Patent Publication Number: US-8539788-B2

Title: Ventilating and air conditioning apparatus

Description:
TECHNICAL FIELD 
     The present invention relates to a ventilating and air-conditioning apparatus for ventilating and air-conditioning a bathroom by using a heat pump. 
     BACKGROUND ART 
     A conventional ventilating and air-conditioning apparatus using a heat pump for a bathroom has worked this way: A first heat exchanger of the heat pump radiates or absorbs heat to/from the air taken in from outside the bathroom, and then blows out the air into the bathroom. A second heat exchanger of the heat pump absorbs or radiates heat from/to air evacuated from the bathroom to the outdoors. The bathroom has been thus air-conditioned (refer to, e.g. Patent Document 1). 
     There is another conventional ventilating and air-conditioning apparatus. A heat pump is split into an outdoor unit and an indoor unit. A heat exchanger placed in the outdoor unit absorbs or radiates heat from/to the open air, and a heat exchanger placed in the indoor unit radiates or absorbs heat to/from the air in a bathroom, which is thus air-conditioned (refer to, e.g. Patent Document 2). 
     As discussed above, various ventilating and air-conditioning apparatus using a heat pump for a bathroom have been proposed. The bathroom air-conditioner disclosed in Patent Document 1 collects heat from air evacuated from the bathroom to the outdoors for air-conditioning the bathroom. However, the heat exchanger disclosed in Patent Document 1 cannot collect 100% of the heat from the evacuated air, so a part of the heat (energy of cooled air) having been used for the air-conditioning of the bathroom leaks to the outdoors. The leak incurs heat loss, which results in a lower thermal efficiency. 
     The bathroom air-conditioner disclosed in Patent Document 2, on the other hand, leaks a smaller amount of the heat having been used for the air-conditioning of the bathroom. However, since the heat pump is separated into the indoors and the outdoors of the bathroom, piping work for refrigerant to travel through is needed in order to connect the inside to the outside of the bathroom, so that installing work becomes inefficient. On top of that, this air-conditioner needs a space for the outdoor unit.
     Patent Document 1: Unexamined Japanese Patent Application Publication No. 2005-180712   Patent Document 1: Unexamined Japanese Patent Application Publication No. 2002-349930   

     DISCLOSURE OF INVENTION 
     A ventilating and air-conditioning apparatus of the present invention comprises the following elements:
         a circulating fan sucking air through a sucking port open to a first indoor space, and blowing out the air through a blowout port open to the first indoor space;   a ventilating fan sucking air through an evacuating port open to a second indoor space, and evacuating the air to the outdoors for ventilation;   a refrigerant circuit including:
           a compressor for compressing a refrigerant;   a first heat exchanger for exchanging heat of the air blown into the first indoor space by the circulating fan with the refrigerant;   an expanding mechanism for expanding the refrigerant; and   a second heat exchanger for exchanging heat of the air blown into the second indoor space by the ventilating fan with the refrigerant, wherein the compressor, the first heat exchanger, the expanding mechanism, and the second heat exchanger are coupled to each other with pipes for the refrigerant to circulate therein.   
               

     The foregoing structure allows the refrigerant in the second heat exchanger to absorb heat from the air evacuated by the ventilating fan from the second indoor space to the outdoors, and allows the refrigerant in the first heat exchanger to radiate heat to the air circulated by the circulating fan in the first indoor space. The heat pump thus works to air-condition the first indoor space, so that the air having undergone the heat exchange in the first heat exchanger does not leak outside the first indoor space. The first indoor space thus can be air-conditioned effectively and the thermal efficiency can be improved. On top of that, the ventilating and air-conditioning apparatus placed under the roof of the first indoor space can accommodate the refrigerant circuit which is formed of the compressor, the first heat exchanger, the expanding mechanism and the second heat exchanger. The structure discussed above thus can improve the installing work, and save a space. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a floor plan of a living space where a ventilating and air-conditioning apparatus in accordance with a first embodiment of the present invention is placed. 
         FIG. 2  shows an air course structure and a refrigerant circuit of the ventilating and air-conditioning apparatus. 
         FIG. 3  schematically shows a refrigerant heater to be employed in a refrigerant heating device of the ventilating and air-conditioning apparatus. 
         FIG. 4  shows a sectional view schematically illustrating a refrigerant-hydrothermal exchanger of the ventilating and air-conditioning apparatus. 
