Abstract:
A heater with several common and inexpensive parts can be used in different vehicles having different heating requirements. Heating partition members for receiving and fixing PTC elements and non-heating partition members are substantially the same. The partition members are spaced apart at substantially equal intervals between a pair of frame members. Metal heat exchange fins are placed in a heat exchange air flow passage adjacent to the heating partition member. A resin dummy member is placed in non-heat exchange air flow passage located between non-heating partition members. The number of heating elements can be varied to suit vehicles of different sizes.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application is based on Japanese Patent Applications No. 2006-245266 filed on Sep. 11, 2006, and No. 2007-99040 filed on Apr. 5, 2007, the disclosure of which is incorporated herein by reference. 
       TECHNICAL FIELD 
       [0002]    The present invention relates to an electrical heater for generating heat by supplying electrical power and a vehicle air conditioner using the electrical heater. 
       BACKGROUND 
       [0003]    U.S. Pat. No. 5,562,844 discloses a conventional electrical heater, which includes a pair of frames and a plurality of partition members (resin frames). The plurality of partition members are generally planar and are located between a pair of frames, which form a reinforcing structure. Fixing portions for fixing a positive temperature coefficient thermistors (PTC elements), which are heating elements of a known type, are formed on the partition members. Air flow passages are formed between the partition members and between the partition members and the frame. 
         [0004]    Furthermore, the electrical heater of U.S. Pat. No. 5,562,844 includes heat exchange fins placed in the air flow passages. The heat exchange fins facilitate heat exchange between the PTC elements and the air. Thus, the electrical heater improves heat transfer from the PTC elements to the air. 
         [0005]    When this kind of electrical heater is applied to a vehicle air conditioner and used as a heating device for air that enters a vehicle passenger compartment, the heating capacity or heat output required of the electrical heater is different depending on the vehicle and, for a given vehicle, the heating requirements may vary depending on the climate of the location where the vehicle is sold. That is, different vehicles have different sized passenger compartments and different heating requirements. Further, even for a passenger compartment of one size, the heating requirements may differ according to the geographic location of the vehicle. To lower the cost of producing the heater, it is preferred that a single fixed frame and electrical heater shape be employed in various different vehicles. 
         [0006]    The number of the PTC elements may be changed to adjust the heating capacity of the electrical heater. However, in this case, the heat exchange fins placed in the air flow passage between partitioned members that are not adjacent to a PTC element do not facilitate heat transfer. In this kind of electrical heater, corrugated fins, which are made of sheet metal that has superior heat transfer characteristics (for example, aluminum alloy or copper), are employed. The existence of unused heat exchange fins increases the cost of the electrical heater. 
       SUMMARY 
       [0007]    In view of the above-described problems, it is an object to provide an electrical heater which adjusts the heat output without changing the frame or shape, and costs are reduced. 
         [0008]    In accordance with one exemplary embodiment, an electrical heater includes a pair of frame members that are spaced apart by a predetermined distance, a heating element that generates heat when energized, a heating partition member for partitioning a space formed between the frame members and for fixing the heating element, a non-heating partition member for partitioning a space formed between the frame members, a heat exchange air flow passage located adjacent to the heating partition member, a non-heating exchange portion located adjacent to the non-heating partition member and not adjacent to the heating partition member, a metal heat exchange member for facilitating heat transfer between the heating element and the air. The heat exchange member is located only in the heat exchange air flow passage. 
         [0009]    According to this aspect, the heating partition member and the non-heating partition member are located a between the frames located in a predetermined interval. By adjusting the number of heating partition members and heating elements, the heat output can easily adjust without changing the frame or shape of the whole electrical heater. 
         [0010]    Furthermore, because the relatively expensive metal heat exchange member is not placed in the non-heat exchange portion, the cost of the electrical heater is reduced. 
         [0011]    Preferably, the non-heat exchange portion is an air flow passage through which air can pass. 
         [0012]    Preferably, the non-heating partition member is one of a pair of non-heating partition members, and the non-heat exchange portion is located between the non-heating partition members 
         [0013]    Preferably, the heating partition member and the non-heating partition member are substantially the same, and the heating partition member includes a portion for receiving the heating element. 
         [0014]    Preferably, the heating partition member is identical to the non-heating partition member except that no heating element is received by the non-heating partition member. 
         [0015]    Therefore, because the heating partition member and the non-heating partition member can be made by the same member, costs are reduced. 
