Patent Publication Number: US-6212900-B1

Title: Automotive air conditioner having condenser and evaporator provided within air duct

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This is a division of application Ser. No. 08/779,705, filed Jan. 7, 1997, now U.S. Pat. No. 5,983,652 which was a division of Ser. No. 08/352,110, filed Nov. 30, 1994, now U.S. Pat. No. 5,685,162 which was a CIP of Ser. No. 08/019,185, filed Feb 17, 1993, now abandoned which was a CIP of Ser. No. 07/873,430, filed Apr. 24, 1992, now U.S. Pat. No. 5,299,431, issued Apr. 5, 1994 is a continuation-in-part application of U.S. application Ser. No. 08/019,185 filed Feb. 17, 1993, now abandoned, entitled Automotive Air Conditioner Having Condenser and Evaporator Provided within Air Duct by IRITANI et al. This application is based upon and claims priority from Japanese Patent Applications No. 3-97290 filed Apr. 26, 1991, 3-253947 filed Oct. 1, 1991, 3-319417 filed Dec. 3, 1991, 3-347130 filed Dec. 27, 1991, 4-29743 filed Feb. 17, 1992, 4-60616 filed Mar. 17, 1992, and 4-207740 filed Aug. 4, 1992 with the contents of each Japanese document and the U.S. application being incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to an automotive air conditioner for conditioning air in a room of an automobile. The automotive air conditioner of the present invention is effectively applied to an automobile which does not have a surplus heat source as, for example, an electric automobile. 
     2. Related Art 
     Usually, an automotive air conditioner makes use, in order to heat air, of heat from cooling water for an engine for driving an automobile. However, heating of air is performed using a heat pump when the amount of heat of cooling water for an engine is insufficient or when an automobile does not originally have engine cooling water such as an electric automobile. 
     For example, in an automotive air Application No. 60-219114, a flow of refrigerant is changed over by means of a four-way valve such that an inside heat exchanger is used either as an evaporator to cool air or as a condenser to heat air. 
     With the automotive air conditioner wherein cooling operation and heating operation are performed alternatively by changing over of a four-way -valve in this manner, since the single heat exchanger changes its function immediately between a function of an evaporator and another function of a condenser, there is the possibility that, particularly when the function is changed over, a large amount of moisture may be blasted from a surface of the inside heat exchanger toward the inside of the room of the automobile. 
     In particular, water condensed on a surface of the inside heat exchanger during cooling operation is evaporated from the surface of the inside heat exchanger as a result of changing over to heating operation and then carried into the room of the automobile by a blower. Such blasting of a large amount of water will instantaneously fog a windshield and/or window glass. The fog will make an obstacle to a field of view in driving the automobile and is very inconvenient. 
     Accumulator cycles are conventionally known wherein a subcooling control valve is disposed on the downstream side of a refrigerant condenser to obtain a subcooled condition of refrigerant. 
     An exemplary one of subcooling control valves is disclosed, for example, in Japanese Utility Model Laid-Open Application No. Showa 55-85671 and is shown in FIG.  100 . Referring to FIG. 100, the subcooling control valve  1100  includes a valve body  1103  for opening or closing a throttle section  1102  by operation of a diaphragm  1101 , a regulating spring  1104  for normally biasing the valve body  1103  to open the throttle section  1102 , and a temperature sensitive tube  1105  for converting a variation of temperature of refrigerant on the downstream side of a refrigerant condenser (not shown) into a variation of pressure. 
     The displacement of the valve body  1103  is adjusted by the balance between the pressure in the temperature sensitive tube  1105  which acts upon the upper side of the diaphragm  1101  via a capillary tube  1106  and the high pressure of the refrigerant and the biasing force of the regulating spring  1104  which both act upon the lower side of the diaphragm  1101 , and the opening of the throttle section  1102  depends upon the displacement of the valve body  1103 . 
     However, in the subcooling control valve  1100  described above, since the biasing force of the regulating spring  1104  is set in advance so that a predetermined subcooling degree (for example, 5 to 10° C.) may be obtained within the refrigerant condenser, when it is tried to construct such a novel subcooling cycle as shown in FIG. 101 or  1017  using the subcooling control valve  1100 , such subjects to be solved as described below are involved. 
     Referring first to FIG. 101, the subcooling cycle shown constitutes a heat pump cycle for an automotive air conditioner and includes a refrigerant compressor  1200 , an interior condenser  1202  disposed in a duct  1201  which introduces blast air into the room of the automobile, a subcooling control valve  1100 , an interior evaporator  1203  disposed in the duct  1201  on the upstream side of the interior condenser  1202 , an evaporation pressure regulating valve  1204 , an exterior evaporator  1205  disposed on the outside of the duct  1201 , an accumulator  1206 , a bypass passageway  1207  for bypassing the interior evaporator  1203  and the evaporation pressure regulating valve  1204 , and a solenoid valve  1208  for opening or closing the bypass passageway  1207 . 
     Now, if the bypass passageway  1207  is closed by the solenoid valve  1208  so that the refrigerant flowing out through the subcooling control valve  1100  is introduced into the interior evaporator  1203 , then air introduced into the duct  1201  by a fan  1209  is cooled when it passes through the interior evaporator  1203 , and thereafter, the air is heated when it passes through the interior condenser  1202 , and then it blown out into the room of the vehicle. In this instance, when the saturation temperature of the refrigerant flowing through the interior condenser  1202  is 50° C. or around it, as cool air of a temperature close to 0° C. cooled by the interior evaporator  1203  is blown to the interior condenser  1202 , ideally a subcooling degree of the temperature of 50° C. or so can be obtained at the interior condenser  1202 . 
     On the other hand, if the bypass passageway  1207  is opened by the solenoid valve  1208  to allow the refrigerant flowing out from the subcooling control valve  1100  to be introduced into the exterior evaporator  1205  while an internal air mode is set so that air in the automobile room of a temperature of 30° C. or around it is introduced into the duct  1201 , then the air introduced in the duct  1201  is blown to the interior condenser  1202  while keeping its temperature (30° C.) without being cooled by the interior evaporator  1203 . Consequently, only a subcooling degree of the temperature of 20° C. or so to the utmost can be obtained at the interior condenser  1202 . 
     In the meantime, the subcooling cycle shown in FIG. 102 constitutes a refrigerating cycle for an automotive air conditioner and includes an exterior evaporator  1210  on the upstream side of an interior condenser  1202 , and an air mixing damper  1211  for adjusting the amount of draft air to the interior condenser  1202 . When the air mixing damper  1211  is opened or closed, cooling air of the temperature of 0° C. or around it cooled by an interior evaporator  1203  is blown to or not blown to the interior condenser  1202 . 
     For example, when the air mixing damper  1211  fully opens the interior condenser  1202  (the position indicated by full lines in FIG. 102) so that cool air of the temperature of 0° C. or around it is blown to the interior condenser, if the saturation temperature of the refrigerant flowing through the interior condenser  1202  is 50° C. or around it, a subcooling degree of the temperature ideally of 50° C. or around it can be obtained. 
     On the other hand, when the air mixing damper  1211  closes the interior condenser  1202  (the position indicated by chain lines in FIG.  102 ), cool air is not blown to the interior condenser  1202 , and the interior condenser  1202  acts as a mere refrigerant passageway. Consequently, if the external air temperature (the temperature of wind blown to the exterior condenser  1210 ) is 30° C., then while the saturation temperature of the refrigerant flowing through the exterior condenser  1201  and the interior condenser  1202  is 50° C., only a subcooling degree of the temperature of 20° C. or so can be obtained even if the refrigerant is cooled ideally to 30° C. of the external air temperature. 
     Accordingly, where the biasing force of the regulating spring  1104  of the subcooling control valve  1100  is set in the subcooling cycles shown in FIGS. 101 and 102 so that the subcooling degree of 20° C. may be obtained at the interior condenser  1202 , the subcooling control valve  1100  tends to control the subcooling degree of 20° C. even when cool wind of the temperature of 0° C. or around it cooled by the interior evaporator  1203  is blown to the interior condenser  1202 . Consequently, a sufficiently high subcooling degree (50° C.) cannot be obtained making use of cool wind of the temperature of 0° C. or around it as described hereinabove. 
     On the contrary, where the biasing force of the regulating spring  1104  of the subcooling control valve  1100  is set so that the subcooling degree of 50° C. may be obtained at the interior condenser  1202 , even when the temperature of draft air blown to the interior condenser  1202  in the refrigerating cycle shown in FIG. 101 is 30° C. or around it or even when the air mixing damper  1211  in the refrigerating cycle shown in FIG. 102 closes the interior condenser  1202 , the subcooling control valve  1100  tends to reduce the opening of the throttle section  1102  until the subcooling degree of 50° C. is obtained at the interior condenser  1202 , and consequently, the pressure on the high pressure side rises to a very high level. 
     In the conventional subcooling control valve  1100 , the biasing force of the regulating spring  1104  is set so that a predetermined subcooling degree may be obtained in the interior condenser  1202  in this manner. Accordingly, the conventional subcooling control valve  1100  cannot cope with the construction of such a cycle wherein the temperature of air blown to the interior condenser  1202  varies over a wide range so that subcooling obtained at the interior condenser  1202  varies over a wide range (the subcooling degree cannot be controlled over a wide range), and consequently, the cycle efficiency is low. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide an automotive air conditioner for an automobile, which has an engine of the type wherein engine cooling water does not make a sufficient heat source or has no surplus heat source such as an electric automobile, wherein desirable air conditioning can be performed making full use of a variation of heat involved in condensation and evaporation in a refrigerating cycle. 
     It is another object of the present wherein the capacity of a compressor can be variably controlled by driving the compressor by means of an electric motor and air conditioning can be performed efficiently with a low power by suitably controlling the discharging capacity of the compressor and re-heating of air by means of a heater. 
     It is a still further object of the present invention to provide an automotive air conditioner wherein cooling operation or heating operation can be performed efficiently by controlling a flow of refrigerant to an outside heat exchanger which is provided to complement the capacities of a heater and an evaporator disposed in a duct. 
     It is a yet further object of the present invention to provide an automotive air conditioner wherein cooling operation, dehumidifying operation and heating operation can be achieved by suitably controlling a flow of refrigerant discharged from a compressor between an evaporator and a heater disposed in a duct and an outside heat exchanger disposed outside the duct. 
     It is a yet further object of the present invention to provide an automotive air conditioner wherein cooling operation, dehumidifying operation and heating operation can be achieved better by varying the heat exchanging capacities of an outside condenser and an outside evaporator provided to complement the condensing and evaporating functions of a heater and an evaporator. 
     It is a yet further object of the present invention to provide an automotive air conditioner wherein the operation thereof can be changed over between heating operation in which refrigerant circulates in the order of a compressor, a heater, decompressing means and an outside heat exchanger and dehumidifying operation in which the refrigerant flows in the order of the compressor, the heater, the outside heat exchanger, the decompressing means and an evaporator by changing over the flow of the refrigerant and heating operation can be maintained while preventing fogging up of the windshield and so forth by changing over the operation suitably to dehumidifying operation when necessary even in a conditioner of heating operation. 
     It is a yet further object of the present invention to provide an automotive air conditioner wherein the operation is changed over between a heating operation condition and a dehumidifying operation condition by changing over means and defrosting of an outside heat exchanger can be achieved by changing over, even in a heating operation condition, the operation to a dehumidifying operation condition in a condition wherein it is forecast that the outside heat exchanger may be frosted. 
     It is a yet further object of the present invention to provide an automotive air conditioner wherein the operation is changed over between a heating operation condition and a dehumidifying operation condition by changing over means and defrosting of an evaporator can be achieved well by changing over, even in dehumidifying operation, the operation to heating operation in a condition wherein it is forecast that the evaporator may be frosted. 
     It is a yet further object of the present invention to provide an automotive air conditioner wherein the condensing pressure of refrigerant in a heater can be varied to control the temperature of the heater by performing condensing of the refrigerant, in dehumidifying operation, by both of the heater and an outside heat exchanger and varying the condensing capacity of the outside heat exchanger. 
     It is a yet further object of the present invention to provide an automotive air conditioner wherein the pressure of refrigerant in an evaporator is prevented from dropping below a predetermined value thereby to prevent fogging up of an inside evaporator by providing a flow of refrigerant which bypasses the inside evaporator and changing over the refrigerant between a flow which flows to the inside evaporator side and another flow which flows to the bypass passageway by means of a solenoid valve. 
     It is a yet further object of the present invention to provide an automotive air conditioner wherein high pressure side refrigerant in a refrigerating cycle can have a sufficient subcooling degree and efficient operation of the refrigerating cycle can be performed by dividing an inside heater into a plurality of inside heaters and using the inside heater on the upstream side of a refrigerant flow as a condenser which performs condensing of the refrigerant while using the flow as a subcooler which performs radiation of heat of condensed high pressure liquid refrigerant. 
     It is a yet further object of the present invention to provide an automotive air conditioner wherein the amount of heat to be absorbed upon operation of a heat pump is increased to enhance the heating capacity by using an inside heater as a condenser and using both of an inside evaporator and an outside heat exchanger as evaporators when the heating load is high such as upon starting of heating operation under a low temperature and particularly when heating by inside air circulation is performed. 
     It is a yet further object of the present invention to provide an automatic air conditioner wherein an inside heater is divided into an inside condenser and an inside subcooler and throttling amount control of expanding means can be performed appropriately even in a condition wherein refrigerant does not substantially flow into either of the inside condenser and the inside subcooler in a cycle in which the throttling amount of the expanding means is varied so that a predetermined subcooling amount may be obtained with the inside subcooler. 
     It is a yet further object of the present invention to provide an automatic air conditioner wherein a receiver for suitably absorbing a variation of a flow rate of refrigerant which circulates in a refrigerating cycle can be installed well in the refrigerating cycle. 
     It is an additional object of the present invention to provide an automatic air conditioner wherein, even in case frost is detected on a surface of an evaporator when dehumidifying operation is to be performed, defogging of the evaporator can be performed without involving a great variation of the temperature of air to be blasted. 
     In order to attain the objects, according to the present invention, the construction is employed wherein an evaporator and a heater which constitute a refrigerating cycle are disposed in a duct which defines an air passageway. 
     Further, according to the present invention, a bypass passageway is formed sidewardly of a heater in a duct, and the amount of air to pass the bypass passageway and the amount of air to pass the heater are variably controlled continuously using an air mixing damper. 
     Further, according to the present invention, the cooling capacity of an evaporator in a duct and the heating capacity of a heater in the duct are suitably controlled by suitably controlling a flow and a flow rate of refrigerant to flow into the heater and the evaporator in the duct and also into an outside heat exchanger outside the duct. 
     Further, according to the present invention, a compressor is driven by an electric motor, and the speed of rotation of the electric motor is continuously controlled by a controller to variably control the discharging capacity of a compressor. 
     Further, according to the present invention, an outside heat exchanger is disposed outside a duct so that the heat exchanging performance of a heater or an evaporator may be complemented by the outside heat exchanger. 
     Further, according to the present invention, changing over means is disposed so that a flow of refrigerant passing an outside heat exchanger may be changed over in response to an operation condition required for the automotive air conditioner, that is, a heating operation condition or a cooling operation condition. Further, according to the present invention, an outside heat exchanger is divided into an outside condenser used only for condensation and an outside evaporator used only for evaporation and varying means are provided for varying the condensing function of the outside condenser and the evaporating function of the outside evaporator. 
     Further, according to the present invention, changing over means is provided so as to effect changing over control among a cooling operation condition wherein refrigerant circulates in the order of a compressor, an outside heat exchanger, decompressing means and an evaporator, a heating operation condition wherein refrigerant circulates in the order of the compressor, the heater, the decompressing means and the outside heat exchanger and a dehumidifying operation condition wherein refrigerant circulates in the order of the compressor, the heater, the outside heat exchanger, the decompressing means and the evaporator. 
     Further, according to the present invention, in a condition wherein it is forecast that the windshield of a room of an automobile is fogged, changing over means is controlled to be driven to change over the dehumidifying operation condition. 
     Further, according to the present invention, in a condition wherein freezing of an evaporator is forecast, changing over means is controlled to be driven to change over the operation from a dehumidifying operation condition to a heating operation condition. 
     Further, according to the present invention, means is provided for changing over, in a condition wherein freezing of an outside heat exchanger is forecast, refrigerant to be admitted into an outside heat exchanger from a low pressure condition after passing expanding means to a high pressure condition before passing the expanding condition. 
     Further, according to the present invention, means for varying the capacity of an outside heat exchanger is provided, and upon dehumidifying operation in which both of the outside heat exchanger and a heater perform condensation of refrigerant, the capacity of the outside heat exchanger is varied to vary the condensing temperature of the heater. 
     Further, according to the present invention, a bypass passageway for flowing refrigerant bypassing an inside evaporator is provided, and a flow of refrigerant is controlled to be changed over by a solenoid valve between a flow which flows to the inside evaporator side and another flow which flows to the bypass passageway side. 
     Further, according to the present invention, an inside heater is divided into a plurality of inside heaters, and the inside heater on the upstream side in a flow of refrigerant operates as an inside condenser while the inside heater on the downstream side in a flow of refrigerant functions as an inside subcooler. 
     Further, according to the present invention, an inner heater functions as a condenser while an outside heat exchanger functions as an evaporator upon heating operation, and when the heating load is particularly high, changing over of a flow of refrigerant is controlled so that also the inside evaporator operates as an evaporator together with the outside heat exchanger. 
     Further, according to the present invention, such a construction is employed that an inside heater is divided into an inside condenser and an inside throttling amount of an expansion valve is controlled so that a predetermined subcooling degree can be obtained, and refrigerant flows into the inside subcooler upon heating operation and upon dehumidifying operation. 
     Further, according to the present invention, such a construction is employed that a refrigerating cycle wherein a receiver is disposed on the upstream side of expanding means in a flow of refrigerant is formed and the location of the receiver is always positioned on the upstream side of the expanding means even if the operation is changed over to any of cooling operation, heating operation or dehumidifying operation. 
     Further, according to the present invention, an automotive air conditioner adopts such a construction that, when a frosted condition of an evaporator is forecast or detected upon dehumidifying operation wherein a heat exchanger on the upstream side in a duct functions as a refrigerant evaporator and another heat exchanger on the downstream side in the duct functions as a refrigerant condenser, the condition of an outside heat exchanger is changed over between a condition wherein it is not used as a heat exchanger between refrigerant and air or it is used as a refrigerant condenser to another condition wherein it is used as a refrigerant evaporator. Because the construction described above is employed, with the automotive air conditioner, the evaporator disposed in the duct only performs cooling of air while the heater disposed in the duct only performs heating of air. Accordingly, such a situation is eliminated that a single heat exchanger alternatively performs cooling of air or heating of air in accordance with an operation condition. Besides, since cooling of air by the evaporator and heating of air by the heater are used in combination, appropriate temperature control can be achieved while performing dehumidification of air. 
     Further, with the automotive air conditioner, the cooling capacity can be varied to vary the temperature of air after passing the evaporator by variably controlling the discharging capacity of the compressor. 
     Further, with the automotive air conditioner, while the outside heat exchanger is disposed outside air and refrigerant, the heat exchanging function of the heater or the evaporator by changing over a flow of refrigerant to flow to the outside heat exchanger between a flow of refrigerant to flow to the heater and a returning flow of refrigerant from the evaporator. In this instance, the outside heat exchanger has a function as a condenser or a function of an evaporator by changing over the flow of refrigerant. However, since the outside heat exchanger performs heat exchanging between air outside the duct and refrigerant, even if moisture is produced by a large amount at some location upon changing over operation, this will not make an obstacle to driving of the automobile or the like. 
     Further, with the automotive air conditioner, since the bypass passageways are provided sidewardly of the evaporator and the heater and the ratio of a flow rate of air flowing through either one of the bypass passageways to another flow rate of air flowing through the evaporator or the heater is controlled by the damper, cooling of air and heating of air in the duct can be controlled. As a result, useless cooling and useless re-heating of air can be eliminated. 
     Further, with the automotive air conditioner, since the outside heat exchanger is divided into the outside condenser and the outside evaporator installed separately, also the outside heat exchanger is always specified in function, and the outside condenser and the outside evaporator are installed at optimum locations in accordance with respective functions. 
     Further, in this instance, since the varying means is employed for varying the heat exchanging functions of the outside condenser and the outside evaporator, the functions of the condenser and the evaporator installed in the duct can be variably controlled in connection with the functions of the outside condenser and the outside evaporator. 
     Further, with the automotive air conditioner, since the bypass passage for flowing refrigerant bypassing the evaporator is provided and a flow of refrigerant is controlled to be changed over between the evaporator side and the bypass passageway side, when the pressure of refrigerant in the evaporator becomes lower than a predetermined value, refrigerant can be flowed to the bypass passageway side. Since refrigerant does not flow through the evaporator when refrigerant flows to the bypass passageway side, the result. Then, when the pressure of refrigerant in the evaporator rises higher than the predetermined value, refrigerant is changed over so that it may be flowed to the evaporator side again. The pressure of refrigerant in the evaporator can be controlled to the predetermined value by performing such changing over as described just above. 
     Further, with the automotive air conditioner, since the inside heater is formed separately as a heat exchanger which functions as a condenser and another heat exchanger which functions as a subcooler for subcooling condensed liquid registrant, refrigerant on the high pressure side in the refrigerating cycle can have a sufficiently high subcooling degree, and efficient operation of the refrigerating cycle can be performed. 
     Further, with the automotive air conditioner, upon heating operation, radiation of heat is performed by the inside heater while the inside heat exchanger serves as an evaporator in which absorption of heat is performed, and when the heating load is particularly high such as upon starting of heating in a low temperature condition, refrigerant passes also through the evaporator so that absorption of heat may be performed also in the evaporator. The heating capacity can be enhanced by increasing the amount of heat absorption in this manner. 
     Further, with the automotive air conditioner, the inside heater is divided into the condenser and the subcooler, and a temperature sensing tube is provided for varying the throttling amount of the expanding means so that the subcooling degree of refrigerant on the exit side of the inside condenser may be substantially constant in order that refrigerant passing the subcooler may have a predetermined subcooling degree. In the refrigerating cycle having such a construction as described just above, even in a condition wherein no refrigerant flows into the inside condenser and the inside subcooler, operation of the refrigerating cycle can be performed with certainty by employing a fixed throttle in addition to throttling for the expanding means provided by the temperature sensing tube. 
     Further, with the automotive air conditioner, since, upon dehumidifying operation, the heat exchanger on the upstream side in the duct functions as a refrigerant evaporator and the heat exchanger on the downstream side in the duct functions as a refrigerant upstream side, it is cooled, whereupon saturated vapor is removed from the air, whereafter it is heated when it passes through the heater on the downstream side, and after then, it is blasted into the room of the automobile. Then, if the temperature of the evaporator drops to a temperature at which frosting occurs or to a temperature near to such temperature at which frosting occurs, the controlling apparatus detects or forecasts such frosting by means of the frost sensor. Then, the controlling apparatus controls the flow passage changing over means to change over the outside heat exchanger from a condition wherein the outside heat exchanger is not used as a heat exchanger between refrigerant and air or is used as a refrigerant condenser to another condition wherein the outside heat exchanger is used as a refrigerant evaporator. 
     Then, since the evaporator and the outside heat exchanger both function as refrigerant evaporators, the evaporating pressure is raised, and frosting of the heat exchanger on the upstream side is prevented. 
     It is an object of the present invention to provide a refrigerating cycle by which an optimal subcooling degree to assure a high cycle efficiency can be obtained even when the subcooling degree obtained is varied over a wide range by a variation of temperature of refrigerant blown to a refrigerant condenser. 
     In order to attain the object described above, according to the present invention, there is provided a refrigerating cycle, which comprise a refrigerant condenser having a heat exchanging section for condensing refrigerant passing therethrough into liquid by heat exchange with a cooling medium, at least a lower stream area portion of the heat exchanging section being disposed in a temperature field in which the temperature of the cooling medium varies over a wide range, and a subcooling control valve including a throttle section for throttling a refrigerant flow passageway on the downstream of the refrigerant condenser, a valve member for opening and closing the throttle section, and a temperature sensitive section for converting a variation of temperature of the refrigerant on the upstream of the lower stream area portion into a variation of pressure, the valve member being displaced to adjust the opening of the throttle portion in accordance with the pressure variation of the temperature sensitive section so that the subcooling degree on the upstream of the lower stream area portion may be a predetermined value. 
     Preferably, the refrigerant condenser includes a mounting pipe for mounting the temperature sensitive section thereon, and the mounting pipe is provided such that it projects sidewardly of the head exchanging section on the upstream of the lower stream area portion. 
     In the refrigerating cycle, the opening of the throttle section of the subcooling control valve is adjusted so that the subcooling degree on the upstream in the downstream area of the refrigerant condenser may be the predetermined value. 
     Accordingly, the refrigerant flowing into the lower stream area portion of the refrigerant condenser is in the form of liquid refrigerant cooled already to the subcooling degree of the predetermined value. Consequently, a maximum subcooling degree which can be obtained in the lower stream area portion can be obtained in response to a variation of temperature of the cooling medium which exchanges heat with the refrigerant in the lower stream area section. In short, even if the temperature of the cooling medium which exchanges heat with the refrigerant in the lower stream area portion varies over a wide range, a subcooling degree corresponding to a temperature difference between the temperature of the cooling medium and the saturation temperature of the refrigerant on the upstream of the lower stream area portion (temperature of the cooling medium saturation temperature of the refrigerant) can be obtained. 
