Patent Publication Number: US-2011056384-A1

Title: Humidity control and ventilation system

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The present application is based on Japanese Patent Application No. 2009-208351 filed on Sep. 9, 2009, the disclosure of which is incorporated herein by reference. 
     FIELD OF THE INVENTION 
     The present invention relates to a humidity control and ventilation system which conditions humidity of an internal space and performs ventilation. 
     BACKGROUND OF THE INVENTION 
     As a related art, a humidity control and ventilation system is disclosed in JP-A-10-61979. The humidity control and ventilation system includes an intake passage for conducting external air into an internal space, an exhaust passage for exhausting internal air into an external space, a dehumidifying unit in which hygroscopic liquid absorbs moisture from air flowing through the intake passage for dehumidification, and a regenerating unit in which moisture is released from hygroscopic liquid into air flowing through the exhaust passage to regenerate the hygroscopic liquid. 
     In the dehumidifying unit, a moisture permeable membrane is placed between the hygroscopic liquid and intake air. Since moisture is transferred to the hygroscopic liquid from the intake air through the moisture permeable membrane, the hygroscopic liquid is prevented from mixing into the intake air and flying into the internal space. 
     In the humidity control and ventilation system of the above-described related art, the moisture permeable membrane that separates the intake air from the hygroscopic liquid for preventing the flying of the hygroscopic liquid is used. Thus, for securing sufficient humidity control performance, there is a problem that a configuration of a humidity control and ventilation system having a dehumidifying unit as a main part becomes complex. 
     SUMMARY OF THE INVENTION 
     The present invention addressed the above disadvantage. 
     According to the present invention, there is provided a humidity control and ventilation system for a building, which includes an air supply passage configured to conduct intake air from an exterior inlet port, which is located at an outside of the building, to an interior outlet port, which is located at an inside of the building; an air discharge passage configured to conduct discharge air from an interior inlet port, which is located at the inside of the building, to an exterior outlet port, which is located at the outside of the building; and a processing unit that is disposed in the air supply passage and stores a hygroscopic liquid. The processing unit performs at least one of: an absorbing process, in which the hygroscopic liquid absorbs moisture from the intake air conducted through the air supply passage; and a releasing process, in which the hygroscopic liquid releases moisture into the intake air conducted through the air supply passage. The air supply passage includes an intake duct that is located between the processing unit and the interior outlet port. The intake duct includes a vertically extending section, which extends in a vertical direction to create an upflow of the intake air conducted from the processing unit toward the interior outlet port. 
     Accordingly, the humidity control and ventilation system includes the vertically extending section to create the upflow of the intake air conducted from the processing unit toward the interior outlet port. Thus, even if droplets of the hygroscopic liquid are taken in the intake air when passing through the processing unit, the droplets of the hygroscopic liquid can be prevented from reaching the interior outlet port by the gravity. Therefore, flying of the hygroscopic liquid can be suppressed by the simple configuration, in which the vertically extending section is arranged in the intake duct from the processing unit to the interior outlet port. 
     Moreover, according to claim  10 , the humidity control and ventilation system includes a processing-unit circulating means configured to circulate the hygroscopic liquid in the processing unit to facilitate the absorbing process and the releasing process, and a regenerating-unit circulating means configured to circulate the hygroscopic liquid in the regenerating unit to facilitate the regenerating process. At least one of the processing-unit circulating means and the regenerating-unit circulating means is stopped when a difference of enthalpies or physical quantities corresponding to the enthalpies between external air and internal air is equal to or lower than a predetermined value based on a temperature and humidity of an external space and a temperature and humidity of an internal space. 
     A ventilation system, which has a heat exchanger at an intersection of an intake passage and an exhaust passage and performs heat exchange between intake air from an external space to an internal space and discharge air from the internal space to the external space, is conventionally known. In the ventilation system, bypass passages that bypass the heat exchanger are formed in each of the intake passage and the exhaust passage, and a damper for opening and closing the bypass passages is arranged. When heat exchanger is not necessary in the spring season and the fall season, for example, the bypass passages are opened by the damper such that the intake air and the discharge air flow so as to bypass the heat exchanger (refer to JP-Y2-55-2367). 
     Since on-off of a heat exchange function between the intake air and the discharge air is switched in the above-described ventilation system, two bypass passages and the damper for opening and closing the bypass passages are necessary. Thus, the configuration of the ventilation system may become complex. However, according to the configuration of claim  10 , on-off of a heat exchange function can be switched with a simple configuration. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description made with reference to the accompanying drawings. In the drawings: 
         FIG. 1  is a system configuration diagram showing an air-conditioning system including a humidity control and ventilation system according to a first embodiment of the present invention; 
         FIG. 2A  is a schematic diagram showing a configuration of a main part of the humidity control and ventilation system; 
         FIG. 2B  is a block diagram showing a control system of the humidity control and ventilation system; 
         FIG. 3  is a graph showing a relation between a droplet diameter and a droplet fall velocity of lithium chloride aqueous solution as hygroscopic liquid of the humidity control and ventilation system; 
         FIG. 4A  is a schematic diagram showing a flow in a vertical duct when droplets of the hygroscopic liquid mix into air, in the case where Reynolds number Re is smaller than critical Reynolds number; 
         FIG. 4B  is a schematic diagram showing a flow in the vertical duct when the droplets of the hygroscopic liquid mix into air, in the case where Reynolds number Re is larger than critical Reynolds number; 
         FIG. 5A  is a table showing a relation between a total floor area of a building and a set ventilatory volume; 
         FIG. 5B  is a table showing a relation between a tube diameter of the vertical duct and an in-tube flow velocity; 
         FIG. 5C  is a table showing a relation between the tube diameter of the vertical duct and Reynolds number Re; 
         FIG. 6  is a graph showing annual data of external temperature and humidity in Nagoya; 
         FIG. 7  is a system configuration diagram showing an air-conditioning system including a humidity control and ventilation system according to a second embodiment of the present invention; 
         FIG. 8  is a system configuration diagram showing an air-conditioning system including a humidity control and ventilation system according to a third embodiment of the present invention; 
         FIG. 9  is a system configuration diagram showing an air-conditioning system including a humidity control and ventilation system according to a fourth embodiment of the present invention; 
         FIGS. 10A to 10C  are schematic diagrams showing connection structures of an intake duct or an air-conditioning intake duct to multiple interior outlet ports; and 
         FIG. 11  is a schematic diagram showing a configuration of a main part of a humidity control and ventilation system according to another embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Hereinafter, embodiments of the present invention will be described with reference to drawings. In the respective embodiments, the component which is the same with that in the antecedent embodiment is designated by the same reference numeral and a description thereof will not be repeated. In the respective embodiments, if only a part of the configuration is described, the other part of the configuration is the same with that described in the antecedent embodiment. The present invention is not limited to the combinations described concretely in the respective embodiments. If there is no contradiction in the combinations, the embodiments can be partially combined. 