         FIG. 5  shows working states of the ventilating and air-conditioning apparatus in response to respective work patterns. 
         FIG. 6  shows an air course structure and a refrigerant circuit of a ventilating and air-conditioning apparatus in accordance with a second embodiment of the present invention. 
         FIG. 7  shows working states of the ventilating and air-conditioning apparatus in response to respective work patterns. 
         FIG. 8  shows timing charts illustrating relations between an indication of a temperature sensor and an air volume of a ventilating fan of the ventilating and air-conditioning apparatus during a cool operation of the ventilating and air-conditioning apparatus. 
         FIG. 9  shows timing charts illustrating relations between an indication of a temperature sensor and an air volume of the ventilating fan of the ventilating and air-conditioning apparatus during a heat operation of the ventilating and air-conditioning apparatus. 
     
    
    
     DESCRIPTION OF REFERENCE MARKS 
     
         
         
           
               3  bathroom (first indoor space) 
               4  dressing room (second indoor space) 
               5  toilet room (second indoor space) 
               8 ,  10  evacuating port 
               12  ventilating fan 
               14  air-conditioner 
               17  sucking port 
               18  blowout port 
               21  circulating fan 
               22  auxiliary heater 
               23  ventilation path 
               24  shutter 
               25  refrigerant circuit 
               26  compressor 
               27  first heat exchanger 
               28  expanding mechanism 
               29  second heat exchanger 
               30  flow-path switching valve 
               31 ,  32  bypass circuit 
               33  first on-off valve 
               34  second on-off valve 
               35  refrigerant heating device 
               38  decompressing device 
               39  pre-heater 
               40  refrigerant heater 
               47  refrigerant-hydrothermal exchanger 
               59  controller 
               100 ,  110  ventilating and air-conditioning apparatus 
           
         
       
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     Embodiment 1 
     The first embodiment of the present invention is demonstrated hereinafter with reference to  FIG. 1-FIG .  5 .  FIG. 1  shows a floor plan of a living space where a ventilating and air-conditioning apparatus in accordance with the first embodiment of the present invention is placed. In  FIG. 1 , living space  1  is divided into living room  2 , bathroom  3  equal to a first indoor space, dressing room  4  and toilet room  5  equal to a second indoor room, and so on. Main unit  6  of the ventilating and air-conditioning apparatus is placed under the roof of bathroom  3 . 
     Main unit  6  is connected with exhausting duct  7  which connects main unit  6  to the outdoors, exhausting duct  9  which connects evacuating port  8  open to a ceiling of dressing room  4  to main unit  6 , and exhausting duct  11  which connects evacuating port  10  open to a ceiling of toilet room  5  with main unit  6 . Ventilating fan  12  is placed inside main unit  6 , and is connected with exhausting duct  7  at its blowout side, exhausting ducts  9  and  11  at its sucking side. 
     When ventilating fan  12  is driven, the air in dressing room  4  and toilet room  5  is sucked by fan  12  from evacuating ports  8  and  10  through exhausting ducts  9  and  11 , and the air is evacuated to the outdoors through exhausting duct  7 . A continuous run of fan  12  prompts living room  1  to fall into a negative pressure, so that fresh air is supplied from the outdoors through air-supply port  13  open to the outdoors of living room  2  through a wall. Living space  1  is thus ventilated. 
     If the ventilating and air-conditioning apparatus discussed above is placed in a highly air-tight building, the ventilating operation needs to be done continuously (around-the-clock ventilation). Ventilating fan  12  thus runs continuously in order to obtain a predetermined ventilation amount, e.g. an hourly ventilation amount corresponding to a volume half of living space  1 . Living room  2  is equipped with air-conditioner  14  which cools room  2  in summer or heats room  2  in winter so that a room temperature can be maintained appropriately. 
     A continuous ventilation throughout the year allows the air cooled down by air-conditioner  14  to a low temperature in summer or the air heated to a high temperature in winter to be sucked into evacuating ports  8  and  10  through a lover or an undercut of door  15  of dressing room  4 , or those of door  16  of toilet room  5 . The air is then evacuated to the outdoors through main unit  6  of the ventilating and air-conditioning apparatus. 