    
    
     The above and other objects, features and advantages of the present invention will become apparent from the following description and the appended claims, taken in conjunction with the accompanying drawings in which like parts or elements are denoted by like reference characters. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a diagrammatic view showing a preferred embodiment of the present invention; 
     FIG. 2 is a Mollier chart illustrating an operating condition of the automotive air conditioner shown in FIG. 1; 
     FIG. 3 is a diagrammatic view showing another preferred embodiment of the present invention; 
     FIG. 4 is a flow chart illustrating an example of control of the automotive air conditioner shown in FIG. 3; 
     FIG. 5 is a diagrammatic view showing a further preferred embodiment of the present invention; 
     FIG. 6 is a Mollier chart illustrating an operation condition of the automotive air conditioner shown in FIG. 5; 
     FIG. 7 is a diagrammatic view showing a still further preferred embodiment of the present invention; 
     FIG. 8 is a Mollier chart illustrating operation of the automotive air conditioner shown in FIG. 7 in a cooling condition; 
     FIG. 9 is a Mollier chart illustrating operation of the automotive air conditioner shown in FIG. 7 in a cooling condition; 
     FIG. 10 is a flow chart illustrating an example of control of the automotive air conditioner shown in FIG. 7; 
     FIG. 11 is a diagrammatic view showing a yet further preferred embodiment of the present invention; 
     FIG. 12 is a flow chart illustrating an example of control of the automotive air conditioner shown in FIG. 11; 
     FIG. 13 is a diagrammatic view showing a yet further preferred embodiment of the present invention; 
     FIG. 14 is a diagrammatic view showing a yet further preferred embodiment of the present invention; 
     FIG. 15 is a Mollier chart illustrating an operation condition of the automotive air conditioner shown in FIG. 14 in cooling operation; 
     FIG. 16 is a Mollier chart illustrating an operation condition of the automotive air conditioner shown in FIG. 14 in a heating condition; 
     FIG. 17 is a diagram illustrating an example of control of the automotive air conditioner shown in FIG. 14; 
     FIG. 18 is a diagrammatic view showing a yet further preferred embodiment of the present invention; 
     FIG. 19 is a diagrammatic view showing a yet further preferred embodiment of the present invention; 
     FIG. 20 is a diagrammatic view showing a yet further preferred embodiment of the present invention; 
     FIG. 21 is a diagrammatic view showing a yet further preferred embodiment of the present invention; 
     FIG. 22 is a Mollier chart illustrating operation of the automotive air conditioner shown in FIG. 21; 
     FIG. 23 is a Mollier chart illustrating another operation of the automotive air conditioner shown in FIG. 21; 
     FIG. 24 is a Mollier chart illustrating a further operation of the automotive air conditioner shown in FIG. 21; 
     FIG. 25 is a Mollier chart illustrating conditioner shown in FIG. 21; 
     FIG. 26 is a Mollier chart illustrating a yet further operation of the automotive air conditioner shown in FIG. 21; 
     FIG. 27 is a Mollier chart illustrating a yet further operation of the automotive air conditioner shown in FIG. 21; 
     FIG. 28 is a diagrammatic view showing a yet further preferred embodiment of the present invention; 
     FIG. 29 is a diagrammatic view showing a yet further preferred embodiment of the present invention; 
     FIG. 30 is a diagrammatic view showing a yet further preferred embodiment of the present invention; 
     FIG. 31 is a diagrammatic view showing a yet further preferred embodiment of the present invention; 
     FIG. 32 is a diagrammatic view showing a yet further preferred embodiment of the present invention; 
     FIG. 33 is a diagrammatic view showing a yet further preferred embodiment of the present invention; 
     FIG. 34 is a diagrammatic view showing a yet further preferred embodiment of the present invention; 
     FIG. 35 is a diagrammatic view showing a yet further preferred embodiment of the present invention; 
     FIG. 36 is a diagrammatic view showing a yet further preferred embodiment of the present invention; 
     FIG. 37 is a diagrammatic view showing a yet further preferred embodiment of the present invention; 
     FIG. 38 is a diagrammatic view showing a yet further preferred embodiment of the present invention; 
     FIG. 39 is a diagrammatic view showing a yet further preferred embodiment of the present invention; 
     FIG. 40 is a diagrammatic view showing a yet further preferred embodiment of the present invention; 
     FIG. 41 is a flow chart illustrating an example of refrigerating cycle control of the present invention; 
     FIG. 42 is a flow chart showing another form of the flow chart shown in FIG. 41; 
     FIG. 43 is a flow chart showing a further form of the flow chart shown in FIG. 41; 
     FIG. 44 is a flow chart showing a still further form of the flow chart shown in FIG. 41; 
     FIG. 45 is a flow chart showing a yet further form of the flow chart shown in FIG. 41; 
     FIG. 46 is a flow chart showing a yet further form of the flow chart shown in FIG. 41; 
     FIG. 47 is a flow chart showing another example of refrigerating cycle control of the present invention; 
     FIG. 48 is a flow chart showing a further example of refrigerating cycle control of the present invention; 
     FIG. 49 is a flow chart showing another form of the flow chart shown in FIG. 48; 
     FIG. 50 is a diagram illustrating a form of control of a blower for an outside heat exchanger of a refrigerating cycle of the present invention; 
     FIG. 51 is a flow chart illustrating an example of control when a refrigerating cycle of the present invention is used in dehumidifying operation; 
     FIG. 52 is a front elevational view showing an example of operation panel used in the present invention; 
     FIG. 53 is a diagrammatic view showing a yet further preferred embodiment of the present invention; 
     FIG. 54 is a flow chart illustrating an example of control of the automotive air conditioner shown in FIG. 53; 
     FIG. 55 is a flow chart illustrating another example of control of the automotive air conditioner shown in FIG. 53; 
     FIG. 56 is a flow chart illustrating a further example of control of the automotive air conditioner shown in FIG. 53; 
     FIG. 57 is a flow chart illustrating a still further example of control of the automotive air conditioner shown in FIG. 53; 
     FIG. 58 is a flow chart illustrating a yet further example of control of the automotive air conditioner shown in FIG. 53; 
     FIG. 59 is a table illustrating operation modes of the automotive air conditioner shown in FIG.  53  and operating conditions of components of the same; 
     FIG. 60 is a diagrammatic schematic view showing a flow of refrigerant upon heating operation of the automotive air conditioner shown in FIG. 53; 
     FIG. 61 is a diagrammatic schematic view showing a flow of refrigerant upon dehumidifying heating operation of the automotive air conditioner shown in FIG. 53; 
     FIG. 62 is a diagrammatic schematic view showing a flow of refrigerant upon cooling operation of the automotive air conditioner shown in FIG. 53; 
     FIG. 63 is a diagrammatic schematic view showing a flow of refrigerant upon defrosting operation of the automotive air conditioner shown in FIG. 53; 
     FIG. 64 is a front elevational view showing an example of operation panel of the automotive air conditioner shown in FIG. 53; 
     FIG. 65 is a diagrammatic view showing a yet further preferred embodiment of the present invention; 
     FIG. 66 is a diagrammatic view showing a yet further preferred embodiment of the present invention; 
     FIG. 67 is a diagrammatic view showing a yet further preferred embodiment of the present invention; 
     FIG. 68 is a diagrammatic view showing a yet further preferred embodiment of the present invention; 
     FIG. 69 is a diagrammatic view showing a yet further preferred embodiment of the present invention; 
     FIG. 70 is a diagrammatic schematic view showing a flow of refrigerant upon heating operation of the automotive air conditioner shown in FIG. 69; 
     FIG. 71 is a diagrammatic schematic view showing a flow of refrigerant upon cooling operation of the automotive air conditioner shown in FIG. 69; 
     FIG. 72 is a diagrammatic schematic view showing a flow of refrigerant upon dehumidifying heating operation of the automotive air conditioner shown in FIG. 69; 
     FIG. 73 is a diagrammatic schematic view showing a flow of refrigerant upon dehumidifying defrosting operation of the automotive air conditioner shown in FIG. 69; 
     FIG. 74 is a refrigerant circuit diagram of an air conditioner according to a yet further embodiment of the present invention; 
     FIG. 75 is a refrigerant circuit diagram of an air conditioner according to a yet further embodiment of the present invention; 
     FIG. 76 is a refrigerant circuit diagram of an air conditioner according to a yet further embodiment of the present invention; 
     FIG. 77 is a refrigerant circuit diagram of an air conditioner according to a yet further embodiment of the present invention; 
     FIG. 78 is a refrigerant circuit diagram of an air conditioner according to a yet further embodiment of the present invention; 
     FIG. 79 is a refrigerant circuit diagram of an air conditioner according to a yet further embodiment of the present invention; 
     FIG. 80 is a refrigerant circuit diagram of an air conditioner according to a yet further embodiment of the present invention; 
     FIG. 81 is a refrigerant circuit diagram of an air conditioner according to a yet further embodiment of the present invention; 
     FIG. 82 is a refrigerant circuit diagram of an air conditioner according to a yet further embodiment of the present invention; 
     FIG. 83 is a refrigerant circuit diagram of an air conditioner according to a yet further embodiment of the present invention; 
     FIG. 84 is a refrigerant circuit diagram of an air conditioner according to a yet further embodiment of the present invention; 
     FIG. 85 is a refrigerant circuit diagram of an air conditioner according to a yet further embodiment of the present invention; 
     FIG. 86 is a schematic diagrammatic view of an automotive air conditioner in which a refrigerating cycle according to the present invention is incorporated; 
     FIG. 87 is a sectional view of a subcooling control valve; 
     FIGS. 88 to  91  are Mollier diagrams illustrating operation of the refrigerating cycle; 
     FIG. 92 is a schematic diagrammatic view of another air conditioner showing a second preferred embodiment of the present invention; 
     FIG. 93 is a schematic diagrammatic view of a further air conditioner showing a third preferred embodiment of the present invention; 
     FIG. 94 is a front elevational view of a refrigerant condenser showing a fourth preferred embodiment ,of the present invention; 
     FIG. 95 is a fragmentary perspective view of part of the refrigerant condenser shown in FIG. 94; 
     FIG. 96 is a sectional view of a mounting pipe and a temperature sensitive tube of the refrigerant condenser shown in FIG. 94; 
     FIG. 97 is a sectional view of a mounting pipe and a temperature sensitive tube for comparison with those shown in FIG. 96; 
     FIG. 98 is a fragmentary perspective view of a modification to a header of the refrigerant condenser shown in FIG. 94; 
     FIG. 99 is a front elevational view of a modification to the refrigerant condenser shown in FIG. 94; 
     FIG. 100 is a schematic view showing general construction of a conventional subcooling control valve; 
     FIG. 101 is a schematic diagrammatic view showing general construction of a conventional air conditioner; and 
     FIG. 102 is a similar view but showing general construction of another conventional air conditioner; 
     FIG. 103 consists of FIGS. 103A and 103B which together show a flow chart showing control flow of switching operation in air conditioners shown in FIGS. 83-85; 
     FIG. 104 is an schematic diagram showing operation condition of each device in the first dehumidifying operation and the second dehumidifying operation; 
     FIG. 105 consists of FIGS. 105A and 105B which together show a flow chart showing control flow of switching operation in first dehumidifying operation and the second dehumidifying operation; 
     FIG. 106 is a perspective view of an example showing the present invention is applied to an automobile; and 
     FIG. 107 is a partial perspective view of an example showing loading position of an air conditioner of the present invention on an automobile. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the following, embodiments of the present invention will be described with reference to the drawings. Referring to FIG. 1, a duct  100  which defines an air passageway is disposed in a room of an automobile. A fan case  101  is connected to an end of the duct  100 , and a blower  132  is disposed in the fan case  101 . The blower  132  is driven to rotate by a motor  133  disposed at a central location thereof. An inside/outside air changing over section  130  is connected in the fan case  101 , and an inside air inlet port  134  and an outside air inlet port  135  are opened at the inside/outside air changing over section  130 . An inside/outside air changing over damper  131  is disposed in the inside/outside air changing over section  130 , and air to be introduced into the duct  100  can be changed over between inside air and outside air of the automobile. 
     The duct  100  has a plurality of spit holes formed at an end portion thereof for blowing out conditioned air into the room of the automobile. The spit holes include a vent spit hole  144  for principally blowing out a cool wind toward the head and breast portions of passengers, a foot spit hole  145  for principally blowing out a warm wind toward the legs of blowing out a warm wind toward the windshield. A vent damper  143 , a foot damper  143  and a def damper  141  are provided at the spit holes  144 ,  145  and  146  for controlling air flows to the spit holes  144 ,  145  and  146 , respectively. 
     An evaporator  207  of a refrigerating cycle is disposed in the duct  100 , and a condenser  203  of the refrigerating cycle is disposed on the downstream side of the evaporator  207  similarly in the duct  100 . It is to be noted that the evaporator  207  operates as a cooler which takes heat of vaporization away from air for conditioning or air upon heat exchanging thereby to cool the air. Meanwhile, the condenser  203  operates as a heater which radiates heat of condensation to air upon heat exchanging thereby to heat the air. 
     A bypass passageway  150  is disposed sidewardly of the inside condenser  203  in the duct  100 , and an air mixing damper  154  is disposed for pivotal motion at an end thereof in the duct  100  for variably continuously controlling the ratio between the amount of air flowing through the bypass passageway  150  and the amount of air flowing through the condenser  203 . It is to be noted that the refrigerating cycle includes a compressor  201  which is driven by an electric motor not shown to compress and discharge refrigerant. Since the compressor  201  is disposed in an enclosed casing integrally with the electric motor, the location thereof is not limited to a particular location. It is only preferable for the compressor  201  to be disposed at any other location than within the room of the automobile for the convenience of maintenance and so forth. Refrigerant in a high temperature, high pressure condition discharged from the compressor  201  is condensed by an outside heat exchanger  202 . The outside heat exchanger  202  operates only as a condenser and is disposed at a forward location in the advancing direction of the automobile so that good heat exchanging can be effected with outside air. In other words, the outside heat exchanger  202  meets with a driving wind during driving of the automobile so that refrigerant thereof can be cooled well. Meanwhile, the condenser  203  is coupled to the outside heat exchanger  202  by way of a refrigerant pipe. Liquid refrigerant condensed by passage through the condenser  203  flows once into a receiver  205 . The receiver  205  has a comparatively great volume so that it can keep surplus refrigerant in the form of liquid the receiver  205 , and only liquid refrigerant is delivered to expanding means  206  side. The expanding means  206  is, in the present automotive air conditioner, a temperature differential expansion valve which varies the throttling amount thereof in response to a degree of superheat of refrigerant on the exit side of the evaporator  207 . In particular, the expansion valve  206  receives a signal from a temperature sensing tube  204  and varies the throttling amount thereof in response to the signal so that the superheat on the exit side of the evaporator  207  may normally be constant. The expansion valve  206  is disposed in the proximity of the evaporator  207 . On the other hand, while the location of the receiver  205  described above is not particularly limited, it is preferably disposed outside the room of the automobile, for example, in the engine room for the convenience of maintenance and so forth. An operation panel  300  is disposed at a location within the room of the automobile at which it can be visually observed readily by a passenger. The operation panel  300  includes a fan lever  301  for controlling the speed of rotation of the blower motor  133 , a temperature adjusting lever  302  for controlling the opening of the air mixing damper  154 , a mode changing over lever  303  for controlling the spit hole dampers  142 ,  143  and  141 , an operating lever  304  for controlling the inside/outside air changing over damper  131  to make a changing over operation, an air conditioner switch  305  for starting operation of the automotive air conditioner, an economy switch  306  for causing the automotive air conditioner to operate in a power saving mode, and an off switch  307  for stopping operation of the automotive air conditioner. A temperature sensor  322  detects a temperature of air on the exit side of the evaporator  207 , and normally the discharging amount of the compressor  201  is controlled in accordance with a signal from the temperature sensor  322  so that the temperature of air on the exit side of the evaporator  207  may range from 3 to 4 degrees. However, when the economy switch  306  is switched on, the discharging amount of the compressor  201  is variably controlled in response to a signal from the sensor  322 —so that the air temperature on the exit side of the evaporator  207  may range from 10 to 11 degrees. A sensor  323  detects a pressure of  206 . A refrigerant pressure detected by the sensor  323  is substantially equal to a pressure of refrigerant in the compressor  203 , and a saturation condensation temperature of refrigerant in the condenser  203  is calculated from the pressure. Subsequently, operation of the automotive air conditioner having such construction as described above will be described. If the air conditioner switch  305  is switched on and the fan switch  301  is set to any of positions LO, MID and HI, then the compressor  201  starts its rotation and the fan motor  133  is rotated at a selected speed. Gas refrigerant in a high temperature, high pressure condition discharged from the compressor  201  is condensed at part thereof in the outside heat exchanger  202  and condensed at the remaining part thereof in the condenser  203  disposed in the duct  100 . Refrigerant thus condensed into liquid is then separated from gas in the receiver  205 , and only the liquid refrigerant is supplied to the expanding means  206 . The liquid refrigerant is adiabatically expanded into mist of a low temperature and a low pressure by the expanding means  206  and then supplied into the evaporator  207 . In the evaporator  207 , the mist refrigerant exchanges heat with air supplied thereto from the blower  132 . In particular, the mist refrigerant takes heat of vaporization away from the air so that it is vaporized while it remains in a low pressure condition. The thus vaporized gas refrigerant is sucked into the compressor  201  again. FIG. 2 is a Mollier chart illustrating an operation condition of the refrigerating cycle. A solid line in FIG. 2 shows a condition wherein the air mixing damper  154  assumes its fully open position as shown in FIG.  1 . In other words, the solid line shows a condition wherein blasting air flows into the condenser  203 . As seen from FIG. 2, condensation is performed by the outside heat exchanger  202  and the condenser  203 . In this condition, an enthalpy ΔI obtained in the condenser  203  is consumed for heating of air, and accordingly, air having passed the evaporator  207  and the condenser  203  will perform a cooling action by an amount corresponding to an enthalpy Ie. A broken line in FIG. 2 shows a condition wherein the air mixing damper  154  assumes its fully closed condition. In this condition, no flow of condensation of refrigerant is performed all by the outside heat exchanger  202 . In this instance, however, since the effective capacity of the heat exchangers is decreased by the capacity of the condenser  203 , the pressure necessary to condense refrigerant is increased. In particular, the pressure on the discharging side of the compressor  201  is increased a little. On the other hand, the pressure on the sucking side of the compressor  201  is maintained constant independently of the opening of the air mixing damper  154  because it is controlled by the expanding means  206 . Then, in such a condition wherein the air mixing damper  154  is in a fully closed position as indicated by the broken line in FIG. 2, since the loss in enthalpy by the condenser  203  can be ignored, the cooling function of the evaporator  207  can be used as it is for cooling. Subsequently, a condition of a flow of air in this instance will be described. Air selectively supplied by the inside/outside changing over damper  131  is supplied into the evaporator  207  by the blower  132 . Here, when the air passes the evaporator  207 , it is cooled by vaporization of refrigerant so that it has a temperature ranging from 3 to 4 degrees on the exit side of the evaporator  207 , and in this condition, it comes to the bypass passageway  150  and the condenser  203 . The air flow is suitably selected by the air mixing damper  154 . In particular, in a condition wherein maximum cooling is required, the air mixing damper  154  closes the condenser  203  so that the cooled air is introduced as it is to the spit hole side. In case it is desired to raise the temperature of air to be blown out, the air mixing damper  154  is opened so that part of the air may be introduced into the condenser  203 . Air introduced into the condenser  203  is re-heated in the condenser  203  to a predetermined temperature and then mixed, in an air mixing chamber  155 , with air having passed the bypass passageway  150 . The thus conditioned air is blown out into the room of the automobile from a selected one or ones of the dampers  142 ,  143  and  141 . When the mode switch  303  is at its vent mode position, only the vent damper  142  is opened while the other dampers  143  and  141  remain closed. Consequently, a cooling wind will be blown out principally to the head and breast portions of passengers. On the other hand, when the mode switch  303  closed while the vent damper  142  and the foot damper  143  are opened. Consequently, a warm wind having passed the condenser  203  will be blown out principally from the foot spit hole  145  toward the feet of passengers while a cooling wind having passed the bypass passageway  150  is blown out principally from the vent spit hole  144  toward the head and breast portions of the passengers. When the mode lever  303  is brought to its foot mode position, only the foot damper  143  is opened while the other dampers  142  and  141  are closed. As a result, air having passed the condenser  203  is blown out from the foot spit hole  143  toward the feet of passengers. When the mode lever  303  is set to its def mode position, only the def damper  141  is opened while the other dampers  142  and  143  are closed. As a result, dehumidified air having passed the condenser  203  is blown out from the def spit hole  146  toward the windshield of the automobile. It is to be noted that, in the automotive air conditioner described above, when the mode lever  303  is set to the foot mode position, air having passed the condenser  203  will be blown out as it is to the foot portions of passengers. Here, as seen from the Mollier chart of FIG. 2, in the condition described above, the difference in enthalpy at the evaporator  207  is greater by a predetermined amount Ie than the difference in enthalpy at the condenser  203 . However, since a considerable part of the cooling capacity of the evaporator  207  is consumed to condense moisture in the air on a surface of the evaporator  207 , air having passed the evaporator  207  and the condenser  203  will rise in temperature. In particular, even if the temperature of the outside air is low, since air cooled when it passes the evaporator  207  is re-heated in the condenser  203 , the temperature of air when it passes the condenser  203  is raised to 20 to 25 degrees or so. However, since the temperature is comparatively low as a temperature of air to be blown out upon heating, it is desirable, in an operating condition wherein heating is required, to use a PCT heater and some other auxiliary heat source. While the receiver  205  in the automotive air conditioner of FIG. 1 is disposed on the downstream of the condenser  203 , it may otherwise be disposed on the downstream of the outside heat exchanger  202  as shown in FIG.  19 . In this instance, condensation of refrigerant heat exchanger  203  acts as a subcooler which radiates heat of high temperature, high pressure liquid refrigerant introduced thereinto from the receiver  205 . Accordingly, in the present invention, the heat exchanger disposed in the duct  100  is not necessarily limited to the condenser  203 , but includes a subcooler. Accordingly, in the present invention, a condenser, a subcooler or the like which radiates heat of high temperature, high pressure refrigerant will be generally referred to as a heater. Further, while, in the automotive air conditioner of FIG. 1, the opening of the air mixing damper  154 , the speed of rotation of the blower motor  133  and the speed of rotation of the compressor  201  are set by manual operations of a passenger of the automobile, they may otherwise be set automatically. FIG. 3 shows such an automatic automotive air conditioner. Referring to FIG.  3 , a sensor  361  detects a temperature of outside air, and another sensor  362  measures a temperature of air in the room of the automobile. A solar radiation sensor  363  measures an amount of the sunlight incident into the room of the automobile, and a temperature sensor  364  measures a temperature of blown out air. Another temperature sensor  365  is disposed on the exit side of the condenser  203  and measures a temperature of air having passed the condenser  203 . An example of control of the automatic automotive air conditioner will be described subsequently with reference to FIG. 4 which illustrates a flow chart of the control. If switching on of the air conditioner switch  305  is detected at step  401 , then inputs from the various sensors are received at step  402 . Then, a necessary blown out air temperature Tao is calculated in accordance with the inputs at step  403 . Then at step  404 , it is determined in accordance with a value of the necessary blown out air temperature Tao whether or not the operation of the compressor  201  should be in an economy mode. In particular, if the necessary blown out air temperature Tao is equal to or higher than a predetermined value, for example, 20 degrees, the temperature Teo at the exit of the evaporator  207  is set to a higher temperature side preset temperature, for example, to 10 degrees. On the other hand, when the necessary blown out air temperature Tao is lower than another predetermined value, for example, 10 degrees, the air temperature at the exit of the evaporator  207  is set, temperature, for example, to 3 degrees. Then at step  405 , a temperature Te of air at the exit of the evaporator  207  is received from the sensor  322 . The temperature Te thus received at step  405  and the air temperature Teo obtained at step  404  are compared with each other at step  406 . When the actual blown out air temperature Te is higher than the aimed blown out air temperature Teo, this is a condition wherein a higher capacity is required for the refrigerating cycle, and consequently, the frequency of an inverter not shown is raised at step  407  to increase the discharging capacity of the compressor  201 . On the contrary when the actual temperature Te is lower than the aimed temperature Teo, this is a condition wherein the capacity of the refrigerating apparatus is excessively high, and consequently, the frequency of the inverter is lowered at step  408  to decrease the discharging capacity of the compressor  201 . Variation of the discharging capacity of the compressor  201  is performed when the aimed temperature Teo is lower than the higher temperature side preset temperature, for example, 10 degrees, and the routine described above is repeated by way of step  409 . Then, in case it is judged at step  409  that the aimed temperature Teo is higher than the higher temperature side preset temperature, the control sequence advances to step  410 , at which the opening of the air mixing damper  154  is controlled. While the opening of the air mixing damper  154  is controlled in accordance with the aimed temperature Tao, it is influenced further by a temperature of refrigerant in the condenser  203 . In particular, when a pressure of refrigerant obtained from the pressure sensor  323  is high, it is judged that also the temperature of refrigerant is high, and in this instance, even if the aimed temperature Tao is equal, the opening of the air mixing damper  154  is varied so that the air mixing damper  154  may be pivoted by a smaller amount. In particular, in the present automotive air conditioner, as control of a cooling operation, the discharging capacity of the compressor  201  is first varied to achieve power saving operation and then the air mixing damper  154  is pivoted so that the temperature control may be available to the high temperature side. Referring now to FIG. 5, there is shown a further automotive air conditioner according to the present invention, in which the refrigerating cycle is an accumulating refrigerant therein is installed on the exit side of the evaporator  207  and the sucking side of the compressor  201 , and a capillary tube  211  of a fixed throttle is employed in place of the expansion valve as the expanding or decompressing means. In this instance, since the capillary tube  211  does not require an excessive installation area, it is disposed in the duct  100 . FIG. 6 is a Mollier chart of the automotive air conditioner shown in FIG. 5. A solid line in FIG. 6 illustrates a condition wherein the air mixing damper  154  is opened fully so that cooling air is introduced into the compressor  203 . Meanwhile, a broken line in FIG. 6 illustrates another example wherein the air mixing damper  154  is closed so that the condenser  203  may not substantially perform a condensing operation. Also with the present automotive air conditioner, it can be seen that, similarly as with the automotive air conditioners of the preceding embodiments described above, the pressure on the higher pressure side rises a little when the air mixing damper  154  is closed. Further, since the refrigerating cycle is an accumulator cycle, superheat is not taken on the exit side of the evaporator  207 . Instead, a predetermined subcooling degree is obtained on the exit side of the condenser  203 . FIG. 7 shows a still further automotive air conditioner of the present invention, in which the outside heat exchanger  202  can be changed over such that it is used as a condenser or as an evaporator in accordance with the necessity. In particular, referring to FIG. 7, a first four-way valve  213  and a second four-way valve  214  are disposed at the opposite end portions of the outside heat exchanger  202 . The first four-way valve  213  is changed over between a first connecting condition (indicated by a solid line) wherein it interconnects the discharging side of the compressor  201  and the outside heat exchanger  202  and interconnects the suction side of the compressor  201  and the refrigerant pipe  220  and a second connecting condition (indicated by a broken line) wherein it interconnects the discharging side of the compressor  201  and the refrigerant pipe  220  and interconnects the outside heat exchanger  202  and the sucking side of the compressor  201 . Also the second four-way valve  214  is changed over between a first connecting condition indicated by a solid line in FIG. 7 and a second  7 . In the first connecting condition, the second four-way valve  214  interconnects the outside heat exchanger  202  and the condenser  203  and interconnects the evaporator  207  and the sucking side of the compressor  201 . On the other hand, in the second connecting condition, the second four-way valve  214  interconnects the refrigerant pipe  220  and the condenser  203  and interconnects the evaporator  207  and the outside heat exchanger  202 . It is to be noted that, in the automotive air conditioner shown in FIG. 7, since it has a condition wherein the evaporator  207  and the outside heat exchanger  202  are connected directly to each other, an evaporation pressure regulating valve  208  is disposed on the downstream of the evaporator  207 . Subsequently, an operation condition of the automotive air condition shown in FIG. 7 will be described with reference to Mollier charts of FIGS. 8 and 9. FIG. 8 illustrates a condition wherein the first and second four-way valves  213  and  214  assume their respective first connecting conditions and the outside heat exchanger  202  acts as a condenser. The condition is used principally upon cooling operation in summer. The condition is basically similar to that of the Mollier chart shown in FIG. 6, and the variation in enthalpy at the condenser  203  is adjusted in response to the opening of the air mixing damper  154 . FIG. 9 illustrates another condition wherein the first and second four-way valves  213  and  214  assume the respective second connecting conditions on the contrary. In the present condition, the outside heat exchanger  202  is used as an evaporator, and the present condition is used principally for heating operation in winter. In this instance, refrigerant discharged from the compressor  201  is supplied to the condenser  203  by way of the refrigerant pipe  220 . Condensation of refrigerant is performed only by the condenser  203 . Accordingly, a great enthalpy difference is obtained at the condenser  203 , and consequently, a sufficient amount of heat can be radiated. Refrigerant condensed into liquid by the condenser  203  is decompressed and expanded when it passes the capillary tube  211  and is supplied in the form of mist into the evaporator  207 . Evaporation of refrigerant is performed by the evaporator  207  and the outside heat exchanger  202 . It is to be noted, however, that the maintained constant since the evaporation pressure regulating valve  208  is disposed on the downstream of the evaporator  207 . In particular, it is prevented that the pressure of refrigerant in the evaporator  207  is lowered excessively so that the temperature at a surface of the evaporator  207  drops to a temperature lower than −2° C. to cause freezing of the surface of the evaporator  207 . Particularly in winter, there is the possibility that, upon admission of outside air, the temperature of the evaporator  207  may be dropped excessively. However, where the evaporating pressure regulating valve  208  is disposed in this manner, otherwise possible freezing of the evaporator  207  can be prevented with certainty. On the contrary, when refrigerant passes the evaporating pressure regulating valve  208 , the pressure thereof is further dropped such that the evaporating temperature in the outside heat exchanger  202  becomes lower than the freezing point. Consequently, freezing likely occurs at the outside heat exchanger  202 . In order to prevent freezing at the outside heat exchanger  202 , high temperature refrigerant on the discharging side of the compressor  201  should be supplied to the outside heat exchanger  202  at suitable time intervals. It is to be noted that, in the automotive air conditioner shown in FIG. 7, the first and second four-way valves  213  and  214  are controlled by changing over of the switches  306 ,  310  and  311 . In particular, in a condition wherein the cooler switch  310  or the economy switch  306  is on, the automotive air conditioner performs cooling operation with the first and second four-way valves  213  and  214  set to the respective first connecting conditions. On the other hand, in another condition wherein the heat switch  311  is on, the first and second four-way valves  213  and  214  assume the respective second connecting conditions, and the automotive air conditioner performs heating operation. It is to be noted that it is also possible to modify the automotive air conditioner shown in FIG. 7 into an automatic automotive air conditioner employing a microcomputer. In this instance, sensors similar to those shown in FIG. 3 may be employed, and the discharging capacity of the compressor  201 , the opening of the air mixing damper  154  and changing over operations of the first and second four-way valves  213  and  214  are controlled by way of the controller  300 . Such control will be described with reference to FIG. 10 calculated at step  403  in accordance with inputs received at step  402  from the various sensors, it is judged at step  411  in accordance with the aimed blown out air temperature Tao whether cooling operation or heating operation should be performed. In case a cooler mode is determined, the first and second four-way valves  213  and  214  are changed over to the respective first connecting conditions indicated by solid lines in FIG. 10 at step  412 . In the cooler mode, control of a blown out air temperature is executed using steps  405 ,  406 ,  407 ,  408 ,  409  and  410  similar to those of the cycle shown in FIG.  4 . In case a heater mode is determined at step  411 , the first and second four-wary valves  213  and  214  are changed over to the respective second connecting positions indicated by broken lines in FIG. 10 at step  413 . In the heater mode, the air mixing damper  154  is basically held in a fully open condition, and to this end, an instruction is delivered at step  414  to fully open the air mixing damper  154 . At step  415  after then, a pressure of refrigerant is inputted from the sensor  233  and a condensing temperature at the condenser  203  is calculated in accordance with the refrigerant pressure. Then, a condensing temperature Tc obtained from the sensor  365  is compared at step  416  with the aimed temperature Tao calculated at step  403 . In case the condensing temperature Tao is higher, the control sequence advances to step  417 , at which the frequency of the invertor is lowered to decrease the discharging capacity of the compressor  201 . On the contrary in case the condensing temperature Tc is lower, the frequency of the invertor is raised at step  418  to increase the discharging capacity of the compressor  201 . In this manner, in the operation illustrated in FIG. 10 of the automotive air conditioner, power saving operation of the compressor  201  by control of the invertor takes precedence in either of the cooler mode and the heater mode. 
     FIG. 11 shows a yet further automotive air conditioner according to the present invention. While the evaporator  207  in all of the automotive air conditioners described above is disposed such that it occupies the entire air passing position in the duct  100 , it is disposed, in the present automotive air conditioner, such that a bypass passageway  160  may be formed sidewardly of the evaporator  207  in the duct  100 . Further, a bypass damper  159  is disposed for pivotal motion in the duct  100  so that the rate between an amount of air flowing in the bypass passageway  160  and another amount of air flowing in the evaporator  207  may be controlled by means of the bypass damper  159 . Construction of the other portion of the automotive air conditioner is similar to that of the automotive air conditioner described hereinabove with reference to FIG.  7 . 