     First Embodiment 
       FIG. 1  is a system configuration diagram showing an air-conditioning system including a humidity control and ventilation system  1  according to the first embodiment of the present invention.  FIG. 2A  is a schematic diagram showing a configuration of a main part of the humidity control and ventilation system  1 . 
     As shown in  FIG. 1 , the humidity control and ventilation system  1  arranged in a building  100  includes an absorption-type humidity controller  10 , an intake pipe  21 , an intake duct  20 , an exhaust duct  30 , and an exhaust pipe  31 . The humidity controller  10  uses, for example, lithium chloride aqueous solution as hygroscopic liquid. The intake pipe  21  has an exterior inlet port  22  at an upstream end thereof and conducts external air into the humidity controller  10 . The intake duct  20  has an interior outlet port  23  at a downstream end thereof and conducts air, which is humidity controlled by the humidity controller  10 , into an internal space. The exhaust duct  30  has an interior inlet port  32  at an upstream end thereof and conducts internal air to the humidity controller  10 . The exhaust pipe  31  has an exterior outlet port  33  at a downstream end thereof and conducts air, which has passed through the humidity controller  10 , to an external space. The humidity controller  10  is placed at an appropriate external space, for example. The exterior inlet port  22  and the exterior outlet port  33  are located at an outside of the building  100 , and the interior outlet port  23  and the interior inlet port  32  are located at an inside of the building  100 . 
     As shown in  FIG. 2A , the humidity controller  10  includes a processing unit  11 , a regenerating unit  12 , and a heat pump unit  13 . The processing unit  11  can perform either an absorbing process, in which the hygroscopic liquid absorbs moisture from intake air, or a releasing process, in which the hygroscopic liquid releases moisture into the intake air. The regenerating unit  12  is configured such that hygroscopic liquid therein releases moisture into discharge air when the processing unit  11  performs the absorbing process and the hygroscopic liquid therein absorbs moisture from the discharge air when the processing unit  11  performs the releasing process. That is, the regenerating unit  12  can perform a regenerating process that regenerates moisture absorbing-releasing capacity of the hygroscopic liquid. A processing capability of the processing unit  11  can be easily maintained. The heat pump unit  13  is a device for transferring heat between the processing unit  11  and the regenerating unit  12 . 
     An outer hull of the processing unit  11  is configured by a processing-unit case  110  made of resin, for example. The processing-unit case  110  has a liquid tank  111 , in which the hygroscopic liquid is stored, at a bottom portion thereof. An air inlet port  112  opens in a side surface portion of the processing-unit case  110  above a liquid level of the hygroscopic liquid. The intake pipe  21  is connected to the processing-unit case  110  such that the air inlet port  112  is located at a downstream end of the intake pipe  21 . In order to prevent a foreign object such as an insect from entering the processing-unit case  110 , an intake, air filter  221  is arranged in the intake pipe  21  (in the present embodiment, at the upstream end of the intake pipe  21 ). An air outlet port  113  opens in the side surface portion of the processing-unit case  110  above the level of the air inlet port  112 . The intake duct  20  is connected to the processing-unit case  110  such that the air outlet port  113  is located at an upstream end of the intake duct  20 . 
     A processing element  114  is arranged inside the processing-unit case  110  at a position above the air inlet port  112  and below the air outlet port  113 . The processing element  114  is configured by laminating multiple nonwoven compression boards made of cellulose fiber, which are formed to have a corrugated shape. The processing element  114  is placed in the processing-unit case  110  such that an extending direction of a peak or a valley of the corrugated shape is along a longitudinal direction (i.e., a vertical direction) and the processing element  114  covers the entire area of the processing-unit case  110  in a lateral direction. The processing element  114  is impregnated with the hygroscopic liquid and the hygroscopic liquid falls through the processing element  114 . Air flows upward through a space between the laminated boards of the processing element  114 . According to the above configuration, the contact area between the falling hygroscopic liquid and the air flowing upward becomes large, and thereby the processes can be performed with high efficiency. 
     A liquid nozzle  115  for dripping the hygroscopic liquid toward the processing element  114  is arranged inside the processing-unit case  110  at a position above the processing element  114 . A circulation circuit  116  for sending the hygroscopic liquid in the liquid tank  111  to the liquid nozzle  115  is formed outside the processing-unit case  110 . A circulation pump  117 , which is used as a processing-unit circulating means, for circulating the hygroscopic liquid is arranged in the circulation circuit  116 . Moreover, a heat exchanger  132 , which will be described below, and an auxiliary heat exchanger  119  are arranged in the circulation circuit  116  at a downstream portion of the circulation pump  117 . The auxiliary heat exchanger  119 , a pump  119   a  and a heat source  119   b  are arranged in an auxiliary circuit  119   c . A medium in the auxiliary circuit  119   c  is cooled or heated by the heat source  119   b . The medium circulates in the auxiliary circuit  119   c  by the pump  119   a . By the auxiliary heat exchanger  119 , the hygroscopic liquid is heat exchanged with the medium. For example, one of cool water, a refrigerant, or hot water is used as the medium in the auxiliary circuit  119   c.    
     The configuration of the regenerating unit  12  is similar to that of the processing unit  11 . 
     An outer hull of the regenerating unit  12  is configured by a regenerating-unit case  120  made of resin, for example. The regenerating-unit case  120  has a liquid tank  121 , in which, the hygroscopic liquid is stored, at a bottom portion thereof. An air inlet port  122  opens in a side surface portion of the regenerating-unit case  120  above a liquid level of the hygroscopic liquid. The exhaust duct  30  is connected to the regenerating-unit case  120  such that the air inlet port  122  is located at a downstream end of the exhaust duct  30 . An air outlet port  123  opens in the side surface portion of the regenerating-unit case  120  above the level of the air inlet port  122 . The exhaust pipe  31  is connected to the regenerating-unit case  120  such that the air outlet port  123  is located at an upstream end of the exhaust pipe  31 . In order to prevent a foreign object such as an insect from entering the regenerating-unit case  120 , an exhaust air filter  331  is arranged in the exhaust pipe  31  (in the present embodiment, at the downstream end of the exhaust pipe  31 ). 
