Patent Publication Number: US-2011061403-A1

Title: Heating and cooling system for vehicle seat

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The present application claims priority to Korean Patent Applications Number 10-2009-0088222 filed on Sep. 17, 2009 and 10-2010-0050013 filed on May 28, 2010 the entire contents of which applications are incorporated herein for all purposes by this reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a heating and cooling system for a vehicle seat, and more particularly, to one which can enhance power efficiency by efficiently cooling and heating the vehicle seat. 
     2. Description of Related Art 
     In general, a vehicle is equipped with an air-conditioning system including a cooler and a heater. The air-conditioning system serves to control the temperature inside the vehicle. However, the air-conditioning system does not have a function of controlling the temperature of a vehicle seat. In the summer, even if an occupant sitting on a vehicle seat lowers the temperature inside the vehicle by operating the cooler, the seat is relatively slowly cooled down. In addition, the seat is continuously warmed by the body heat of the occupant. Then, the occupant may sweat at the buttocks and the back, which would otherwise develop into heat rashes. 
     In the winter, even if the occupant sitting on the vehicle seat raises the temperature inside the vehicle by operating the heater, the occupant may feel chilly or cold at the buttocks or back since the seat has stayed cold for a long time before the heater is operated. 
     Accordingly, these days, a seat-dedicated heating and cooling system is additionally provided, which is designed to control the temperature of the seat. In particular, among such systems, which control both heating and cooling, most prominent is the technology that employs a thermoelectric element based on Peltier effect as a heat source. 
     In a conventional heating and cooling system for a vehicle seat using a thermoelectric element as a heat source, the vehicle seat has a porous structure or air passages through which air can freely flow. The heating and cooling system controls the temperature of the seat by blowing air, heated or cooled by the thermoelectric element, to the seat. 
     The heating and cooling system is configured to heat or cool air using only the thermoelectric element. However, the problem of the thermoelectric element is that the efficiency of a heating part is about 50% of that of a cooling part under the same power supply conditions. 
     The problem is not significant in the case of cooling the seat using the thermoelectric element. However, in the case of heating the seat, the low efficiency of the heating part of the thermoelectric element increases power consumption, thereby lowering the efficiency of the heating and cooling system. 
     The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art. 
     BRIEF SUMMARY OF THE INVENTION 
     Various aspects of the present invention are directed to provide a heating and cooling system for a vehicle seat, in which can ensure improvement in power efficiency and heating performance in the case of heating the vehicle seat. 
     In an aspect of the present invention, the heating and cooling system for a vehicle seat, may include a heat exchanger cooling or heating air before the air is introduced into the seat, and a blower blowing air toward the heat exchanger, wherein the heat exchanger includes a positive temperature coefficient element assembly provided inside a housing of the heat exchanger to heat the air supplied from the blower, and wherein the positive temperature coefficient element assembly operates in a case of heating the seat but does not operate in a case of cooling the seat. 
     The heat exchanger and the blower may be connected to each other by a duct, and the heat exchanger is detachably attached to the duct. 
     The housing may be an integral housing enclosing the blower and the heat exchanger therein, wherein the heat exchanger is disposed in an output port of the integral housing and the positive temperature coefficient element assembly and the Peltier element assembly of the heat exchanger are aligned in series along a longitudinal direction of the output port, and wherein one or more of the integral housings are provided in one or more of a sitting part and a back of the seat. 
     The heating and cooling system may include two of the heat exchangers coupled to both ends of the blower, wherein one or more of the heat exchangers are provided in one or more of a sitting part and a back of the seat. 
     In another aspect of the present invention, the heating and cooling system for a vehicle seat, may include a heat exchanger cooling or heating air before the air is introduced into the seat, and a blower blowing air toward the heat exchanger, wherein the heat exchanger includes: a positive temperature coefficient element assembly provided inside a housing of the heat exchanger to heat the air supplied from the blower, and a Peltier element assembly provided adjacent to the positive temperature coefficient element assembly to cool or heat air supplied from the blower, wherein the positive temperature coefficient element assembly operates in a case of heating the seat, and the Peltier element assembly operates in a case of cooling or heating the seat. 