     Accordingly, in the automotive air conditioner shown in FIG. 11, the low rate of air to flow into the evaporator  207  principally upon heating operation can be decreased by means of the damper  159 . Since the blown out air temperature of the evaporator  207  is that for cooling of air even upon heating, if the flow rate of air to pass the evaporator  207  is decreased by means of the damper  159  in this manner, then the heating capacity is enhanced as much. 
     Subsequently, an example of control of the controller  300  in the automotive air conditioner shown in FIG. 11 will be described. The present control is characterized particularly in control of the opening of the damper  159 . In the flow chart of FIG. 12, control of the damper  159  is executed when a heater mode is determined at step  411 . In other words, in case a cooler mode is determined at step  411 , the damper  159  closes the bypass passageway  160  so that the entire amount of air from the blower  132  may pass the evaporator  207 . 
     When a heater mode is determined at step  411 , a necessary dehumidifying amount is calculated at step  419 . The necessary dehumidifying amount is calculated depending upon whether or not the inside/outside air changing over damper  131  is in an inside air admitting condition and in accordance with an amount of a wind of the blower  132 , a relative humidity in the room of the automobile and so forth. Then, at step  420 , the damper  159  is continuously controlled in accordance with the necessary dehumidifying amount. In particular, when the necessary dehumidifying amount is great, air is introduced into the evaporator  207  to increase the dehumidifying amount of the evaporator  207 . Then, after pivoting control of the damper  159  is executed at step  420 , the discharging capacity of the compressor  201  is varied by varying the frequency of the invertor similarly as in the control described hereinabove with reference to FIG. 4, thereby controlling the blown out air temperature. Also in this instance, the air mixing damper  154  is in the fully open condition so that the entire amount of air is flowed into the condenser  203 . 
     Accordingly, with the automotive air conditioner shown in FIG. 11, cooling operation and heating operation can be performed well, and particularly upon heating operation, the heating efficiency can be enhanced by restricting the function of the evaporator  207  to a minimum limit necessary for dehumidification. 
     An automotive air conditioner according to a yet further embodiment of the present invention will be described subsequently with reference to FIG.  13 . The present automotive air conditioner includes fourth check valves  216 ,  217 ,  218  and  219  in place of the second four-way valve  214  described hereinabove. 
     In the following, description will be given of functions of the check valves. When the first four-way valve  213  is at the first connecting position indicated by a solid line in FIG. 13, high pressure refrigerant discharged from the compressor  201  comes to the check valves  216  and  218  by way of the outside heat exchanger  202 . Then, due to a function of the check valve  218 , the refrigerant will not flow to the evaporation pressure regulating valve  208  side but will all flow to the condenser  203  side past the check valve  216 . After then, the refrigerant is decompressed by the decompressing or expanding means  211  and introduced to the evaporation pressure regulating valve  208  and the check valve  219  by way of the evaporator  207 . The check valve  218  on the downstream of the evaporation pressure regulating valve  208  can mechanically flow refrigerant therethrough toward the downstream of the evaporation pressure regulating valve  208 . However, since the downstream of the check valve  218  is in a high pressure condition on the discharging side of the compressor  201  as described hereinabove, the low pressure refrigerant cannot pass the check valve  218 . On the other hand, since the check valve  219  is communicated with the low pressure side of the compressor  201  by way of the accumulator  212 , refrigerant can pass the check valve  219  readily. Accordingly, refrigerant will all be returned to the compressor  201  past the check valve  219 . 
     Subsequently, a flow of refrigerant when the first four-way valve  213  is in the second connecting position indicated by a broken line in FIG. 13 will be described. In this instance, refrigerant in a high pressure condition discharged from the compressor  201  comes to the check valves  219  and  217 . Then, the flow of refrigerant is stopped by the check valve  219 , and consequently, all of the refrigerant flows to the check valve  217  side. Then, the flow of the refrigerant having passed the check valve  217  is stopped by the check valve  216 , and consequently, all of the refrigerant flows to the condenser  203  side. 
     The refrigerant having flowed through the condenser  203  is then put into a low pressure condition when it passes the decompressing means  211  and then flows to the evaporation pressure regulating valve  208  side by way of the evaporator  207 . Thus, since the check valve  219  is acted upon at an end thereof by a high pressure on the discharging side of the compressor  201 , refrigerant after having passed the evaporator  207  cannot pass the check valve  219 . Accordingly, all of the refrigerant passes the check valve  218  past the evaporation pressure regulating valve  208 . The refrigerant having passed the check valve  218  will all flow into the outside heat exchanger  202 . This is because the exit side of the check valve  216  is at a high pressure on the discharging side of the compressor  201  and the refrigerant cannot pass check valve  216 . The refrigerant having passed the outside heat exchanger  202  will thereafter return to the suction side of the compressor  201  by way of the first four-way valve  213 . 
     In this manner, with the automotive air conditioner shown in FIG. 13, the functions of the second four-way valve  213  are substituted by the four check valves  216 ,  217 ,  218  and  219 . Accordingly, electric movable elements can be reduced, and consequently, the automotive air conditioner has an a improved durability. 
     Subsequently, a yet further automotive air conditioner of the present invention will be described with reference to FIG.  14 . 
     In the automotive air conditioners of the foregoing embodiments described hereinabove, only one outside heat exchanger, that is, the heat exchanger  202 , is employed and is either used as a condenser (embodiments shown in FIGS. 1,  3  and  5 ) or is charged over between a function of a condenser and another function of an evaporator (embodiments shown in FIGS. 7,  11  and  13 ). However, in the automotive air conditioner of the embodiment shown in FIG. 14, two outside heat exchangers are provided including an outside condenser  202  and an outside evaporator  210 . Besides, in the automatic air conditioner of the present embodiment, a condensing damper  253  is provided as condensing side varying means so that the flow rate of air to flow into the outside condenser  202  may be varied. Similarly, an evaporating side damper  254  is provided as evaporating side varying means so that the flow rate of air to be sucked into the outside evaporator  210  may be variably controlled. 
     In this manner, in the automotive air conditioner of the embodiment shown in FIG. 14, the two outside heat exchangers are always used individually as a condenser (outside condenser  202 ) and an evaporator (outside evaporator  210 ). Here, the outside condenser  202  is used principally upon cooling operation to cool refrigerant into liquid. Accordingly, preferably the outside condenser  202  is installed, for example, at a front portion of the automobile so that it may meet with a driving wind of the automobile. In the meantime, the outside evaporator  210  is used to evaporate refrigerant principally upon heating. Preferably, the outside evaporator  210  is disposed such that, for evaporation of refrigerant upon heating, it may not meet with a driving wind of the automobile or the like when the temperature of outside air is low. More particularly, preferably the outside evaporator  210  exchanges heat with ventilation air from within the room of the automobile. Therefore, the outside evaporator  210  is disposed intermediately of a flow of ventilation air at a rear location of the room of the automobile. 
     In this manner, with the automotive air conditioner shown in FIG. 14, the outside condenser  202  and the outside evaporator  210  can both be disposed at respective optimum locations. 
     Further, since the dampers  253  and  254  are employed in the present automotive air conditioner, the heat exchanging capacities of the outside heat exchangers  202  and  210  for which no function is required for construction of a refrigerating cycle can be minimized. For example, it is demanded, upon cooling operation, that refrigerant be evaporated only at the evaporator  207 , and in this instance, the evaporator damper  254  closes the outside evaporators  214  and  210  so that a flow of air may not flow into the outside evaporator  210 . On the other hand, upon heating operation, it is desirable that condensation of refrigerant be performed in the condenser  203  disposed in the duct  100 , and in this instance, the condensing damper  253  closes the outside condenser  202 . 
     Those conditions will be described with reference to the Mollier charts of FIGS. 15 and 16. FIG. 15 illustrates a cooling condition, in which refrigerant compressed to a high pressure by the compressor  201  is first condensed by the outside condenser  202  and then condensed by the condenser  203  disposed in the duct  100 . Further, in this condition, the outside evaporator  210  is substantially prevented from performing heat exchanging by the evaporation damper  254 , and consequently, evaporation of refrigerant is performed only by the inside evaporator  207 . 
     On the other hand, FIG. 16 shows a heating condition. In this condition, the condensing damper  253  closes the outside condenser  202 , and consequently, condensation of refrigerant is performed only by the inside condenser  203 . The evaporating pressure of the evaporator  207  is regulated by the evaporation pressure regulating valve  208 , and evaporation of refrigerant which has been further decompressed upon passing through the evaporation pressure regulating valve  208  is performed by the outside evaporator  210 . 
     In the automotive air conditioner shown in FIG. 14, in addition to the discharging capacity of the compressor  210 , the opening of the air mixing damper  154  and the opening of the bypass damper  159 , also the openings of the condensing side damper  253  and the evaporating side damper  254  are controlled by the controller  300 . The openings and the capacity are controlled principally in accordance with an aimed blown out air temperature Tao calculated in accordance with values inputted from the various sensors. A concept of the control is illustrated in FIG.  17 . The axis of abscissa of FIG. 17 indicates the aimed blown out air temperature Tao, which increases in the rightward direction in FIG.  17 . In particular, a heating condition is shown at a right-hand side portion while a cooling condition is shown at a left-hand side portion of FIG.  17 . 
     The location A in FIG. 17 shows a maximum cooling condition, in which the capacity of the compressor  210  presents its maximum and the amount of pivotal motion of the air mixing damper  154  is 0, that is, no air is blown to the condenser  203 . Meanwhile, the amount of pivotal motion of the bypass damper  159  is at its 100%, and consequently the entire amount of air passes the evaporator  207 . Further, the condensing side varying means  253  is open to allow air to be admitted into the outside condenser  202 . In the meantime, the damper  254  on the evaporating side varying means is closed so that no air is admitted into the outside evaporator  210 . When the cooling capacity required for the automotive air conditioner decreases (point B in FIG. 17) as the cooling load decreases after then, the capacity of the compressor  201  is decreased first. In particular, the speed of rotation of the compressor driving motor is lowered to decrease the cooling capacity so that the temperature of air on the exit side of the evaporator  207  is raised. Consequently, power saving operation is achieved first. After the capacity of the compressor  210  is minimized, the air mixing damper  154  begins to open (point C in FIG. 17) so that air may be re-heated by the condenser  203 . 
     As the aimed blown out air temperature Tao further rises (point D in FIG.  17 ), the bypass damper  159  begins to close so that air may be flowed to the condenser  203  side bypassing the evaporator  207 . This condition corresponds to dehumidifying operation principally in autumn and winter and in an intermediate time. 
     As the aimed blown out air temperature Tao further rises (point E in FIG. 17) after then, the operation mode of the automotive air conditioner is changed over from cooling operation to heating operation. In particular, the damper  253  which is the condensing side varying means is closed to stop the function of the outside condenser  202 . Meanwhile, the damper  254  which is the evaporating side varying means is opened to cause the outside evaporator  210  to function. 
     Then, the discharging capacity of the compressor  201  is raised as the aimed blown out air temperature Tao rises to raise the condensing temperature at the condenser  203  (points F to G in FIG.  17 ). It is to be noted that, in the heating condition, when the aimed blown out air temperature Tao is comparatively low, the bypass damper  159  is held in a somewhat open condition so that dehumidifying operation can be performed simultaneously 
     Then, in maximum heating operation (point H in FIG.  17 ), the discharging capacity of the compressor  201  presents it maximum and the air mixing damper  154  introduces the entire amount of a flow of air into the condenser  203 . Meanwhile, the bypass damper  159  closes the evaporator  207  so that air may be flowed to the condenser  203  side bypassing the evaporator  207 . Further, the evaporating side varying means  253  stops the function of the outside condenser  202  while the evaporating side varying means  254  causes the outside evaporator  210  to function. 
     It is to be noted that, while, in the control described hereinabove with reference to FIG. 17, the condensing side damper  253  and the evaporating side damper  254  are individually changed over between the fully closed condition and the fully open condition, pivotal motion of the dampers  253  and  254  may otherwise be controlled continuously if necessary. Further, while, in the automotive air conditioner described above, the air mixing damper  154  begins to open after the discharging capacity of the compressor  201  has been minimized, the point of time at which the air mixing damper  154  begins to open may be advanced. In other words, the components described above can be changed suitably if necessary. 
     Further, while, in the automotive air conditioner shown in FIG. 14, the dampers  253  and  254  are employed as condensing side varying means and evaporating side varying means, respectively, alternatively a condensing fan  261  may be provided as condensing side varying means while an evaporating fan  252  is provided as evaporating side varying means as shown in FIG.  18 . In particular, the heat exchanging functions of the outside condenser  202  and the outside evaporator  210  may be varied by controlling rotation of the fans  251  and  252 , respectively. 
     It is to be noted that, while the bypass passageway  150  is formed sidewardly of the condenser  203  in the automotive air conditioner described above, alternatively the entire amount of air in the duct  100  may pass the condenser  203  as seen from FIG.  20 . 
     A pair of auxiliary heaters  700  and  701  are disposed on the downstream of the condenser  203  in the duct  100 . Each of the auxiliary heaters  700  and  701  may be formed from a PCT heater or an electric heater. In the automotive air conditioner shown in FIG. 20, cooling operation, dehumidifying operation and heating operation are achieved individually by controlling flow rates of refrigerant into the evaporator  207  and the condenser  203  both disposed in the duct  100 . 
     Referring now to FIG. 21, there is shown a refrigerating cycle of the automotive air conditioner shown in FIG.  20 . In the refrigerating cycle shown, the four-way valve  213  changes over, upon energization thereof, the refrigerating passage in such a manner as indicated by a solid line, but changes over, upon deenergization thereof, to such a manner as indicated by a broken line. Further, the outside heat exchanger  202  includes a fan  251 . 
     In the present refrigerating cycle, the four-way valve  213  and the solenoid valves  260  and  261  are suitably changed over to control a flow of refrigerant to achieve various air conditioning operation. First, a cooling operation condition will be described. In this condition, the four-way valve  213  is energized so that refrigerant discharged from the compressor  201  is flowed to the outside heat exchanger  202  side by way of the four-way valve  213  and the check valve  262 . Here, the refrigerant meets with a wind from the fan  251  so that it is condensed in the outside heat exchanger  202  while remaining in a high temperature, high pressure condition. Meanwhile, the solenoid valve  261  remains closed in this condition, and accordingly, the refrigerant condensed in the outside heat exchanger  202  flows into the expanding means  211  and is decompressed and expanded into mist in a low temperature, low pressure condition when it passes the expanding means  211 . The refrigerant in the form of mist then flows into the evaporator  207 , in which it is evaporated, whereupon it takes heat of vaporization away from conditioning air to cool the air. 
     Then, the refrigerant evaporated in the evaporator  207  is sucked into the compressor  210  again by way of the accumulator  212 . It is to be noted that, in this instance, since the refrigerant passage is communicated at a branching point  264  on the upstream of the accumulator  212  with the condenser  203  side by way of the four-way valve  213 , the check valve  265  positioned on the downstream of the condenser  203  closes the refrigerating passage in accordance with a difference in pressure, and consequently, substantially no refrigerant will flow into the condenser  203 . 
     It is to be noted that there is no possibility that part of refrigerant having flowed to the condenser  203  side may be liquefied and accumulated in the condenser  203 . This is because refrigerant in the condenser  203  is sucked into the compressor  201  by way of the four-way valve  213 . 
     Subsequently, a flow of refrigerant when the automotive air conditioner operates as a heating apparatus will be described. In this instance, the compressor  201  and the condenser  203  are communicated with each other by way of the four-way valve  213 . Meanwhile, the solenoid valve  260  is closed to cause refrigerant to flow to a capillary element  266  side. Further, the solenoid valve  261  is opened to cause refrigerant from the outside heat exchanger  202  to flow to the accumulator  212  side. 
     Accordingly, upon heating operation, refrigerant put into a high temperature, high pressure condition by the compressor  201  flows by way of of the four-way valve  213  into the condenser  203 , in which it exchanges heat with air from the blower  132 . In this instance, since the condensing temperature is 40 to 60° C. or so, air passing in the duct  100  is heated when it passes the condenser  203 . The refrigerant condensed in the condenser  203  is subsequently decompressed and expanded, when it passes the capillary element  266 , into mist of a low temperature and a low pressure. The refrigerant mist then flows into the outside heat exchanger  202  by way of the check valve  265 . The outside heat exchanger  202  acts as an evaporator, and in the outside heat exchanger  202 , the refrigerant exchanges heat with air supplied thereto from the blower  251  so that it is evaporated. The refrigerant having passed the outside heat exchanger  202  can flow to both of the solenoid valve  261  side and the capillary tube  211  side, but since the communication resistance is higher on the capillary tube  211  side, the refrigerant flows, as a result, into the accumulator  212  by way of the solenoid valve  261  past the branching point  264 . It is to be noted that, while the refrigerant passage is communicated with the four-way valve  213  at the branching point  264 , the refrigerant will not circulate into the outside heat exchanger  202  again due to a difference in pressure. 
     Subsequently, a dehumidifying operation condition of the present automotive air conditioner will be described. In this instance, the solenoid valve  260  is opened and the solenoid valve  261  is closed in such a heating operation condition as described hereinabove. Consequently, refrigerant partially condensed in the outside heat exchanger  202  is decompressed at the capillary tube  211  and flows, in this condition, into the evaporator  207 . Then, in the evaporator  207 , the refrigerant will be evaporated to cool air blasted thereto from the blower  132 . 
     Accordingly, in the dehumidifying operation, air is cooled once in the evaporator  207  and then heated in the condenser  203 . Consequently, when the air passes the evaporator  207 , the saturation evaporating temperature drops to cause moisture in the air to be condensed and adhere to a surface of the evaporator  207 . Then, since the air is re-heated in this condition when it passes the condenser  203 , the relative humidity is dropped remarkably, and consequently, good dehumidification is performed. 
     FIGS. 22,  23  and  24  are Mollier charts illustrating cooling operation, heating operation and dehumidifying operation, respectively, of the refrigerating cycle shown in FIG.  21 . As described above, upon cooling operation, the outside heat exchanger  202  acts as a condenser while an evaporating action is performed in the evaporator  207 . On the other hand, upon heating operation, refrigerant is condensed in the condenser  203  while the outside heat exchanger  202  acts as an evaporator. 
     It is to be noted that the difference in evaporating pressure between FIGS. 22 and 23 arises from the fact that the temperature of air flowing into the evaporator  207  upon cooling is higher than the temperature of air flowing into the outside heat exchanger  202  upon heating. 
     On the other hand, as seen from FIG. 24, upon dehumidifying operation, condensation of refrigerant is performed by the condenser  203  and the outside heat exchanger  202  while evaporation of refrigerant is performed by the evaporator  207 . In this instance, the enthalpy is higher at the evaporator  207  than at the condenser  203 , but since condensation of moisture in air proceeds in the evaporator  207 , the temperature of air is not lowered very much when it passes the evaporator  207  due to latent heat involved in the condensation of water. Meanwhile, since the enthalpy of the condenser  203  is all used to raise the temperature of air, the temperature of air having passed both of the evaporator  207  and the condenser  203  either has a substantially same level or is raised as a result. 
     Subsequently, control of the temperature of air of the automotive air conditioner upon dehumidifying operation will be described. FIGS. 25,  26  and  27  are Mollier charts all illustrating operating conditions upon dehumidifying operation, and FIG. 25 shows a Mollier chart upon normal operation. In the normal operation, the blower  251  is rotated weakly so that a predetermined amount of air is blasted to the outside heat exchanger  202  to assure heat exchanging at the outside heat exchanger  202 . As a result, the air temperature lowering capacity of the evaporator  207  substantially coincides with the air temperature raising capacity of the condenser  203 , and air having passed both of the evaporator  207  and the condenser  203  raises its temperature a little. 
     FIG. 26 shows a condition wherein it is desired to raise the blown out air temperature in dehumidifying operation. In this instance, the blower  251  stops its action in order to reduce the heat exchanging capacity of the outside heat exchanger  202 . As a result, the condensing capacity is decreased generally while the condensing pressure is increased. As the condensing pressure rises, the temperature of air when it passes the condenser will be raised. 
     FIG. 27 shows another condition wherein it is desired to lower the blown out air temperature in dehumidifying operation. In this instance, the blower  251  for the outside heat exchanger  202  is rotated at a high speed to raise the condensing capacity of the outside heat exchanger  202 . As a result, the condensing pressure is lowered, and air cooled when it passes the evaporator  207  will be blown out into the room of the automobile without being heated very much. 
     It is to be noted that, in the case of FIG. 27, since the total condensing capacity of the outside heat exchanger  202  and the condenser  203  is increased, the condensing pressure in the refrigerating cycle is lowered, and as a result, also the evaporating pressure at the evaporator  207  is lowered. Consequently, there is the possibility that frost may appear on the evaporator  207 . Therefore, in this instance, the speed of rotation of the compressor  201  is controlled so that dehumidifying operation may continuously proceed without lowering the pressure in the evaporator  207 , that is, the sucking pressure of air into the compressor  201 , very much. 
     Subsequently, defrosting of the outside heat exchanger  202  upon heating operation will be described. As described hereinabove, since the outside heat exchanger  202  functions as an evaporator in heating operation, particularly when the temperature of outside air is low, the temperature of a surface of the outside heat exchanger  202  becomes lower than the freezing point and frost adheres to the outside heat exchanger  202 . Then, if frost adheres in this manner, the heat exchanging function of the outside heat exchanger  202  is deteriorated remarkably so that good operation of the refrigerating cycle cannot be achieved and consequently heating operation of the condenser  203  is not performed. Thus, in this instance, refrigerant in a high temperature, high pressure condition will be passed through the outside heat exchanger  202  to melt the frost adhering to the outside heat exchanger  202 . In the dehumidifying operation, operation of the outside blower  251  is stopped first. Meanwhile, the inside blower  132  is rotated at a low speed. Then, the inside/outside air changing over damper  131  is put into an inside air admitting condition so that the temperature of blown out air from the duct  100  may not be lowered. Further, power is made available simultaneously to the auxiliary heater  700  and  701 . In this condition, the solenoid valve  260  is opened while the solenoid valve  261  is closed. Consequently, refrigerant having passed the compressor  201  flows into the condenser  203  and the outside heat exchanger  202  while it remains in a high temperature, high pressure condition. As a result, the temperature of the outside heat exchanger  202  rises and frost adhering to the surface of the outside heat exchanger  202  will be melted. The refrigerant condensed in the outside heat exchanger  202  is then decompressed and expanded in the capillary tube  211  and then flows into the evaporator  207 . As a result, the temperature of air in the duct  100  becomes low, but since, in this condition, the amount of a wind of the blower  132  is small and the auxiliary heaters  700  and  701  can work to the utmost, remarkable deterioration of the blown out air temperature can be prevented. 
     Further, in order to accomplish defrosting of the outside heat exchanger  202  in a short period of time, the compressor  201  has a capacity as high as possible and the invertor thereof has a frequency as high as possible. 
     It is to be noted that, when defrosting operation is proceeding in this manner, a lamp may be lit so that this may be recognized by a passenger of the automobile. 
     Further, when operation of the automotive air conditioner is automatic operation, changing over between heating operation and defrosting operation is performed in accordance with the following conditions: 
     (1) The temperature of the outside heat exchanger  202  is lower by 10° C. or more than the temperature of outside air; 
     (2) The temperature of the outside heat exchanger  202  is lower than −3° C. or so; and 
     (3) Heating operation has continued for longer than a predetermined period of time (60 minutes). 
     Whether or not defrosting is required is judged in accordance with the conditions. 
     FIG. 28 shows a yet further automotive air conditioner according to the present invention. The present automotive air conditioner adopts a three-way valve  269  in place of the four-way valve  213  of the automotive air conditioner shown in FIG.  21 . In addition, a solenoid valve  268  is disposed in a cooling pipe adjacent the branching point on the upstream of the accumulator  212 . 
     Upon cooling operation, the three-way valve  269  is changed over to a position indicated by a solid line so that refrigerant discharged from the compressor  201  may be introduced to the outside heat exchanger  202 . In this instance, the outside heat exchanger  202  acts as a condenser, and refrigerant decompressed and expanded in the capillary tube  211  is then supplied to the evaporator  207 . The refrigerant evaporated in the evaporator  207  is fed back to the accumulator  212  side past the branching point  264 . The solenoid valve  268  opens the refrigerant pipe upon cooling operation. Consequently, also refrigerant accumulated in the condenser  203  is supplied, due to sucking action of the compressor  201 , from the refrigerant pipe to the compressor  201  side by way of the solenoid valve  268  and the branching point  264 . In this instance, the pressure of refrigerant in the condenser  203  is decreased suddenly so that also the evaporating temperature of the refrigerant is lowered. Consequently, immediately after starting of cooling operation, also refrigerant accumulated in the condenser  203  is evaporated thereby to complement the cooling capacity. On the other hand, upon heating operation, the three-way valve  269  is changed over so that refrigerant discharged from the compressor  201  is now introduced into the condenser  203 . Further, the solenoid valve  260  is closed so that refrigerant condensed in the condenser  203  is supplied to the outside heat exchanger  202  by way of the capillary element  266 . Meanwhile, the solenoid valve  261  is opened so that refrigerant evaporated in the outside heat exchanger  202  is sucked from the solenoid valve  261  toward the accumulator  212  side. In this instance, the solenoid valve  268  is in a closed condition, and refrigerant discharged from the compressor  201  is prevented from being short-circuited to be sucked to the accumulator  212  side. 
     Upon dehumidifying operation, the three-way valve  296  introduces refrigerant discharged from the compressor  201  to the condenser  203 . Meanwhile, the solenoid valve  260  opens the refrigerant passage so that refrigerant of a high pressure is supplied from the condenser  203  to the outside heat exchanger  202 . Then, the solenoid valve  261  is closed so that refrigerant condensed by the condenser  203  and the outside heat exchanger  202  is supplied to the evaporator  207  by way of the capillary tube  211 . 
     It is to be noted that actions in defrosting operation and dehumidifying operation of the automotive air conditioner of FIG. 28 are similar to those of the automotive air conditioner shown in FIG.  21 . 
     FIG. 29 shows a yet further automotive air conditioner according to the present invention. The present automotive air conditioner employs a pair of solenoid valves  270  and  271  in place of the three-way valve  269  of the automotive air conditioner of FIG.  28 . Actions in cooling operation, heating operation and dehumidifying operation are similar to those of the automotive air conditioner of FIG.  28 . 
     FIG. 30 shows a yet further automotive air conditioner according to the present invention. The present automotive air conditioner employs a single three-way valve  272  in place of the two solenoid valves  270  and  268  of the automotive air conditioner of FIG.  29 . 
     FIG. 31 shows a yet further automotive air conditioner according to the present invention. The present automotive air conditioner is constructed such that the operation thereof between cooling operation and heating operation is performed by changing over of the four-way valve  213 . 
     In particular, upon cooling operation, the four-way valve  213  introduces high pressure refrigerant discharged from the compressor  201  into the outside heat exchanger  202 . The refrigerant condensed in the outside heat exchanger  202  is decompressed and expanded in the capillary tube  211  and supplied to the evaporator  207 . It is to be noted that a back flow of the refrigerant to the condenser  203  side then is prevented by a check valve  273 . Then, the refrigerant evaporated in the evaporator  207  is sucked into the compressor  201  by way of the accumulator  212 . 
     On the other hand, upon heating, the four-way valve  213  is changed over so that refrigerant discharged from the compressor  201  is supplied to the condenser  203 . Then, the refrigerant condensed in the condenser  203  is decompressed and expanded when it passes the capillary element  266 , and after then, it flows to the branching point  274  by way of the check valve  273 . Most of the refrigerant coming to the branching point  274  flows to the outside heat exchanger  202  side due to a difference in pressure. Meanwhile, part of the refrigerant flows to the evaporator  207  by way of the capillary, tube  211 . Then, the refrigerant evaporated in the outside heat exchanger  202  and the evaporator  207  is supplied to the accumulator  213  and then fed back to the compressor  201 . 
     In such heating operation, refrigerant will not flow much to the evaporator  207  side due to a resistance of the capillary tube  211 . However, some refrigerant is supplied to the evaporator  207 , at which part of the refrigerant is evaporated. Consequently, even during heating, some dehumidifying operation is achieved. 
     FIG. 32 shows a yet further automotive air conditioner according to the present invention. In the present automotive air conditioner, changing over of a cycle is performed by the single four-way valve  213  and a single on/off solenoid valve  290 . Upon cooling operation, the four-way valve  213  is changed over to a position indicated by a solid line in FIG.  32  and the solenoid valve  290  is opened. As a result, refrigerant discharged from the compressor  201  is condensed in the outside heat exchanger  202  and then decompressed and expanded in the capillary tube  211 , whereafter it flows into the evaporator  207 . Then, the refrigerant cools air by an evaporating action of the evaporator  207 . On the other hand, upon heating, the four-way valve  213  is changed over to another position indicated by a broken line in FIG. 32, and also the solenoid valve  290  is put into an open condition. As a result, refrigerant discharged from the compressor  201  is condensed in the condenser  203  and then decompressed and expanded in the capillary  266 . After then, the refrigerant passes the check valve  273  and then flows mainly to the outside heat exchanger  202  side due to a difference in pressure. Meanwhile, part of the refrigerant flows into the evaporator  207  by way of the capillary tube  211 . Then, the refrigerant having passed the outside heat exchanger  202  and the evaporator  207  is collected into the accumulator  212  and then fed back into the compressor  201 . In this condition, since some refrigerant flows into the evaporator  207 , dehumidifying operation is performed suitably upon heating. 