       FIG. 2  shows an air course structure and a refrigerant circuit of the ventilating and air-conditioning apparatus. As shown in  FIG. 2 , main unit  6  of ventilating and air-conditioning apparatus  100  is placed under the roof of bathroom  3 . Main unit  6  includes sucking port  17  and blowout port  18  at its underside both, and both of ports  17  and  18  are open to the ceiling of bathroom  3 . Filter  19  is placed on port  17  detachably for catching dust. 
     Main unit  6  includes circulation path  20  therein for connecting sucking port  17  to blowout port  18 , and circulating fan  21  is placed inside path  20  for sucking the air in bathroom  3  from sucking port  17  and blowing out the air from blowout port  18 . 
     Radiation type auxiliary heater  22  is placed around blowout port  18  placed in circulation path  20  for heating at least a part of the air blown by circulating fan  21 . Auxiliary heater  22  is placed such that it can dissipate the heat radiated by itself into bathroom  3 . Main unit  6  also includes ventilation path  23  therein for connecting sucking port  17  to a sucking side of ventilating fan  12 , and path  23  is connected with exhausting duct  9  communicating with dressing room  4 , and with exhausting duct  11  communicating with toilet room  5 . 
     Ventilation path  23  includes shutter  24  at its course between sucking port  17  in path  23  and the sucking side of ventilating fan  12 . Shutter  24  is equipped with a damper mechanism for opening/closing ventilation path  23 . During the operation of ventilating fan  12 , when shutter  24  is set to open path  23 , air is sucked into main unit  6  through sucking port  17 , and exhausting ducts  9 ,  11 . When shutter  24  is set to close path  23 , the air can be sucked from exhausting ducts  9 ,  11 . The air thus sucked by ventilating fan  12  is then evacuated to the outdoors through exhausting duct  7  coupled to the blowout side of ventilating fan  12 . 
     Refrigerant circuit  25  is formed in main unit  6 . Circuit  25  is filled with one of the following refrigerants: HCFC based refrigerant (its molecule contains atoms of chlorine, hydrogen, fluorine, carbon), HFC based refrigerant (its molecule contains atoms of hydrogen, carbon, fluorine), carbon hydride, and carbon dioxide (natural refrigerant). In this refrigerant circuit  25 , the following elements are placed: compressor  26  for compressing the refrigerant, first heat exchanger  27  for exchanging heat between supplied air and the refrigerant, expanding mechanism  28  formed of electronic expanding valve for expanding the refrigerant, and second heat exchanger  29  for exchanging heat between the supplied air and the refrigerant. 
     Flow path switching valve  30  is placed in refrigerant circuit  25 , and switching valve  30  switches a heating cycle to a cooling cycle. To be more specific, during the heating cycle, the refrigerant compressed by compressor  26  flows in circuit  25  this order: first heat exchanger  27 , expanding mechanism  28 , second heat exchanger  29 , and returns to compressor  26 . During the cooling cycle, the refrigerant compressed by compressor  26  flows to second heat exchanger  29 , expanding mechanism  28 , first heat exchanger  27 , then returns to compressor  26 . 
     On top of that, bypass circuit  31  is formed in refrigerant circuit  25 , and bypass circuit  31  branches off from a pipe which connects flow-path switching valve  30  to first heat exchanger  27 , and merges to a pipe which connects expanding mechanism  28  to second heat exchanger  29 . Another bypass circuit  32  is also formed in refrigerant circuit  25 , and bypass circuit  32  branches off from a pipe which connects first heat exchanger  27  to expanding mechanism  28 , and merges into a pipe which connects second heat exchanger  29  to flow-path switching valve  30 . In bypass circuit  31 , first on-off valve  33  for opening/closing circuit  31  is placed. In bypass circuit  32 , second on-off valve  34  for opening/closing circuit  32  and refrigerant heating device  35  are placed. Refrigerant heating device  35  can employ a refrigerant heater, or a refrigerant-hydrothermal exchanger described later. 
     First heat exchanger  27  is placed in circulation path  20 , and second heat exchanger  29  is placed on the sucking side of ventilating fan  12  placed in ventilation path  23 . The refrigerant in first heat exchanger  27  thus radiates or absorbs heat to/from the air circulated by circulating fan  21  in bathroom  3 . The refrigerant in second heat exchanger  29  absorbs or radiates heat from/to the air evacuated by ventilating fan  12  to the outdoors. 