     The housing of the heat exchanger may have a seat inlet passage, through which cooled or heated air in the housing is introduced toward the seat, and an outlet passage, through which air in the housing is exhausted from the seat, wherein the housing further has a partition forming a boundary between the seat inlet passage and the outlet passage, and the Peltier element assembly is arranged to extend from the partition toward an entrance of the housing to guide air into the seat inlet passage and the outlet passage respectively. 
     The housing may further have an entrance-side partition provided in an entrance area of the housing and extending from the Peltier element assembly toward the entrance to prevent air heat-controlled by the Peltier element assembly and air heat-controlled by the Peltier element assembly from being mixed with each other, and the positive temperature coefficient element assembly is arranged along one lateral side of the entrance-side partition and is located in a passage leading to the seat inlet passage. 
     The positive temperature coefficient element assembly may be located more adjacent to the blower than the Peltier element assembly is, and the positive temperature coefficient element assembly selectively operates to evaporate condensed water, which is produced due to the Peltier element assembly, in case of cooling the seat. 
     The positive temperature coefficient element assembly may be arranged in series from the Peltier element assembly toward the entrance of the housing and the heating and cooling system may further include heat sink fins attached to one lateral side of the Peltier element assembly, which faces the seat inlet passage. 
     The heating and cooling system may further include heat sink fins attached to both sides of the Peltier element assembly and the positive temperature coefficient element assembly. 
     The eat exchanger and the blower may be connected to each other by a duct, and the heat exchanger is detachably attached to the duct. 
     The housing may be an integral housing enclosing the blower and the heat exchanger therein, wherein the heat exchanger is disposed in an output port of the integral housing and the positive temperature coefficient element assembly and the Peltier element assembly of the heat exchanger are aligned in series along a longitudinal direction of the output port, and wherein one or more of the integral housings are provided in one or more of a sitting part and a back of the seat. 
     The heating and cooling system may include two of the heat exchangers coupled to both ends of the blower, wherein one or more of the heat exchangers are provided in one or more of a sitting part and a back of the seat. 
     According to various aspects of the present invention as set forth above, the heating and cooling system for a vehicle seat has the following effects: 
     First, since the seat is heated using the PTC element having excellent heating performance, the efficiency of the heater can be raised when compared to the conventional heating using the Peltier element. Accordingly, the heating of the vehicle seat and the power efficiency can be improved. 
     Second, since the heating is performed using the PTC element, it is not necessary to convert the direction of a current supplied to the Peltier element unlike the related art. As a result, the circuit configuration is simplified. 
     The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description of the Invention, which together serve to explain certain principles of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic configuration view showing an exemplary heating and cooling system for a vehicle seat of the present invention. 
         FIG. 2  is a perspective view showing important parts of the exemplary heating and cooling system for a vehicle seat shown in  FIG. 1 . 
         FIG. 3  is a side cross-sectional view showing a heat exchanger in accordance with an exemplary heating and cooling system for a vehicle seat of the present invention. 
         FIG. 4  is a side cross-sectional view showing a heat exchanger in accordance with an exemplary heating and cooling system for a vehicle seat of the present invention. 
         FIG. 5  is a side cross-sectional view showing a heat exchanger in accordance with an exemplary heating and cooling system for a vehicle seat of the present invention. 
         FIG. 6  is a side cross-sectional view showing a heat exchanger in accordance with an exemplary heating and cooling system for a vehicle seat of the present invention. 
         FIG. 7  is a side cross-sectional view showing a heat exchanger in accordance with an exemplary heating and cooling system for a vehicle seat of the present invention. 
         FIG. 8  is a side cross-sectional view showing a sixth exemplary embodiment of the heating and cooling system for a vehicle seat of the invention; and 
         FIG. 9  is a perspective view showing important parts of the heating and cooling system for the vehicle seat shown in  FIG. 8 . 
     
    
    
     It should be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various features illustrative of the basic principles of the invention. The specific design features of the present invention as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes will be determined in part by the particular intended application and use environment. 
     In the figures, reference numbers refer to the same or equivalent parts of the present invention throughout the several figures of the drawing. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Reference will now be made in detail to various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the invention(s) will be described in conjunction with exemplary embodiments, it will be understood that present description is not intended to limit the invention(s) to those exemplary embodiments. On the contrary, the invention(s) is/are intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims. Above all, reference should be made to the drawings, in which the same reference numerals and signs are used throughout the different drawings to designate the same or similar components. In the following description of the present invention, a detailed description of known functions and components incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. 