     Further, when dehumidifying operation is to be performed, the four-way valve  213  is changed over similarly as upon heating operation described above, and the solenoid valve  290  is opened and closed at suitable timings. When the solenoid valve  290  closes the refrigerant passage, refrigerant flows into the evaporator  207  by way of the capillary tube  211  so that the cooling capacity of the evaporator  207  is increased. Consequently, the dehumidifying function of the evaporator  207  is increased. Then, a required dehumidifying amount is obtained by suitably changing over the opening/closing operation of the solenoid valve  290  at a suitable duty ratio. Upon dehumidifying operation, the solenoid valve  290  may be held closed normally. 
     FIG. 33 shows a yet further automotive air conditioner according to the present invention. Upon cooling operation, the four-way valve  213  is changed over to a position indicated by a solid line in FIG.  33  and the solenoid valve  203  opens its refrigerant pipe while the solenoid valve  294  closes its refrigerant pipe. Meanwhile, the solenoid valve  291  opens its refrigerant pipe. It is to be noted that the solenoid valve  292  performs opening and closing operations of the refrigerant pipe suitably in accordance with a required cooling capacity. Accordingly, in this condition, refrigerant discharged from the compressor  201  flows into the outside heat exchanger  202  by way of the four-way valve  213  and the solenoid valve  293  and is condensed in the outside heat exchanger  202 . After then, the refrigerant passes the solenoid valve  291  and is decompressed and expanded in the capillary tube  211 , whereafter it is evaporated in the evaporator  207 . After then, it passes the accumulator  212  and is fed back to the compressor  201 . 
     Upon heating operation, the four-way valve  213  is changed over to another position indicated by a broken line in FIG.  33  and the solenoid valve  291  closes its refrigerant pipe. Meanwhile, the solenoid valve  292  opens its refrigerant pipe; the solenoid valve  293  opens its refrigerant pipe; and the solenoid valve  294  closes its refrigerant pipe. As a result, refrigerant discharged from the compressor  201  flows into the condenser  203  by way of the four-way valve  213  and is then decompressed and expanded in the capillary element  266 , whereafter it is evaporated in the outside heat exchanger  202 . After then, it is fed back to the compressor  201  by way of the solenoid valve  293 , the four-way valve  213  and the accumulator  212 . 
     Subsequently, dehumidifying operation will be described. In this instance, both of the solenoid valves  291  and  294  are opened. As a result, refrigerant discharged from the compressor  201  is divided into a flow which then is liquefied in the condenser  203  and flows to the evaporator  207  by way of the capillary  211  and another flow which then flows by way of the solenoid valve  294  into the outside heat exchanger  202 , in which it is liquefied, whereafter it flows to the evaporator  207  by way of the solenoid valve  291  and the capillary tube  211 . In particular, condensation of refrigerant is performed in parallel by the condenser  203  and the outside heat exchanger  202 . Then, the refrigerant evaporated in the evaporator  207  flows into the accumulator  212  by way of the refrigerant pipe. 
     Here, upon such dehumidifying operation, the condensing pressure can be controlled by varying the heat exchanging capacity of the outside heat exchanger  202 . The capacity control of the outside heat exchanger  202  is performed by varying the amount of blown out air by the blower  251 . Alternatively, a damper for the outside heat exchanger  202  may be provided in place of the blower  251 . Further, the opening and closing times of the solenoid valve  294  may be controlled to control the condensing pressure, that is, the blown out air temperature. 
     FIG. 34 shows a yet further automotive air conditioner according to the present invention. In the present automotive air conditioner, cooling operation, heating operation and dehumidifying operation are selectively performed by suitably changing over solenoid valves  295 ,  296  and  297 . First, cooling operation will be described. In this instance, the solenoid valve  295  closes its refrigerant passage while the solenoid valve  296  opens its refrigerant passage and also the solenoid valve  297  opens its refrigerant passage. Further, the four-way valve  213  is changed over to a position indicated by a broken line. Consequently, refrigerant discharged from the compressor  201  flows by way of the four-way valve  213  into the outside heat exchanger  202 , in which it exchanges heat with outside air so that it is condensed. The refrigerant then flows into the solenoid valve  296  by way of the check valve  280  and then passes the capillary element  266 , whereupon it is decompressed and expanded. After then, the refrigerant flows into the evaporator  207 , in which it takes heat of vaporization away from air so that is it evaporated. After then, the refrigerant flows into the accumulator  212  by way of the solenoid valve  297  and the four-way valve  213 . 
     On the other hand, upon heating, the solenoid valve  295  opens its refrigerant pipe while the solenoid valve  296  closes its refrigerant pipe and also the solenoid valve  297  closes its refrigerant pipe. Further, the four-way valve  213  is changed over to another position indicated by a solid line in FIG.  34 . Consequently, upon heating operation, refrigerant discharged from the compressor  201  successively passes the four-way valve  213 , the check valve  281  and the solenoid valve  295  and is then condensed in the condenser  203 . After then, the refrigerant is decompressed and expanded when it passes the capillary tube  211 , and then flows into the outside heat exchanger  202  by way of the check valve  282 . Then, the refrigerant is evaporated in the outside heat exchanger  202  and is fed back into the compressor  201  by way of the four-way valve  213  and the accumulator  212 . 
     Subsequently, dehumidifying operation will be described. In this instance, the solenoid valve  295  is opened while the solenoid valve  296  is closed and also the solenoid valve  297  is closed. Then, the four-way valve  213  is changed over to the position indicated by the broken line in FIG.  34 . Accordingly, refrigerant discharged from the compressor  201  flows by way of the four-way valve  213  into the outside heat exchanger  202 , in which it is condensed. Further, the refrigerant flows by way of the check valve  280  and the solenoid valve  295  into the compressor  203 , in which it is condensed. Then, when the refrigerant passes the capillary tube  211 , it is decompressed and expanded into a low temperature, low pressure condition and then flows, in this condition, into the evaporator  207 . The refrigerant is evaporated in the evaporator  207  and then fed back into the compressor  201  by way of the solenoid valve  297 , the four-way valve  313  and the accumulator  212 . Accordingly, in the automotive air conditioner shown in FIG. 34, upon dehumidifying operation, condensation of refrigerant is performed by the outside heat exchanger  202  and the condenser  203 , and the blown out air temperature is controlled by controlling the amount of blown out air by the blower  251  to control the heat exchanging capacity of the outside heat exchanger  202  to vary the condensing pressure of the condenser  203 . 
     In particular, in the automotive air conditioner shown in FIG. 34, upon dehumidifying operation, refrigerant flows first into the outside heat exchanger  202  and then into the condenser  203 . On the other hand, in the automotive air conditioner shown in FIG. 21, refrigerant flows first into the condenser  203  and then into the outside heat exchanger  202 . Here, in case refrigerant flows first into the condenser  203 , the refrigerant having high superheat immediately after discharged from the compressor  201  flows into the condenser  203 , and consequently, the blown out air temperature from the condenser  203  becomes higher and dehumidification having some heating effect can be performed. 
     FIG. 35 shows a yet further automotive air conditioner according to the present invention. In the present automotive air conditioner, the operation is changed over among cooling operation, heating operation and dehumidifying operation by means of the four-way valve  213  and a solenoid valve  298 . 
     First, in cooling operation, the four-way valve  213  is changed over to a position indicated by a broken line in FIG. 35, and the solenoid valve  298  opens its passage. As a result, refrigerant discharged from the compressor  201  flows by way of the four-way valve  213  into the outside heat exchanger  202 , in which it is condensed. Then, the condensed refrigerant passes the check valve  283  and the solenoid valve  298  and is then decompressed and expanded in the capillary tube  211 . After then, the refrigerant is evaporated in the evaporator  207  and is fed back into the compressor  201  by way of the accumulator  212 . 
     On the other hand, upon heating operation, the four-way valve  213  is changed over to another position indicated by a solid line in FIG. 35, and the solenoid valve  298  closes its refrigerant pipe. Accordingly, refrigerant discharged from the compressor  201  flows by way of the four-way valve  213  into the condenser  203 , in which it is condensed. After then, the refrigerant flows by way of the check valve  294  into the capillary element  266 , in which it is decompressed and expanded, whereafter it flows into the outside heat exchanger  202 . Then, the refrigerant is evaporated in the outside heat exchanger  202  and then is fed back into the compressor  201  by way of the four-way valve  213  and the accumulator  212 . 
     Upon dehumidifying operation, the four-way valve  213  is changed over similarly to the position indicated by the solid line in FIG. 35, and the solenoid valve  298  opens its refrigerant pipe. Consequently, refrigerant discharged from the compressor  201  flows into the condenser  203 , in which it is condensed and liquefied. The refrigerant liquefied in the condenser  203  is then divided into a flow which flows into the outside heat exchanger  202  by way of the capillary  266  and another flow which flows into the evaporator  207  by way of the solenoid valve  298  and the capillary tube  211 . Thus, the refrigerant is evaporated in the outside heat exchanger  202  and the evaporator  207 . The thus evaporated refrigerant is collected into the accumulator  212  again and is then fed back into the compressor  201 . In this manner, upon dehumidifying operation, refrigerant flows in parallel through the outside heat exchanger  202  and the evaporator  207 , and control of the dehumidifying capacity then is achieved by controlling the blower  251  to vary the heat exchanging capacity of the outside heat exchanger  202 . 
     FIG. 36 shows a yet further automotive air conditioner according to the present invention. The present automotive air conditioner is a modification to the automotive air conditioner shown in FIG. 35 in that it additionally includes a refrigerant pipe which interconnects, upon dehumidifying operation, the downstream of the outside heat exchanger  202  and the evaporator  207  and further includes a solenoid valve  299  and another solenoid valve  289  for controlling flows of refrigerant. Operations upon cooling operation and heating operation are similar to those of the refrigerating cycle described hereinabove with reference to FIG.  35 . Upon dehumidifying operation, the solenoid valve  299  is opened while the solenoid valve  289  is closed, and in this instance, refrigerant is evaporated in both of the outside heat exchanger  202  and the evaporator  207  similarly as in the refrigerating cycle shown in FIG.  35 . However, in case, upon dehumidifying operation, the solenoid valve  298  is closed and also the solenoid valve  299  is closed while the solenoid valve  289  is opened, refrigerant flows in series through the outside heat exchanger  202  and the evaporator  207 . In particular, in this condition, refrigerant discharged from the compressor  201  flows by way of the four-way valve  213  into the condenser  203 , in which it is condensed. The thus condensed refrigerant flows by way of the check valve  284  into the capillary element  266 , in which it is decompressed and expanded, whereafter it is evaporated in the outside heat exchanger  202 . After then, the refrigerant flows by way of the solenoid valve  289  into the evaporator  207 , in which it is evaporated similarly. Then, the thus evaporated refrigerant is fed back into the compressor  201  again by way of the accumulator  212 . In this manner, the cycle shown in FIG. 36 can be changed over, upon dehumidifying operation, between a condition wherein refrigerant condensed by the condenser  203  is admitted in parallel into both of the evaporator  207  and the outside heat exchanger  202  and another condition wherein the outside heat exchanger  202  and the evaporator  207  are disposed in series so that refrigerant is evaporated in both of them. 
     FIG. 37 shows a yet further automotive air conditioner according to the present invention. In the present automotive air conditioner, the evaporator  207  and the outside heat exchanger  202  are also disposed in series upon dehumidifying operation, but the order in arrangement of them is reverse to that in the automotive air conditioner shown in FIG.  36 . In particular, while, in the refrigerating cycle shown in FIG. 36, the outside heat exchanger  202  and the evaporator  207  are connected in series upon dehumidifying operation such that the outside heat exchanger  202  may be positioned on the upstream side, in the refrigerating cycle shown in FIG. 37, the evaporator  207  and the outside heat exchanger  202  are connected such that the evaporator  207  may be positioned on the upstream side of the outside heat exchanger  202 . 
     Subsequently, the refrigerating cycle shown in FIG. 37 will be described. First, upon cooling operation, the four-way valve  213  is changed over to a position indicated by a broken line in FIG. 37, and the solenoid valve  288  closes its refrigerant passage while the solenoid valve  298  opens its refrigerant passage. Accordingly, refrigerant discharged from the compressor  201  flows by way of the four-way valve  213  into the outside heat exchanger  202 , in which it is condensed. The thus liquefied refrigerant flows through the check valve  213  and the solenoid valve  298  into the capillary tube  211 , and it is decompressed and expanded when it passes the capillary tube  211 . Then, the refrigerant is evaporated in the evaporator  207  and then flows into the accumulator  212  by way of the four-way valve  213 , whereafter it is fed back into the compressor  201 . 
     On the other hand, upon heating operation, the four-way valve  213  is changed over to another Position indicated by a solid line in FIG. 37, and the solenoid valve  288  is opened while the solenoid valve  298  is closed. Accordingly, in this condition, refrigerant discharged from the compressor  201  flows into the condenser  203  by way of the four-way valve  213 . Then, the refrigerant condensed in the condenser  203  flows into the capillary element  266  by way of the solenoid valve  288  and is deompressed and expanded when it passes the capillary element  266 . After then, the refrigerant is evaporated in the outside heat exchanger  202 , and then the thus evaporated refrigerant flows into the accumulator  212  by way of the four-way valve  213 , whereafter it is fed back to the compressor  201  again. 
     Further, upon dehumidifying operation, the four-way valve  213  is changed over to the position indicated by the solid line in FIG.  37  and the solenoid valve  298  is opened while the solenoid valve  288  is closed. Accordingly, refrigerant discharged from the compressor flows through the four-way valve  213  into the condenser  203 , in which it is condensed and liquefied. After then, the refrigerant flows through the solenoid valve  298  into the capillary tube  211  and is decompressed and expanded when it passes the capillary tube  211 . After then, the refrigerant flows into the evaporator  207 , in which it is evaporated. After then, the refrigerant flows through the check valve  286  into the outside heat exchanger  202 , in which it is further evaporated. Then, the refrigerant is fed back into the compressor  201  by way of the four-way valve  213  and the accumulator  212 . Accordingly, upon such dehumidifying operation, refrigerant is evaporated in both of the evaporator  207  and the outside heat exchanger  202 , and besides the evaporator  207  is located on the upstream side of the outside heat exchanger  202 . 
     Here, it is suitably selected in accordance with the necessity, when the outside heat exchanger  202  and the evaporator  207  are disposed in series upon dehumidifying operation, which one of them is located on the upstream side. However, in a cycle which includes the accumulator  212 , there is no significant difference in function whichever one of them is disposed on the upstream side. In particular, since the outside heat exchanger  202  and the evaporator  207  do not present different evaporating pressures while the temperatures of air admitted into them are different from each other, the evaporating capacity of the evaporator  207  is equal whether it is located on the upstream side or on the downstream side. 
     FIG. 38 shows a yet further automatic air conditioner according to the present invention. In the present automotive air conditioner, the evaporator  207  includes a damper  159  having a variable capacity. Upon cooling operation and upon dehumidifying operation, the damper  159  opens the duct  100  so that air may be admitted into the evaporator  207 , but upon heating operation, the damper  159  is closed so that air may not be admitted into the evaporator  207 . Meanwhile, a flow of refrigerant to the condenser  203  is changed over by the three-way valve  213  and the solenoid valve such that refrigerant may be condensed, upon heating operation and upon dehumidifying operation, in the condenser  203 , but refrigerant may flow, upon cooling operation, directly to the outside heat exchanger  202  bypassing the condenser  203 . 
     FIG. 39 shows a yet further automatic air conditioner according to the present invention. While a flow of refrigerant is changed over, in the automatic air conditioner shown in FIG. 38, between the condenser  203  side and the other side bypassing the condenser  203 , in the automatic air conditioner shown in FIG. 39, the capacity of the condenser  203  is changed over by means of the damper  154 . In particular, upon dehumidifying operation and upon heating, the damper  154  opens the duct  100  so that air may be admitted into the condenser  203 , but upon cooling operation, the damper  154  is closed so that air may not be admitted into the condenser  203 . However, even during cooling operation, when the damper  154  operates as an air mixing damper for varying the blown out air temperature, the damper  154  opens its passage in response to a necessary blown out air temperature so that part of air may be re-heated. 
     FIG. 40 shows a yet further automatic air conditioner according to the present invention. The present automatic air conditioner includes, similarly to the automatic air conditioner described hereinabove with reference to FIG. 13, the dampers  154  and  159  for both of the condenser  203  and the evaporator  207 , respectively. However, the present automatic air conditioner is different in circuit of the refrigerating cycle from the automatic air conditioner shown in FIG. 13. A flow of refrigerant is controlled in the refrigerating cycle by changing over of the solenoid valves  260  and  261 . Upon heating operation, the solenoid valve  260  is opened while the solenoid valve  261  is closed. Consequently, refrigerant discharged from the compressor  201  flows through the condenser  203  and the solenoid valve  260  into the outside heat exchanger  202 , in which it is evaporated. It is to be noted that, in this instance, the condenser  203  does not perform a condensing action in principle as the damper  154  is held closed. Then, the refrigerant condensed in the outside heat exchanger  202  is decompressed and expanded when it passes the capillary tube  211 , and consequently, the refrigerant in a low temperature, low pressure condition flows into the evaporator  207 . In this condition, the damper  159  holds the duct  100  in a closed condition, and consequently, air from the blower  132  flows into the evaporator  207  to evaporate the refrigerant. The thus evaporated refrigerant is then fed back into the compressor  201  by way of the accumulator  212 . 
     On the other hand, upon heating operation, the solenoid valve  260  is closed while the solenoid valve  261  is opened. In this condition, refrigerant discharged from the compressor  201  flows into the condenser  203 , in which it is condensed. In particular, in this condition, the damper  154  is opened so that air may be admitted into the condenser  203 . After then, the refrigerant is decompressed and expanded when it passes the capillary element  266 , and is then evaporated in the outside heat exchanger  202 . The thus evaporated refrigerant is fed back into the compressor  201  by way of the solenoid valve  261  and the evaporator  207 . In this condition, the evaporator  207  is closed by the damper  159 , and consequently, refrigerant is little evaporated in the evaporator  207 . 
     Subsequently, upon dehumidifying operation, the solenoid valve  260  is opened while the solenoid valve  261  is closed. Accordingly, refrigerant discharged from the compressor  201  flows into the condenser  203 , in which it is condensed. The refrigerant then flows through the solenoid valve  260  into the outside heat exchanger  202 , also which accomplishes a condensing function to condense the refrigerant. After then, the refrigerant is decompressed and expanded when it passes the capillary tube  211 , and is then evaporated in the evaporator  207 . Then, the refrigerant thus evaporated in the evaporator  207  is fed back to the compressor  201  by way of the accumulator  212 . In this condition, the evaporating capacity of the evaporator  207  and the condensing capacity of the condenser  203  are variably controlled by adjusting the circuits of the dampers  159  and  154 , respectively. Further, in order to control the condensing capacity of the condenser  203 , the condensing capacity control of the outside heat exchanger  202  by control of the amount of air of the fan  151  for the outside heat exchanger  202  or the like may be employed additionally similarly as in the case of the automotive air conditioner shown in FIG.  21 . 
     As described so far, with the automotive air conditioner of the present invention, the operation can be changed over among cooling operation, heating operation and dehumidifying operation by controlling the routes of flows of refrigerant through the compressor  201 , the outside heat exchanger  202 , the condenser  203 , the evaporator  207  and the decompressing or expanding means  211 . Further, according to the present invention, further advantageous air conditioning operation described below can be achieved by suitably controlling changing over particularly between a dehumidifying operation condition and a heating operation condition. 
     In case fogging of the windshield of the automobile is forecast or detected in a heating operation condition, the condition of the windshield can be prevented well by changing over the flow of refrigerant into that of a dehumidifying operation condition. Particularly upon dehumidifying operation, since the drop in temperature of blown out air at the evaporator  207  is greater than the rise at the condenser  203  as described above, dehumidification having somewhat heating effect can be achieved. Accordingly, even if the operation is changed over from a heating operation condition to a humidifying operation condition, the temperature of blown out air will not be lowered remarkably, and consequently, good heating can be achieved. 
     Meanwhile, in a humidifying operation condition, since the evaporator  207  performs an evaporating action, particularly when the temperature of air sucked into the evaporator  207  is low as in winter, there is the possibility that the evaporator  207  may be frozen. Thus, in such a case, otherwise possible freezing of the evaporator  207  can be prevented well by changing over the operation from the dehumidifying operation to a heating operation. 
     FIG. 41 shows a flow chart when the operation is changed over from a heating operation condition to a dehumidifying operation condition. The present flow chart is used to control changing over of the solenoid valves of the refrigerating cycle described hereinabove. After operation is started at step  440 , it is judged at step  441  whether or not the air conditioner switch  305  is on or off. In case the air conditioner switch  305  is on, it is then judged at step  442  whether or not the refrigerating cycle is in an operation condition wherein it blows out only a weak wind or in an air conditioning operation condition wherein the compressor  201  is operating. If an air conditioning operation condition is judged at step  442 , judgment of a cooling operation condition, a dehumidifying operation or a heating operation condition is performed at step  443 . 
     As described hereinabove, in any of the refrigerating cycles, in a cooling operation condition, refrigerant discharged from the compressor  201  is condensed in the outside heat exchanger  202 , and then decompressed and expanded, whereafter it is supplied into the evaporator  207 . Then, the refrigerant takes heat of vaporization away from air in the evaporator  207  to cool the air. On the other hand, in a heating operation condition, refrigerant discharged from the compressor  201  flows into the condenser  203 , in which it radiates heat of condensation into air to heat the air. After then, the refrigerant is decompressed and expanded, and then it is evaporated in the outside heat exchanger  202  and fed back into the compressor  201  again. 
     Upon dehumidifying operation, the manner of use of the outside heat exchanger  202  is different among the different refrigerating cycles, but the condenser  203  performs a condensing function to radiate heat of condensation into air to heat the air. Further, the evaporator  207  performs an evaporating action to cool air by heat of vaporization to condense moisture from within the air. Then, the outside heat exchanger- 202  acts as an evaporator or a condenser depending upon a circuit of the refrigerating cycle. Further, as described already, a flow of refrigerant flowing to the outside heat exchanger  202  may flow in series to the condenser  203  or in parallel to the condenser  203 . In particular, in a first condition, refrigerant discharged from the compressor  201  first flows into the condenser  203  and then into the outside heat exchanger  202  so that it may undergo a condensing action by both of condenser  203  and the outside heat exchanger  202 , whereafter it flows into the evaporator  207  by way of the capillary tube  211 . On the other hand, in a second condition, refrigerant discharged from the compressor  201  is supplied in parallel into both of the condenser  203  and the outside heat exchanger  202 , and then the refrigerant condensed in both of the condenser  203  and the outside heat exchanger  202  is supplied into the evaporator  207  by way of the capillary tube  211 . 
     Further, also when the outside heat exchanger  202  acts as an evaporator upon dehumidifying operation, similarly two cases are available including a first case wherein refrigerant flows in series and a second case wherein refrigerant flows in parallel. In particular, in the first case, refrigerant condensed in the condenser  203  flows, after passing the capillary tube  212 , in series through the outside heat exchanger  202  and the evaporator  207  such that an evaporating action is achieved by both of the outside heat exchanger  202  and the evaporator  207 , whereafter the refrigerant is sucked into the compressor  201 . Particularly in this instance, either the evaporator  207  may be located on the upstream side of the outside heat exchanger  202  or the outside heat exchanger  202  may be located on the upstream side of the evaporator  207 . 
     Meanwhile, in the second case, liquid refrigerant condensed in the condenser  203  is supplied, after passing the capillary tube  211 , in parallel to both of the outside heat exchanger  202  and the evaporator  207 . 