     A regenerating element  124  is arranged inside the regenerating-unit case  120  at a position above the air inlet port  122  and below the air outlet port  123 . The configuration of the regenerating element  124  is similar to that of the processing element  114 . The regenerating element  124  is arranged inside the regenerating-unit case  120  as with the processing element  114  arranged inside the processing-unit case  110 . 
     A liquid nozzle  125  for dripping the hygroscopic liquid toward the regenerating element  124  is arranged inside the regenerating-unit case  120  at a position above the regenerating element  124 . A circulation circuit  126  for sending the hygroscopic liquid in the liquid tank  121  to the liquid nozzle  125 , is formed outside the regenerating-unit case  120 . A circulation pump  127 , which is used as a regenerating-unit circulating means, for circulating the hygroscopic liquid is arranged in the circulation circuit  126 . Moreover, a heat exchanger  134 , which will be described below, and an auxiliary heat exchanger  129  are arranged in the circulation circuit  126  at a downstream portion of the circulation pump  117 . The auxiliary heat exchanger  129 , a pump  129   a  and a heat source  129   b  are arranged in an auxiliary circuit  129   c . A medium in the auxiliary circuit  129   c  is cooled or heated by the heat source  129   b . The medium circulates in the auxiliary circuit  129   c  by the pump  129   a . By the auxiliary heat exchanger  129 , the hygroscopic liquid is heat exchanged with medium. For example, one of cool water, a refrigerant, or hot water is used as the medium in the auxiliary circuit  129   c.    
     A compressor  131  for compressing a refrigerant, the heat exchanger  132 , a decompressing means  133  for decompressing and expanding the refrigerant (example for electronic controlled expansion valve), and the heat exchanger  134  are circularly-connected so that the heat pump unit  13  is configured. Both the heat exchangers  132 ,  134  are finned double-pipe countercurrent heat exchangers, for example. The heat exchanger  132  is configured such that heat is exchanged between the refrigerant and the hygroscopic liquid flowing through the circulation circuit  116 , and the heat exchanger  134  is configured such that heat is exchanged between the refrigerant and the hygroscopic liquid flowing through the circulation circuit  126 . 
     The heat pump unit  13  is configured such that a circulation direction of the refrigerant can be changed by switching a four-way valve or the like (not shown). The hygroscopic liquid can be heated in the heat exchanger  134  when the hygroscopic liquid is cooled in the heat exchanger  132 , and the hygroscopic liquid can be cooled in the heat exchanger  134  when the hygroscopic liquid is heated in the heat exchanger  132 . 
     The inside of the liquid tank  111  of the processing unit  11  communicates with the inside of the liquid tank  121  of the regenerating unit  12  through a communication portion  14 . The hygroscopic liquid in the liquid tank  111  and the hygroscopic liquid in the liquid tank  121  flow mutually (that is, circulate between the liquid tanks  111 ,  121 ) so that a concentration of the hygroscopic liquid in the liquid tank  111  becomes the same with that in the liquid tank  121 . 
     As shown in  FIG. 1 , the interior outlet ports  23  are formed in respective rooms such as a living room  102 , a Japanese room  103 , a bedroom  104 , a child&#39;s room  105 , and a study room  106 . The interior inlet ports  32  are formed in internal communication areas such as a vestibule  107  and a bathroom  108 , which communicate with the respective rooms through gap communication portions such as door undercut portions (not shown). Although only a part is shown in the drawing, an indoor unit  91 , which is connected to an outdoor unit  92  of an air conditioner  90  through a refrigerant pipe, is arranged in the respective rooms such as the living room  102  as needed, and thereby the room equipped with the indoor unit  91  can be air-conditioned individually. 
     The intake duct  20  connects the processing unit  11  of the humidity controller  10  to the interior outlet port  23 , that is, forms an air passage to the interior outlet port  23  from the processing unit  11 . The intake duct  20  includes a vertical duct  24  extending in the vertical direction (in the present embodiment, extending in an up-and-down direction). The vertical duct  24  is formed by a pipe member made of resin (in the present embodiment, made of vinyl chloride resin). As shown in  FIG. 1 , the vertical duct  24  extends in a pipe shaft (not shown) inside an exterior wall  101  of the building  100  from the level of the processing unit  11  of the humidity controller  10  (refer to  FIG. 2A ) to an attic. An intake blower  40  is arranged in the intake duct  20  at a downstream portion of the vertical duct  24 . The intake duct  20  is divided at a downstream portion of the intake blower  40  into a first-floor intake duct  25  and a second-floor intake duct  26 . Each of the first-floor intake duct  25  and the second-floor intake duct  26  extends to the interior outlet ports  23  of each floor. 
     A return pipe  28 , which communicates between the inside of the intake duct  20  and the inside of the processing-unit case  110 , is arranged at a bottom end portion of the vertical duct  24 . The return pipe  28  is configured to return the hygroscopic liquid in the intake duct  20 , which is released from the processing unit  11 , to the processing unit  11 . 
     As shown in  FIG. 2A , the intake duct  20  has a circular trap groove  27 , which is formed such that a diameter of an inner wall of the trap groove  27  is enlarged, at the bottom end portion of the vertical duct  24 . An upstream end of the return pipe  28  is connected to the trap groove  27 . In contrast, a downstream end of the return pipe  28  is connected to the liquid tank  111  of the processing unit  11 . The trap groove  27  and the return pipe  28  configure a recirculating means of the hygroscopic liquid in the present embodiment. 
     It is preferable that, even if an intake pressure in the return pipe  28  at a side of the trap groove  27  is lower than that at a side of the liquid tank  111 , the hygroscopic liquid is recirculated stably by using a backflow preventing means such as a check valve in the return pipe  28  or by configuring such that an open end of the return pipe  28  at a side of the processing unit  11  opens in the hygroscopic liquid in the liquid tank  111 , for example. 