       FIG. 1  is a schematic configuration view showing a heating and cooling system for a vehicle seat of the present invention,  FIG. 2  is a perspective view showing important parts of the heating and cooling system for a vehicle seat shown in  FIG. 1 , and  FIG. 3  is a side cross-sectional view showing a heat exchanger in accordance with a first exemplary embodiment of the heating and cooling system for a vehicle seat of the present invention. 
     Referring to  FIG. 1 , the heating and cooling system  1  for a vehicle seat of the present exemplary embodiment is provided in the rear side of a vehicle seat S, and supplies air into the seat S by heating or cooling it. The seat S includes a sitting part S 1  and a back S 2 . The sitting part S 1  and the back S 2  has a number of pores such that air, supplied from the heating and seating system  1 , can uniformly spread across the seat S. 
     The heating and cooling system  1  for a vehicle seat includes two heat exchangers  10  and  20 , a blower  30 , and ducts  41  and  42 . The heat exchanger  10  is provided inside the rear side of the back S 2  of the seat S, and the heat exchanger  20  is provided inside the rear side of the sitting part S 1  of the seat S. The heat exchangers  10  and  20  heat or cool air, which is directed toward the pores of the seat S. The blower  30  blows air toward the heat exchangers  10  and  20 . The ducts  41  and  42  connect the blower  30  with the heat exchangers  10  and  20 , respectively. 
     The heat exchanger  10  and  20  perform heat exchange in order to convert air, supplied from the blower  30 , is into cold or warm air. 
     More in detail, the heat exchangers  10  and  20  include the first heat exchanger  10 , which is provided in the rear side of the back S 2  to supply cold or warm air to the back S 2 , and the second heat exchanger  20 , which is provided in the rear side of the sitting part S 1  to supply cold or warm air to the sitting part S 1 . 
     The heat exchangers  10  and  20  are connected to the blower  30  by the first duct  41  and the second duct  42 , respectively. The ducts  41  and  42  serve as passages that deliver air, blown by the blower  30 , to the heat exchangers  10  and  20 , respectively. The ducts  41  and  42  and the heat exchangers  10  and  20  can be provided so as to be attachable to and detachable from each other. 
     The blower  30  supplies wind to the heat exchangers  10  and  20  through the ducts  41  and  42  by taking in air from outside. A fan, which operates when electric power is supplied, is provided inside the blower  30  to generate a flow of air. For this, an air intake port, from which air is introduced from outside, can be formed in one side of the blower  30 , and an air blowing port communicating with the respective ducts  41  and  42  can be formed in the other side of the blower  30 . 
     The first heat exchanger  10  is connected with the first duct  41  to supply wind, blown from the blower  30 , to the back S 2  by heating or cooling it. For this, a heater and a cooler are provided inside the first heat exchanger  10  in order to heat and cool air, which is supplied from the blower  30 . 
     As shown in  FIG. 3 , the first heat exchanger  10  includes a housing  11  defining the outline of the first heat exchanger  10 , a seat inlet passage A through which air heat-exchanged inside the housing  11  is introduced into the back S 2  of the seat S, and an outlet passage B through which air is exhausted from the seat S. 
     The seat inlet passage A forms one passage inside the housing  11 , and the distal end of the passage defines a seat inlet port  11   a , through which air is supplied into the pores of the seat S. 
     The outlet passage B is located adjacent to the seat inlet passage A, forming a passage through which air is exhausted. The distal end of the outlet passage B defines an outlet port  11   b . Another connector such as a duct can be connected to the outlet port  11   b  such that air exhausted through the outlet port  11   b  does not flow back into the seat S. 
     The second heat exchanger  20  is for introducing air, which is heated or cooled down, into the sitting part S 1  of the seat S. Except for this feature, the second heat exchanger  20  has substantially the same function and structure as the first heat exchanger  10 . 
     The most important feature of the present invention is that the heater and the cooler are provided in the first heat exchanger  10  and in the second heat exchanger  20 , respectively, in order to heat and cool air to be supplied into the seat S. A Peltier element  13  is used as a main cooler, and a Positive Temperature Coefficient (PTC) element  16  is used as a heater. 