     In the present flow chart of FIG. 41, it is judged, at step  444 , in accordance with a changed over condition of the inside/outside air changing over damper  131  whether a heating operation or a dehumidifying operation should be performed in a heating operation condition. Then, in case an outside air admitting condition is detected at step  444 , the heating operation condition is maintained. This is because, normally in an outside air introducing condition, ventilation of the room of the automobile is performed and the windshield is not likely fogged. In case it is judged at step  444  that the inside/outside air changing over damper  131  is in an inside air admitting condition, it is judged subsequently at step  445  whether or not a cancelling switch is on or off. The cancelling switch is provided, though not shown, on the control panel for preventing, by manual operation thereof, operation of the automatic air conditioner from automatically changing over from a heating operation condition to dehumidifying operation. However, in case the cancelling switch is on, even if it is forecast at step  444  that the windshield may be fogged, heating operation will still be continued. Only when the cancelling switch is not on, dehumidifying operation is performed in case fogging of the windshield is forecast at step  444 . Preferably, the dehumidifying operation here is dehumidifying operation having some heating effect. This is achieved by lowering, in the refrigerating cycle in which the outside heat exchanger acts as a condenser, the heat exchanging function of the outside heat exchanger. It is to be noted that such dehumidifying operation having some heating effect will be hereinafter described. It is to be noted that, while, in the flow chart of FIG. 41, a fogged condition of the windshield is judged in accordance with a changing over condition of the inside/outside changing over damper  131 , changing over may otherwise be performed in accordance with a blowing out mode or an outside air condition as seen from the flow chart shown in FIG.  42 . In particular, even if an outside air admitting condition is detected at step  444 , if it is judged at step  446  that air flows to the def spit hole  146 , then it is determined that the passenger requires dehumidification, and consequently, the operation is changed over to the dehumidifying operation side. It is to be noted that judgment of a mode at step  444  and judgment of changing over between spit holes at step  446  are different from each other as described subsequently. In particular, the judgment of a mode at step  444  is made principally based on a necessary blown out air temperature while changing over of a mode at step  446  is performed by selection of the passenger. At step  447 , it is judged whether or not the temperature of outside air is equal to or higher than 0° C. Here, in case it is judged that the outside air temperature is lower than 0° C., heating operation is selected because, otherwise if dehumidifying operation is performed, then there is the possibility that the evaporator  207  may be frozen. Then, when the outside air temperature is equal to or higher than 0° C. and there is no possibility that the evaporator  207  may be frozen, dehumidifying operation is selected. The DEF mode at step  446  mentioned above denotes a condition wherein air flows to the def spit hole  146  and includes not only a case wherein the entire amount of air flows to the def spit hole  146  but also another case wherein air flows to both of the def spit hole  146  and the foot spit hole  145 . FIG. 43 shows another flow chart of changing over between heating operation and dehumidifying operation. In the flow chart of FIG. 43, fogging of the windshield is judged at step  448 . The judgment is performed using a dewing sensor not shown. The dewing sensor identifies from a temperature of a glass portion and a humidity of air whether or not the surface of the glass is lower than a dew point of moisture in the air in order to forecast occurrence of fogging. Then, in case occurrence of fogging is not detected or forecast at step  448 , the automotive air conditioner enters heating operation. In case occurrence of fogging is forecast at step  448 , a temperature of outside air is detected at step  447 , and if the outside air temperature is equal to or higher than 0° C., then dehumidifying operation having some heating effect is selected. In this instance, the inside/outside air changing over damper is put into an inside air admitting condition in order to achieve a high heating efficiency while the damper  141  is opened so that warm air may advance from the def spit hole  146  toward the windshield. In case a temperature of outside air equal to or higher than 0° C. is detected at step  447 , heating operation is selected in order to prevent freezing of the evaporator  207 . However, since this condition is a condition wherein fogging of the windshield is forecast, the inside/outside air changing over damper  131  is put into the outside air admitting condition. Further, the damper  141  opens the def passage  146  so that air warmed by heating operation may be blown out from the def spit hole  146  toward the windshield. In case it is judged at step  447  that the outside air temperature is equal to or higher than 0° C., dehumidifying operation having some heating effect is performed. In this instance, the inside/outside air changing over damper  131  is changed over to the inside air admitting condition in order to lower the heating load. Further, the def spit hole  146  is opened so that fogging of the windshield may be prevented well. FIG. 44 is a flow chart illustrating a further control for the prevention of fogging of the windshield. In the present flow chart, detection of occurrence of fogging is executed in accordance with the position of the inside/outside air changing over damper  131  (step  444 ). Then, in case an inside air admitting condition is judged at step  444 , since this is a condition wherein fogging of the windshield is forecast, an actual situation of the windshield is judged at step  448 . Then, in case it is detected that the windshield is actually fogged or is entering into a fogged condition, dehumidifying operation having some heating effect is selected. On the contrary if fogging of the windshield is not detected at step  448 , even if an inside air admitting condition is judged at step  444 , heating operation will be continued. FIG. 45 shows a flow chart of another example of controlling changing over between dehumidifying operation having some heating effect and heating operation. In the present example, a changed over position of the inside/outside air changing over damper  131  is judged at step  444  and the changing over is controlled in accordance with the judgment similarly as in the flow chart described hereinabove. However, even when an inside air admitting condition is detected at step  444 , when the cancelling switch is in an on-state, heating operation is continued (step  445 ) similarly as in the flow chart shown in FIG.  42 . Further, in the flow chart shown in FIG. 45, a step  449  is added so that an elapsed time after the inside/outside changing over damper  131  has been changed over to the inside air admitting condition may be judged. This is because, even if the inside/outside air changing over damper  131  is changed over to the inside air admitting condition, this will not immediately result in fogging of the windshield. Thus, in case it is judged at step  449  that the inside air admitting condition has continued for a predetermined period of time, for example, for 1 to 3 minutes or so, dehumidifying operation having some heating effect is entered. On the other hand, in case it is detected at step  449  that the inside air admitting condition has continued but for a period of time shorter than the predetermined period of time, for example, 1 to 3 minutes, heating operation will be continued. This is because, depending upon a driving condition of the automobile, the automotive air conditioner is sometimes used in such a manner that the admitting time of inside air comes to an end after a comparatively short period of time such that the inside air admitting condition may be entered and continued only while the automobile is driving, for example, in a tunnel. It is to be noted that, while, in the flow chart shown in FIG. 45, dehumidifying operation having some heating effect is performed if dehumidification is necessary when heating operation is selected at step  443 , alternatively dehumidifying operation having some heating effect and heating operation may be performed alternately as seen from FIG.  46 . In this instance, such alternate operation may be performed at intervals of 5 to 10 minutes or so. Consequently, even upon dehumidifying operation, heating of the room of the automobile can be performed well. A flow chart of control wherein, when dehumidifying operation is selected at step  443 , the operation is changed over to heating operation is shown in FIG.  47 . This is because, since the evaporator  207  operates, in a dehumidifying operation condition, so that cool air is normally admitted into the evaporator  207  from outside the automobile as described above, there is the possibility that the evaporator  207  may be frozen. If the evaporator  207  is frozen, then the ventilation resistance is increased and the heat exchanging efficiency is deteriorated. Therefore, in the flow chart of FIG. 47, a frozen condition of the evaporators is judged at step  450 . The judgment at step  450  determines a frozen condition of the evaporator  207  when the detection temperature signal from the temperature sensor for detecting a temperature of the surface of the evaporator  207  is lower than 0° C. and the temperature of air having passed the evaporator  207  is lowered to 0° C. or so. If a frozen condition of the evaporator  207  is not determined at step  450 , dehumidifying operation is performed. However, when a frozen condition of the evaporator  207  is detected at step  450 , the control sequence advances to step  451 . At step  451 , it is judged whether or not the room temperature is equal to or higher than a preset temperature. Then, if a condition wherein the room temperature is equal to or higher than the preset temperature is determined at step  451 , then this is a condition wherein no heating is required for the room of the automobile. Accordingly, in this instance, the operation is not changed over to heating operation. However, since a frozen condition of the evaporator  207  has been determined at step  450 , the discharging capacity of the evaporator  201  is lowered in order to cancel the frozen condition. Consequently, the evaporating capacity of the evaporator  207  is lowered so that at least freezing at the evaporator  207  may not proceed any more. If a condition wherein the room temperature is lower than the preset temperature is determined at step  451 , then since heating operation will not cause the passenger to have a disagreeable feeling in this condition, the operation is changed over-to heating operation. It is to be noted that it is naturally possible to eliminate the step  451  in the control flow chart of FIG.  45 . In other words, the operation may be changed over to heating operation if freezing at the evaporator  207  is detected at step  450 . Subsequently, control when a frosted condition of the outside heat exchanger  202  is detected in a heating operation condition and the operation is changed over to dehumidifying operation will be described. Referring to the flow chart of FIG. 48, when a heating mode is selected at step  443 , a frosted condition of the outside heat exchanger  202  is detected at subsequent step  452 . This is because, since the outside heat exchanger  202  operates as an evaporator in a heating operation condition as described hereinabove, there is the possibility that frost may appear on the surface of the outside heat exchanger  202  when the temperature of of outside air is low. The judgment at step  452  is performed in the following conditions. First, it is judged whether or not the heating operation time in a condition wherein the temperature of the outside heat exchanger  202  is lower then −3° C. has continued for more than one hour, and then it is judged whether or not the temperature of the outside heat exchanger  202  is lower by 12° C. or more than the temperature of outside air. When the temperature of the outside heat exchanger  202  is not lower than −3° C., this indicates that the temperature of the surface of the outside heat exchanger  202  is not so low as will lead to frosting, and when the temperature of the outside heat exchanger  202  is not lower by 12° C. or more than the temperature of outside air, this indicates that a sufficient evaporating function is assured with the outside heat exchanger  202 . In other words, if frost appears on the surface of the outside heat exchanger  202 , then passage of heat is obstructed, and as a result, the evaporating action of the outside heat exchanger  202  is deteriorated. Therefore, the evaporating pressure of refrigerant is decreased in order to maintain the function of the refrigerating cycle. Then, refrigerant having such a decreased evaporating pressure exhibits further decrease of the evaporating temperature, and as a result, the temperature of the outside heat exchanger  202  becomes lower by 12° C. or more than the temperature of outside air supplied to the outside heat exchanger  202 . Further, the reason why it is judged whether or not the refrigerant supplying time to the outside heat exchanger  202  has elapsed for more than one hour is that normally it is a phenomenon which appears after continuous operation for more than one hour that frost appears on the outside heat exchanger  202  to such a degree that it has a significant effect on the heating performance of the outside heat exchanger  202 . A condition of the outside heat exchanger  202  is detected in this manner at step  452 , and if no frost is determined, then heating operation is continued. On the contrary if a frosted condition is determined at step  452 , then a display of such frosting is provided at step  452 . The passenger can find the necessity of defrosting from the frosting display. FIG. 52 shows an example of an operation panel which includes an LED  315  for displaying a frosted condition. The operation panel further includes a defrosting switch  314  for starting defrosting, and if the defrosting switch  314  is switched on, then this is detected at step  453 . In response to such detection, the operation of the automotive air conditioner is changed over to dehumidifying operation. It is to be noted that the dehumidifying operation in this instance is a refrigerating cycle wherein the outside heat exchanger  202  acts as a condenser. In other words, even in dehumidifying operation, a cycle wherein the outside heat exchanger  202  acts as an evaporator is excepted in the present control. It is to be noted that, with the operation panel shown in FIG. 52, not only operation of the automotive air condition but also operation of the blower  132  are stopped simultaneously by means of a stop switch  307 . When only the blower  132  is to operate, a blower switch  316  will be switched on. Changing over of the capacity of the blower  132  upon air blasting is performed by way of the switch  301 . In order to facilitate defrosting,. the compressor  201  has a great capacity. Further, the inside/outside air changing over damper  131  is changed over to an inside air mode position so that the heating capacity may not be deteriorated when dehumidifying operation is entered. Further, the auxiliary heaters  700  and  701  are rendered operative if necessary. Besides, the blowing air amount of the blower  132  is decreased to prevent a drop of the blown out air temperature. In addition, the blower  251  for the outside heat exchanger  202  is stopped. As a result, high pressure refrigerant discharged from the compressor  201  is supplied into the outside heat exchanger  202  so that frost adhering closely to the surface of the outside heat exchanger  202  can be melted by heat of the refrigerant. It is to be noted that, while, in the flow chart shown in FIG. 48, dehumidifying operation is performed when defrosting is required, alternatively dehumidifying operation having some heating effect and heating operation may be performed alternately as seen from the flow chart shown in FIG.  49 . In particular, as seen at step  454  of FIG. 49, dehumidifying operation and heating operation may be performed alternately in such a manner that dehumidifying operation is performed for a predetermined period of time, for example, for 1 to 5 minutes or so after heating operation has been performed for another predetermined period of time, for example, for 30 minutes to one hour. It is to be noted that, in this instance, the condition whether or not the function of the outside heat exchanger  202  as an evaporator has continued for more than one hour is eliminated from the conditions for detection of frosting at step  452 . In other words, presence or absence of frost is judged depending upon whether or not the temperature of the outside heat exchanger  202  is lower by more than the predetermined temperature than the temperature of outside air and whether or not the temperature of the outside heat exchanger  202  is lower than −3° C. Here, the temperature difference between the temperature of the outside heat exchanger  202  and the temperature of outside air is not set to 12° C. or more as at step  452  of the flow chart shown in FIG. 48 but set to 8° C. or more at step  452  of the flow chart shown in FIG.  49 . This is because it is intended to precautionarily detect possible or forecast frost on the outside heat exchanger  202  before the outside heat exchanger  202  is completely frosted. Further, in the present flow chart, in dehumidifying operation having some heating effect at step  454 , the inside/outside air changing over damper  131  need not completely be changed over to its inside air admitting position but may be set to another position at which both of inside air and outside air can be admitted. Subsequently, dehumidifying operation having some heating effect described in the control above will be described. In dehumidifying operation, air is first cooled in the evaporator  207  and then heated in the condenser  203 , but since heat is used for sensible heat for condensing moisture in air in the evaporator  207  as described hereinabove, the temperature of the air is not lowered very much, and as a result, the temperature of air having passed both of the evaporator  207  and the condenser  203  rises. Further, since dehumidifying operation involves at least three heat exchangers including the condenser  203 , the evaporator  207  and the outside heat exchanger  202 , the refrigerant condensing pressure, that is, the condensing temperature, of the condenser  203  can be variably controlled by variably controlling the heat exchanging capacity of the outside heat exchanger  202 . For example, when both of the condenser  203  and the outside heat exchanger  202  perform a condensing action in such a refrigerating cycle as shown in FIG. 21, the condensing capacity as a refrigerating cycle can be varied by controlling the blower  251  for the outside heat exchanger  202 . When the blower  251  operates to blast a great amount of air, the condensing capacity is increased, and as a result, the condensing pressure of refrigerant is lowered. This signifies a drop of the condensing temperature of refrigerant and will cause a drop of the temperature of the condenser  203 . 
     On the contrary when the blower  251  stops its operation, the heat exchanging capacity of the outside heat exchanger  202  is lowered, and as a result, the condensing capacity of the refrigerating cycle is lowered. Consequently, the condensing pressure of refrigerant is increased and the condensing temperature of refrigerant in the condenser  203  is raised. This will raise the temperature of the condenser  203 , thereby achieving dehumidifying operation having some heating effect. Various means for varying the condensing capacity of the outside air conditioner may be available in addition to such control of the blower  251  as described above. For example, in a refrigerating cycle which employs a damper such as the refrigerating cycle shown in FIG. 14 which employs the damper  253 , the circuit of the damper  253  may be controlled so as to regulate the amount of air to be admitted into the outside heat exchanger  202  thereby to vary the heat exchanging capacity of the outside heat exchanger  202 . Further, where the outside heat exchanger  202  is divided into a plurality of outside heat exchangers, the heat exchanging capacity may be controlled by controlling the effective heat exchanging area of the outside heat exchanger  202 . Further, if necessary, coolant such as water is flowed into the outside heat exchanger, and the amount of the coolant may be controlled to control the heat exchanging capacity of the outside heat exchanger  202 . Further, in an apparatus wherein air to be admitted into the outside heat exchanger  202  is changed over between outside air and air in the room of the automobile, the temperature of air to be admitted into the outside heat exchanger  202  may be varied to control the heat exchanging capacity of the outside heat exchanger  202 . Further, in such an apparatus as shown in FIG. 33 wherein refrigerant discharged, upon dehumidifying operation, from the compressor  201  is supplied in parallel to both of the condenser  203  and the outside heat exchanger  202 , the flow rate of refrigerant to be supplied to the heat exchanger  202  may be varied by opening/closing control of the valve  294 . In particular, when the valve  294  is in an open condition, refrigerant flows to both of the outside heat exchanger  202  and the condenser  203  so that a sufficient condensing action is performed by the two heat exchangers  202  and  203 . On the contrary when the valve  294  is closed, a condensing action is performed only in the condenser  203 , and consequently, the condensing capacity is low. The capacity controls of the outside heat exchanger  202  described above may be used not only for dehumidifying operation having some heating effect but also for control of the an entire refrigerating cycle. For example, when the pressure of the high pressure side refrigerant rises abnormally during dehumidifying operation, the capacity of the outside heat exchanger  202  may be varied in order to protect the refrigerating cycle. FIG. 50 shows a flow chart of operation for controlling the blower  251  for the outside heat exchanger  202  for the object described just above. Where fleon R 22  is employed as refrigerant, when the high pressure side refrigerant pressure becomes higher than 24.5 kg/cm 2 G, the blower  251  is rotated at a high speed. On the contrary when the high pressure side refrigerant temperature becomes lower than 22.5 kg/cm 2 G, the blower  251  is stopped. In an intermediate region between them, the blower  251  is rotated at a low speed with some predetermined hysteresis. FIG. 51 shows a control flow chart when capacity control of the outside heat exchanger  202  is executed in order to achieve both of protection of the refrigerating cycle and achievement of agreeability in operation. Upon dehumidifying operation, a pressure on the high pressure side of the refrigerating cycle is compared with a preset value at step  460 . If the high pressure side pressure is higher than the preset value, for example, 24.5 kg/cm 2 G, then the capacity of the blower  251  for the outside heat exchanger  202  is increased at step  461 . Consequently, the condensing capacity is enhanced and a rise in pressure to a high pressure in the refrigerating cycle is prevented. In case it is determined that the high pressure side pressure is not higher than the preset value, a room temperature is compared with a preset temperature subsequently at step  462 . In case the room temperature is higher by 1° C. or more than the preset temperature, it is determined that the heating capacity is not required very much any more, and the amount of air of the blower  251  is increased to increase the condensing capacity. On the contrary, when the room temperature is lower by 1° C. or more than the preset temperature, it is determined that an increase of the heating capacity is required, and the amount of air to be blasted from the blower  251  is decreased. Consequently, the condensing capacity of the outside heat exchanger  202  is decreased thereby to increase the condensing pressure and the condensing temperature of the condenser  203 . If the room temperature is within ±1° C. of the preset temperature, the current condition of the blower  251  is maintained after then. FIG. 53 shows a yet further automotive air conditioner according to the present invention. In the present automotive air conditioner, three heaters  203  are arranged in series at three stages in the direction of a flow of air in the duct  100 . A temperature sensing tube  204  is disposed at a refrigerant pipe on the upstream side of the subcooler  203   c  which is positioned on the most upstream side in the direction of a flow of air among the heaters  203 , and the expansion valve  206  variably controls the refrigerating passage so that refrigerant may present a predetermined temperature at the entrance of the subcooler  203   c . In the present automotive air conditioner, the expansion valve  206  controls the refrigerant passage so that refrigerant having passed the condenser  203   b  has a subcooling degree of 2 to 3° C. When the temperature of air which passes the heaters  203  is low or when the flow rate of air is high, refrigerant is liable to be condensed in the heaters  203  and refrigerant having passed the condenser  203   b  may possibly have a sufficient subcooling degree. In this instance, a drop of the temperature of refrigerant is detected by the temperature sensing tube  204  and fed back to the expansion valve  206 , and consequently, the expansion valve  206  varies the refrigerating passage in an expanding direction. As a result, the pressure of refrigerant on the heaters  203  side is dropped, and the subcooling degree of refrigerant upon passage of the condenser  203   b  is decreased. On the contrary when the flow rate of air to be admitted into the heaters  203  is low or the like, sufficient radiation of heat cannot be performed with the condensers  203   a  and  203   b . As a result, even after refrigerant passes the condenser  203   b , a sufficient subcooling degree of refrigerant cannot be achieved. In this condition, the temperature of refrigerant at the heat sensing tube  204  rises, and a signal thereof is fed back to the expansion valve  206 . Consequently, the expansion valve  206  varies the refrigerating passage in a narrowing direction. As a result, the pressure of refrigerant in the heaters  203  on the downstream side of the expansion valve  206  is raised, and refrigerant becomes liable to be condensed. In other words, it becomes liable to achieve subcooling with an equal flow rate of air. In this manner, the subcooling degree of refrigerant at the location of the temperature sensing tube  204  can be maintained to a predetermined value by variably controlling the passage of refrigerant by means of the expansion valve  206  in response to the temperature sensing tube  204 . Since, in the present automotive air conditioner, refrigerant at the location of the temperature sensing tube  204  has the subcooling degree of 2 to 3° C. as described above, the subcooler  203   c  located on the downstream side of the temperature sensing tube  204  in a flow of refrigerant can provide a subcooling degree of refrigerant with certainty. In particular, since the subcooler  203   c  admits on the entrance side thereof refrigerant which already has a predetermined (2 to 3° C.) subcooling degree, refrigerant after passing the subcooler  203   c  has a higher subcooling degree. While the width of the subcooling degree is not fixed depending upon the temperature and/or the flow rate of air admitted into the subcooler  203   c , the subcooling degree can be increased with certainty. To increase the subcooling degree leads to an increase of the enthalpy of refrigerant on the heat radiation side and hence to enhancement of the operation efficiency of the refrigerating cycle. Particularly in the present automotive air conditioner, since the subcooler  203   c  is disposed on the downstream side of the location of the temperature sensing tube  204 , improvement in operation efficiency of the refrigerating cycle can be achieved with certainty by subcooling by the subcooler  203   c . Particularly where the subcooler  203   c  is used together with the air mixing damper  154  as in an automotive air conditioner, the flow rate of air flowing into the heaters  203  side varies to a great extent in response to the opening of the air mixing damper  154 . Further, the temperature of air flowing into the heater  204  is different to a great extent between that when refrigerant flows through the evaporator  207  and that when refrigerant flows along the bypass passageway  230  bypassing the evaporator  207 . In this manner, in an automotive air conditioner, since the flow rate and the temperature of air flowing into the heaters  203  vary to a great extent, in order to assure a subcooling degree in any operating condition, preferably the subcooler  203   c  is disposed on the downstream side of the temperature sensing tube  204  as in the present automotive air conditioner. Further, in the automotive air conditioner of FIG. 53, a shutter  255  for limiting admission of air is provided forwardly of the outside heat exchanger  202 . The shutter  255  corresponds to the function of the damper  253  in the automotive air conditioner shown in FIG. 4, and the occupying area can be reduced by provision of the shutter  255  shown in FIG. 53 in place of the damper  253 . Further, the automotive air conditioner shown in FIG. 53 includes, similarly to the automotive air conditioner shown in FIG. 53, a fan  251  for electrically controlling air to be admitted into the outside heat exchanger  202 . The shutter  255  described above is particularly effective upon defrosting operation of the refrigerating cycle. The defrosting operation is operation wherein refrigerant in a high temperature, high pressure condition is admitted, when frost on the outside heat exchanger  202  is detected during heating operation, into the outside heat exchanger  202  to raise the temperature of the outside heat exchanger  202  to melt the frost frozen on the outside heat exchanger  202 . Since defrosting operation is performed during heating operation wherein the temperature of outside air is low in this manner, if a large amount of outside air is admitted into the outside heat exchanger during defrosting operation, then much time is required for such defrosting and defrosting may sometimes be impossible. Particularly with an automotive heat exchanger, since the outside heat exchanger  202  is disposed at a position at which it likely meets with a driving wind of the vehicle, it will have a significant influence upon defrosting operation that the outside heat exchanger  202  is cooled by a driving wind during running of the automobile. Thus, with the present automotive air conditioner, upon defrosting operation, the shutter  255  is closed to prevent a driving wind from being admitted into the outside heat exchanger  202 , and also operation of the fan  251  for the outside heat exchanger  202  is stopped. Subsequently, a controlling method for the refrigerating cycle shown in FIG. 53 will be described. Judgment whether the refrigerating cycle should operate in heating operation, dehumidifying heating operation, dehumidifying operation, cooling operation or defrosting operation for the outside heat exchanger is made in accordance with a flow of operations similar to that of the control shown in FIG.  48 . The four-way valve  213 , solenoid valve  231  and shutter  255  are opened and closed in the individual modes in such a manner as seen from FIG. 54. 213 is changed over, similarly as in the automotive air conditioners described hereinabove, between a position (cooler condition) in which refrigerant discharged from the compressor  201  flows to the outside heat exchanger  202  side and returning refrigerant from the evaporator  207  side is sucked into the compressor  201  and another position (heater condition) in which refrigerant discharged from the compressor  201  flows to the heaters  203  side and returning refrigerant is sucked from the outside heat exchanger  202  into the compressor  201 . Meanwhile, the solenoid valve  231  opens or closes the bypass passageway  230  for flowing refrigerant bypassing the evaporator  207  therethrough. Accordingly, when the solenoid valve  231  is open, refrigerant flows through the bypass passageway  230  and does not substantially flow to the evaporator  207  side. On the contrary, when the solenoid valve  231  is in a closed condition, refrigerant flows to the evaporator  207  side. As seen from the control illustrated in FIG. 54, upon heating operation and upon dehumidifying heating operation, the four-way valve  213  is changed over to the heater condition, in which refrigerant in a high temperature, high pressure condition is supplied to the heaters  203 . On the other hand, upon dehumidifying operation, upon cooling operation and upon defrosting operation, the four-way valve  213  is changed over to the cooler condition wherein refrigerant in a high temperature, high pressure condition is supplied to the outside heat exchanger  202 . The solenoid valve  231  is opened only upon heating operation but is closed in any other mode. In particular, only upon heating operation, refrigerant flows bypassing the evaporator  207 . As a result, upon heating operation, the evaporator  207  does not function, and air flowing in the duct  100  is not cooled by the evaporator  207  at all. In any other operation condition, refrigerant is supplied into the evaporator  207  after passing the capillary tube  211 , and the evaporator  207  functions as a cooler for air. The shutter  255  is closed only upon defrosting of the outside heat exchanger  202  as described above but is open in any other operation condition. In a heating condition A and a dehumidifying heating condition B of FIG. 54, such control as illustrated in FIG. 55 is executed. In particular, referring to FIG. 55, in a heating operation condition, the fan  251  for the outside heat exchanger  202  is rotated at its maximum speed at step  470 . Consequently, when the heat pump is operated, absorption of heat from outside air is maximized. In particular, upon heating operation, refrigerant discharged from the compressor  201  flows through the four-way valve  213  into the heaters  203 , in which it is condensed and liquefied, whereafter it flows through the expansion valve  206  and the bypass passageway  230  into the outside heat exchanger  203 . Thus, the outside heat exchanger  202  acts as an evaporator to evaporate the refrigerant, and after then, the refrigerant is fed back to the compressor  201  by way of the four-way valve  203 . Accordingly, since, upon heating operation, refrigerant is evaporated in the outside heat exchanger  202  to absorb heat from outside air, also the outside heat exchanger  201  to maximize the amount of heat to be absorbed is rotated at its maximum speed. The speed of rotation of the compressor  201  is determined from a result of comparison between an aimed blown out air temperature TAO and a blown out air temperature TA. The blown out air temperature TA is determined in accordance with a signal from the blown out air temperature sensor  323 . The blown out air temperature sensor  232  is disposed at a position at which a warm wind having passed the heaters  203  and a cool wind having bypassed the heaters  203  are mixed with each other. When the aimed blown out air temperature is higher than the actual blown out air temperature, this condition is determined at step  471 , and the frequency of the invertor is increased at step  472 . On the contrary when the actual blown out air temperature TA is higher than the aimed blown out air temperature TAO, the frequency of the invertor is decreased at step  473 . The air mixing damper  154  is positioned at step  474  such that the entire amount of air is not flown to the heaters  203  side in order to prevent a cool wind from being blown out into the room of the automobile upon heating operation and also upon dehumidifying heating operation described below. Subsequently, control of dehumidifying heating operation B of FIG. 54 will be described. In dehumidifying heating operation, the solenoid valve  231  is closed so that refrigerant flows to the evaporator  207  side. In particular, in this condition, the heater  204  acts as a condenser while both of the evaporator  207  and the outside heat exchanger  202  operate as evaporators. It is judged at step  475  whether or not the temperature of air having passed the evaporator  207  is equal to or lower than 3° C. It is to be noted that the air temperature is judged in accordance with a signal from a temperature sensor  361  disposed on the downstream side of the evaporator  207 . When the air temperature is higher than 3° C., the heat exchanging capacity of the outside heat exchanger  202  is lowered and the fan  251  for the outside heat exchanger  202  is stopped in order to lower the evaporating pressures in the evaporator  207  and the outside heat exchanger  202  at step  276 . In any other condition, the speed of rotation of the fan  251  for the outside heat exchanger  202  is controlled in accordance with a result of comparison between the aimed blown out air temperature and the actual blown out air temperature. In case the aimed blown out air temperature is higher than the actual blown out air temperature TA, this condition is detected at step  477 , and the speed of rotation of the fan  251  for the outside heat exchanger  202  is raised at step  478 . Consequently, the amount of heat to be absorbed in the outside heat exchanger  202  is increased to raise the blown out air temperature. On the contrary, when the actual blown out air temperature TA is higher than the aimed blown out air temperature TAO, the speed of rotation of the fan  251  is lowered so as to lower the amount of heat to be absorbed in the outside heat exchanger  202 . While rotation of the fan  251  for the outside heat exchanger  202  is controlled in response to the aimed blown out air temperature TAO in this manner, when the rotation is in an intermediate region or is advancing from a maximum or minimum region to the intermediate region, this condition is detected at step  480 , and the air mixing damper  154  is opened to its maximum opening at step  474 . In any other condition, the control sequence advances to step  471  to control rotation of the invertor for the compressor  201 . In particular, in the control illustrated in FIG. 55, control of the capacity of the refrigerating cycle upon dehumidifying heating is first executed by the fan  251  for the outside heat exchanger  202 , and only after rotation of the fan  251  for the outside heat exchanger  202  becomes equal to its maximum or minimum, control of the discharging capacity of the compressor  201  by the invertor is executed. Subsequently, dehumidifying operation C shown in FIG. 54 will be described. In such dehumidifying operation, the four-way valve  213  is changed over so that the outside heat exchanger  202  and the heaters  203  act as condensers and evaporation of refrigerant is performed in the evaporator  207 . Also upon dehumidifying operation, it is judged at step  475  whether or not the temperature of outside air is equal to or lower than 3° C., and in case the outside air temperature is equal to or lower than 3° C., the fan  251  for the outside heat exchanger  202  is stopped at step  476 . Further, in this instance, the circuit of the air mixing damper  154  is changed over at step  481  to a condition wherein the entire amount of air flows to the heaters  203  side. Temperature control of the refrigerating cycle when the outside air temperature is higher than 3° C. is performed first by the air mixing damper  154  and then by the fan  251  for the outside heat exchanger  251  and finally by capacity control of the compressor  201 . The capacity controls of the outside heat exchanger and the compressor are similar to those in a dehumidifying heating operation condition described hereinabove. In the control by the air mixing damper  154 , before it is detected at step  482  whether or not the air mixing damper  154  is at its maximum heating position, the aimed blown out air temperature TAO and the actual blown out air temperature TA are compared with each other at step  483  and then the opening of the air mixing damper  154  is regulated at step  484  or  485 . Subsequently, cooling operation D in FIG. 54 will be described with reference to FIG.  57 . Upon cooling operation, refrigerant first flows into the outside heat exchanger  202  and is then decompressed and expanded in the expansion valve  206  after passing the heaters  203 , whereafter it flows into the evaporator  207 . The refrigerant is thus evaporated in the evaporator  207  and then returns to the compressor  207  by way of the accumulator  212 . Upon such heating operation, since air is not heated by the heaters  203 , the air mixing damper  154  is displaced at step  486  to a position at which it closes the heaters  203 . Meanwhile, since the outside heat exchanger  202  operates as a condenser, rotation of the fan  251  for the outside heat exchanger  202  is raised to its maximum in order to maximize the heat radiating capacity of the condenser  202  at step  487 . In this condition, control of the cooling capacity is performed by varying the discharging capacity of the compressor  201  at steps  471  and  272  or  473 . Subsequently, defrosting operation E in FIG. 54 will be described with reference to FIG.  58 . In defrosting operation, a flow of refrigerant is basically similar to that in cooling operation, and refrigerant in a high temperature, high pressure condition flows into the outside heat exchanger  202 . However, in order to quicken defrosting, the shutter  255  is closed as described hereinabove. Further, since this condition is basically a condition wherein heating is required, the air mixing damper  154  is displaced at step  488  to a position at which the entire amount of air flows to the heaters  203  side. Further, the fan  251  for the outside heat exchanger  202  is stopped or kept inoperative at step  489  so that a cool wind may not come to the outside heat exchanger  202 . Further, in order to complete defrosting in a short interval of time, the invertor is controlled to maximize the discharging capacity of the compressor  201  at step  490 . Operating conditions of the four-way valve  213 , the solenoid valve  231 , the shutter  255 , the air mixing damper  154 , the fan  251  for the outside heat exchanger  202  and the invertor for controlling the discharging amount of the compressor  201  in the various operation conditions described above are listed up in the table shown in FIG.  59 . Further, directions of flows of refrigerant in the heating operation condition, the dehumidifying heating operation condition, the heating operation condition and the defrosting operation condition described above are shown in FIGS. 60 to  63 , respectively. A flow of refrigerant is indicated by a thick line in each of FIGS. 60 to  63 . In the heating operation condition shown in FIG. 60, the heaters  203  operate as condensers and a subcooler; the outside heat exchanger  202  operates as an evaporator; and the evaporator  207  disposed in the duct  100  does not operate. This is intended to prevent cooling of air in the duct  100  upon heating by keeping the evaporator  207  inoperative. However, when the heating load is particularly high such as upon warming up immediately after starting of heating, the refrigerating cycle is set similarly as in dehumidifying heating operation shown in FIG. 61 such that refrigerant flows also to the evaporator  207  so that the evaporator  207  may operate as a heat sink. This arises from the facts that, since the temperature of air sucked is low when the heating load is high in this manner, a drop of the temperature of air by the evaporator  207  does not matter very much, that absorption of heat at the evaporator  207  is cancelled by a variation of visible heat of air and the temperature of air itself does not drop very much, and that, since absorption of heat in the entire refrigerating cycle is performed in both of the evaporator  207  and the outside heat exchanger  202 , the amount of absorbed heat is increased and as a result the amount of heat radiation from the heaters  203  is increased. 