     The recirculating means of the hygroscopic liquid is not limited to the configuration formed by the trap groove  27  and the return pipe  28 . The intake duct  20  may be arranged such that an upstream portion of the vertical duct  24  is downwardly slanted toward the air outlet port  113  from the bottom end portion of the vertical duct  24 , for example. Furthermore, the intake duct  20  may be configured such that the upstream portion of the vertical duct  24  extends in a horizontal direction and a recirculation guiding member, which is downwardly slanted toward the air outlet port  113  from the bottom end portion of the vertical duct  24 , is arranged to extend in the extending upstream portion, for example. 
     The exhaust ducts  30  connected to the interior inlet ports  32  of the respective floors join together and the joined exhaust duct  30  extends to the regenerating unit  12  of the humidity controller  10  (refer to  FIG. 2A ) in the above-described pipe shaft (not shown). An exhaust blower  50  is arranged in the exhaust duct  30  at a downstream portion of a point, at which the exhaust ducts  30  join together. 
     Each of the intake blower  40  and the exhaust blower  50  may be a blower having a sirocco fan, for example. In  FIG. 1 , the intake blower  40  and the exhaust, blower  50  are separately arranged. However, by arranging the intake duct  20  and the exhaust duct  30  suitably, the intake blower  40  and the exhaust blower  50  may be housed in one case and share a drive motor portion. 
     In the present embodiment, the intake duct  20  and the intake pipe  21  correspond to an air supply passage that conducts air from the exterior inlet port  22  to the interior outlet port  23  of the building  100 , and the exhaust duct  30  and the exhaust pipe  31  correspond to an air discharge passage that conducts air from the interior inlet port  32  of the building  100  to the exterior outlet port  33 . Thus, the processing unit  11  of the humidity controller  10  is arranged in the air supply passage. Moreover, in the present embodiment, the vertical duct  24  corresponds to a vertically extending section that extends in the vertical direction to create an upflow of the intake air conducted from the processing unit  11  toward the interior outlet port  23 . 
     As shown in  FIG. 2A , the exhaust pipe  31  connected to the air outlet port  123  of the regenerating-unit case  120  has a vertically extending section that extends in the vertical direction to create an upflow of the discharge air conducted from the regenerating unit  12  toward the exterior outlet port  33  as with the intake duct  20 . In the present embodiment, the exhaust pipe  31  has a portion used as a recirculating means of the hygroscopic liquid, which is downwardly slanted toward the air outlet port  123  from a bottom end portion of the vertically extending section. Furthermore, the exhaust air filter  331  arranged at the downstream end of the exhaust pipe  31  also has a function of trapping droplets of the hygroscopic liquid, which have passed through the vertically extending section of the exhaust pipe  31 , other than a function of preventing the foreign object from entering the regenerating-unit case  120 . 
     Next, the operation of the humidity control and ventilation system  1  will be described based on the above-described configuration. 
     The humidity control and ventilation system  1  of the present embodiment includes a control device (i.e., an ECU  60 ) and detecting means (i.e., an external temperature/humidity sensor  71  and an internal temperature/humidity sensor  72 ) that detect a temperature and humidity of the external air and a temperature and humidity of the internal air. The control device  60  as a controlling means is configured to control the operation of the humidity control and ventilation system  1  based on the temperature information and the humidity information of the external space and the internal space, which are detected by the respective detecting means  71 ,  72 .  FIG. 2B  shows a control system of the humidity control and ventilation system  1 . As shown in  FIG. 2B , the ECU  60  is configured to operate the circulation pumps  117 ,  127 , the blowers  40 ,  50 , the compressor  131 , the decompressing means  133 , the pumps  119   a ,  129   a , and the heat sources  119   b ,  129   b  (an auxiliary heat exchanger controller) based on the information of the sensors  71 ,  72 . 
     When the external space is in conditions of high temperature and humidity, and thus dehumidification is required, the control device  60  operates the circulation pumps  117 ,  127  and the blowers  40 ,  50 , and drives the compressor  131  and the decompressing means  133 . Thus, the refrigerant circulates in the heat pump unit  13  in a counterclockwise direction in  FIG. 2A , and the hygroscopic liquid is heated by the heat exchanger  134  and the hygroscopic liquid is cooled by the heat exchanger  132 . When the capacity of the heat pump unit  13  is lower than target capacity, the control device  60  operates the pumps  119   a ,  129   a  and the heat sources  119   b ,  129   b , and the auxiliary heat exchangers  119 ,  129  compensate for the shortage. 
     The intake air conducted from the exterior inlet port  22  contacts the low-temperature hygroscopic liquid when passing through the processing element  114  of the processing unit  11  of the humidity controller  10 , and thereby the intake air is cooled and dehumidified. The intake air, which is cooled and dehumidified so that a temperature and humidity thereof are adjusted, is supplied by the intake blower  40  to the respective rooms such as the living room  102 , the Japanese room  103 , the bedroom  104 , the child&#39;s room  105 , and the study room  106  from the respective interior outlet ports  23  through the intake duct  20  made of resin. 
     The air in the respective rooms is conducted from the interior inlet ports  32  formed respectively in the vestibule  107  and the bathroom  108  through gaps such as door undercut portions of the rooms, and the air is sent by the exhaust blower  50  to the regenerating unit  12  of the humidity controller  10  through the exhaust duct  30  made of resin. The discharge air from the internal space contacts the high-temperature hygroscopic liquid when passing through the regenerating unit  12  of the humidity controller  10 , and thereby the discharge air is heated and humidified. The discharge air that has passed through the regenerating unit  12  is exhausted from the exterior outlet port  33  to the external space. 
     In contrast, when the external space is in conditions of low temperature and humidity, and thus humidification is required, the control device  60  operates the circulation pumps  117 ,  127  and the blowers  40 ,  50 , and drives the compressor  131  and the decompressing means  133 . Thus, the refrigerant circulates in the heat pump unit  13  in a clockwise direction in  FIG. 2A , and the hygroscopic liquid is heated by the heat exchanger  132  and the hygroscopic liquid is cooled by the heat exchanger  134 . When the capacity of the heat pump unit  13  is lower than target capacity, the control device  60  operates the pumps  119   a ,  129   a  and the heat sources  119   b ,  129   b , and the auxiliary heat exchangers  119 ,  129  compensate for the shortage. 