     As is well known in the art, when a current is passed around the Peltier element, one side is heated and the other side is cooled. The side to be heated is changed according to the direction of the current applied. 
     Accordingly, when the current is supplied to the Peltier element  13  of the present exemplary embodiment, one side of the Peltier element  13 , which is heated, and one group of heat sink fins  14  adjacent thereto serve as a heater. At the same time, the other side of the Peltier element  13 , which is cooled, and the other group of the heat sink fins  14  adjacent thereto serve as a cooler. 
     The PTC element is a semiconductor element that experiences a rapid increase in electrical resistance at a temperature equal to or more than Curie temperature. The PTC element has a self-temperature control function that maintains a constant heating temperature regardless of surrounding temperature when a voltage is applied. 
     The heat sink fins  14  are attached to both sides of the Peltier element  13  in a heat conductive structure, thereby constructing a Peltier element assembly  12 . The heat sink fins  14  are constructed to maximize the contact area between heat or cold air created by the Peltier element  13  and air flowing inside the heat exchanger  10 . 
     In addition, heat sink fins  17  are also attached to both sides of the PTC element  16 , thereby producing a PTC element assembly  15 . The heat sink fins  17  raise the heat exchange efficiency between heat generated by the PCT element  16  and air flowing inside the heat exchanger  10 . 
     Although the heat sink fins  14  and  17  are shaped as corrugated plates, they can be modified into fin shapes. The heat sink fins  14  and  17  can have any shape that allows air to come into contact with the heat sink fins  14  and  17  while flowing inside the heat exchanger  10 . 
     The housing  11  also has a partition  11   d  defining the boundary between the seat inlet passage A and the outlet passage B, and the Peltier element  13  extends in the longitudinal direction of the partition  11   d . Specifically, the Peltier element  13  is oriented such that one side faces the seat inlet passage A and the other side faces the outlet passage B. Accordingly, the opposite sides of the Peltier element  13  form the boundary of the seat inlet passage A and the boundary of the outlet passage B. 
     An entrance-side partition  11   d , which extends from the Peltier element  13 , is also provided adjacent to an entrance  11   c  of the housing  11 . The entrance-side partition  11   d  further separates the seat inlet passage A from the outlet passage B so that air heated by the Peltier element  13  and air cooled by the Peltier element  13  are not mixed with each other inside the housing  11 . 
     The PTC element assembly  15  is arranged along one side of the entrance-side partition  11   d  and is located inside the seat inlet passage A. Among the two passages A and B in the heat exchanger  10 , the seat inlet passage A extends from the area of the entrance  11   c  of the housing  11  to the seat inlet port  11   a  or  21   a.    
     This is because the PTC element assembly  15  generates only heat unlike the Peltier element assembly  12 . Thus, it is not necessary to exhaust air, heated by the PTC element assembly  15 , through the outlet port  11   b  or  21   b  while the seat S is being heated. 
     When the PTC element assembly  15  is located in the passage A extending from the entrance  11   c  of the housing  11  to the seat inlet port  11   a  as described above, it is possible to exclusively supply air, heated by the PTC element assembly  15 , to the seat S through the seat inlet port  11   a . This, as a result, can raise heating efficiency and power efficiency by reducing heat loss. 
     Below, a description will be given of the operation of the heating and cooling system for a vehicle seat in accordance with the first exemplary embodiment of the present invention with reference to the above-described components. 
     First, in the case of attempting to supply cold air to the seat S in the summer, a controller of the vehicle controls the heating and cooling system  1  so that the Peltier element  13  operates but the PTC element  16  does not operate. 
     When a current is applied to the Peltier element  13 , one side of the Peltier element  13  adjacent to the seat inlet port  11   a  is cooled down and the other side of the Peltier element  13  adjacent to the outlet port  11   b  is heated. At the same time, the heat sink fins  14  in contact with the Peltier element  13  are cooled or heated according to their position and perform heat exchange with air, which flows inside the heat exchanger  10 . 
     Air performs heat exchange with the cooler of the Peltier element assembly  12  while it is flowing along the passage A, which extends from the entrance  11   c  of the heat exchanger  10  to the seat inlet port  11   a . As a result, cooled air is supplied to the seat S. In contrast, air performs heat exchange with the heater of the Peltier element assembly  12  while it is flowing along the passage B, which extends from the entrance  11   c  of the heat exchanger  10  to the outlet port  11   b . As a result, heated air is exhausted from the seat S through outlet port  11   b.    