     In particular, while heat of air sucked into the evaporator  207  is absorbed in the evaporator  207 , heat absorption then is performed first by condensation of water in air, and consequently, the temperature of the air is not lowered very much even after it passes the evaporator  207 . Rather, a rise of the amount of heat radiation of the heaters  203  acts effectively upon a rise of the temperature. 
     In particular, the amount of heat radiation of the heaters  203  results immediately in a rise of the temperature of air passing the heaters  203 , and there is no variation in latent heat. Besides, since absorption of heat is performed in both of the evaporator  207  and the outside heat exchanger  202 , the amount of heat absorption is increased and as a result, the evaporating pressure of refrigerant is raised. As the evaporating pressure rises, the specific volume of refrigerant sucked into the compressor  201  is decreased, and consequently, the flow rate by weight of recirculating refrigerant by the compressor is increased. In this manner, also the amount of heat of refrigerant supplied to the heaters  203  is increased and the amount of heat radiation by the heaters  203  is increased. However, since the operation condition requires higher power for the compressor  201 , such a flow of refrigerant as shown in FIG. 60 is taken in normal heating operation as described hereinabove. FIG. 64 shows an example of a controlling operation panel for the cycle of the automotive air conditioner shown in FIG.  53 . Since the automotive air conditioner shown in FIG. 53 has a dehumidifying heating operation mode as described hereinabove, a switch for dehumidifying heating is additionally provided comparing with the panel shown in FIG.  52 . 
     A yet further automotive air conditioner according to the present invention will be described with reference to FIG.  65 . The automotive air conditioner shown in FIG. 65 eliminates the evaporating pressure regulating valve  208  comparing with the automotive air conditioner shown in FIG.  53 . Prior to description of control of the automotive air conditioner shown in FIG. 65, a function of the evaporating pressure regulating valve  208  will be described first with reference to FIG.  53 . 
     The evaporating pressure regulating valve  208  is provided to prevent frosting on the surface of the evaporator  207  when, particularly upon dehumidifying heating operation, both of the evaporator  207  and the outside heat exchanger  202  serve as heat sinks to effect evaporation of refrigerant. In particular, since there is the possibility that frost may adhere to the surface of the evaporator  207  when the evaporating pressure of refrigerant in the evaporator  207  is excessively lowered until the refrigerant evaporation temperature becomes lower than the freezing point, the pressure of refrigerant at the exit of the evaporator  207  is kept higher than a predetermined value by means of the evaporating pressure regulating valve  208  in order to prevent such possible frosting. 
     In the automotive air conditioner shown in FIG. 65, the function of the evaporating pressure regulating valve  208  is achieved by opening/closing movement of the bypass passageway  230 . In particular, also in the present automotive air conditioner, both of the evaporator  207  and the outside heat exchanger  202  operate, upon dehumidifying heating operation, as heat sinks to effect evaporation of refrigerant similarly as in the automotive air conditioner described hereinabove with reference to FIG.  53 . 
     In this instance, when the pressure of refrigerant in the evaporator  207  is lowered below a predetermined value, this condition is detected by means of a temperature sensor  329  disposed on a refrigerant pipe on the exit side of the evaporator  207  and the solenoid valve  231  is opened. Since the communication resistance to refrigerant is lower in the bypass passageway  230  than in the evaporator  207 , when the solenoid valve  231  is opened, refrigerant flows to the bypass passageway  230  while admission thereof into the evaporator  207  side is limited. 
     Due to the limit in supply amount of refrigerant, evaporation of refrigerant does not occur in the evaporator  207 , and as a result, the cooling capacity of the evaporator  207  is decreased remarkably. In the meantime, since the temperature of air admitted into the evaporator  207  is equal to a room temperature, if operation is continued in the condition wherein the cooling capacity is decreased remarkably, then frost appearing on the surface of the evaporator  207  will be melted. In this manner, the evaporation temperature of refrigerant in the evaporator  207  can be restricted within a predetermined width by controlling opening/closing movement of the solenoid valve  231  in response to a temperature of refrigerant on the exit side of the evaporator  207  in this manner, and as a result, a function similar to that of the evaporating pressure regulating valve described hereinabove can be achieved. A yet further automotive air conditioner according to the present invention will be described with reference to FIG.  66 . 
     While, in the automotive air conditioner shown in FIG. 53, the bypass passageway is provided sidewardly of the heaters  203  and, upon cooling, the air mixing damper  154  closes the heaters  203  so that air may flow along the bypass passageway, the heaters  203  in the automotive air conditioner shown in FIG. 66 is disposed over the entire area in the duct  100 . Then, upon heating, a bypass passageway  234  is opened so that refrigerant may not flow to the heaters  203 . The bypass passageway  234  is provided to communicate a refrigerant pipe on the entrance side and another refrigerant pipe on the exit side of the heaters  203  with each other, and a solenoid valve  232  for opening or closing the bypass passageway  234  is disposed intermediately of the bypass passageway  234 . 
     Accordingly, upon heating operation, the solenoid valve  232  is opened to open the bypass passageway  234 . Simultaneously, another solenoid valve  233  provided in the entrance side refrigerant pipe is closed so that refrigerant may not flow to the heaters  203 . Accordingly, upon cooling, refrigerant is not supplied to the heaters  203 , and refrigerant accumulated in the heaters  203  will have a high subcooling degree. Since the expansion valve  206  is controlled so that refrigerant on the entrance side of the subcooler  203   c  may have a predetermined subcooling degree as described hereinabove, in a condition wherein refrigerant is not supplied any more and has a predetermined subcooling degree in this manner, such signal is inputted to the expansion valve  206  and consequently, the expansion valve  206  is opened until its opening area presents its maximum in order to maximize the flow rate of refrigerant. 
     Accordingly, suitable cooling operation cannot be performed in this condition. However, in the present automotive air conditioner, since the capillary tube  211  is provided in series to the expansion valve  206 , refrigerant is decompressed and expanded suitably by the capillary tube  211  even in such a condition as described just above. Subsequently, a yet further automotive air conditioner according to the present invention will be described with reference to FIG.  67 . 
     The automotive air conditioner shown in FIG. 67 employs a receiver  205  similarly to the automotive air conditioner shown in FIG.  3 . In the present automotive air conditioner, however, the receiver  205  is disposed between the exit side of the condenser  203   b  and the entrance side of the subcooler  203   c  of the heaters  203 . Since the receiver  205  has a gas/liquid interface and only delivers liquid refrigerant, liquid refrigerant is supplied with certainty to the subcooler  203   c . Consequently, the subcooler  203   c  can provide a subcooling degree of refrigerant with certainty. As described hereinabove, when the air conditioner is used as an automotive air conditioner, the variation in amount of air admitted into the heaters  203  when the air mixing damper  154  is opened and closed and the variation in temperature of air when the evaporator  207  operates and does not operate are great, but where the subcooler  203   c  is disposed on the downstream of the receiver  205  as in the present automotive air conditioner, a sufficient subcooling degree can be obtained with certainty in any operation condition. Further, in the present automotive air conditioner, the expansion valve  206  varies the throttling amount of the refrigerant pipe so that a predetermined dryness may be obtained for refrigerant on the sucking side of the compressor  201  sensing tube for the expansion valve  206  is disposed between the four-valve  214  and the compressor  201 , to whichever position the four-way valve  214  is changed over, a temperature of suction refrigerant returning to the compressor  201  can always be detected. 
     It is to be noted that, in the automotive air conditioner shown in FIG. 67, the auxiliary heater  700  is disposed on the downstream side of the heaters  203  in a flow of air in order to complement the heating capacity upon heating or upon dehumidifying heating. A yet further automotive air conditioner according to the present invention will be described subsequently with reference to FIG.  68 . The automotive air conditioner shown in FIG. 68 solves a disadvantage when an evaporating pressure regulating valve of the fully closed type is employed as the evaporating pressure regulating valve  208 . When the evaporating pressure regulating valve  208  is of the fully closed type, if cold air flows into the evaporator  207  as upon, for example, starting at a low temperature, the temperature of refrigerant on the exit side of the evaporator  207  is lowered below a predetermined value and consequently the evaporating pressure regulating valve  208  will close the refrigerant pipe. 
     If the refrigerant pipe is closed in this manner, refrigerant will not return to the compressor  201 , and consequently, such a disadvantage as seizure of the compressor  201  may take place. Therefore, in an operation condition wherein the evaporation pressure regulating valve  208  closes the refrigerant passage in this manner, the solenoid valve  231  is opened temporarily so that refrigerant may flow to the downstream side of the evaporating pressure regulating valve  208  by way of the bypass passageway  230  bypassing the evaporating pressure regulating valve  208 . While, in this condition, the evaporator  207  does not function temporarily, if air to be sucked into the duct  100  is changed over to inside air and the temperature of air passing the duct  100  rises, then also the temperature of refrigerant in the evaporator  207  rises, and consequently, the evaporating pressure regulating valve  208  will open the refrigerant passage. 
     Accordingly, after then, the bypass passageway  230  can be closed to flow refrigerant to the evaporator  207  side. Accordingly, in the present automotive air conditioner, the bypass passageway  230  is only required to bypass the evaporating pressure regulating valve  208  and need not necessarily bypass the evaporator  207 . Further, if the evaporating pressure regulating valve  208  is of the type which can pass a predetermined amount of refrigerant even when it assumes its minimum throttling condition, the bypass passageway  230  need not necessarily be provided. Subsequently, a yet further automatic air conditioner according to the present invention will be described with reference to FIG.  69 . 
     The automotive air conditioner shown in FIG. 69 can achieve defrosting of the outside heat exchanger  202  during heating operation and during dehumidifying heating operation without considerable deterioration of the dehumidifying heating function. To this end, in the automatic air conditioner shown in FIG. 69, the three-way valves  275 ,  276  and  277  are changed over to change over a sequence of a flow of refrigerant. In particular, in any of heating operation and dehumidifying heating operation in which defrosting is involved, refrigerant in a high temperature, high pressure condition is supplied from the compressor  201  into the heater  203 , which thus operates as a heat radiator. Further, refrigerant in a low temperature, low pressure condition is supplied to both of the evaporator  207  and the outside heat exchanger  202 , which both operate thus as heat sinks. 
     However, in heating operation and in dehumidifying heating operation in which defrosting is involved, refrigerant flows in different orders through the evaporator  207  and the outside heat exchanger  202 . Upon dehumidifying heating operation, refrigerant condensed by the heater  203  flows, after passing the expanding means  206 , first into the evaporator  207  and then into the outside heat exchanger  202 . This is intended, because it is normally forecast that the temperature of outside air is low upon dehumidifying heating operation, to assure operation of the automotive air conditioner even in such condition. In particular, when the outside air temperature is, for example, lower than 0° C., the evaporating temperature of refrigerant is lower than the freezing point and lower than the outside air temperature so that refrigerant may be evaporated in the outside heat exchanger  202  in such outside air temperature condition. 
     Here, if the evaporator  207  is disposed on the downstream side of the outside heat exchanger  202  in a flow of refrigerant, then the evaporating temperature of refrigerant in the evaporator  207  will be lower than the evaporating temperature of refrigerant in the outside heat exchanger  202  and lower than the freezing point. Consequently, frosting takes place on the surface of the evaporator  207  and the ventilation resistance in the duct  100  is increased. 
     As a result, good dehumidifying heating operation cannot be achieved. On the other hand, if the evaporator  207  is disposed on the upstream side of the outside heat exchanger  202  in a flow of refrigerant, then the evaporating temperature of refrigerant in the evaporator  207  can be made higher than the evaporating temperature of refrigerant in the outside heat exchanger  202 . Consequently, the refrigerant temperature of refrigerant in the evaporator  207  can always be held to a predetermined temperature of 2 to 3° C. In this instance, frosting of the outside heat exchanger  202  seems to matter. However, since the disadvantage by frosting is more serious with the evaporator  207  than with the outside heat exchanger  202 , the evaporator  207  is disposed on the upstream side in a flow of refrigerant upon normal dehumidifying heating operation. Then, in case frosting of the outside heat exchanger  202  becomes particularly significant in such operation condition, the flow of refrigerant is changed over so that refrigerant having passed the heater  203  first flows into the outside heat exchanger  202 . 
     Consequently, refrigerant in a high temperature, high pressure condition is supplied into the outside heat exchanger  202  to raise the temperature of the surface of the outside heat exchanger  202 . As a result, frost appearing on the surface of the outside heat exchanger  202  is melted. In this operation condition, operation of the fan  251  for the outside heat exchanger  202  is stopped in order to accelerate defrosting. Then, the refrigerant having passed the outside heat exchanger  202  is decompressed and expanded in the capillary tube  211  and then flows into the evaporator  207 . Further, as described hereinabove, preferably an inside air mode is entered to set the amount of a wind of the inside blower to the Lo position. 
     FIGS. 70 to  73  show flows of refrigerant in the automatic air conditioner shown in FIG.  69 . In particular, FIG. 70 shows a heating operation condition and FIG. 71 shows a cooling operation condition. Further, FIG. 72 shows a dehumidifying heating operation condition, and FIG. 73 shows a condition wherein defrosting of the outside heat exchanger  202  is performed. In all of FIGS. 70 and 73, only a pipe in which refrigerant flows is indicated with a thick line. Subsequently, a yet further automotive air conditioner according to the present invention will be described with reference to FIG.  74 . The refrigerating cycle shown in FIG. 74 is an accumulator cycle which additionally includes, it comparing with the cycle shown in FIG. 21, a passageway  297  bypassing the capillary tube  211  and a solenoid valve  294  for opening or closing the passageway  294 . Refrigerant flow passage changing over means changes over flowing directions of refrigerant upon cooling operation, upon heating operation, upon dehumidifying operation, and upon defrosting operation during dehumidifying operation (hereinafter referred to as defrosting operation). Similarly as in the automotive air conditioner described hereinabove, the refrigerant flow passage changing over means includes a four-way valve  213  for changing over the discharging direction of the refrigerant compressor  201  between that upon cooling operation and that upon any other operation, a first solenoid opening/closing valve  201  for bypassing, upon heating operation, the first decompressing apparatus  211  and the evaporator  207  on the upstream side, a second solenoid opening/closing valve  260  for bypassing, upon dehumidifying operation, the second decompressing apparatus  266 , and a third solenoid opening/closing valve  298  for bypassing, upon defrosting operation, the first decompressing apparatus  211 . 
     A pair of check valves  262  and  265  for controlling flowing directions of refrigerant are also provided. The flow passage changing over means changes over a flow of refrigerant in the following manner upon cooling operation, upon heating operation, upon dehumidifying operation and upon defrosting operation. Upon cooling operation, refrigerant discharged from the refrigerant compressor  201  flows in the order of four-way valve  213 —outside heat exchanger  202 —first decompressing apparatus  211 —evaporator  207 —accumulator  212 —refrigerant compressor  201  (refer to arrow marks C in FIG.  74 ). discharged from the refrigerant compressor  201  flows in the order of four-way valve  213 —heater  203 —second decompressing apparatus  266 —outside heat exchanger  202 —first solenoid opening/closing valve  261 —accumulator  212 —refrigerant compressor  201  (refer to arrow marks H in FIG.  74 ). 
     Upon dehumidifying operation, refrigerant discharged from the refrigerant compressor  201  flows in the order of four-way valve  213 —heater  203 —second solenoid opening/closing valve  260 —outside heat exchanger  202  (the outside blower  251  is inoperative then)—first decompressing apparatus  211 —evaporator  207 —accumulator  212 —refrigerant compressor  201  (refer to arrow marks D in FIG.  74 ). Upon defrosting operation wherein defrosting of the evaporator  207  is performed in a dehumidifying operation condition, refrigerant discharged from the refrigerant compressor  201  flows in the order of four-way valve  213 —heater  203 —second decompressing apparatus  266 —outside heat exchanger  202  (the outside blower  251  is operative then) —third solenoid opening/closing valve  298 —evaporator  207  —accumulator  212 —refrigerant compressor  201  (refer to arrow marks F in FIG.  74 ). 
     The controlling apparatus  300  includes a temperature sensor for detecting a temperature of a fin or a tube of the evaporator  207  or a temperature of air having passed the evaporator  207 . The temperature sensor is provided to detect frost on the evaporator  207 , and when the temperature of the fin of the evaporator  207  detected by the temperature sensor is lowered to 0° C., the controlling apparatus  300  forecasts frosting and executes defrosting of the evaporator  207  in order to prevent frosting. 
     Subsequently, defrosting operation during dehumidifying operation of the automotive air conditioner shown in FIG. 74 will be described. If the temperature detected by the temperature sensor during dehumidifying operation becomes lower than 0° C., then the controlling apparatus  300  closes the second solenoid opening/closing valve  260 , opens the third solenoid opening/closing valve  298  and renders the outside blower  251  operative to effect defrosting operation. Then, if the temperature detected by the temperature sensor rises higher than 1° C., then the controlling apparatus  300  opens the second solenoid opening/closing valve  260 , closes the third solenoid opening/closing valve  298  and renders the outside blower  251  inoperative to return the operation to dehumidifying operation. If dehumidification is set by means of the air conditioning mode setting switch  314  of the operation panel by the passenger, then outside air or inside air selected by the inside/outside air changing over means  131  is sucked into the duct  100  by the blower  132 , passes through the evaporator  207 , the heater  203  and the auxiliary heaters  700  and  701  and is blown out into the room of the automobile from a spit hole set by the blowing mode changing over switch  303 . The amount of a wind then is set by means of the wind amount setting switch  301 . In the refrigerating cycle upon dehumidifying operation, refrigerant in a high temperature, high pressure condition discharged from the refrigerant compressor  201  is introduced into the heater  203  by means of the four-way valve  213 . Here, the refrigerant exchanges heat with air flowing in the duct  100  to heat the air in the duct  100  while it is condensed and liquefied in the heater  203 . The thus liquefied refrigerant then flows into the outside heat exchanger  202  by way of the second solenoid opening/closing valve  260 . In this instance, since the outside blower  251  is inoperative, the liquefied refrigerant passes through the outside heat exchanger  202  and is then decompressed and expanded into low temperature, low pressure mist in the first decompressing apparatus  211 . The refrigerant in the form of mist flows into the evaporator  207 , in which it takes heat away from air flowing in the duct  100  so that it is evaporated. Then, the thus evaporated refrigerant is resucked into the refrigerant compressor  210  by way of the accumulator  212 . Air sucked into the duct  100  is lowered in temperature when it passes the evaporator  203 , and consequently, saturated vapor in the air is condensed and adheres to the evaporator  207 . After then, the air is heated when it passes the heater  203 , and consequently, the moisture in the air decreases remarkably. As a result, good dehumidifying operation is performed. If the temperature of air sucked into the duct  100  during dehumidifying operation becomes so low that the temperature of the evaporator  207  detected by the temperature sensor is lower than 0° C., then the controlling apparatus  300  controls the flow passage changing over means to change over the refrigerant flow passage of the refrigerating cycle to that for dehumidifying operation. In short, the second solenoid opening/closing valve  260  is closed while the third solenoid opening/closing valve  298  is opened. Consequently, refrigerant condensed and liquefied in the heater  203  is decompressed and expanded into low temperature, low pressure mist in the first decompressing apparatus  266 , and then flows into the outside heat exchanger  202 . In this instance, since the outside blower  251  is operating, the outside heat exchanger  202  functions as a refrigerant evaporator together with the evaporator  207 . The refrigerant admitted into the evaporator  207  by way of the outside heat exchanger  202  and the third solenoid opening/closing valve  298  exchanges heat with outside air passing the outside heat exchanger  202  and also with air flowing in the duct  100  and passing the evaporator  207  so that it is evaporated. The thus evaporated refrigerant is then re-sucked into the refrigerant compressor  201  by way of the accumulator  212 . The evaporating pressure is raised by using the outside heat exchanger  202  as a refrigerant evaporator together with the evaporator  207 . Consequently, while the evaporator  207  functions as a refrigerant evaporator, the temperature of the evaporator  207  rises and as a result, frosting of the evaporator  207  can be prevented. Then, if the temperature of the fin of the evaporator  207  detected by the temperature sensor becomes higher than 1° C., then the controlling apparatus  100  controls the flow passage changing over means to open the second solenoid opening/closing valve  260  and close the third solenoid opening/closing valve  298  to change over the refrigerant flow passage of the refrigerating cycle to that for dehumidifying operation. Further, the outside blower  251  is rendered inoperative, thereby performing dehumidifying operation described hereinabove. In the automotive air conditioner shown in FIG. 74, since the evaporator  207  in the duct  100  always functions, upon dehumidifying operation, as a refrigerant evaporator such that dehumidifying operation is maintained even in defrosting operation as described hereinabove, the temperature in the room of the automobile can normally be kept low. Further, since defrosting can be performed without lowering the capacity of the refrigerant compressor  201 , no drop in blown out air temperature is invited upon defrosting operation. FIG. 75 is a refrigerant circuit diagram of a yet further automotive air conditioner according to the present invention. The present automotive air conditioner includes a three-way valve  269  in place of the four-way valve  213  of the automotive air conditioner shown in FIG.  74  and additionally includes a fourth solenoid opening/closing valve  268  for returning, upon cooling operation, refrigerant accumulated in the heater  203  to the accumulator  212 . FIG. 76 is a refrigerant circuit diagram of a yet further automotive air conditioner according to the present invention. The present automotive air conditioner includes two fifth and sixth solenoid opening/closing valves  270  and  271  in place of the three-way valve  269  of the automotive air conditioner shown in FIG.  75 . 
     FIG. 77 is a refrigerant circuit diagram of a yet further automotive air conditioner according to the present invention. The present automotive air conditioner includes a three-way valve  272  in place of the fifth solenoid opening valve  270  for changing over the discharging direction of the refrigerant compressor  201  in the automotive air conditioner shown in FIG.  76  and the fourth solenoid opening/closing valve  268  for returning, upon cooling operation, refrigerant accumulated in the heater  203  to the accumulator  212 . FIG. 78 is a refrigerant circuit diagram of a yet further automotive air conditioner according to the present invention. The refrigerating cycle of the present automotive air conditioner is changed over in the following manner in accordance with various operation modes by flow passage changing over means. Upon cooling operation, refrigerant discharged from the refrigerant compressor  201  flows in the order of the four-way valve  213 —outside heat exchanger  202 —seventh solenoid opening/closing valve  296 —first decompressing apparatus  211 —evaporator  207 —accumulator  212 —refrigerant compressor  201  (refer to arrow marks C in FIG.  78 ). Upon heating operation, refrigerant discharged from the refrigerant compressor  201  flows in the order of the four-way valve  213 —heater  203 —second decompressing apparatus  266 —seventh solenoid opening/closing valve  296 —outside heat exchanger  202 —four-way valve  213 —accumulator  212 —refrigerant compressor  201  (refer to arrow marks H in FIG.  78 ). Upon dehumidifying operation, refrigerant discharged from the refrigerant compressor  201  flows in the order of the four-way valve  213 —heater  203 —second decompressing apparatus  266 —eighth solenoid opening/closing valve  298 —evaporator  207 —accumulator  212 —refrigerant compressor  201  (refer to arrow marks D in FIG.  78 ). Upon defrosting operation, refrigerant discharged from the refrigerant compressor  201  passes in the order of the four-way valve  213 —heater  203 —second decompressing apparatus  266 . The refrigerant having passed the second to decompressing apparatus  266  is divided into two flows. In one of the two flows, the refrigerant flows in the order of the eighth solenoid opening/closing valve  298 —evaporator  207 —accumulator  212 —refrigerant compressor  201 . Meanwhile, in the other flow, the refrigerant flows in the order of the seventh solenoid opening/closing valve  296 —outside heat exchanger  202 —four-way valve  213 —accumulator  212 —refrigerant compressor  201  (refer to arrow marks F in FIG.  78 ). 
     FIG. 79 shows a refrigerant circuit diagram of a yet further automotive air conditioner according to the present invention. The refrigerating cycle of the present automotive air conditioner is changed over in the following manner in accordance with various operation modes by flow passage changing over means. Upon cooling operation, refrigerant discharged from the refrigerant compressor  201  flows in the order of the four-way valve  213 —ninth solenoid opening/closing valve  295 —outside heat exchanger  202 —tenth solenoid opening/closing valve  291 —first decompressing apparatus  211 —evaporator  207 —accumulator  212 —refrigerant compressor  201 . Upon heating operation, refrigerant discharged from the refrigerant compressor  201  flows in the order of the four-way valve  213 —heater  203 —eleventh solenoid opening/closing valve  292 —second decompressing apparatus  266 —outside heat exchanger  202 —ninth solenoid opening/closing valve  293 —four-way valve  213 —accumulator  212 —refrigerant compressor  201 . Upon dehumidifying operation, refrigerant discharged from the refrigerant compressor  201  is divided into two flows one of which flows to the four-way valve  213  and the other of which flows to a twelfth solenoid opening/closing valve  294 . The refrigerant flowing to the four-way valve  213  flows in the order of the four-way valve  213 —heater  203 —tenth solenoid opening/closing valve  291 —first decompressing apparatus  211 —evaporator  207 —accumulator  212 —refrigerant compressor  201 . On the other hand, the refrigerant flowing to the twelfth solenoid opening/closing valve  294  flows in the order of the twelfth solenoid opening/closing valve  294 —outside heat exchanger  202 —tenth solenoid opening/closing valve  291 —first decompressing apparatus  211 —evaporator  207 —accumulator  212 —refrigerant compressor  212 . Upon defrosting operation, refrigerant discharged from the refrigerant compressor  201  passes in the order of the four-way valve  213 —heater  203 . The refrigerant having passed the heater  203  is divided into two flows. In one of the two flows, the refrigerant flows in the order of the tenth solenoid opening/closing valve  291 —first decompressing apparatus  211 —evaporator  207 —accumulator  212 —refrigerant compressor  201 . Meanwhile, in the other flow, the refrigerant flows in the order of the eleventh solenoid opening/closing valve  292 —second decompressing apparatus  266 —outside heat exchanger  202 —ninth solenoid opening/closing valve  293 —four-way valve  213 —accumulator  212 —refrigerant compressor  201 . FIG. 80 is a refrigerant circuit diagram of a yet further automotive air conditioner according to the present invention. The present automotive air conditioner adopts the construction wherein refrigerant always flows in the evaporator  207 . Thus, a bypass wind passageway for flowing air bypassing the evaporator  207  is provided in the duct  100 , and upon heating operation, the evaporator  207  is closed by the damper  159  on the upstream side so that refrigerant may not exchange heat with air in the duct  100 . The refrigerating cycle of the present automotive air conditioner is changed over in the following manner in accordance with various operation modes by flow passage changing over means. Upon cooling operation, refrigerant discharged from the refrigerant compressor  201  flows in the order of the four-way valve  213 —outside heat exchanger  202 —first decompressing apparatus  211 —evaporator  207 —accumulator  212 —refrigerant compressor  201 . Upon heating operation, refrigerant discharged from the refrigerant compressor  201  flows in the order of the four-way valve  213 —heater  203 —second decompressing apparatus  266 —outside heat exchanger  202 —solenoid opening/closing valve  298 —evaporator  207 —accumulator  212 —refrigerant compressor  201 . Upon dehumidifying operation, refrigerant discharged from the refrigerant compressor  201  flows in the order of the four-way valve  213 —heater  203 —solenoid opening/closing valve  260 —outside heat exchanger  201 —first decompressing apparatus  211 —evaporator  207 —accumulator  212 —refrigerant compressor  201 . Upon defrosting operation, refrigerant discharged from the refrigerant compressor  201  flows in the order of the four-way valve  213 —heater  203 —second decompressing apparatus  266 —outside heat exchanger  202 —solenoid opening/closing valve  298 —evaporator  207 —accumulator  212 —refrigerant compressor  201 . FIG. 81 is a refrigerant circuit diagram of a yet further automotive air conditioner according to the present invention. The present automotive air conditioner adopts the construction wherein refrigerant always flows in the evaporator  207 . Thus, a bypass wind passageway for flowing air bypassing the heater  203  is provided in the duct  100 , and upon cooling operation, the heater  203  is closed by the damper  154  on the downstream side so that refrigerant and air in the duct  100  may not exchange heat in the heater  203 . The refrigerating cycle of the present automotive air conditioner is changed over in the following manner in accordance with various operation modes by flow passage changing over means. Upon cooling operation, refrigerant discharged from the refrigerant compressor  201  flows in the order of the heater  203 —solenoid opening/closing valve  260 —outside heat exchanger  202 —first decompressing apparatus  211 —evaporator  207 —accumulator  212 —refrigerant compressor  201 . Upon heating operation, refrigerant discharged from the refrigerant compressor  201  flows in the order of the heater  203 —second decompressing apparatus  266 —outside heat exchanger  202 —solenoid opening/closing valve  261 —accumulator  212 —refrigerant compressor  201 . Upon dehumidifying operation, refrigerant discharged from the refrigerant compressor  201  flows in the order of the heater  203 —solenoid opening/closing valve  260 —outside heat exchanger  202 —first decompressing apparatus  211 —evaporator  207 —accumulator  212 —refrigerant compressor  201 . Upon defrosting operation, refrigerant discharged from the refrigerant compressor  201  flows in the order of the heater  203 —second decompressing apparatus  266 —outside heat exchanger  202 —solenoid opening/closing valve  298 —evaporator  207 —accumulator  212 —refrigerant compressor  201 . A yet further automotive air conditioner according to the present invention can be attained by a circuit similar to the refrigerating circuit shown in FIG.  40 . The present automotive air conditioner will thus be described with reference to FIG.  40 . The present automotive air conditioner adopts the construction wherein refrigerant always flows in the evaporator  207  and the heater  203 . Thus, a bypass wind passageway for flowing air bypassing the evaporator  207  and another bypass wind passageway for flowing air bypassing the heater  203  are provided in the duct  100 , and upon heating operation, the evaporator  207  is closed by the damper  159  on the upstream side, but upon cooling operation, the heater  203  is closed by the damper  154  on the downstream side. The refrigerating cycle of the present automotive air conditioner is changed over in the following manner in accordance with various operation modes by flow passage changing over means. Upon cooling operation, refrigerant discharged from the refrigerant compressor  201  flows in the order of the heater  203 —solenoid opening/closing valve  260 —outside heat exchanger  202 —first decompressing apparatus  211 —evaporator  207 —accumulator  212 —refrigerant compressor  201 . Upon heating operation, refrigerant discharged from the refrigerant compressor  201  flows in the order of the heater  203 —second decompressing apparatus  266 —outside heat exchanger  202  solenoid opening/closing valve  261 —evaporator  207 —accumulator  212 —refrigerant compressor  201 . Upon dehumidifying operation, refrigerant discharged from the refrigerant compressor  201  flows in the order of the heater  203 —solenoid opening/closing valve  260 —outside heat exchanger  202 —first decompressing apparatus  211 —evaporator  207 —accumulator  212 —refrigerant compressor  201 . Upon defrosting operation, refrigerant discharged from the refrigerant compressor  201  flows in the order of the heater  203 —second decompressing apparatus  266 —outside heat exchanger  202 —solenoid opening/closing valve  261 —evaporator  207 —accumulator  212 —refrigerant compressor  201 . A yet further automotive air conditioner according to the present invention can be attained by a circuit similar to the refrigerating circuit shown in FIG.  7 . The present automotive air conditioner will thus be described with reference to FIG.  7 . The present automotive air conditioner adopts the construction wherein refrigerant always flows in —the evaporator  207  and the heater  203 . Thus, a bypass wind passageway for flowing air bypassing the heater  203  is provided in the duct  100 , and the opening of the damper  154  on the downstream side is varied to adjust the mount of air to pass the heater  203  and the amount of air to pass the bypass passageway to adjust the blown out air temperature. The refrigerating cycle of the present automotive air conditioner is changed over in the following manner by flow passage changing over means which employs two four-way valves  213  and  214 . Upon cooling operation and upon defrosting operation, refrigerant discharged from the refrigerant compressor  201  flows in the order of the four-way valve  213  —outside heat exchanger  202 —four-way valve  214 —heater  203 —first decompressing apparatus  211 —evaporator  207 —four-way valve  213 —accumulator  212 —refrigerant compressor  201 . Upon heating operation and upon defrosting operation, refrigerant discharged from the refrigerant compressor  201  flows in the order of the four-way valve  213 —four-way valve  214 —heater  203 —first decompressing apparatus  211 —evaporator  207 —four-way valve  214 —outside heat exchanger  203 —our-way valve  213 —accumulator  212 —refrigerant compressor  201 . Further, dehumidifying operation and defrosting operation can be achieved even with such a construction as shown in FIG. 11 wherein a bypass wind passageway is formed sidewardly of the evaporator  207 . Further, dehumidifying operation and defrosting operation can be achieved similarly even with a construction wherein the four-way valve  214  is replaced by four check valves  216 ,  217 ,  218  and  219  as shown in FIG.  13 . 