     The intake air conducted from the exterior inlet port  22  contacts the high-temperature hygroscopic liquid when passing through the processing element  114  of the processing unit  11  of the humidity controller  10 , and thereby the intake air is heated and humidified. The intake air, which is heated and humidified so that a temperature and humidity thereof are adjusted, is supplied by the intake blower  40  to the respective rooms such as the living room  102 , the Japanese room  103 , the bedroom  104 , the child&#39;s room  105 , and the study room  106  from the respective interior outlet ports  23  through the intake duct  20  made of resin. 
     The air in the respective rooms is conducted from the interior inlet ports  32  formed respectively in the vestibule  107  and the bathroom  108  through the gaps such as the door undercut portions of the rooms, and the air is sent by the exhaust blower  50  to the regenerating unit  12  of the humidity controller  10  through the exhaust duct  30 . The discharge air from the internal space contacts the low-temperature hygroscopic liquid when passing through the regenerating unit  12  of the humidity controller  10 , and thereby the discharge air is cooled and dehumidified. The discharge air that has passed through the regenerating unit  12  is exhausted from the exterior outlet port  33  to the external space. 
     In this manner, a latent heat process of the external air that is to be conducted by ventilation is performed in the processing unit  11  of the humidity controller  10  in advance, and thereby increasing of an air-conditioning load of the air conditioner  90  can be limited. In particular, since dehumidifying operation frequency of the air conditioner  90  is decreased in the season when the external space is in conditions of high temperature and humidity, a temperature of a low-pressure side heat exchanger of the indoor unit  91  is increased and operation with high-energy efficiency can be performed. 
     In a place where a person often stays in, for example, the living room  102  equipped with the indoor unit  91  of the air conditioner  90 , the air conditioner  90  is operated with high efficiency by specializing in a sensible heat process and thereby a comfortable space can be achieved with saving energy. 
     Moreover, other than the living room  102  equipped with the indoor unit  91  of the air conditioner  90 , in another room that is not equipped with the indoor unit  91  of the air conditioner  90 , the rooms such as the vestibule  107  and the bathroom  108 , and a space in which an air conditioner is not operated, a sense of warmth can be improved compared to the case where humidity control and ventilation are not performed. 
     According to the humidity control and ventilation system  1  of the present embodiment, the vertical duct  24  is arranged in the intake duct  20  that connects the processing unit  11  to the interior outlet port  23 . Therefore, even if droplets of the hygroscopic liquid are taken in the intake air when the intake air passes through the processing unit  11  of the humidity controller  10 , flying of the droplets of the hygroscopic liquid can be suppressed by the gravity and the droplets can be prevented from reaching the interior outlet port  23 . 
     In the present embodiment, the building  100  is a two-story building, and the vertical duct  24  extends from the level of the processing unit  11  of the humidity controller  10  placed in the external space to the attic of the building  100 . The intake duct  20  is divided into the first-floor intake duct  25  and the second-floor intake duct  26  at the attic. Accordingly, the vertical duct  24  can obtain a length of, for example, 5 m or more, and the droplets of the hygroscopic liquid that reach the interior outlet port  23  can be reliably suppressed. 
     Furthermore, by forming the vertical duct  24 , a liquid filter for trapping the droplets of the hygroscopic liquid or a complicated gas-liquid separating device does not need to be arranged. Therefore, duct pressure loss can be reduced, and a compact humidity control and ventilation system can be realized at low cost. 
       FIG. 3  is a graph showing a relation between a droplet diameter and a droplet fall velocity of lithium chloride aqueous solution as one example of the hygroscopic liquid of the humidity control and ventilation system  1  of the present embodiment. Values of a viscosity of air, a density of air, a density of the hygroscopic liquid are substituted to Stokes equation, and the relation between the droplet diameter and the droplet fall velocity of the spherical droplet is calculated. The density of the hygroscopic liquid changes with temperature relatively a lot. Thus, in  FIG. 3 , the relation in the case where the density of the hygroscopic liquid is 1050 kg/m 3  when the hygroscopic liquid is heated to be in a high-temperature state is shown by the solid line, and the density of the hygroscopic liquid is 1250 kg/m 3  when the hygroscopic liquid is cooled to be in a low-temperature state is shown by the dashed line. 
     As is clear from  FIG. 3 , when a flow velocity in the vertical duct  24  is 4 m/s, a droplet having a diameter of 330 to 360 μm or more cannot ascend in the vertical duct  24 . Moreover, when a flow velocity in the vertical duct  24  is 2 m/s, a droplet having a diameter of 230 to 255 μm or more cannot ascend in the vertical duct  24 . Therefore, large droplets that have a significant influence if a large quantity of droplets fly (for example, large droplets that considerably shorten a period of time for maintenance when the liquid filter is arranged) can be removed by the vertical duct  24  without increasing pressure loss. 
     According to the explanation using  FIG. 3 , minute droplets each having a relatively small diameter can ascend with the upward intake air flow in the vertical duct  24 . In the present embodiment, by setting an inner diameter of the vertical duct  24  to have a suitable value, the minute droplets are made to adhere to an inner wall surface of the vertical duct  24 , and are prevented from flying downstream. 
       FIGS. 4A and 4B  are schematic diagrams each showing a flow in the vertical duct  24  when droplets of the hygroscopic liquid mix into air, in the case where Reynolds number Re is smaller than critical Reynolds number (about 2000 to 4000) (shown in  FIG. 4A ), and in the case where Reynolds number Re is larger than critical Reynolds number (shown in  FIG. 4B ). As shown in  FIG. 4A , in the case where Reynolds number of the flow in the duct is smaller than critical Reynolds number, the flow in the duct becomes a laminar flow, and is in a droplets dispersion state called as axial-centered distribution in which the droplets of the hygroscopic liquid having large specific gravity compared to air tend to flow with centered around the central axis of the duct. As shown in  FIG. 4B , in the case where Reynolds number of the flow in the duct is larger than critical Reynolds number, distribution of droplets of the hygroscopic liquid is diffused outward in a radial direction by turbulence of a turbulent boundary layer, and the droplets of the hygroscopic liquid come close to the wall surface of the vertical duct  24 . 