         [0016]    Preferably, the electrical heater further includes a ventilation flow resistance member placed in the non-heat exchange air flow passage. The ventilation flow resistance member creates ventilation flow resistance against the air passing though the non-heat exchange air flow passage. The ventilation flow resistance of the non-heat exchange air flow passage per unit area is substantially the same as that of the heat exchange air flow passage. 
         [0017]    Therefore, even though the heat exchange members is only located in the heat exchange air flow passage, the ventilation flow resistance of the electrical heater can be made the same as a heater in which all air flow passages are heat exchange air flow passages. 
         [0018]    In this situation, the phrase “substantially the same” does not mean that the ventilation flow resistance of the heat exchange air flow passage in which the heat exchange member is located and the ventilation flow resistance of the non-heat exchange air flow passage in which the heat exchange member is not located are identical, but also includes situations where there are minute differences between the ventilation flow resistance of the heat exchange and non-heat exchange air flow passages as a result of a production error or an assembly error. 
         [0019]    Preferably, the ventilation flow resistance member is generally ladder-shaped. Therefore, according to the change of the number and shape of pillars of the ladder shape, the ventilation flow resistance of the ventilation flow resistance member can be adjusted easily. 
         [0020]    Preferably, the ventilation flow resistance member is made with resin. Therefore, costs are further reduced. 
         [0021]    Preferably, the heating element is a PTC element. 
         [0022]    Preferably, the electrical heater includes a ventilation flow resistance member placed in the non-heat exchange air flow passage and for causing ventilation flow resistance against the air passing though the non-heat exchange air flow passage. The ventilation flow resistance member comprises an outer frame member defining the non-heat exchange air flow passage. The outer frame member serves as the non-heating partition member. A pillar is placed between opposed sections of the outer frame member. 
         [0023]    Preferably, the electrical heater forms part of a vehicle air conditioner. 
         [0024]    It accordance with another aspect of the invention, an electrical heater includes a pair of frame members that are spaced apart by a predetermined distance, a plurality of heating elements that generate heat when energized, a plurality of partition members for partitioning a space formed between the frame members, a heat exchange air flow passage, a non-heat exchange air flow passage, and a metal heat exchange member for facilitating heat transfer between the heating element and the air. Each of the partition members is adapted to receive at least one of the heating elements. The heat exchange air flow passage is located adjacent to one of the heating elements. The non-heat exchange air flow passage is spaced apart from each of the heating elements. The heat exchange member is located only in the heat exchange air flow passage. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0025]    Other objects, features and advantages will become more apparent from the following detailed description made with reference to the accompanying drawings, in which: 
           [0026]      FIG. 1  is a diagrammatic sectional view of an interior air conditioning unit of a vehicle air conditioner according to an exemplary embodiment; 
           [0027]      FIG. 2  is an overall perspective view showing a diagrammatic configuration of an electrical heater according to an exemplary embodiment; 
           [0028]      FIG. 3  is a top view of a heating partition member of an electrical heater according to the exemplary embodiment of  FIG. 2 ; 
           [0029]      FIG. 4  is an exploded perspective view of area E of  FIG. 2 ; 
           [0030]      FIG. 5  is an exploded perspective view of area F of  FIG. 2 ; and 
           [0031]      FIG. 6  is an exploded perspective view showing a part of an electrical heater according to another exemplary embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0032]    With reference to  FIGS. 1-4 , a first exemplary embodiment will be described.  FIG. 1  shows a configuration in which an electrical heater  20  is applied to a vehicle air conditioner. 
         [0033]    The vehicle air conditioner is installed a vehicle in which it is difficult to raise the engine coolant temperature when the engine is first started (for example, a hybrid vehicle or a diesel engine vehicle) or a vehicle used in a cold climate. The vehicle air conditioner employs an electrical heater  20  as an auxiliary heating device for heating air to be forced into the passenger compartment when the passenger compartment is first heated. 
         [0034]    The interior air conditioning unit  1  is placed inside of a dashboard (an instrument panel) of the passenger compartment of the vehicle. The interior air conditioning unit  1  includes a case  2  made of resin. The case  2  forms an outer part of the unit  1 . An air flow passage through which air flows toward the passenger compartment is formed in the case  2 . An inside and outside air switching box  3  is placed at the most upstream portion of the case  2 . 