     Further, while a temperature sensor is employed as a sensor for detecting frost on the evaporator in the automotive air conditioners described hereinabove, not a temperature but a pressure of refrigerant in the pipe on the exit side of the evaporator may alternatively be detected to forecast frosting from an evaporating temperature of refrigerant. Or else, a sensor for detecting a loss in pressure of the evaporator may be used to detect frosting from a variation in loss in pressure of a wing passing the evaporator. FIGS. 82 to  85  show refrigerating cycles of a yet further automotive air conditioner according to the present invention. In particular, FIGS. 82 to  85  illustrate cooling, heating, dehumidifying heating and defrosting conditions, respectively, and indicate a pipe in which refrigerant flows by a thick line. The expansion pipe  206  employed here is a temperature differential expansion valve which varies the throttling amount of the refrigerant flow passage so that refrigerant on the exit-side of the heater  203  adjacent the condenser may have a predetermined subcooling degree. Upon cooling operation, refrigerant discharged from the refrigerant compressor  201  flows in the order of the four-way valve  213 —outside heat exchanger  202 —expanding means  260 —evaporator  207 —accumulator  212 —refrigerant compressor  201 . Upon heating operation, refrigerant flows in the order of the compressor  201 —four-way valve  213 —heater  203 —expansion valve  206 —outside heat exchanger  202 —accumulator  212 —refrigerant compressor  201 . When there is the possibility upon heating that the windshield may be fogged, dehumidifying heating operation is performed, and in this instance, refrigerant flows in the order of the compressor  201 —heater  203 —expansion valve  206 —outside heat exchanger  202 —solenoid opening/closing valve  266 —evaporator  207 —accumulator  212 —refrigerant compressor  201 . In case the surface of the outside heat exchanger  202  is frozen upon heating, the condition of the outside heat exchanger  202  is detected and defrosting operation is started. Upon defrosting operation, refrigerant circulates in the refrigerant cycle in the order of the refrigerant compressor  201 —heater  203 —solenoid valve  298 —outside heat exchanger  202 —expanding capillary tube  260 —evaporator  207 —accumulator  212 —compressor  201 . The difference of the refrigerating cycles from those of the automotive air conditioner shown in FIG. 63 is that, while refrigerant flows, upon defrosting operation, in the order of the outside heat exchanger  202 —heater  203  in the automotive air conditioner shown in FIG. 63, refrigerant flows in the reverse order of the heater  203 —outside heat exchanger  202  in the present automotive air conditioner. When discharged refrigerant flows, upon defrosting operation, first into the heater  203  as in the present automotive air conditioner, a predetermined subcooling degree can always be obtained at the heater  203 . This will be described subsequently. Since, in the automotive air conditioner shown in FIG. 63, refrigerant is condensed first in the outside heat exchanger  202 , when the temperature of outside air is low at 0° C. or so, it is forecast that refrigerant after passing the outside heat exchanger  202  may be cooled to 10° C. or so and condensed. Here, if it is assumed that the refrigerant has a subcooling degree of 2 to 3° C. or so when it passes the outside heat exchanger  202 , the temperature corresponding to a condensing pressure of the refrigerant when it passes the outside heat exchanger  202  is 12 to 13° C. or so. On the other hand, for a while after the operation is changed over from heating operation to defrosting operation, air is not cooled sufficiently in the evaporator  207  and comparatively warm air of a temperature equal to the room temperature or so will flow into the heater  203 . The air temperature is in most cases 12 to 13° C. or more and may sometimes be higher than a temperature corresponding to the condensing pressure described above. In this instance, refrigerant condensed once in the outside heat exchanger  202  will be evaporated again when it passes the heater  203 . The refrigerant does not have a subcooling degree at least when it passes the condenser portion of the heater  203 . As a result, the expansion valve  206  of the temperature differential type will throttle the flow rate of refrigerant so as to obtain a subcooling degree, and consequently, the amount of refrigerant which circulates in the cycle will be reduced remarkably. On the other hand, in the automotive air a conditioner shown in FIG. 85, since refrigerant discharged from the compressor  201  flows, even upon defrosting operation, similarly as upon heating operation, first into the heater  203 , such a disadvantage as described above does not occur even upon changing over from heating operation to defrosting operation. In the present automotive air conditioner, refrigerant having passed the heater  203  after defrosting is lowered in temperature, and while the temperature of refrigerant in the outside heat exchanger  202  is low comparing with that of refrigerant which advances from the compressor  201  directly to the outside heat exchanger  202 , since refrigerant of a temperature higher than 0° C. flows any way into the outside heat exchanger  202 , defrosting operation is achieved well. 
     Moreover, in FIG. 85 the shutter  225  is drawn in an open state, but when performing defrosting it is not preferable that cold air be introduced into the outside heat exchanger  202 , and the shutter  225  closes during defrosting operation. 
     After performing defrosting with the refrigeration cycle indicated in FIG. 83, when the frost of the outside heat exchanger  202  melts, a return to the heating operation mode indicated in FIG. 83 again effected. At this time, however, in the defrosting operation mode indicated in FIG. 83 high-pressure, high-temperature refrigerant flows into the outside heat exchanger  202 . Consequently, whereas condensation of refrigerant was performed by the outside heat exchanger  202 , in the heating operation mode indicated in FIG. 85 the outside heat exchanger  202  functions as an evaporator, and refrigerant is immediately taken from the outside heat —exchanger, through the accumulator  212 , and into the compressor  201  side. 
     Consequently, when changing from the defrosting operation mode indicated in FIG. 83 immediately to the heating operation mode indicated in FIG. 85, refrigerant condensed and maintained within the outside heat exchanger  202  is taken at once through the accumulator  212  into the compressor  201  side. Here, the accumulator  212  operates so as to absorb fluctuations in refrigerant flow, but along with the large capacity of the outside heat exchanger  202 , in a case where a large amount of refrigerant has been momentarily sucked from the outside heat exchanger  202 , a state wherein vapor-liquid separation cannot be performed sufficiently even by accumulator  212  is hypothesized. In this case, liquid vapor which has not undergone vapor-liquid separation is taken into the compressor  201  side, and leads to liquid compression in the compressor  201  which is not desirable. Accordingly, when returning to the heating operation mode indicated in FIG. 85 from the defrosting operation mode indicated in FIG. 83 preferable to pass once through the dehumidifying operation mode indicated in FIG.  82 . That is to say, in the dehumidifying operation mode indicated in FIG. 82 because an evaporator  207  is interposed downstream of the outside heat exchanger  202 , liquid refrigerant condensed within the outside heat exchanger  202  is also discharged once to the evaporator  107  side. Accordingly, if, after the amount of liquid refrigerant within the outside heat exchanger  202  drops, the heating operation mode indicated in FIG. 85 is enabled, the above-described problem of liquid compression does not occur. Moreover, refrigerant comes to be retained within the evaporator  207  at this time, but the refrigerant within this evaporator  207  comes to be moved to the foregoing accumulator  212  side by means of suction of the compressor  201 . 
     Additionally, in the refrigerant circuit indicated in FIG. 83, because the evaporator  207  and heater  203  operate together, air passing through the duct  100  comes to be heated by the heater  203  after being chilled by the evaporator  207 . As a result of this, good dehumidification is performed even in the refrigeration cycle state indicated in FIG.  83 . During this dehumidifying operation the shutter  255  operates so as to open an air path as shown in FIG.  88 . The refrigeration cycle indicated in FIG. 83 was treated as defrosting operation in the above-described example, but control is performed similarly also when dehumidifying operation is performed. That is to say, in a case wherein it is caused to change to the heating operation mode indicated in FIG. 85 after dehumidification is performed in the cycle indicate in FIG. 83, it is preferable not to switch abruptly to heating operation, but rather to effect heating operation after once performing the dehumidifying operation mode indicated in FIG.  82 . 
     FIG. 103 is a flowchart indicating the above-described control. In step  443  either the cooling, heating, or dehumidifying mode is selected, but if heating operation is selected, determination is made in step  494  whether the immediately previous operation was the refrigeration cycle indicated in FIG.  85 . Moreover, for convenience the cycle indicated in FIG. 85 is termed No.  2  dehumidifying, defrosting operation, or dehumidifying C operation. Additionally, the refrigeration cycle state indicated in FIG. 84 is termed No.  1  dehumidifying operation or dehumidifying H operation for convenience. 
     If it is determined in step  494  that the immediately previous operation was dehumidifying C operation, dehumidifying H operation is performed in step  495  for a specified time (between about 30 seconds to 60 seconds). 
     Additionally, if frosting is detected during heating operation and defrost switch is switched on (step  453 ), defrosting operation is performed in the refrigeration cycle indicated in FIG.  85 . That is to say, in this case the cycle is defrosting C, and in order to be able to release defrosting quickly the compressor  201  operates at high capacity, or in order to be able to maintain the heating function, passenger compartment inner air is caused to be recirculated in the duct  100 , and furthermore an auxiliary heater  700  is also caused to be operated. Accordingly, the amount of air of the blower  132  is set to low and also the outside heat exchanger fan  251  is caused to stop. After the end of this defrosting is detected in step  497 , dehumidifying H operation is caused to be performed once for a specified time before moving to heating operation. 
     As a result of being able to perform the above-described dehumidifying H operation indicated in FIG.  84  and dehumidifying C operation as shown in FIG. 85, it is preferable to switch this dehumidifying H operation and dehumidifying C operation appropriately according to the refrigeration cycle state. Briefly, in a state wherein the refrigerant pressure or temperature of the compressor discharge side is low, dehumidifying H indicated in FIG. 85 is set, the outside heat exchanger  202  is employed as an evaporator, and absorption of heat is performed. 
     Conversely, in a state wherein high-pressure pressure is high, the dehumidifying C operation indicated in FIG. 85 is set, the outside heat exchanger  202  is caused to operate as a condenser, and heat radiation is performed. Accordingly, moreover, an optimal state can be attained by controlling the capacity of the compressor  201  and the amount of air of the outside heat exchanger fan  251  on the basis of the low-pressure side pressure of the refrigeration cycle. 
     FIG. 104 indicates this operation state typically. Ambient air temperature is taken for the horizontal axis, and the vertical axis indicates, sequentially from the top, condensation temperature of high-pressure side refrigerant (Tc), evaporation temperature of low-pressure refrigerant (Te), amount of air of the outside heat exchanger blower  251 , discharge capacity of the compressor  201 , and degree of opening of the air-mix damper  154 . FIG. 87 indicates the time of dehumidifying operation. A difference exists according to the inner/outer air mode, but in a case of the outer air mode, at an ambient air temperature of roughly −5° C. or less, effective dehumidification cannot be performed and so heating operation is effected. Moreover, this freezing limit temperature comes to be a lower temperature during the inner air mode. Additionally, at an ambient air temperature of 20° C. or more, normal cooling is performed and dehumidification of the air inside the passenger compartment is achieved during cooling, and so special dehumidification is not performed. Consequently, dehumidifying operation switching of an ambient air temperature of roughly −5° C. to 20° C. is performed. In a state of comparatively low ambient air temperature, the dehumidifying average operation indicated in FIG. 84 is set and heat absorption from the outside heat exchanger  202  is performed. Conversely, in a state of comparatively high ambient air temperature, the dehumidifying C operation indicated in FIG. 85 is set, and heat radiation by means of the outside heat exchanger  202  is performed. Furthermore, foregoing dehumidifying operation the air-mix damper  154  is normally set at MAX HOT and the total quantity of air is caused to flow to the heater  203  side, but when ambient air temperature is high and cooling-tinged operation is demanded, the air-mix damper  154  is set to cooling-side operation which causes the heater  203  to be bypassed. 
     The capacity of the compressor  201  is set to high capacity when ambient air temperature is particularly low and sufficient refrigerant flow for absorbing heat from outside air is required, and in other states the capacity of the compressor is reduced in accordance with load to achieve operation that gives priority to saving energy. Additionally, the outside heat exchanger blower  251 , primarily during switching of dehumidifying H operation and dehumidifying C operation, causes the amount of air to increase in accordance with a drop (rise) in ambient air temperature from that point. By means of this, the high-pressure side refrigerant temperature Tc is set to a substantially uniform value, and dehumidifying operation can be achieved. 
     FIG. 105 is a flowchart concretely representing the control modes conceptually indicated in FIG.  104 . This flowchart shown in FIG. 105 indicates entirely the methods of dehumidification during dehumidifying operation. That is to say, control at the state wherein dehumidifying operation has been selected in step  443  is indicated. 
     First, in step  425  the difference between the target blowing temperature TAO and the blowing temperature TA is seen. A state wherein this difference is 1° C. or more is a state wherein actual blowing temperature is not high, and in this case basically the dehumidifying H operation indicated in FIG. 84 is set and heat absorption from the outside heat exchanger  202  is performed. Conversely, when the difference between TAO and TA is −1° C. or less, it is a state wherein a sufficient amount of heating is attained by the condenser  203 , and in this case basically the dehumidifying C operation indicated in FIG. 85 is set and heat radiation at the outside heat exchanger  202  is performed. Accordingly, if the difference between TAO and TA is between −1° C. and 1° C., and basically it is indicated that the operation state is near the target value in the auto mode or the limit value in the manual mode. 
     Next, refrigerant temperature Te at the low-pressure side in the respective modes is determined (step  426 ). If Te is 3° C. or more in a state wherein TAO-TA is 1° C. or more, the dehumidifying H mode is set in step  427  and, along with this, the outside heat exchanger blower  251  stops and the capacity of the compressor  201  increases. That is to say, in this state the low-pressure side pressure of the compressor  201  is at a high state, and the low-pressure side pressure is cause to be lowered by increasing the capacity of the compressor. 
     In a case wherein Te is from 0 to 3° C. in step  426 , basically the high-pressure pressure is high and the high-pressure side pressure is a state which is appropriate at the proximity of the freezing limit or in the proximity of the freezing temperature, and so the dehumidifying H mode is set and also the capacity of the compressor is set to rise somewhat. 
     In a state wherein it is determined in step  426  that Te is 0° C. or less, basically both high-pressure side pressure and the low-pressure side pressure exhibit a low state. In this case, the dehumidifying H mode is set and, along with this, the amount of air of the outside heat exchanger blower  251  is increased and the amount of heat absorption is increased. Accordingly, in step  430  it is determined whether the amount of air of the outside heat exchanger blower has risen to the maximum amount of air, if the maximum amount of air has not been reached dehumidifying H operation is performed at that state, no further heat absorption is performed when maximum heating has been reached, or if there is danger of the evaporator  207  freezing switching to the heating operation mode and not the dehumidifying H mode is performed. 
     Next, Te temperature determination by means of step  426  at a state wherein the difference between TAO and TA is determined to be between −1° C. and 1° C. in step  425  will be described. In this case, in a state wherein Te is determined to be 3° C. or more in step  426 , the high-pressure side pressure state is the target value or the limit value, and also the low-pressure side pressure exhibits a high state. In this case heat absorption by means of the outside heat exchanger  202 , and dehumidification is set to the dehumidifying C mode indicated in FIG.  85 . However in this case as well it is not necessary to actively perform heat radiation, and so the outside heat exchanger blower  251  is stopped. 
     When Te is determined to be between0 and 3° C. in step  426 , the state is such that the high-pressure side refrigerant is at the refrigerants target value or limit value, and also that the low-pressure side refrigerant is at the target value or within the appropriate range, and optimal dehumidifying operation comes to be promoted. That is to say, the dehumidifying H mode is set and because heat absorption at the outside heat exchanger  202  is not even necessary, the blower  251  is caused to stop. Is a state wherein Te is determined to be 0° C. or less in step  426 , whereas the high-pressure side refrigerant is at the target value or the limit value, the low-pressure side refrigerant exhibits a low-temperature (low-pressure) state. In this case the dehumidifying H mode is set and, along with this, the amount of air of the outside heat exchanger blower  251  is increased and the amount of heat absorption is caused to increase. Accordingly, it is determined in step  430  whether the amount of air of the outside heat exchanger blower  251  is at maximum, and at a maximum state in dehumidifying operation there is danger of the evaporator  207  freezing and so operation is switched to heating operation. 
     Next, Te temperature determination at a state wherein TAO-TA is −1° C. or less in step  425  will be described. In this case a Te of 3° C. or more indicates a state wherein the high-pressure side refrigerant and the low-pressure refrigerant are both high-temperature (high-pressure). Because sufficient heat absorption is being performed in this case, dehumidifying C is set and the outside heat exchanger  202  is employed as a heat radiator. Furthermore, the amount of air of the blower  251  is raised to increase the amount of heat radiation. According it is determined in step  430  whether the amount of air of the outside heat exchanger blower  251  is at maximum, and at a maximum state first the air-mix damper  154  is caused to close gradually (step  437 ). Accordingly the difference between TAO and TA is determined in this state and if it is still −1° C. or less, the capacity of the compressor  201  is presently caused to drop. This indicates that the blowing temperature is higher even in this state, and causes the quantity of heat at the heater  203  to decline by causing the capacity to drop. 
     In a state wherein Te is between0 and 3° C. in step  426 , although the high-pressure side refrigerant is high-pressure (high-temperature), the low-pressure side refrigerant exhibits the freezing limit or optimal temperature of the evaporator  207 , and in this state dehumidifying C operation is set and heat radiation is performed by the outside heat exchanger  202  and, along with this, the capacity of the compressor  201  is caused to drop. 
     Additionally, a state wherein Te is 0° C. or less in step  426  indicates that although the high-pressure side refrigerant is high-pressure (high-temperature), the low-pressure side refrigerant is at a low-pressure (low-temperature) state, and in this state dehumidifying C operation is set and heat radiation is performed by the outside heat exchanger  202  and, along with this, the capacity of the compressor  201  is caused to drop in an attempt to raise the low-pressure side pressure. Additionally, the amount of air of the blower  251  is caused to drop. 
     A refrigeration cycle of an air-conditioning apparatus for automobile use has heretofore been variously described, but an example of an example layout of an automobile of the foregoing respective structures will be described. In FIG. 106 a so-called one-box car is taken to be an electric automobile, and an example of a layout of the respective devices in this one-box car is indicated. In the FIG. 800 is a battery, and in the present example sixteen 12 V batteries are taken to be mounted.  801  is a safety plug, and interrupts the high-voltage power supply when inspecting or replacing the battery or the like. Furthermore, the high-voltage power supply is a voltage power supply of 200 V, and a travel motor  803  and compressor  201  are driven by this high-voltage power supply.  803  is a fuse which prevents excessive current from flowing to the foregoing high-voltage power supply. 
     According to the present example an air-conditioning apparatus control unit  300  and inverter of a compressor are both disposed within the passenger compartment. This is done in order to provide protection from the penetration or rainwater and the like to maintain electrical insulation. 
     In the FIG. 804 is a DC converter which supplies a specified voltage of about 12 V to an auxiliary battery  805  the voltage of which is caused to be lower than the main battery  800 . Also, in the FIG. 806 is a filler water plug cover, and replenishment of electrolyte to the battery  800  is performed after detaching this cover. In the FIG. 807 is an inverter for drive to the motor  800 . Also, in the FIG. 708 is an ECU which controls this inverter to adjust the traveling state of the automobile.  809  is a controller which controls a power steering motor  810 . In the FIG. 811 is a vacuum pump, and vacuum created battery pump is maintained in a reservoir tank and employed to drive the vehicles brakes. 
     FIG. 107 is a conceptual diagram indicating the disposed state of respective devices for air-conditioning use in an automobile disposed in this manner. The outside heat exchanger  202  is disposed substantially horizontally below a driver seat. For this reason a shutter  255  not illustrated is employed as an air guide, and when the shutter  255  is open wind is led to the outside heat exchanger  202  by means of a louver of the shutter. Additionally, a duct disposed with an evaporator, heater, and so on is disposed on the inner side of an instrument panel in front of a passenger seat. Furthermore, a unit for inner/outer air switching damper  151  use and a unit for vent switching damper use are arranged to be adjacent to this duct  100 . A unit housing a compressor  201 , accumulator  202 , and four-way valve  213  is disposed below the passenger compartment floor to a side of the outside heat exchanger  202 . As described above, an inverter  852  and the control box  300  are disposed within the passenger compartment into which rainwater and the like do not penetrate. Additionally, a control panel  851  is disposed in a location easily operated from the driver seat. 
     Moreover, according to the above-described example the compressor  201  is driven by an electric motor and the discharge amount of the compressor  201  is controlled by varying the speed of the motor, but it is also acceptable to use an article which does not vary discharge capacity as the compressor  201 . Along with this, it is also acceptable to make the drive of the compressor  201  as well not exclusively an electric motor but employ an engine or the like. 
     Additionally, according to the above-described example a temperature-operated type expansion valve or capillary tube is employed as an expansion means, but it is also acceptable to another electrical type expansion valve which varies an amount of aperture in accordance with an electrical signal. 
     Additionally, an air-conditioning apparatus according to the present invention is not exclusively for air conditioning of a passenger compartment of an electric automobile, but may be employed for air conditioning of a passenger compartment of an ordinary automobile employing an internal combustion engine or for general air conditioning of other passenger vehicles. However, the present invention is more effective in a vehicle such as an electric automobile not having an auxiliary heat source. 
     EFFECTS OF THE INVENTION 
     As has been described above, the present invention disposes a heater and evaporator structuring a refrigeration cycle within a duct such that air is heated by means of heat radiation from the heater, and so temperature control for blown air can be performed over a wider range. 
     Additionally, because the present invention takes a heat exchange disposed within a duct as a heater and an evaporator and specifies the functioning thereof, the respective heat exchangers can maintain the functioning thereof even during switching from cooling operation to heating operation, and sudden fogging of window glass and the like can be prevented. 
     Additionally, one invention according to the present invention can vary discharge amount of a compressor by means of speed control of an electric motor, and provides a bypass path to a side of a heater so as to perform control of air flow with an air-mix damper, and so by a combination of discharge capacity control of the compressor and speed control of the air-mix damper, the temperature of blown air can be controlled more exactly. 
     Furthermore, because one invention according to the present invention employs both an outside condenser for dedicated condenser use and an outside evaporator for dedicated evaporator use as outside heat exchangers, the outside condenser and the outside evaporator can respectively be disposed in optimal locations, and a high-efficiency refrigeration cycle can be performed. 
     Moreover, because one invention according to the present invention can continuously switch dehumidifying operation and heating operation in accordance with application, prevention of fogging of window glass during heating operation, prevention of freezing of an evaporator during dehumidifying operation, and defrosting of an outside heat exchanger during heating operation, can be favorably performed. 
     Additionally, one invention according to the present invention utilizes three heat exchangers comprising an outside heat exchanger, condenser, and evaporator during dehumidifying operation, and heat-radiating capacity of the condenser can be controlled by means of varying the heat-exchanging capacity of the heat exchanger. By means of this, dehumidifying operation can be switched to heating-tinged dehumidification or normal dehumidification. Along with this, high-pressure protection of the effect during dehumidifying operation can be favorably achieved. 
     Additionally, whereas one invention according to the present invention employs both an evaporator and an outside heat exchanger as heat absorbers during dehumidifying operation and causes refrigerant to be evaporated, dehumidifying operation can be performed while favorable preventing frosting on the evaporator, even in a state of low ambient air temperature, by disposing an evaporator pressure adjustment valve on a downstream side of the evaporator. 
     Additionally, in one invention according to the present invention a bypass path is provided which causes refrigerant flow to bypass an evaporator and the opening and closing of this bypass path are controlled with an electromagnetic valve, and so the evaporation temperature of refrigerant within the evaporator can be controlled by means of appropriately switching to a state of refrigerant flow to the evaporator or a state of refrigerant flow to the bypass path. 
     Furthermore, in one invention according to the present invention a heater disposed within a duct is divided into a condenser which performs condensation of refrigerant and an over-chiller which performs over-chilling of condensed liquid refrigerant, and so over-chilling can be reliably provided even if the flow of air or temperature of air flowing into the heater fluctuates. Because of this, according to one invention according to the present invention, a refrigeration cycle can be operated in a state constantly providing sufficient over-chilling, and operation of good efficiency can be achieved. 
     Moreover, according to one invention according to the present invention, a state wherein heat absorption is performed only by an outside heat exchanger during heating operation and a state wherein it is performed by both the outside heat exchanger and an evaporator are switched, and so heat is absorbed from the evaporator side as well at a time such as during warmup when heating load is particularly large, and heating can be achieved more rapidly. Furthermore, according to one invention according to the present invention, because a cycle comprising a compressor, a heater, an outside heat exchanger, and an evaporator is caused to be interposed when switching heating operation and defrosting operation, liquid refrigerant condensed and collected by the outside heat exchanger  202  is prevented from being sucked directly to the compressor side. By means of this liquid compression of the compressor can favorably be avoided. 
     Moreover, according to the present invention optimal dehumidification in accordance with the refrigerant state can be achieved by employing a switching means to switch between No. 1 dehumidifying operation using a compressor, a heater, a pressure-reducing means, an outside heat exchanger, and an evaporator and No. 2 dehumidifying and defrosting operation using the condenser, the heater, the outside heat exchanger, the pressure-reducing means, and the evaporator. It is to be noted that, while, in the automotive air conditioners described above, the compressor  201  is driven by means of an electric motor and the discharging capacity of the compressor  201  is controlled by varying the speed of rotation of the motor, the compressor  201  may otherwise be another type which does not have a variable discharging capacity. Further, the compressor  201  need not necessarily be driven by an electric motor but may be driven by an engine or the like. 
     Further, while, in the automotive air conditioners described above, a temperature differential expansion valve or a capillary tube is employed as expanding means, alternatively an electric expansion valve which varies a throttling amount in response to an electric signal may be employed. Further, an automotive air conditioner according to the present invention may be used not only for air conditioning of a room of an electric automobile but also for air conditioning of a room of an ordinary automobile employing an internal combustion engine and any other common vehicle. However, an automotive air conditioner according to the present invention is most effective for use with a vehicle which does not have an auxiliary heat source such as an electric automobile. As described so far, according to the present invention, since a heater and an evaporator which constitute a refrigerating cycle is disposed in a duct and air is heated by radiation of heat from the heater, the temperature of air to be blown out can be controlled in wider range. Further, according to the present invention, since heat exchangers disposed in a duct have individually specified functions as a heater and an evaporator, even upon changing over from cooling operation to heating operation, the heat exchangers can maintain the respective functions thereof, and sudden fogging of the windshield and so forth can be prevented invention, since the discharging capacity of a compressor can be varied by controlling rotation of an electric motor and a bypass passageway is provided sidewardly of a heater such that the flow rate of air may be controlled by means of an air mixing damper, the temperature of air to be blown out can be controlled very finely by combination of control of the discharging amount of the compressor and control of pivotal motion of the air mixing damper. 