     Accordingly, in the present embodiment, by setting the inner diameter of the vertical duct  24  such that Reynolds number of the flow in the vertical duct  24  is larger than critical Reynolds number, the turbulent boundary layer is generated and the droplets of the hygroscopic liquid can be diffused outward in the radial direction from the central axis of the duct. Thus, the probability that the droplets adhere to the wall surface of the vertical duct  24  by the collision with the inner surface of the vertical duct  24  is increased. Since a viscosity of lithium chloride aqueous solution is relatively high, lithium chloride aqueous solution is hard to move downstream (i.e., upward in the drawing) in the intake air flow when lithium chloride aqueous solution has adhered to the wall surface. Thus, lithium chloride aqueous solution can be reliably prevented from reaching the interior outlet port  23 . 
       FIGS. 5A to 5C  show, in the case where a total floor area of a building is 116 m 2  to 198 m 2 , ventilatory volume, a tube diameter of the duct (i.e., a duct inner diameter) and an in-tube flow velocity, and Reynolds number Re of a flow in the tube, respectively.  FIG. 5A  shows a volume of the internal space, and a set ventilatory volume (i.e., a desired value of the ventilatory volume) in the case where 50% of the volume is ventilated per hour, with respect to the total floor area.  FIG. 5B  shows the in-tube flow velocity for achieving the above set ventilatory volume in each of typical tube diameters.  FIG. 5C  shows Reynolds number Re in the above in-tube flow velocity in each of the typical tube diameters. 
     As is clear from  FIGS. 5A to 5C , in the case where the total floor area of the building is 116 m 2  to 198 m 2 , Reynolds number Re can achieve a safety factor three times or more of critical Reynolds number when the inner diameter of the vertical duct  24  is in the range of 100 to 250 mm. 
     Since the vertical duct  24  is made of resin, even if lithium chloride aqueous solution as the hygroscopic liquid adheres to the inner surface of the vertical duct  24 , the vertical duct  24  is not adversely affected, for example, is not corroded. 
     The hygroscopic liquid that is prevented from flying in the vertical duct  24 , that is, the hygroscopic liquid that does not ascend in the vertical duct  24  and the hygroscopic liquid that adheres to the inner surface of the vertical duct  24  and falls in the vertical duct  24 , is trapped by the circular trap groove  27  formed at the bottom end portion of the vertical duct  24 , and can be returned to the liquid tank  111  of the processing unit  11  through the return pipe  28 . Therefore, decreasing of the hygroscopic liquid in the humidity controller  10  can be prevented. 
     Moreover, since the intake blower  40  is arranged at the downstream portion of the vertical duct  24 , adhering of the droplets of the hygroscopic liquid to the intake blower  40  can be suppressed. Thus, a failure of the intake blower  40  by corrosion or the like can be prevented. 
     Furthermore, since the vertical duct  24  is arranged in the pipe shaft inside the exterior wall  101  of the building  100 , the intake air whose temperature and humidity are adjusted by the humidity controller  10  can be prevented from generating heat loss due to the influence of external temperature. That is, the vertical unit  24  can be prevented from being exposed to the external air. Thus, the air, which is humidity controlled by the processing unit  11 , is not affected by the external temperature while ascending in the vertical duct  24 . 
     Moreover, air in the building  100  is conducted from the interior inlet port  32  and is exhausted from the exterior outlet port  33  through the regenerating unit  12  of the humidity controller, 10. Therefore, by using the discharge air from the internal space, whose quality is higher than that of the external air (that is, the discharge air from the internal space is in conditions of low temperature and humidity in the summer season, and is in conditions of high temperature and humidity in the winter season, compared to the external air), the moisture absorbing-releasing capacity of the hygroscopic liquid in the humidity controller  10  can be regenerated (that is, moisture is released from the hygroscopic liquid in the summer season, and moisture is absorbed by the hygroscopic liquid in the winter season). Thermal energy of the discharge air is used as regenerating energy of the humidity controller  10 , and thereby a heat recovery function (i.e., recovering of the thermal energy) can be obtained. That is, the thermal energy of the discharge air from the internal space can be used as energy for the regenerating process of the hygroscopic liquid in the regenerating unit  12 . Therefore, the thermal energy in the internal space can be recovered even if the internal space is ventilated. 
       FIG. 6  shows data of the external temperature and the humidity in Nagoya. In  FIG. 6 , the heat recovery is indicated by HR, and the humidity control is indicated by HC. As shown in  FIG. 6 , in the case where desired air-conditioned temperature is set to be 22 to 28° C. and desired absolute humidity is set to be 6 to 9 g/kg, for example, there is a period in which the heat recovery is unnecessary when humidity control is unnecessary depending on seasons (i.e., there is no advantage even if heat is recovered from the discharge air from the internal space). 
     In the humidity control and ventilation system  1  of the present embodiment, with or without the humidity control and with or without the heat recovery can be easily controlled by selecting on or off of the operation of the humidity controller  10 . Thus, compared to the case where heat is exchanged between the intake air and the discharge air in a heat exchanger, the pressure loss in ventilation when the humidity control and the heat recovery are not performed becomes smaller, and ventilation can be performed with saving energy throughout one year. Furthermore, compared to the case where a heat exchanger that performs heat exchange between the intake air and the discharge air is arranged and passages for the intake air and the discharge air that bypass the heat exchanger when the heat recovery is unnecessary are formed, the humidity control and ventilation system  1  can be reduced in size by simplifying the configuration thereof. By stopping at least one of the circulation pumps  117 ,  127  of the humidity controller  10 , the heat recovery is stopped, and thus, power for the pumps can be reduced. 
     In particular, enthalpy of the intake air conducted from the exterior inlet port  22  and enthalpy of the discharge air conducted from the interior inlet port  32  are calculated and compared to each other, based on the temperature information and the humidity information of the external space and the internal space, which are detected by the respective detecting means  71 ,  72 , and based on pressure information of the external air and the internal air as necessary. When a difference of the enthalpies is equal to or lower than a predetermined setting value, at least one of the circulation pumps  117 ,  127  of the humidity controller  10  is stopped. At this time, the operation of the compressor  131  may be stopped. 
     The present embodiment is not limited to the case where the enthalpy of the external air and the enthalpy of the internal air are calculated and a difference of the enthalpies is compared. The present embodiment may be configured as follows. A difference of physical quantities corresponding to the enthalpy of the external air and the enthalpy of the internal air is compared, and at least one of the circulation pumps  117 ,  127  of the humidity controller is stopped when the difference of the physical quantities is equal to or lower than a predetermined setting value. As an example of the physical quantity, a temperature or humidity can be used. 