     Next, in the case of attempting to supply warm air to the seat S in the winter, the controller of the vehicle controls the heating and cooling system  1  so that the PTC element  16  operates but the Peltier element  13  does not operate. 
     When a current is applied to the PTC element  16 , the PTC element  16  is heated and the heat sink fins  17  in contact with the PTC element  16  are heated along with the PTC element  16  so as to perform heat exchange with air introduced into the heat exchanger  10 . Since the PTC element assembly  15  is located in the passage A, which extends from the entrance of the heat exchanger  10  to the seat inlet port  11   a , the PTC element assembly  15  heats only a portion of air, which is exhausted to the seat inlet port  11   a , when the air is introduced into the heat exchanger  10 . In contrast, the remaining portion of the air simply passes through the heat exchanger  10  without heat exchange, and is then exhausted to the outlet port  11   b.    
     As such, the Peltier element  13  cools air in the case of attempting to supply cold air to the seat S, and the PTC element  16  having excellent power efficiency heats air in the case of attempting to supply warm air to the seat S. This, as a result, makes it possible to improve heating and cooling efficiency as well as to raise power efficiency. 
       FIG. 4  is a side cross-sectional view showing a heat exchanger in accordance with a second exemplary embodiment of the heating and cooling system for a vehicle seat of the present invention. The present exemplary embodiment will be described mainly with reference to the parts different from those of the foregoing embodiment. 
     Unlike the foregoing embodiment, a heat exchanger  10   a  of the present exemplary embodiment does not include the entrance-side partition  11   d  (see  FIG. 3 ), but a PTC element  16   a  further extends in the longitudinal direction of a Peltier element  13 . Thus, PTC element  16   a  is located more adjacent to an entrance  11   c , that is, the blower  30 . 
     Like the foregoing embodiment, heat sink fins  14  and  17   a  are attached to both sides of the Peltier element  13  and the PTC element  16   a , thereby constructing a Peltier element assembly  12  and a PTC element assembly  15   a . However, in the present exemplary embodiment, the PTC element  16   a  also forms the boundary between the seat inlet passage A and the outlet passage B. Accordingly, the PTC element  16   a  also acts as the entrance-side partition  11   c  of the foregoing embodiment. 
     Like the foregoing embodiment, in the case of attempting to supply cold air to the seat S in the summer, the heating and cooling system  1  of the present exemplary embodiment is controlled by a controller of the vehicle so as to operate the Peltier element  13   a  without operating the PTC element  16   a.    
     In addition, in the case of attempting to supply warm air to the seat S, the controller of the vehicle controls the heating and cooling system  1  so that the PTC element  16   a  operates but the Peltier element  13   a  does not operate. 
       FIG. 5  is a side cross-sectional view showing a heat exchanger in accordance with a third exemplary embodiment of the heating and cooling system for a vehicle seat of the present invention. The present exemplary embodiment will be described mainly with reference to the parts different from those of the foregoing second embodiment. 
     Unlike the foregoing embodiment, in a heat exchanger  10   b  of the present exemplary embodiment, heat sink fins  14   a  are attached to one side of a Peltier element  13   a , which faces a seat inlet passage A. However, heat sink fins are not attached to the other side of the Peltier element  13   a , which faces an outlet passage B. 
     According to this configuration, in the case of attempting to supply warm air to the seat S, a controller of the vehicle controls the heating and cooling system so that the PTC element  16   a  operates but the Peltier element  13   a  does not operate. This, as a result, can prevent heat loss, i.e., heat generated by the PTC element  16   a  is transmitted to the Peltier element  13   a , from which the heat is exhausted through the outlet passage. 
     Meanwhile, the heat exchangers  10 ,  10   a , and  10   b  of the first to third exemplary embodiments can be controlled so that only the Peltier element  13 ,  13   a  operates in the case of cooling the seat S but both the Peltier element  13  and the PTC element  16   a  operate in the case of heating the seat S. 
     In addition, if condensed water is produced due to the Peltier element  13  in the case of cooling the seat S, the heat exchanger can be controlled so that also the PTC element  16  operates to evaporate the condensed water. 