     Further, according to the present invention, since the function of an outside heat exchanger is changed over between a condenser function and an evaporator function in response to changing over between cooling operation and heating operation, the refrigerating cycle can be operated efficiently in any of cooling operation, heating operation As and dehumidifying operation. Further, according to the present invention, since two outside heat exchangers are used including an outside condenser which serves only as a condenser and an outside evaporator which serves only as an evaporator, the outside condenser and the outside evaporator can be located at respective optimum positions, and the refrigerating cycle can be achieved efficiently. 
     Further, according to the present invention, since the operation can be changed over successively between dehumidifying operation and heating operation in accordance with an application, prevention of fogging of the windshield upon heating operation, prevention of freezing of an evaporator upon dehumidifying operation and defrosting of an outside heat exchanger upon heating operation can be performed well. Further, according to the present invention, making use of the fact that three heat exchangers are used upon dehumidifying operation including an outside heat exchanger, a condenser and an evaporator, the heat radiating capacity of the condenser can be controlled by varying the heat exchanging capacity of the outside heat exchanger. Consequently, dehumidification can be changed over between ordinary dehumidification and dehumidification having some heating effect. In addition, protection of the refrigerating cycle against a high pressure upon dehumidifying operation can be achieved well. 
     Further, according to the present invention, while both of an evaporator and an outside heat exchanger are used Gas heat sinks to evaporate refrigerant upon dehumidifying operation, since an evaporating pressure regulating valve is disposed on the downstream side of the evaporator, even when the temperature of outside air is low, dehumidifying operation can be performed while preventing frosting of the evaporator well. 
     Further, according to the present invention, since a bypass passageway for flowing refrigerant bypassing an evaporator is provided and opening/closing movement of the bypass passageway is controlled by means of a solenoid valve, the evaporating temperature of refrigerant in the evaporator can be controlled by suitably changing over between a condition wherein refrigerant flows into the evaporator and another condition wherein refrigerant flows into the bypass passageway. Further, according to the present invention, since a heater disposed in a duct is divided into a condenser for condensing refrigerant and a subcooler for subcooling condensed liquid refrigerant, refrigerant can have a subcooling degree with certainty even if the flow rate or the temperature of air to be admitted into the heater varies. Consequently, according to the present invention, the refrigerating cycle can always be operated while refrigerant has a sufficient subcooling degree, and efficient operation can be achieved. 
     Further, according to the present invention, since the heat absorbing condition upon heating operation is changed over between a condition wherein heat is absorbed only by means of an outside heat exchanger and another condition wherein heat is absorbed by means of both of the outside heat exchanger and an evaporator, when the heating load is particularly high such as upon warming up, heat is absorbed also from the evaporator side and heating can be achieved quickly. 
     The other embodiment of the present invention is described hereinafter. 
     Referring first to FIG. 86, there is shown an automotive air conditioner in which a refrigerating cycle according to the present invention is incorporated. The automotive air conditioner shown is carried on an electric automobile and includes a duct  1001  for introducing draft air into the room of the automobile, a fan  1002  disposed in the duct  1001  for producing an air flow to be introduced into the room of the automobile, and a refrigerating cycle  1003  of the accumulator type. 
     The duct  1001  has, at an upstream end thereof, an internal air inlet port  1004  for taking air in the automobile room (internal air) into the duct  1001  and an external air inlet port  1005  for taking air outside the automobile room (external air) into the duct  1001 . The amounts of air to be taken in through the inlet ports  1004  and  1005  are adjusted by a damper  1006 . A downstream end of the duct  1001  communicates with a DEF outlet port  1007  for discharging draft air therethrough toward a window glass of the automobile, a VENT outlet port  1008  for discharging draft air therethrough toward the upper half of the body of the driver, and a FOOT outlet port  1008  for discharging draft air therethrough toward the feet of the driver or around them. The outlet ports  1007  to  1009  are opened or closed by outlet port switching dampers  1010 ,  1011  and  1012 , respectively, which operate in accordance with a selected outlet port mode. 
     An interior evaporator  1013  and an interior condenser  1014  of the refrigerating cycle  1003  are disposed in the duct  1001 , and an air mixing damper  1015  for adjusting the amount of draft air to be introduced into the interior condenser  1014  is provided in the duct  1001 . The air-mixing damper  1015  adjusts the ratio between the amount of air to pass through the interior condenser  1014  and the amount of air to pass through a bypass passageway  1016  (passageway which bypasses the interior condenser  1014 ) formed in the duct  1001  to effect adjustment of the temperature of air to be blown out. 
     The refrigerating cycle  1003  includes a four-way valve  1017  which can change over the circulating direction of refrigerant, and accordingly, it can a perform heating operation and a cooling operation based on the change-over of the four-way valve  1017 . 
     The refrigerating cycle  1003  includes, in addition to the interior evaporator  1013  and the interior condenser  1014  mentioned above, a refrigerant compressor  1019  which is driven to rotate by an electric motor  1018 , an exterior heat exchanger  1021  which receives draft wind of an electric fan  1020  and functions as an evaporator upon heating operation buts functions as a condenser upon cooling operation, a subcooling control valve  1022  for controlling the subcooling degree obtained by the interior condenser  1014 , an evaporation pressure regulating valve  1023  interposed between the interior evaporator  1013  and the exterior heat exchanger  1021 , and-an accumulator  1024  disposed on the upstream side of the refrigerant compressor  1019 . Those functioning parts are connected to each other by a refrigerant pipe  1025 . 
     Further, the refrigerating cycle  1003  has a bypass passageway  1026  for communicating the subcooling control valve  1022  and the exterior heat exchanger  1021  with each other bypassing the exterior evaporator  1013  and the evaporation pressure regulating valve  1023 . Upon heating operation, refrigerant flows along the bypass passageway  1026  so that dehumidifying heating is not performed but heating based on an external air mode (in which external air is introduced in) can be performed. A solenoid valve  1027  for opening or closing the bypass passageway  1026  is provided for the bypass passageway  1026 . The solenoid valve  1027  is controlled so that the bypass passageway  1026  may be closed when a cooling operation or a dehumidifying heating operation is performed. Further, a plurality of check valves  1028  to  1031  for preventing a back flow of refrigerant upon cooling operation or upon heating operation are provided suitably for the refrigerant pipe  1025 . 
     The interior condenser  1014  has a heat exchanging section where heat is exchanged between refrigerant and draft air, and the heat exchanging section has a three-layer structure wherein it is divided into three stream area portions including an upper stream area portion  1014   a , a middle stream area portion  1014   b  and a lower stream area portion  1014   c  and the upper stream area portion  1014   a  is disposed on the lee side of the middle stream area portion  1014   b  in the duct  1001  while the lower stream area portion  1014   c  is disposed on the windward side of the middle stream area portion  1014   b  in the duct  1001  so that the stream area portions  1014   a ,  1014   b  and  1014   c  may provide opposing flows to draft air flowing in the duct  1001 . 
     The subcooling control valve  1022  is shown in more detail in FIG.  87 . Referring to FIG. 87, the subcooling control valve  1022  includes a valve body  1022   b  in which a throttle section  1022   a  is formed, a diaphragm  1022   c  provided at the top of the valve body  1022   b , a valve member  1022   d  for opening or closing the throttle section  1022  upon displacement of the diaphragm  1022   c , a regulating spring  1022   g  for normally biasing the valve member  1022   d  by way of a pin  1022   e  and a spring guide  1022   f  so that the opening of the throttle section  1022   a  may be increased (in the upward direction in FIG.  87 ), a temperature sensitive tube  1022   h  for transmitting a variation of the internal pressure of the valve body  1022   b  to the upper side of the diaphragm  1022   c , and a mantle pipe  1022   i  for transmitting a high pressure on the upstream side of the throttle section  1022   a  to the lower side of the diaphragm  1022   c.    
     An entrance port  1022   j  and an exit port  1022   k  are attached to the valve body  1022   b , and the entrance port  1022   j  is communicated with the exit of the interior condenser  1014  while the exit port  1022   k  is communicated with the entrance of the interior evaporator  1013  and the entrance of the bypass passageway  1026 . The entrance and exit ports  1022   j  and  1022   k  are communicated with each other by way of the throttle section  1022   a.    
     The temperature sensitive tube  1022   h  has gas refrigerant enclosed in the inside thereof and is provided in contact with a refrigerant passageway  1014   d  which interconnects the middle stream area portion  1014   b  and the lower stream area portion  1014   d  of the interior condenser  1014 . The temperature sensitive tube  1022   h  thus converts a variation of temperature of the refrigerant flowing through the refrigerant passageway  1014   d  into a variation of pressure and transmits the pressure variation to the upper side of the diaphragm  1022   c  by way of a capillary tube  1221 . 
     The mantle tube  1022   i  extracts a high pressure on the upstream of the lower stream area portion  1014   c , that is, at the refrigerant passageway  1014   d , and transmits the high pressure to the lower side of the diaphragm  1022   c  in order to prevent an influence of a pressure loss which may be caused by the flow resistance of the lower stream area portion  1014   c  of the interior condenser  1014 . 
     The valve member  1022   d  is held on a stopper  1022   n  which fits with the top of the valve body  1022   b  with an O-snap ring  1022   m  interposed therebetween, and opens or closes the throttle section  1022   a  when the stopper  1022   n  is slidably moved (in the upward or downward direction in FIG. 87) on the valve body  1022   b  by displacement of the diaphragm  1022   c . The valve member  1022   d  is moved to a position at which the pressure in the temperature sensitive tube  1022   h  acting upon the upper side of the diaphragm  1022   c  and the high pressure and the biasing force of the regulating spring  1022   g  which both act upon the lower side of the diaphragm  1022   c  are balanced with each other, and the opening of the throttle section  1022   a  depends upon the displacement of the valve member  1022   d.    
     The regulating spring  1022   g  is provided so that the biasing force thereof may be adjusted by means of an adjusting screw  1220 . The adjusting screw  1220  is screwed in a hitching  1022   q  mounted at the bottom end of the valve body  1022   b  with an O-snap ring  22   p  interposed therebetween. 
     The subcooling control valve  1022  is constructed such that a low pressure on the downstream side of the throttle section  1022   a  is prevented from being transmitted to the lower side of the diaphragm  1022   c  by the O-snap ring  1022   m  while a high pressure is transmitted to the lower side of the diaphragm  1022   c  only by way of the mantle pipe  1022   i . Meanwhile, a communicating hole  1022  is formed in the spring guide  1022   f  and communicates a spring accommodating chamber  1022   r  for accommodating the regulating spring  1022   g  therein and the upstream side of the throttle section  1022   a  with each other. Thus, the high pressure on the upstream side of the throttle section  1022   a  is introduced into the spring accommodating chamber  1022   r  through the communicating hole  1022   s  so that the influence of the high pressure applied to the spring guide  1022   f  is cancelled. 
     In the subcooling control valve  1022  having the construction described above, the biasing force of the regulating spring  1022   g  is set so that the subcooling degree between the middle stream area portion  1014   b  and the lower stream area portion  1014   c  of the interior condenser  1014  with which the temperature sensitive tube  1022   h  contacts may be a predetermined value (2 to 10° C.). 
     Operation of the automotive air conditioner will be described subsequently with reference to the Mollier diagrams shown in FIGS. 88 to  91 . It is to be noted that any point on any of the Mollier diagrams shown in FIGS. 88 to  91  indicates a state point of the refrigerant on the refrigerating cycle shown in FIG.  86 . (a) In Heating Operation 
     The passageway of the four-way valve  1017  is changed over to the position indicated by solid lines in FIG. 86, and the air mixing damper  1015  closes (the position indicated by solid lines in FIG. 86) the bypass passageway  1016  which bypasses the interior condenser  1014  so that all draft air may pass the interior condenser  1014 . 
     High temperature, high pressure gas refrigerant (point A in FIG. 88) compressed by the refrigerant compressor  1019  is introduced into the interior condenser  1014  as indicated by solid line arrow marks in FIG.  86  through the four-way valve  1017  and the check valve  1029 . In the interior condenser  1014 , the gas refrigerant having a subcooling degree is first cooled in the upper stream area portion  1014   a  and then condensed into liquid in the middle stream area portion  1014   b  so that, at the exit of the middle stream area portion  1014   b  with which the temperature sensitive tube  1022   h  contacts, the subcooling degree of a predetermined value (point B in FIG. 88) is obtained by control of the subcooling control valve  1022 . 
     The liquid refrigerant having such subcooling degree is further cooled, as dehumidifying heating operation based on the internal air mode (in which internal air is introduced in) is performed, by cooling wind cooled by the interior evaporator  1013  when it passes the lower stream area portion  1014   c  of the interior condenser  1014 . Consequently, at the exit of the interior condenser  1014 , a maximum subcooling degree (point C in FIG. 88) which can possibly be obtained at the lower stream area portion  1014   c  in accordance with a temperature difference between the temperature of the cool wind and the saturation temperature of the refrigerant on the upstream of the lower stream area portion  1016   c  can be obtained. 
     The liquid refrigerant flowing out from the interior condenser  1014  is decompressed (point D in FIG. 88) at the subcooling control valve  1022 , and then exchanges, when it passes the interior evaporator  1013 , heat (point E in FIG. 88) with the draft air flowing in the duct  1001 , whereafter it is decompressed (point F in FIG. 88) at the evaporation pressure regulating valve  1023  and then exchanges, when it passes the exterior heat exchanger  1021 , heat (point G in FIG. 88) with draft air blown by the electric fan  1020 . The refrigerant evaporated in the exterior heat exchanger  1021  is introduced through the four-way valve  1017  into the accumulator  1024 , from which only gas refrigerant is sucked into the refrigerant condenser  1019 . 
     Meanwhile, internal air introduced into the duct  1001  by operation of the fan  1002  is dehumidified when it passes the exterior evaporator  1013 , and then is overheated when it passes the interior condenser  1014 , whereafter it is blown out into the automobile room from a selected one or ones of the outlet ports  1007  to  1009 . 
     When dehumidification is not performed during such heating operation, the solenoid valve  1027  is opened. Consequently, the refrigerant (point F in FIG. 89) decompressed at the subcooling control valve  1022  is introduced into the exterior heat exchanger  1021  by way of the bypass passageway  1026  without passing the interior evaporator  1013  and the evaporation pressure regulating valve  1023  and then evaporated in the external heat exchanger  1021 , whereafter it is sucked (point G in FIG. 89) into the refrigerant compressor  1019  past the accumulator  1024 . 
     In such heating operation in the external air mode, liquid refrigerant having a subcooling degree of a predetermined value (point B in FIG. 89) at the exit of the middle stream area portion  1014   b  of the interior condenser  1014  is cooled, when it subsequently passes the lower stream area portion  1014   c , by draft wind of external air introduced into the duct  1001 . Accordingly, the refrigerant flowing in the lower stream area portion  1014   c  can ideally obtain a subcooling degree (point C in FIG. 89) of a temperature difference between the temperature of draft air (external air temperature) and the saturation temperature of the refrigerant on the upstream of the lower stream area portion  1014   c  . (b) In Cooling Operation 
     The passageway of the four-way valve  1017  is changed over to the position indicated by broken lines in FIG. 86 while the solenoid valve  1027  provided in the bypass passageway  1026  is closed. 
     High temperature, high pressure gas refrigerant (point A in FIG. 90) compressed by the refrigerant compressor  1019  is introduced, after it passes the four-way valve  1017 , into the external heat exchanger  1021  as indicated by broken line arrow marks in FIG.  86  and then condensed in the external heat exchanger  1021  by draft air blown from the electric fan  1020 . Then, the refrigerant is introduced into the interior condenser  1014  through the check valve  1031  and then exchanges heat with draft air in the interior condenser  1014  so that it is condensed into liquid. In the interior condenser  1014 , a subcooling degree of a predetermined value (point B in FIG. 90) is obtained at the exit of the middle stream area portion  1014   b  by the subcooling control valve  1022 , similarly as upon heating operation. 
     Here, when a maximum cooling degree (MAX COOL) is set by the operator, the air mixing damper  1015  fully closes (position indicated by chain lines in FIG. 86) the interior condenser  1014 . Consequently, cool wind cooled by the interior evaporator  1013  is not blown to the interior condenser  1014 , and accordingly, the lower stream area portion  1014   c  of the interior condenser  1014  serves as a mere passage for refrigerant. 
     Accordingly, the liquid refrigerant having a subcooling degree of the predetermined value is not cooled any more when it passes the lower stream area portion  1014   c  of the interior condenser  1014 , and consequently, it flows out from the interior condenser  1014  while it keeps the subcooling degree of the predetermined value. 
     Thereafter, the refrigerant decompressed (point F in FIG. 90) at the subcooling control valve  1022  is evaporated by heat exchange thereof with draft air in the interior evaporator  1013 , and then, after it passes the check valve  1028  and the four-way valve  1017 , it is sucked (point G in FIG. 90) into the refrigerant compressor  1019  past the accumulator  1024 . 
     Meanwhile, the draft air (internal air) introduced into the duct  1001  by operation of the fan  1002  is cooled when it passes the interior evaporator  1013 , and then passes the bypass passageway  1016  without passing the interior condenser  14 , whereafter it is blown out into the automobile room from a selected one or ones of the outlet ports  1007  to  1009 . 
     When, in such cooling operation, part of cool wind cooled in the interior evaporator  1013  is allowed to pass the interior condenser  1014  in accordance with the opening of the air mixing damper  1015  so as to effect adjustment of the temperature, liquid refrigerant having a subcooling degree of the predetermined value (point B in FIG. 91) is further cooled by the cool air flowing to the interior condenser  1014  side when it passes the lower stream area portion  14   c  of the interior condenser  1014 . Accordingly, the refrigerant flowing out from the interior condenser  1014  can ideally obtain a subcooling degree (point C of FIG. 91) of a value equal to a temperature difference between the temperature of the cool wind and the saturation temperature of the refrigerant on the upstream of the lower stream area portion  1014   c.    
     As described above, in the present embodiment, the opening of the throttle portion  1022   a  of the subcooling control valve  1022  is adjusted so that a subcooling degree of the predetermined value may be obtained at the exit of the middle stream area portion  1014   b  of the interior condenser  1014  with which the temperature sensitive tube  22   h  contacts. Consequently, at the lower stream area portion  1014  of the interior condenser  1014 , a maximum possible subcooling degree which can be obtained at the lower stream area portion  1014   c  in accordance with the temperature of draft air blown to the lower stream area portion  1014   c  can be obtained. 
     It is to be noted that, while the interior condenser  1014  in the present embodiment has a three-layer structure, alternatively a two-layer structure including the lower stream area portion  1014   c  and the upper and middle area portion with respect to the location where the temperature sensitive tube  1022   h  contacts may be employed. Further, no layer structure may necessarily be employed, and the upper stream area portion  1014   a , the middle stream area portion  1014   b  and the lower stream area portion  1014   c  in the embodiment described above may be formed on a same plane. 
     Further, while the subcooling control valve  1022  includes the mantle pipe  1022   i  in order to prevent a possible influence of a pressure loss in the interior condenser  1014 , the mantle pipe  1022   i  need not be employed where the influence of a pressure loss at the lower stream area portion  1014   c  need not be taken into consideration. 
     While the air is employed as the cooling medium which exchanges heat with refrigerant flowing in the interior condenser  1014 , such liquid as water or oil may be employed instead. 
     Referring now to FIG. 92, there is shown another air conditioner for an electric automobile. The air conditioner can perform a dehumidifying heating operation and includes an interior evaporator  1033 , a subcooling heat exchanger  1032  and a main condenser  1033  all disposed in this order from the upstream side in a duct  1001 . An exterior evaporator  1034  for receiving draft air from an electric fan  1030  to evaporate refrigerant is provided outside the duct  1001 . 
     A subcooling control valve  1022  includes a temperature sensitive tube  1022   h  held in contact with a refrigerant passageway  1014   d  interconnecting the subcooling heat exchanger  1032  and the main condenser  1033  and is set so that a subcooling degree of a predetermined value may be obtained at the exit of the main condenser  1033 . 
     In the present embodiment, the subcooling heat exchanger  1032  and the main condenser  1033  cooperatively constitute a refrigerant condenser, and the subcooling heat exchanger  1032  acts as a lower stream area portion. 
     When a dehumidifying heating operation is to be performed, liquid refrigerant having a subcooling degree of a predetermined value at the exit of the main condenser  1033  is further cooled, when it passes the subcooling heat exchanger  1032 , by cool wind cooled in the interior evaporator  1013  so that it can obtain a maximum possible subcooling degree which can be obtained at the subcooling heat exchanger  1032 . 
     On the other hand, when a dehumidifying heating operation is not performed, the liquid refrigerant having a subcooling degree of the predetermined value receives, when it passes the subcooling heat exchanger  1032 , draft wind of external air introduced into the duct  1001  based on the external air mode so that it can obtain a subcooling degree corresponding to the temperature of the external air. 
     Referring now to FIG. 93, there is shown a further air conditioner for an electric automobile. The air conditioner in the present embodiment can perform a cooling operation and includes an interior evaporator  1013  provided in a duct  1001 , and an interior head exchanger  1035  provided on the lee side of the interior evaporator  1013  in the duct  1001 . The amount of draft air to the interior heat exchanger  1035  is adjusted in accordance with the opening of an air mixing damper  1015 . An external condenser  1036  is provided on the outside the duct  1001  and receives draft wind from an electric fan  1020  to condense high temperature, high pressure gas refrigerant compressed by a refrigerant compressor  1019 . 
     A subcooling control valve  1022  includes a temperature sensitive tube  1022   h  held in contact with a refrigerant passageway  1014   d  interconnecting the interior heat exchanger  1035  and the exterior condenser  1036  and is set so that a subcooling degree of a predetermined value may be obtained at the exit of the exterior condenser  1036 . 
     In the present embodiment, the interior heat exchanger  1035  and the external condenser  1036  constitute a refrigerant condenser while the interior heat exchanger  1035  serves as a lower stream area portion, and the external condenser  1036  is disposed outside the duct  1001 . 
     Now, when a maximum cooling degree (MAX COOL) is set by the operator, the air mixing damper  1015  fully closes (position indicated by chain lines in FIG. 93) the interior heat exchanger  1035 , and consequently, the interior heat exchanger  1035  serves as a mere passage for refrigerant. Accordingly, liquid refrigerant condensed by the exterior condenser  1036  is not cooled any more when it passes the interior heat exchanger  1035 , but flows out from the interior heat exchanger  1035  while it keeps the subcooling degree of the predetermined value. 
     When part of cool wind cooled in the interior evaporator  1013  is allowed to pass the interior heat exchanger  1035  in accordance with the opening of the air mixing damper  1015  so as to effect adjustment of the temperature, liquid refrigerant having a subcooling degree of the predetermined value is further cooled by the cool air flowing to the interior heat exchanger  1035  side when it passes the interior heat exchanger  1035 , and consequently, a subcooling degree corresponding to the temperature of the cool wind can be obtained. 
     Referring now to FIG. 94, there is shown a front elevational view of a refrigerant condenser of a refrigerating cycle according to a fourth preferred embodiment of the present invention. The refrigerant condenser  1014  is constructed as a heat exchanger of the layer type which includes a heat exchanging section including a large number of ( 1006  in the present embodiment) tubes  1037  serving as refrigerant passageways and a large number of heat radiating fins  1038  layered alternately with the tubes  1037 , and a pair of headers  1039  and  1040  disposed on the opposite ends of the tubes  1037 . 
     The tubes  1037  are extrusion molded articles of aluminum and each formed in a flattened profile. 
     The fins  1038  are roller-shaped articles of a thin aluminum plate shaped into a corrugated profile and each has a large number of louvers (not shown) formed on a surface thereof. 
     The headers  1039  and  1040  have a circular cross section and each has one or a plurality of partition plates  1041  provided in the inside thereof. The partition plates  41  partition the inside of each of the headers  1039  and  1040  in the longitudinal direction so that refrigerant flowing in the heat exchanging section may be turned back. The partition plates  1041  are provided, in the header  1039 , between the second and third tubes  1037  from above in FIG. 94, between the fourth and fifth tubes  1037  and between the fifth and sixth tubes  1037 , and, in the other header  1040 , between the fourth and fifth tubes  1037  from above in FIG.  94 . 
     Here, when portions of the header  1039  partitioned by the three partition plates  1041  are called, in order from above in FIG. 94, first header portion  1039   a  second header portion  1039   b , third header portion  1039   c  and fourth header portion  1039   d , an entrance pipe  1042  and an exit pipe  1043  for refrigerant are connected to the first header portion  1039   a  and the fourth header portion  1039   d , respectively, and the opposite ends of a mounting pipe  1044  (which will be hereinafter described) having a channel-shaped profile as viewed from the front are connected to the second and third header portions  1039   b and  1039   c.    
     The headers  1039  and  1040  have elongated holes  1045  formed therein in which the opposite end portions of the tubes  1037  are inserted, and further have three and one insertion holes  1046  (refer to FIG. 95) formed in the side walls opposite to the elongated holes  1045  thereof, respectively. The partition plates  1041  are individually inserted in the insertion holes  1046  of the headers  1039  and  1040 . The header  1039  further has a pair of connecting holes (not shown) formed therein to which the input pipe  1042  and the exit pipe  1043  are connected, and has another pair of connecting holes  1047  (refer to FIG. 95) formed therein to which the mounting pipe  1044  are connected. 
     A method of assembling the refrigerant condenser  1014  will be described subsequently with reference to FIG. 95 in which the header  1039  is shown. 
     First, the tubes  1037  and the fins  1038  are layered alternately to form the heat exchanging section, and then the opposite end portions of the tubes  1037  are inserted into the elongated holes  1045  of the headers  1039  and  1040  to assemble the headers  1039  and  1040  thereby to fix the tubes  1037 , the fins  1038  and the headers  1039  and  1040 . 
     Then, one of the partition plates  1041  is assembled to the header  1040 , and the other partition plates  1041 , the entrance pipe  1042 , the exit pipe  1043  and the mounting pipe  1044  are assembled to the other header  1039 , whereafter portions of the components to be brazed are joined by integral brazing, thereby completing the assembly of the refrigerant condenser  1014 . 
     The mounting pipe  1044  described above is provided for mounting the temperature sensitive tube  1022   h  of the subcooling control valve  1022  thereon. The mounting pipe  1044  is formed so as to have, at a portion thereof for contacting with the temperature sensitive tube  1022   h  , a concave recessed face as shown in FIG. 96 in order to assure a large contact area with the temperature sensitive tube  1022   h  . Further, where the contact portion of the mounting pipe  1044  with the temperature sensitive tube  1022   h  is recessed, the mounting height H of the mounting pipe  1044  and the temperature sensitive tube  1022   h  can be reduced comparing with that of an alternative arrangement wherein the temperature sensitive tube  1022   h  is mounted on an alternative mounting pipe  1044   a  having a circuit cross section as shown in FIG.  97 . Consequently, the mounting space of the temperature sensitive tube  1044  can be reduced. It is to be noted that, in order to prevent the duct  1001  from being increased in size by an arrangement of the mounting pipe  1044  in the duct  1001 , in the present embodiment, the mounting pipe  1044  is provided such that it extends outwardly of the duct  1001 . 
     Since the refrigerant condenser  1014  in the present embodiment is controlled by the subcooling control valve  1022  so that the subcooling degree may have a predetermined value in the mounting pipe.  1044  on which the temperature sensitive tube  1022   h  is mounted, on the downstream side (in the lower stream area portion) of the mounting pipe  1044 , a subcooling degree of up to a temperature difference between the temperature of draft air blown to the refrigerant condenser  1014  and the saturation temperature of refrigerant flowing in the mounting pipe  1044  can be obtained. In short, since a temperature variation of draft air is absorbed on the downstream side of the mounting pipe  1044 , a substantially uniform temperature distribution in a two gas-liquid phase condition can be obtained on the upstream side of the mounting pipe  1044 . 
     Consequently, when the refrigerant condenser  1014  is to be used as a heating heat exchanger of a heat pump cycle, since the temperature distribution of the heat exchanging section in the leftward and rightward directions of the refrigerant condenser  1014  (leftward and rightward directions in FIG. 94) can be maintained substantially uniform, the temperature distribution of draft air to be blown into the automobile room can be kept uniform between the drivers seat side and the passengers seat side. 
     It is to be noted that, while, in the present embodiment, the headers  1039  and  1040  have a circular cross section, such a header  1048  of the split type which is constituted from a plate header  1048   a  and a tank header  1048   b  as shown in FIG. 98 may be employed instead. In this instance, each partition plate  1041  is assembled not by a method wherein it is inserted into the header  1039  or  1040  from the outside but by another method wherein it is held between the plate header  1048   a  and the tank head  1048   b.    
     Further, while the refrigerant condenser  1014  in the present embodiment is formed as a heat exchanger of the layer type, such a heat exchanger of the serpentine type as shown in FIG. 1014 may be employed instead. In this instance, the mounting pipe  1044  can be formed by partially extending a tube  1037 , which is curved in a serpentine-like shape, such that it projects outwardly from a bracket  1049  for mounting the refrigerant condenser  1014  on the automobile. 
     Having now fully described the invention, it will be apparent to one of ordinary skill in the art that many changes and modifications can be made thereto without departing from the spirit and scope of the invention as set forth herein.