     As described above, when the difference of the enthalpies or the difference of the physical quantities between the external air and the internal air is equal to or lower than a predetermined value based on at least the temperature and the humidity of the external space and those of the internal space, at least one of the circulation pumps  117 ,  127  is stopped. Therefore, even if the humidity control and ventilation system  1  does not have the vertical duct  24  the above-described effect can be obtained. 
     Furthermore, each of the intake blower  40  and the exhaust blower  50  is a blower that is connected to a duct, that is, a duct fan, and can secure a predetermined ventilatory volume. In the present embodiment, the intake blower  40  and the exhaust blower  50  are separately arranged. However, the intake blower  40  and the exhaust blower  50  can be housed in one case by arranging the ducts suitably. Therefore, a fan case, a power source, and a controller can be reduced in size at low cost. 
     Second Embodiment 
     Next, the second embodiment of the present invention will be described with reference to  FIG. 7 . 
     A configuration of the intake duct  20  and arranged positions of the intake blower  40  and the exhaust blower  50  in the second embodiment are different from those of the first embodiment. It is to be noted that the component which is the same with that in the first embodiment is designated by the same reference numeral and a description thereof will not be repeated. 
     As shown in  FIG. 7 , in the present embodiment, the intake duct  20  is branched to the first-floor intake duct  25  in the middle of the vertical duct  24 . Moreover, the intake blower  40  is arranged in the intake pipe  21  at an upstream side of the processing unit  11 , and the exhaust blower  50  is arranged in the exhaust pipe  31  at a downstream side of the regenerating unit  12 . 
     Since the first-floor intake duct  25  is branched in the middle of the vertical duct  24 , the first-floor intake duct  25  does not need to be extended downward from the attic as shown in the first embodiment. Thus, the first-floor intake duct  25  can be shortened and work for sending air can be reduced. 
     Furthermore, since the intake blower  40  is arranged at the upstream side of the processing unit  11 , the droplets of the hygroscopic liquid in the humidity controller  10  can be reliably prevented from adhering to the intake blower  40 . Since the exhaust blower  50  is arranged at the downstream side of the regenerating unit  12 , the intake blower  40  and the exhaust blower  50  are arranged closely to each other. Thus, a case for a blower, a power source, and a control board can be shared between the intake blower  40  and the exhaust blower  50 , and can be reduced in size at low cost. 
     The present embodiment may be configured as follows. The exhaust blower  50  is arranged in the exhaust duct  30  at the downstream portion (i.e., at a position adjacent to the regenerating unit  12  at the upstream side of the regenerating unit  12 ) and the ducts are arranged suitably, such that the intake blower  40  and the exhaust blower  50  are arranged closely to each other. Accordingly, the droplets of the hygroscopic liquid in the humidity controller  10  can also be reliably prevented from adhering to the exhaust blower  50 . 
     Third Embodiment 
     Next, the third embodiment of the present invention will be described with reference to  FIG. 8 . 
     The third embodiment is different from the first and second embodiments in that a duct-type air conditioner, which conditions air in multiple rooms simultaneously, that is, a central air conditioner, is used as the air conditioner  90  of the building in place of a room air conditioner, which conditions air in each of the rooms individually. It is to be noted that the component which is the same with that in the first and second embodiments is designated by the same reference numeral and a description thereof will not be repeated. 
     As shown in  FIG. 8 , in the present embodiment, the indoor unit  91  for the central air conditioner is arranged in the attic, and an air-conditioning intake duct  93  is extended from the indoor unit  91  to the interior outlet ports  23  formed in the respective rooms such as the living room  102 , the Japanese room  103 , the bedroom  104 , the child&#39;s room  105 , and the study room  106 . 
     The downstream end of the intake duct  20  is connected to the indoor unit  91 , and the intake air, which is humidity controlled by the processing unit  11  of the humidity controller  10 , is supplied to the indoor unit  91 . An intake air filter  41  as a filter member is arranged in the intake duct  20  at the downstream portion of the vertical duct  24 , and the hygroscopic liquid can be reliably prevented from reaching the indoor unit  91 . A stair portion  107   a  of the vestibule  107  has an air-conditioning inlet port  95 . The air-conditioning inlet port  95  is the upstream end of an air-conditioning return duct  94 , and the downstream end of the air-conditioning return duct  94  is connected to the indoor unit  91 . 
     The airflow in the humidity control and ventilation system  1  of the present embodiment will be described. The intake air conducted from the exterior inlet port  22  passes through the processing unit  11  of the humidity controller  10  by the intake blower  40 , ascends to the attic through the vertical duct  24 , and passes through the intake air filter  41 , and then, the intake air flows into the indoor unit  91 . 
     Air in the building  100  conducted from the air-conditioning inlet port  95 , which is formed in the stair portion  107   a  of the vestibule  107 , and the intake air that has passed through the processing unit  11  of the humidity controller  10  are mixed in the indoor unit  91  (for example, the intake air and air-conditioning return air from the air-conditioning inlet port  95  are mixed such that a flow ratio thereof is 1:5 to 10). The mixed air is temperature controlled, and then, is supplied to the respective rooms from the interior outlet ports  23  through the air-conditioning intake duct  93 . The air supplied to the respective rooms passes through the door undercut portions or the like (not shown) and the air in the first floor and the air in the second floor are gathered. The gathered air is conducted from the air-conditioning inlet port  95  and returns to the indoor unit  91  through the air-conditioning return duct  94 . 
     The outdoor unit  92  of the central air conditioner is connected to the indoor unit  91  of the central air conditioner through the refrigerant pipe so that the central air conditioner is configured. 
     The air in the building  100  is conducted from the interior inlet port  32 , which is formed in the vestibule  107 , a bathroom or the like, passes through the exhaust duct  30  and the regenerating unit  12  of the humidity controller  10 , and is exhausted to the external space from the exterior outlet port  33  by the exhaust blower  50 . 
     According to the humidity control and ventilation system  1  of the present embodiment, almost all of the droplets of the hygroscopic liquid can be removed out of the intake air in the vertical duct  24 . Thus, the hygroscopic liquid that may adhere to the intake air filter  41 , which is arranged at the downstream portion of the vertical duct  24 , can be extremely reduced. Therefore, a period of time for maintenance of the intake air filter  41  can be extended, and increasing of pressure loss of the intake air filter  41  due to adhesion of the hygroscopic liquid can be suppressed. 