       FIG. 6  is a side cross-sectional view showing a heat exchanger in accordance with a fourth exemplary embodiment of the heating and cooling system for a vehicle seat of the present invention. The present exemplary embodiment will be described mainly with reference to the parts different from those of the foregoing embodiments. 
     Unlike the foregoing embodiments, in a heat exchanger  10   c  of the present exemplary embodiment, only a seat inlet port  11   a  is formed in a housing  11  but an outlet port is not formed. In addition, although a PTC element assembly  15   a  including a PTC element  16   a  and heat sink fins  17   a  is arranged inside the housing  11 , a Peltier element is not provided. 
     Accordingly, the heating and cooling system of the present exemplary embodiment is operated differently from those of the foregoing embodiments, i.e., the PTC element  16  is operated in the case of heating the seat S, but cooling is performed by operating only the blower  30  without operating the PTC element  16  in the case of cooling the seat S. 
       FIG. 7  is a side cross-sectional view showing a heat exchanger in accordance with a fifth exemplary embodiment of the heating and cooling system for a vehicle seat of the present invention. 
     Unlike the foregoing embodiments, according to the feature of the present exemplary embodiment, an integral housing H, which encloses a heat exchanger and a blower therein, is provided. The integral housing H may include an entrance  22  at one side thereof and the positive temperature coefficient element  15  and the Peltier element  12  may be disposed in an output port  24  aligned in series along a longitudinal direction of the output port  24 . 
     As a result, the configuration of the heating and cooling system for a vehicle seat is simplified. 
     In other words, the foregoing embodiments are realized inside one housing by arranging a blower  30  in the center of the housing and heat exchanging components, including a Peltier element assembly  12  and a PTC element assembly  15 , on both sides of the blower. 
     As such, according to the heating and cooling system of the present exemplary embodiment, one simple device can replace complicated components. Accordingly, the heating and cooling system can be easily installed in and separated from the seat, and the maintenance of the heating and cooling system is made easier. It should be understood that the configuration shown in  FIG. 7  is only a schematic illustration and the configurations of the foregoing embodiments can be adopted for the heat exchanger unit of the present exemplary embodiment. 
       FIG. 8  is a side cross-sectional view showing a sixth exemplary embodiment of the heating and cooling system for a vehicle seat of the invention, and  FIG. 9  is a perspective view showing important parts of the heating and cooling system for the vehicle seat shown in  FIG. 8 . 
     In this embodiment, a heat exchanger  10  includes a duct  27   a , and a heat exchanger  20  includes a duct  27   b . The ducts  27   a  and  27   b  introduce air, which is heated or cooled, to the seat. In addition, a PTC element assembly  15   a , which heats air, is mounted on each of the heat exchangers  10  and  20 . 
     As shown in  FIG. 9 , referring to the first heat exchanger  10  by way of example, a housing  110  has an air inlet port  11   a , but an air outlet port is not provided. 
     In addition, a PTC element assembly  15   a , which includes a PTC element  16   a  and heat sink fins  17   a , is disposed inside the housing  11 . However, a Peltier element is not provided inside the housing  11 . 
     In addition, a blower  30  includes an integral housing H communicating with the ducts  27   a  and  27   b , a blower fan  31  mounted inside the central portion of the integral housing H, and Peltier element assemblies  12  mounted inside the integral housing H. The Peltier element assemblies  12  are provided in the portions of the integral housing H that are connected to the ducts  27   a  and  27   b.    
     Here, as in the foregoing exemplary embodiments, each of the Peltier element assemblies  12  can include a Peltier element (not shown) and heat sink fins (not shown) attached to one or both sides of the Peltier element. 
     In this exemplary embodiment, the PTC element  16   a  operates when the seat S is heated (or warmed), whereas the Peltier element operates when the seat S is cooled. Accordingly, in this exemplary embodiment, it is possible to immediately provide warm air to the seat S using the PTC elements  16   a , located on the distal ends of the ducts  27   a  and  27   b , during the heating. These characteristics of this exemplary embodiment can advantageously prevent hot air, which is supplied from the PTC element inside the integral housing H, from making the duct flexible. Otherwise, in the structure of the foregoing embodiment shown in  FIG. 7 , the hot air might make the duct flexible when it flows through the duct. 
     The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and their practical application, to thereby enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents.