31 ) with heat-conducting elements ( 28 ), the insulation plates ( 34 ) and the insulators ( 32 , 33 ) over themselves extend the entire depth of the heat exchanger ( 14 ) seen in the direction of air flow. 8. Installation according to claim 7, characterized in that each water channel ( 23 ) into several, seen in the depth of the heat exchanger ( 14 ), side by side, each with a channel wall ( 231 ) separate channel tubes ( 231 ) with a rectangular cross section is divided. 9. Plant according to one of claims 1-8, characterized in that a control device ( 35 ) is provided for controlling the additional electrical heater ( 20 ) depending on the heat-determining variables, such as outside temperature, cooling water temperature, which on the heat exchanger ( 14 ) is arranged so that it is swept by the air flowing into the heat exchanger ( 14 ). 10. Plant according to claim 9, characterized in that the control device ( 35 ) has power electronics and heat-dissipating heat sinks ( 36 ) and that the arrangement of the control device ( 35 ) on the air inlet side of the heat exchanger ( 14 ) and is made such that at least the The heat sink ( 36 ) is in the air flow. 11. Plant according to claim 9 or 10, characterized in that the control device ( 35 ) is arranged on a plastic frame ( 40 ) which is placed on the air inlet side of the heat exchanger ( 14 ) and connected to it, preferably clipped or screwed . 12. Plant according to claim 11, characterized in that between the water channels ( 23 ) of the heat exchanger ( 14 ) arranged electric heating elements ( 27 ) of the auxiliary heater ( 20 ) each in one of the heat exchanger ( 14 ) facing the bottom of the plastic frame ( 40 ), preferably in one piece, projecting, frame-like trough ( 47 ) which is immersed in the heat exchanger ( 14 ) and preferably that the longer trough walls ( 471 ) which run between the heating elements ( 27 ) and the water channels ( 23 ) with heat-conducting elements ( 26 ) Form insulation plates ( 34 ). 13. Plant according to claim 12, characterized in that the heating rods ( 27 ) in the troughs ( 47 ) are received so that their connections having the same polarity on the same frame leg of the plastic frame ( 40 ) and connections of different polarity on opposite frame legs each lie above the plastic frame ( 40 ). 14. Plant according to claim 13, characterized in that the plastic frame ( 40 ) carries a first contact strip ( 46 ) which is electrically connected to the additional heater ( 20 ) and is electrically connected to the connections ( 301 , 311 ) of the heating rods ( 27 ), that the power electronics with heat sink ( 36 ) on a plastic frame ( 40 ) can be fastened, preferably clipped or screwed, is arranged ( 37 ) and that the board ( 37 ) on the one hand a second contact strip contacting the first contact strip ( 46 ) and on the other hand sockets ( 38 ) for electrical connectors ( 39 ). 15. Plant according to claim 14, characterized in that the plastic frame ( 40 ) for holding the circuit board ( 37 ) from the heat exchanger ( 14 ) facing away from the top of the plastic frame ( 40 ) integrally projecting, rectangular frame part ( 401 ) which the board ( 37 ) with power electronics projecting through the frame part ( 401 ) with heat sinks ( 36 ) is placed flush and fastened. 16. Plant according to claim 14 and 15, characterized in that the first contact strip ( 46 ) on the with the plastic frame ( 40 ) lying in one plane lower frame leg of the frame part ( 401 ) is arranged. 17. Plant according to one of claims 14-16, characterized in that the electrical connecting lines between the heating element connections ( 301 , 311 ) and the first contact strip ( 46 ) are designed as contact rails ( 49 ) which are laid in the plastic frame ( 40 ). 18. Plant according to claim 17, characterized in that the contact rails ( 49 ) carry contact tongues at the ends, which together form the first contact strip ( 46 ), and in that the second contact strip on the circuit board ( 37 ) is composed of contact shoes which overlap the contact tongues. 19. System according to the preamble of claim 1, in particular according to one of claims 1-18, characterized in that an on / off switch ( 53 ) for the electrical auxiliary heater ( 20 ) spatially integrated in the auxiliary heater ( 20 ) and by one in Dashboard of the vehicle placed manual control button is actuated. 20. System according to claim 19, characterized in that the on / off switch ( 53 ) is arranged with a switch contact in the circuit of the auxiliary heater ( 20 ) and with a switch contact actuating plunger ( 55 ) in the swivel path of a via the control button, preferably by means of a Bowden cable ( 58 ), pivotably fixed cam ( 56 ) protrudes. 21. The system according to claim 20, characterized in that the cam ( 56 ) is arranged on an air mixing flap ( 57 ) for mixing a cold air flow bypassing the heat exchanger ( 14 ) and a warm air flow heated by the heat exchanger ( 14 ), that the inlet / Switch ( 53 ) is adjusted so that its switching contact is closed in the swivel end position of the air mixing flap ( 57 ) for maximum warm air supply, and that the control button is formed by a temperature adjuster which specifies the swivel position of the air mixing flap ( 57 ). 22. System according to the preamble of claim 1, in particular according to one of claims 1-18, with a heat exchanger ( 14 ) upstream fan ( 11 ) for generating the heat exchanger ( 14 ) and the additional electrical heater ( 20 ) flowing air flow, thereby characterized in that an on / off switch ( 53 ) for the additional heating ( 20 ) is arranged spatially on the blower ( 11 ) and can be actuated by a manual control button placed in the dashboard. 23. System according to claim 22, characterized in that the on / off switch ( 53 ) is arranged with a switch contact in the circuit of the additional heater ( 20 ) and with a switch contact actuating plunger ( 55 ) in the swivel path of a via the control button, preferably by means of a Bowden cable ( 68 ), pivotable lever ( 66 ) protrudes. 24. System according to claim 23, characterized in that a resilient switching tongue ( 67 ) is arranged between the switch contact actuating plunger ( 55 ) and the pivoting lever ( 66 ) and that the pivoting lever ( 66 ) engages the switching tongue ( 67 ), which in turn engages the switching contact actuating plunger ( 55 ) acted upon.