     Moreover, the air in the building  100  conducted from the air-conditioning inlet port  95  and the intake air that has passed through the processing unit  11  of the humidity controller  10  are mixed in the indoor unit  91 , and the mixed air is temperature controlled, and then, is supplied to the respective rooms. Therefore, increasing of an air-conditioning load for the external air due to ventilation and decreasing of efficiency due to a dehumidifying operation of the air conditioner  90  can be suppressed. 
     In particular, since a central air conditioner conditions air in an entire building, an air conditioner with large capacity is generally needed. However, a part for the latent heat process of the external air (for example, about one-half of a load for humidity control and air-conditioning in the summer season) is preprocessed in the humidity controller  10 , and thereby a compact and high-efficient air conditioner can be used. Conventionally, since the inside of a building is processed by air that is temperature conditioned by one indoor unit for a central air conditioner, differences in preferences of men and women of all ages have easily become a problem. However, by combining the humidity controller  10 , air conditioning that widely suits preferences of users can be performed, compared to the case where air conditioning is performed based on only the temperature. For example, high-temperature and low-humidity cooling or low-temperature and high-humidity heating can be easily performed. 
     Fourth Embodiment 
     Next, the fourth embodiment of the present invention will be described with reference to  FIG. 9 . 
     An arranged position of the indoor unit  91  for the central air conditioner in the fourth embodiment is different from that in the third embodiment. It is to be noted that the component which is the same with that in the first to third embodiments is designated by the same reference numeral and a description thereof will not be repeated. 
     As shown in  FIG. 9 , in the present embodiment, the indoor unit  91  for the central air conditioner is arranged in the first floor of the building  100  by using a space below a stair. Also in the present embodiment, the intake air that has passed through the processing unit  11  of the humidity controller  10  is conducted into the indoor unit  91  through the vertical duct  24  of the intake duct  20 . The intake air filter  41  is arranged in the vertical duct  24  at the most downstream portion adjacent to and in front of the indoor unit  91 . 
     Therefore, a mixing ratio of the droplets of the hygroscopic liquid in the intake air can be reduced by the vertical duct  24 , and the period of time for maintenance of the intake air filter  41  can be extended. In order to improve the effect of the vertical duct  24 , if the vertical duct  24  is extended above the indoor unit  91  and is connected to the indoor unit  91  such that the intake air is conducted thereto from above, the effect of the vertical duct  24  can be further improved. 
     Although a detailed description is omitted in the first to fourth embodiments, arbitrary structures can be applied to connection structures of the intake duct  20  or the air-conditioning intake duct  93  to the interior outlet ports  23 . 
     For example, a double-duct system may be applied as shown in  FIG. 10A , or a single-duct system may be applied as shown in  FIG. 10B . Furthermore, a multiple-duct system, in which multiple ducts respectively correspond to the interior outlet ports  23 , may be applied as shown in  FIG. 10C . Alternatively, the above systems may be arbitrary combined. 
     Other Embodiments 
     Hereinbefore, the preferred embodiments of the present invention are described. However, the present invention is not limited to the above-described embodiments, and various changes can be made without departing from the scope of the invention. 
     In the above-described embodiments, the vertically extending section of the intake duct  20  is the vertical duct  24 . However, the vertically extending section may be slanted as long as the vertically extending section extends in the vertical direction and the intake air that has passed through the processing unit  11  flows upward. 
     In the above-described embodiments, the trap groove  27  that configures a part of the recirculating means of the hygroscopic liquid is arranged at the bottom end portion of the vertical duct  24 . However, the trap groove  27  may be located on a slightly upper side of the bottom end portion of the vertical duct  24  as long as most of the hygroscopic liquid can be recirculated from the vertical duct  24 . 
     In the above-described embodiments, the vertical duct  24  extends in the pipe shaft inside the exterior wall  101  of the building  100 . However, the vertical duct  24  may be arranged between the exterior wall  101  and insulating material arranged inside the exterior wall  101  or in the insulating material arranged inside the exterior wall  101  as long as the vertical duct  24  is located inside the exterior wall  101  configuring the building  100 . 
     In the above-described embodiments, a detailed description of material for the intake blower  40  and the exhaust blower  50  is omitted. However, it is preferable that, when the intake blower  40  is arranged at a downstream side of the processing unit  11  in an intake air flow and the exhaust blower  50  is arranged at an upstream side of the regenerating unit  12  in a discharge air flow, both the blowers  40 ,  50  are made of resin material other than the respective drive motor portions. 
     In the above-described embodiments, the intake pipe  21  is connected to the air inlet port  112  of the processing unit  11 , and the exhaust pipe  31  is connected to the air outlet port  123  of the regenerating unit  12 . However, the air inlet port  112  and the air outlet port  123  may not be formed. That is, the air inlet port  112  of the processing unit  11  may be used as an exterior inlet port, and the air outlet port  123  of the regenerating unit  12  may be used as an exterior outlet port. 
     In the above-described embodiments, the air passing through the regenerating unit  12  is the discharge air from the internal space. However, if the heat recovery from the discharge air is unnecessary, the air passing through the regenerating unit  12  may be external air. As shown in  FIG. 11 ; a regenerating-side intake pipe  30   a  that conducts the external air may be connected to the air inlet port  122  of the regenerating unit  12 , and an intake air filter  331   a  may be arranged in the regenerating-side intake pipe  30   a  (in the example shown by  FIG. 11 , at the upstream end thereof). 
     In the above-described embodiments, the processing unit  11  of the humidity controller  10  can perform both the absorbing process and the releasing process, and performs either of the absorbing process or the releasing process in accordance with conditions such as an external environment. However, the processing unit  11  may perform at least one of the absorbing process and the releasing process. 
     In the above-described embodiments, the humidity controller  10  of the humidity control and ventilation system  1  includes the regenerating unit  12 . However, the humidity controller  10  without a regenerating unit can be applied to the present invention. 
     While the invention has been described with reference to preferred embodiments thereof, it is to be understood that the invention is not limited to the preferred embodiments and constructions. The invention is intended to cover various modification and equivalent arrangements. In addition, while the various combinations and configurations, which are preferred, other combinations and configurations, including more, less or only a single element, are also within the spirit and scope of the invention.