         [0035]    The inside and outside air switching box  3  includes an inside air introducing inlet  4 , outside air introducing inlet  5 , and an inside and outside air switching door  6 . The inside air introducing inlet  4  is an inlet that permits inside air (air in the passenger compartment) to enter the inside of the case  2 . The outside air introducing inlet  5  is an inlet that permits outside air (air from outside of the passenger compartment) to enter the inside of the case  2 . The inside and outside air switching door  6  is placed to pivot in the inside and outside air switching box  3 . The inside and outside air switching door  6  is an inside and outside air switching means, which is driven by an unillustrated servo motor. 
         [0036]    More specifically, the mode of the inside and outside air switching box  3  can be changed among any of an inside air mode, in which inside air is introduced from the introducing inlet  4 , a outside air mode, in which outside air is introduced from the outside air introducing inlet  5 , and an inside/outside air mode, in which inside air and outside air are introduced at the same time because of the rotational position of the inside and outside air switching door  6 .  FIG. 1  shows the inside air mode in which inside air is introduced into case  2  as shown by arrow A. 
         [0037]    A electrical blower  7 , which forces air into the passenger compartment is placed at an upstream end of the case  2  in the inside and outside air switching box  3 . The blower  7  blows air in the direction of the arrow B by rotationally driving a well-known centrifugal multi-blade fan  7   a  with an electric motor  7   b.  An evaporator, which is a cooling heat exchanger that cools the air, is placed downstream of the blower  7 . 
         [0038]    The evaporator  8  is one of the elements of a refrigerating circuit (not shown). The evaporator  8 , as is well-known, cools air by absorbing heat from the air blown by the blower  7  when low pressure refrigerant, which flows into evaporator  8 , evaporates. A heater core  9  heats the air (cool air) that has passed through the evaporator  8  is placed downstream of the evaporator  8 . 
         [0039]    The heater core  9  is a heat exchanger for heating the air (cool air) after the air has passed through the evaporator  8  by using engine coolant (the engine coolant circuit is not illustrated.). A bypass passage  10  is formed on one side of the heater core  9  in the case  2 . In the bypass passage  10 , air (cool air) that has passed through the evaporator  8  bypasses the heater core  9 . 
         [0040]    In the vehicle air conditioner of the present embodiment, a electrical heater  20  is placed at the downstream side of the heater core  9 . The electrical heater  20  is an auxiliary heater for generating heat with electrical power from an unillustrated control unit and for heating the air that has passed though the heater core  9  when the heater core  9  cannot sufficiently heat the air from the evaporator  8 . Details of the electrical heater  20  are described below. 
         [0041]    As for the control of the electrical heater  20  by the control unit, for example, the following control may be adopted. The control unit (unillustrated) detects the temperature of the engine coolant passing though the heater core  9 . When the temperature is lower than a predetermined temperature, the control unit determines that the heater core  9  cannot sufficiently heat the air that has passed though the evaporator  8 , and the control unit supplies electrical power to the heater  20 . 
         [0042]    An air mix door  11  is placed between the evaporator  8  and the heater core  9 . The air mix door  11  can pivot in the case  2 . The rotational position (open degree) of the air mix door  11  can be adjusted by driving an unillustrated servo motor. 
         [0043]    According to the open degree of the air mixing door  11 , a flow ratio of the air quantity passing through the heater core  9  and the electrical heater  20  (a warm air quantity as shown by arrow C) and the air quantity of air passing through the bypass passages  10  (a cool air quantity as shown by arrow D) is adjusted. Because the warm air (arrow C) and the cold air (arrow D) are mixed at the downstream side of the heater core  9 , the electrical heater  20 , and bypass passages  10 , and are forced into the passenger compartment, the temperature of the air entering the passenger compartment is adjusted by the adjustment of the flow ratio. 
         [0044]    Three kinds of outlets  12 - 14  are placed at the most downstream end of the case  2 . One of the outlets  12 - 14  is a defroster outlet  12  for blowing conditioned air toward a front window glass (front windshield) of the vehicle. Another of the outlets  12 - 14  is a face outlet  13  for blowing conditioned air toward the faces of passengers. Another of the outlets  12 - 14  is a foot outlet  14  for blowing conditioned air toward the feet of the passengers. 
         [0045]    A defroster door  15 , a face door  16  and a foot door  17  are placed to pivot, respectively, at the upstream side of those outlets  12 - 14 . The doors  15 - 17  are rotationally operated to open and close by a common servo motor (not shown) through an unillustrated link structure.  FIG. 1  shows a defroster mode in which both the defroster door  15  and the foot door  17  are open at the same time. 
         [0046]    Next, according to  FIGS. 2-4 , details of the electrical heater  20  are described.  FIG. 2  is an overall diagrammatic perspective view showing the configuration of the electrical heater  20  of the present embodiment. The top and bottom, right and left arrows of  FIG. 2  show directions in the state in which the electrical heater  20  is installed in the vehicle air conditioner. 
         [0047]    The electrical heater  20  includes a pair of frame members  21 , a plurality of partition members  22 ,  22 ′, which are stacked between the frames  21 , heat exchange fins  23 , which are placed an air flow passage  25   a  described below, and a resin dummy member  24  placed an air flow passage  25   b  described below. The electrical heater  20  is a so-called PTC heater that generates heat by energizing PTC elements  22   a,  which are fixed to a heating partition member  22  described below. 
         [0048]    The frame members  21  form the outer shape of the electrical heater  20  and reinforce the perimeter of the electrical heater  20 . Unillustrated springs, which apply force inwardly in stacking direction (the top to bottom directions) of the partition members  22 ,  22 ′, the heat exchange fins  23  and the resin dummy member  24 , are provided in the frame  21 . The stack of parts  22 ,  22 ′,  23 ,  24  is fixed in place by the force of the springs. 
         [0049]    Housings  26   a,    26   b  are respectively fitted to the pair of frame members  21  from the direction (left and right direction in  FIG. 2 ) perpendicular to the stacking direction. Thus, the housings determine the space between the frame members  21 . 
         [0050]    The partition members  22 ,  22 ′ partition a space formed between the frame members  21 . The partition members  22 ,  22 ′ are composed of resin materials having heat resistance (for example, a polyamide synthetic fiber or polybutadiene tere phthalate (PBT)). The partition members  22 ,  22 ′ include heating partition members  22 , to which are fixed PTC elements  22   a  described below, and non-heating partition members  22 ′, to which no PTC elements  22   a  are fixed. 
         [0051]    Details of the partition members  22  are shown in  FIG. 3 .  FIG. 3  is a top view of one of the heating partition members  22 . As shown in  FIG. 3 , the heating partition members  22  are composed of thin plate shape members that extend in the longitudinal direction of the frame  21 . Holes  22   b  that penetrate through in the stacking direction (top to bottom direction in  FIG. 2 ) are formed on the heating partition members  22 . Each hole  22   b  functions to receive and fix one of the PTC elements  22   a.    
         [0052]    The heating partition member partition members  22  function as frames or supports for the PTC elements  22   a.  Though four holes  22   b  are shown in  FIG. 3 , the number of holes  22   b  is not so limited. In  FIG. 3 , though PTC elements  22   a  are received and fixed in all of four holes  22   b,  there may be a hole  22   b  in which no PTC element  22   a  is received to adjust the heat output of the electrical heater  20 . 
         [0053]    On the other hand, the non-heating partition members  22 ′ are planar members that are shaped the same as the heating partition members  22 . There are no PTC elements  22   a  in any of the holes  22   b  in the non-heating partition members  22 ′. In other words, the non-heating partition members  22 ′ are the same as the heating partition members  22  except for the absence of the PTC elements  22   a.    
         [0054]    Each PTC element  22   a  is a positive temperature coefficient thermistor having a self temperature control function. Specifically, the temperature of each of the PTC elements  22  arises immediately when it is energized. The electrical resistance value increases rapidly to limit the electrical current and to maintain the heat generation when the temperature reaches a predetermined temperature (a Curie point). The PTC elements  22   a  may be referred to herein as heating elements. 
         [0055]    The partition members  22 ,  22 ′ are stacked at predetermined intervals, such that the partition members  22 ,  22 ′ are spaced at equal intervals from one another and from the frame members  21  as shown in  FIG. 2 . Air flow passages  25   a,    25   b  through which air passes are formed between adjacent pairs of the partition members  22 ,  22 ′ and between the frame members  21  and the partition members  22  that are adjacent to the frame members  21 . Two non-heating partition members  22 ′ are placed next to each other as shown in  FIG. 2 . Heating partition members  22  are placed between the frame members  21  and the non-heating partition members  22 ′. 
         [0056]    Among the air flow passages  25   a,    25   b,  the air flow passages that are adjacent to a heating partition member  22  that holds at least one PTC element  22   a  are heat exchange air flow passages  25   a  in which air is heated by the heat of the PTC elements  22   a.  In other words, the air flow passages located between the frame members  21  and the non-heating partition members  22 ′ are heat exchange air flow passages  25   a.  Among the air flow passages  25   a,    25   b,  the air flow passage located between the two non-heating partition members  22 ′ is a non-heat exchange air flow passage  25   b.  In other words, the air flow passage other than the heat exchange air flow passages  25   a  is the non-heat exchange air flow passage  25   b.    
         [0057]    Heat exchange members  23  facilitate heat exchange between the PTC elements  22   a  and the air. The heat exchange members  23  are only located in the heat exchange air flow passages  25   a.    
         [0058]    As shown in an exploded perspective view of  FIG. 4 , each heat exchange member  23  includes a corrugate fin  23   a,  which is a thin metal plate (for example, aluminum alloy or copper)that has superior heat transfer characteristics. Each fin  23   a  has the shape of a wave pattern. Metal plates  23   b  (aluminum alloy plate in the present embodiment) made of the same metal as the corrugate fins  23   a  surround the fins  23   a  as shown in  FIG. 4 . Each corrugate fin  23   a  is inserted between the metal plates  23   b.  The metal plates  23   b  hold the fin  23   a  in a certain shape and form a contact area for making surface-to-surface contact with the partition member  22 ,  22 ′. The metal plates  23   b  and the corrugate fins  23   a  are brazed. 
         [0059]    A resin dummy member  24  is placed in the non-heat exchange air flow passage  25   b.  The resin dummy member  24  is a ventilation flow resistance member formed such that the ventilation flow resistance of the non-heat exchange air flow passage  25   b  is equivalent to the ventilation flow resistance that would exist if a heat exchange fin  23  were placed in the non-heat exchange air flow passage  25   b.  In other words, the ventilation flow resistance of the non-heat exchange air flow passage  25   b  per unit area is substantially the same as that of the heat exchange air flow passage  25   a.    
         [0060]    The resin dummy member  24  is made of resin material having same heat-resistance as the partitioned members  22 ,  22 ′. As shown in the exploded perspective view of  FIG. 5 , the resin dummy member  24  includes outer frames  24   a  formed along the perimeter of the non-heat exchange air flow passage  25   b  and pillars  24   b,  which are placed between the outer frames  24   a.  The pillars  24   b  extend in the stacking direction (top to bottom direction in  FIG. 2 ). The resin dummy member  24  has the shape of ladder when it is viewed from the air flow direction, as shown in  FIG. 2 . 
         [0061]    Thus, because the resin dummy member  24  has the shape of ladder, the resin dummy member  24  can maintain a predetermined shape. Also, the ventilation flow resistance can be adjusted easily by changing the shape or the number of pillars  24   b.    
         [0062]    The details of the stacked structure of the parts  22 ,  22 ′,  23 ,  24  in the electrical heater  20  of the present embodiment are illustrated in  FIGS. 4-5 . 
         [0063]      FIG. 4  is an exploded perspective view of an area E of the electrical heater  20  in  FIG. 2 .  FIG. 5  is an exploded perspective view of an area F of the electrical heater  20  in  FIG. 2 . 
         [0064]    As shown in  FIG. 4 , each PTC element  22   a  is received in and fixed in one of the holes  22   b  of the heating partition member  22 . Thus, the air flow passage adjacent to the heating partition member  22  is the heat exchange air flow passage  25   a  (See part E of  FIG. 2 ). Heat exchange fins  23  are placed on both sides of each heating partition member  22  as shown, for example, in part E of  FIG. 2 . 
         [0065]    On the other hand, as shown in  FIG. 5 , no PTC element  22   a  is fixed to the hole  22   b  of the non-heating partition member  22 ′ located at part F of  FIG. 2 . Thus, the air flow passage heating partition member between the non-heating partition members  22 ′ is the non-heat exchange air flow passage  25   b.  The resin dummy member  24  is placed below the non-heating partition member  22 ′ at area F of  FIG. 2 , as shown in  FIG. 5 . 
         [0066]    The PTC elements  22   a  in the heating partition member  22  are supplied with power through a terminal  26   c  installed in the housing  26   a,  an unillustrated electrode plate, and the metal heat exchange fin  23 . An electrode plate that can directly supply power to the PTC elements  22   a  from the terminal  26   c  may be provided. 
         [0067]    The operation of the electrical heater  20  is described below. The electrical heater  20  generates heat when supplied with electrical power from the control unit, when the vehicle air conditioner performs warming of air and the heater core  9  cannot sufficiently heat the air that passes though the evaporator  8 . Therefore, because the electrical heater  20  can heat air being delivered to the passenger compartment, immediate heating of air is enabled in the vehicle air conditioner of the present embodiment. 
         [0068]    Furthermore, in the electrical heater  20  of the present embodiment, the partition members  22 ,  22 ′ are spaced from one another and from the frame members  21  by equal intervals as shown in  FIGS. 2-5 . The heat output or capacity of the electrical heater  20  is set by placing only a predetermined number of the PTC elements  22   a  in corresponding ones of the holes  22   b  of the heating partition member  22 . Therefore, the heat capacity or output of the electrical heater  20  can be adjusted easily without changing the frame or the shape of the heater  20 . 
         [0069]    Because the relatively expensive metal heat exchange fin  23  is not placed in the non-heat exchange air flow passage  25   b,  costs are reduced. 
         [0070]    Furthermore, because the heating partition member  22  and the non-heating partition member  22 ′ are composed of the same plates, the cost of the electrical heater  20  is reduced. 
         [0071]    The resin dummy member  24  is formed such that the ventilation flow resistance of the non-heat exchange air flow passage  25   b  is equivalent to the ventilation flow resistance that would exist if a heat exchange fin  23  were placed in the non-heat exchange air flow passage  25   b.  Because the resin dummy member  24  is placed in the non-heat air flow passage  25   b  the ventilation flow resistance of the electrical heater  20  does not change even when the heat output of the electrical heater  20  is adjusted by changing the number of PTC elements. 
         [0072]    Also, because the resin dummy member  24  is made with resin, the cost of the electrical heater  20  is reduced. 
       Other Embodiments 
       [0073]    Although the present invention has been fully described in connection with the preferred embodiments thereof with reference to the accompanying drawings, various changes and modifications will become apparent to those skilled in the art. 
         [0074]    (1) In the illustrated embodiment, the heating partition members  22  and the non-heating partition members  22 ′ are composed of the same parts for reducing costs. However the present invention is not so limited. The non-heating partition member  22 ′ may be composed of a plate that does not include the holds  22   b.    
         [0075]    (2) In the illustrated embodiment, the resin dummy member  24  is placed in the non-heat exchange air flow passage  25   b.  However, when it is not a problem that the ventilation flow resistance of the electrical heater  20  changes from one vehicle type to another when the heating output is varied, the resin dummy member  24  may be omitted. 
         [0076]    In another variation, the non-heating partition member  22 ′ forming the non-heat exchange air flow passage  25   b  can be omitted, and the outer frame  24   a  of the resin dummy member  24  may be used as the non-heating partition member  22 ′ as shown  FIG. 6 . In this modification, the cost of the electrical heater  20  can be further reduced. 
         [0077]    (3) In the illustrated embodiment, four heat exchange air flow passages  25   a  and one non-heat exchange air flow passage  25   b  are formed in the electrical heater  20  as shown in  FIG. 2 . However, the number of the heat exchange air flow passages  25   a  and non-heat exchange air flow passages  25   b  is not so limited. The number of the heat exchange air flow passages  25   a  and the non-heat exchange air flow passages  25   b  may be changed appropriately depending on the heat output of the electrical heater  20 . 
         [0078]    (4) In the illustrated embodiment, the electrical heater  20  is placed at the downstream side of the heater core  9 . However, it may be placed in a foot duct (not shown) at the downstream side of the foot outlet  14  and leading the conditioned air toward the feet of the passengers. Further, the electrical heater  20  may be incorporated in the heater core  9 . 
         [0079]    (5) The electrical heater can be employed various ways without being limited to the vehicle air conditioner. 
         [0080]    (6) In the illustrated embodiment, the non-heat exchange air flow passage  25   b  is formed between the non-heating partition members  22 ′. However, air flow between the non-heating partition members  22 ′ may be blocked. 
         [0081]    (7) In the illustrated embodiment, the non-heat exchange air flow passage  25   b  is formed between the non-heating partition members  22 ′. However, the non-heat exchange air flow passage  25   b  may be formed between the non-heating partition members  22 ′ and the frame  21 . 
         [0082]    Such changes and modifications are to be understood as being within the scope as defined by the appended claims.