     The refrigerant of first heat exchanger  27  flows in the pipe in which decompressing device  38  formed of third on-off valve  36  and capillary tube  37  are placed. First heat exchanger  27  is placed such that when the flow direction of the refrigerant is switched to the heating cycle, i.e. along the solid line of flow-path switching valve  30 , the air in bathroom  3  circulated by circulating fan  21  exchanges heat with the refrigerant flowing downstream of decompressing device  38 , and then exchanges heat with the refrigerant flowing upstream of decompressing device  38 . 
     In ventilation path  23 , pre-heater  39  capable of self-controlling its temperature is placed at the windward side of second heat exchanger  29 . When pre-heater  39  works, the air sucked from dressing room  4 , the air in toilet room  5  and the air in bathroom  3  into ventilation path  23  can be pre-heated before being supplied to second heat exchanger  29 . 
       FIG. 3  schematically shows a refrigerant heater to be employed in refrigerant heating device  35 . As shown in  FIG. 3 , refrigerant heater  40  is formed of refrigerant conduit  41 , electric-heat pipe  42 , and heat conductive cylinder  46 . Refrigerant conduit  41  is formed by winding a refrigerant pipe, through which the refrigerant ravels, into a coil shape, and heat pipe  42  is shaped like a letter “U” and placed inside the coil shaped refrigerant conduit  41 . Heat conductive cylinder  46  is a solid cylinder (not hollow one) and made of metal such as aluminum. Cylinder  46  covers entire surface of heater  40  except inlet  43 , outlet  44  of refrigerant conduit  41 , and terminals  45  of heat pipe  42 . 
     An application of a given voltage to terminals  45  of electric-heat pipe  42  prompts pipe  42  to generate heat, which then travels in heat conductive cylinder  46  for heating refrigerant conduit  41  placed on a perimeter of heat pipe  42 . The refrigerant is input at inlet  43  of refrigerant conduit  41 , and flows in conduit  41  at the coil shaped section of which outer wall is covered with heat conductive cylinder  46 . At this time the refrigerant is heated via heat conductive cylinder  46 , and then the refrigerant arrives at outlet  44 . Refrigerant heater  40  heats the refrigerant as discussed above, and heat pipe  42  placed at the core section of heat conductive cylinder  46  generates the heat to refrigerant conduit  41  placed along the perimeter of heat pipe  42 . This structure allows reducing the leak of the heat to the outside. The heat generated by heat pipe  42  travels along heat conductive cylinder  46 . As a result, refrigerant conduit  41  can be heated uniformly by the heat generated by electric-heat pipe  42 , and a heating efficiency can be improved, which allows downsizing refrigerant heating device  35 . 
       FIG. 4  shows a sectional view schematically illustrating a structure of refrigerant-hydrothermal exchanger to be used in refrigerant heating device  35 . As shown in  FIG. 4 , exchanger  47  employs a dual-pipe construction in which refrigerant conduit  50  is placed within hot-water supply conduit  49  where the hot water supplied from heat-pump type water-heater  48  flows. 
     Refrigerant conduit  50  is branched off into two lines in hot-water conduit  49 , and each one of the branched lines are spirally twisted together so that a heat conductive area can be enlarged for improving a heat exchange efficiency. The hot water enters from inlet  51  into refrigerant-hydrothermal exchanger  47  flows along the perimeter of refrigerant conduit  50  and flows out from outlet  52  to the outside of exchanger  47  and drops to drain-pan  53  placed under outlet  52 . 
     This drain-pan  53  also receives drain-water of the dew formed on first and second heat exchangers  27 ,  29 . The hot water dropped onto drain pan  53  together with the drain water of the dew is evacuated to the outside of main unit  6  through drain pipe  54 . 
     The refrigerant entering from refrigerant-inlet  55  into exchanger  47  flows in the respective twisted pipes along the direction opposite to the flow of the hot water, and exchanges the heat with the hot water, so that the refrigerant is heated, and then flows out from refrigerant-outlet  57 . The hot water used in heating the refrigerant is heated by using the atmospheric heat in heat-pump type water-heater  48 , so that the heating efficiency of refrigerant heating device  35  can be improved, and the running cost of device  35  can be thus lowered. 
     Water at an ordinary temperature can be supplied to hot-water conduit  49  instead of the hot water heated to a high temperature by water heater  48 . In this case, if flow-path switching valve  30  is switched to the cooling cycle and second on-off valve is set to an open state, the refrigerant compressed by compressor  26  and in a high temperature and a high pressure is supplied to refrigerant conduit  50 . The refrigerant can be thus cooled in exchanging heat with the water at the ordinary temperature. 
     Next, working of ventilating and air-conditioning apparatus  100  is demonstrated hereinafter.  FIG. 5  shows a list including working states in response to respective work patterns. The list shows the respective work patterns of air-conditioning apparatus  100  in the columns sequentially, and working states of major structural elements in response to the work patterns in the rows. 
     Ventilating and air-conditioning apparatus  100  can perform 6 patterns as listed in  FIG. 5 , namely, “around-the-clock ventilation”, “dry”, “dehumidify”, “cool”, “pre-heat”, and “heat for bathing”. The work pattern of “around-the-clock ventilation” carries out ventilation for 24 hours/day continuously in order to obtain a ventilated amount of the air necessary for living space  1 . During the operation of this pattern, ventilating fan  12  is set to a weak notch which assures the necessary ventilation amount, and shutter  24  placed in ventilation path  23  is set to the “open” state. Other major structural elements including circulating fan  21 , compressor  26 , auxiliary heater  22 , pre-heater  39 , and refrigerant heating device  35  are all set to “halt” state. A predetermined amount of the air corresponding to a necessary amount of air is thus sucked from sucking port  17  open to bathroom  3 , evacuating port  8  open to dressing room  4 , and evacuating port  10  open to toilet room  5  into ventilating fan  12  through ventilation path  23 , and then the air is evacuated to the outdoors. An amount of fresh air corresponding to the amount of the evacuated air is taken into air-supply port  13  open to living room  2 . The air evacuated from living space  1  can be thus replaced with the fresh air, so that living space  1  can be ventilated. 
     Next, the pattern of “dry” is demonstrated hereinafter. This dry pattern is selected when laundry is hung in bathroom  3  to dry. In the case of carrying out this “dry” pattern, ventilating fan  12  is set to a strong notch which gives a greater wind volume than that of the “around-the-clock ventilation” operation, shutter  24  is set to the open state, and circulating fan  21  is set to a given notch which drives fan  21  at a wind volume set by a user. Then compressor  26  is driven. 
     Flow-path switching valve  30  is set to the “heating cycle”, expanding mechanism  28  is set its electronic expanding valve to a given open angle, first on-off valve  33  placed in bypass circuit  31  is set to the closed state, second on-off valve  34  placed in bypass circuit  32  is set to the closed state, third on-off valve  36  placed in the refrigerant conduit is set to the open state, and other elements including auxiliary heater  22 , pre-heater  39 , refrigerant heating device  35  are set to the halt state. The foregoing settings allow the refrigerant, compressed by compressor  26  and in a high temperature and a high pressure state, to flow through flow-path switching valve  30  set to the heating cycle, and then, to arrive at first heat exchanger  27  because first on-off valve  33  is set to the closed state. In first heat exchanger  27 , circulating fan  21  works at the given notch, so that the air sucked from bathroom  3  through sucking port  17  into main unit  6  is supplied to first heat exchanger  27 . 
     Since third on-off valve  36  is set to the open state, the refrigerant in a high temperature and a high pressure state and entering into first heat exchanger  27  passes through exchanger  27  free from an extreme decompressing action. At this time, the refrigerant exchanges heat with the supplied air, i.e. the refrigerant radiates heat for heating the air, which is then blown out from blowout port  18  into bathroom  3 . The entire refrigerant having radiated the heat in first heat exchanger  27  arrives at expanding mechanism  28  because second on-off valve  34  is set to the open state. The refrigerant is then decompressed and expands when the refrigerant passes the electronic expanding valve which is set to a given open angle, and then arrives at second heat exchanger  29 . 
     In second heat exchanger  29 , since ventilating fan  12  works at the strong notch, the air in dressing room  4  and toilet room  5  is supplied to second heat exchanger  29  via exhausting ducts  9  and  11 . Since shutter  24  is set to the open state, the air in bathroom  3  travels from sucking port  17  to second heat exchanger  29  via ventilation path  23 . The mechanics discussed above allows the refrigerant in second heat exchanger  29  to absorb heat from the air supplied from bathroom  3 , the air supplied from dressing room  4 , and the air supplied from toilet room  5 . 
     The refrigerant having absorbed the heat in second heat exchanger  29  returns to compressor  26  via flow-path switching valve  30 , so that the refrigerant resultantly circulates through refrigerant circuit  25 . The heat of the air supplied to second heat exchanger  29  is absorbed by the refrigerant. Thereby, the enthalpy of the air is reduced. Finally, the air is evacuated to the outdoors from exhausting duct  7 . 
     The laundry is hung in bathroom  3  during the dry operation discussed above, then the air heated to a high temperature by first heat exchanger  27  circulates in bathroom  3  and promotes evaporation of water from the laundry. The air in bathroom  3  traps the water evaporated from the laundry and is sucked into main unit  6  by ventilating fan  12 , and then collected its heat by second heat exchanger  29  before the air is evacuated to the outdoors. On top of that, second heat exchanger  29  receives a greater amount of air than the air amount supplied thereto during the around-the-clock ventilation operation, so that the refrigerant can absorb a greater amount of heat. As a result, the refrigerant can dissipate a greater amount of heat, thereby drying the laundry quickly. 
     Next, the “dehumidify” operation is demonstrated hereinafter. The “dehumidify” pattern is selected in dehumidifying bathroom  3 , e.g. after taking a bath, in order to prevent bathroom  3  from going moldy. In the case of carrying out the “dehumidify” operation, ventilating fan  12  is set to the weak notch which is able to obtain a necessary amount of ventilation air, shutter  24  is set to the closed state, circulating fan  21  is set to a predetermined notch at which fan  21  works with the air volume set by a user. Then compressor  26  is driven. Flow-path switching valve  30  is set to the heating cycle, first on-off valve  33  is set to the closed state, second on-off valve  34  is set to the open state, and third on-off valve  36  is set to the closed state. Other elements including auxiliary heater  22 , pre-heater  39 , and refrigerant heating device  35  are set to the halt state. 
     The foregoing settings allow the refrigerant compressed by compressor  26  and in a high temperature and a high pressure flows through flow-path switching valve  30  set to the heating cycle, and then the entire refrigerant arrives at first heat exchanger  27  because first on-off valve  33  is set to the closed state. In first heat exchanger  27 , circulating fan  21  works at the given notch, so that the air sucked from sucking port  17  into main unit  6  is supplied to bathroom  3 . 
     Since third on-off valve  36  is set to the closed state, the refrigerant at a high temperature and a high pressure and entering into first heat exchanger  27  is decompressed by capillary tube  37  and expands, and then the refrigerant at a low temperature and at a low pressure passes in the remaining refrigerant conduit. The air of bathroom  3  flows into circulation path  20 , and is firstly supplied to the downstream side of capillary tube  37  of first heat exchanger  27 . The refrigerant absorbs heat from the supplied air at this downstream side, so that the supplied air is cooled and dehumidified. 
     The cooled and dehumidified air of bathroom  3  is then supplied to the upstream side of capillary tube  37  of first heat exchanger  27 , where the refrigerant radiates heat to the supplied air of low temperature and low humidity, so that the air increases its temperature only. The air thus becomes dry air at a high temperature and a low humidity, and returns to bathroom  3  via blowout port  18 . Repeating the foregoing air circulation will make bathroom  3  an environment of high temperature and low humidity, namely, bathroom  3  is dehumidified. 
     The refrigerant having radiated and absorbed the heat to/from the supplied air in first heat exchanger  27  flows entirely toward bypass circuit  32  because the first on-off valve  33  is set to the closed state, and second on-off valve  34  is set to the open state. The refrigerant then returns to compressor  26  via flow-path switching valve  30 . The refrigerant resultantly circulates through refrigerant circuit  25 . Ventilating fan  12  is driven at the weak notch which is capable of supplying an air volume necessary for ventilating the living space  1 . Since shutter  24  is set to the closed state, only the air in dressing room  4  and toilet room  5  can be sucked by ventilating fan  12  via exhausting ducts  9  and  11 , and the air is evacuated to the outdoors. 
     The mechanics discussed above allows supplying fresh air corresponding to the necessary ventilation volume to living space  1 . The fresh air is sucked from air-supply port  13 , so that the ventilation is carried out. The dry air of high temperature and low humidity and dehumidified in circulation path  20  cannot be evacuated outside bathroom  3 , thereby preventing the dehumidifying efficiency from decreasing. 
     Next, the “cool” operation is demonstrated hereinafter. The “cool” pattern is selected when a user in bathroom  3  wants to lower a high temperature, e.g. in summer, for cooling bathroom  3  in order to take a bath pleasantly, or clean bathroom  3  lightly. 
     In the case of carrying out this “cool” operation, ventilating fan  12  is set to a strong notch which gives a greater volume of wind than that of the “around-the-clock ventilation”, shutter  24  is set to the closed state, and circulating fan  21  is set to a given notch which drives fan  21  at a wind volume set by a user. Then compressor  26  is driven. Flow-path switching valve  30  is set to “cooling cycle”, expanding mechanism  28  is set its electronic expanding valve to a given open angle, first on-off valve  33  is set to the closed state, second on-off valve  34  is set to the closed state, third on-off valve  36  is set to the open state, and other elements including auxiliary heater  22 , pre-heater  39 , refrigerant heating device  35  are set to the halt state. 
     The settings discussed above allow the refrigerant compressed by compressor  26  and in a high temperature and a high pressure state to flow through flow-path switching valve  30  set to the cooling cycle, and then the entire refrigerant arrives at second heat exchanger  29  because second on-off valve  34  is set to the closed state. In second heat exchanger  29 , ventilating fan  12  works at the strong notch, so that the air in dressing room  4  and toilet room  5  is supplied to second heat exchanger  29  through exhausting ducts  9  and  11 , and the refrigerant radiates heat to the supplied air. The temperature of the air sucked from dressing room  4  and toilet room  5  becomes high due to the heat radiation from the refrigerant, and the air is evacuated to the outdoors through exhausting duct  7 . The refrigerant having radiated the heat in second heat exchanger  29  entirely arrives at expanding mechanism  28  because first on-off valve  33  is set to the closed state. The refrigerant is then decompressed and expands when it passes the electronic expanding valve before it arrives at first heat exchanger  27 . 
     In first heat exchanger  27 , circulating fan  21  works at the given notch, so that the air sucked from bathroom  3  through sucking port  17  to main unit  6  is supplied to first heat exchanger  27 , and the refrigerant absorbs heat from this supplied air. The refrigerant then returns to compressor  26  via flow-path switching valve  30 . The refrigerant thus resultantly circulates through refrigerant circuit  25 . The temperature of the air supplied to first heat exchanger  27  becomes low due to the heat absorption by the refrigerant, and returns to bathroom  3  through blowout port  18 . The air circulation discussed above is repeated, thereby lowering the temperature in bathroom  3 , which is thus cooled. 
     Shutter  24  is set to the closed state, so that the air cooled to a low temperature in circulation path  20  cannot be evacuated to the outside of bathroom  3 . The foregoing mechanics thus prevent an air-conditioning efficiency from lowering. 
     If a user encounters an extraordinary high temperature in summer, the air is supplied at a high temperature to second heat exchanger  29 , so that the refrigerant cannot radiates enough heat, thereby sometimes causing a lack of cooling power. In such a case, water at an ordinary temperature instead of hot water can be supplied to hot-water conduit  49  of refrigerant-hydrothermal exchanger  47  as discussed previously, and second on-off valve  34  is set to the open state. Then the refrigerant compressed by compressor  26  and in a high pressure and a high temperature state is circulated through exchanger  47  for the refrigerant to radiate heat to the water at an ordinary temperature. This mechanics allows preventing the cooling power from lowering. 
     Next, the “pre-heat” operation is demonstrated hereinafter. The “pre-heat” pattern is selected for heating bathroom  3  before a user take a bath in a low-temperature season like winter so that a heat shock can be softened. In the case of carrying out the “pre-heat” operation, ventilating fan  12  is set to the strong notch which gives a greater wind volume than that of the “around-the-clock ventilation”, shutter  24  is set to the open state, and circulating fan  21  is set to the given notch which drives fan  21  at a wind volume set by a user. Then compressor  26  is driven. Flow-path switching valve  30  is set to the “heating cycle”, expanding mechanism  28  is set its electronic expanding valve to a given open angle, first on-off valve  33  is set to the closed state, second on-off valve  34  is set to the closed state, third on-off valve  36  is set to the open state, and other elements including auxiliary heater  22 , pre-heater  39 , refrigerant heating device  35  are set to the halt state. 
     The settings discussed above allow the refrigerant compressed by compressor  26  and in a high temperature and a high pressure state to flow through flow-path switching valve  30  set to the heating cycle, and then the entire refrigerant arrives at first heat exchanger  27  because first on-off valve  33  is set to the closed state. In first heat exchanger  27 , circulating fan  21  works at the given notch, so that the air sucked from bathroom  3  through sucking port  17  into main unit  6  is supplied to first heat exchanger  27 . 
     Since third on-off valve  36  is set to the open state, the refrigerant at a high temperature and a high pressure enters into first heat exchanger  27  and passes through exchanger  27  free from a decompressing action. At this time, the refrigerant exchanges heat with the air sucked from bathroom  3  and supplied to exchanger  27 , i.e. the refrigerant radiates heat for heating the air, which is then blown out from blowout port  18  to bathroom  3 . 
     The entire refrigerant having radiated heat in first heat exchanger  27  arrives at expanding mechanism  28  because second on-off valve  34  is set to the closed state. The refrigerant is then decompressed and expands when the refrigerant passes the electronic expanding valve which is set to the given open angle, and then arrives at second heat exchanger  29 . Since ventilating fan  12  works at the strong notch in second heat exchanger  29 , the air in dressing room  4  and toilet room  5  is supplied to second heat exchanger  29  via exhausting ducts  9  and  11 . The refrigerant absorbs heat from the supplied air. 
     The refrigerant having absorbed the heat in second heat exchanger  29  returns to compressor  26  via flow-path switching valve  30 , so that the refrigerant resultantly circulates through refrigerant circuit  25 . The heat in air supplied to second heat exchanger  29  is absorbed by the refrigerant. Thereby, the enthalpy of air is reduced. Finally, the air is evacuated to the outdoors through exhausting duct  7 . The foregoing operation raises the temperature in bathroom  3 , which is thus pre-heated. Shutter  24  is set to the closed state, so that the air heated in circulation path  20  to a high temperature cannot be evacuated to the outside of bathroom  3 . The foregoing mechanism thus prevents an air-conditioning efficiency from lowering. 
     When a user encounters an extraordinary low temperature in winter, the air sucked by ventilating fan  12  from dressing room  4  and toilet room  5  and supplied to second heat exchanger  29  lowers its temperature, so that second heat exchanger  29  is sometimes frosted during the pre-heat operation discussed above. If the frost is left as it is, second heat exchanger  29  lowers its heat absorption power, and this phenomenon entails that first heat exchanger  27  reduces its heat radiation amount, so that bathroom  3  cannot be sufficiently heated. 
     In order to prevent the foregoing problem, the following measures should be taken: Monitor the temperature of the refrigerant conduit in second heat exchanger  29  during the pre-heat operation, and carry out a frost-removal operation for removing the frost attached to second heat exchanger  29  if the temperature lowers to a predetermined temperature. 
     The frost removal operation is demonstrated hereinafter. In the case of carrying out the frost removal operation during the pre-heat, both of ventilating fan  12  driven at the strong notch and circulating fan  21  driven at the given notch are halted. Then flow-path switching valve  30  set to the heating cycle is switched over to the cooling cycle. 
     These settings allows the refrigerant compressed by compressor  26  and in a high pressure and a high temperature state to flow through flow-path switching valve  30  which has been switched over to the cooling cycle, and to arrive at second heat exchanger  29 . This refrigerant at the high temperature flows through the refrigerant conduit in second heat exchanger  29 , so that a temperature of the conduit rises, thereby melting the frost attached to the conduit surface. The melted frost drops as draining water to drain-pan  53 , and is evacuated to the outside of bathroom  3  via drain pipe  54 . 
     The refrigerant which has radiated heat in second heat exchanger  29  for melting the frost flows through expanding mechanism  28 , first heat exchanger  27 , and flow-path switching valve  30  in this order, and then returns to compressor  26 . The refrigerant thus resultantly circulates through refrigerant circuit  25 . A continuous operation of the foregoing frost-removing operation will completely melt the frost attached to second heat exchanger  29 , so that the conduit raises its temperature. The temperature of the conduit is monitored continuously, and when it rises to a predetermined value, the frost-removal operation is switched again to the pre-heat operation. The foregoing process allows preventing the heating power from extremely lowering during a low temperature period, and allows performing a sufficient pre-heat. 
     Next, the “heat for bathing” operation is demonstrated hereinafter. This pattern is selected for heating bathroom  3  when a user washes himself or herself in bathroom  3  during a low-temperature season like in winter so that the user can take a bath comfortably without feeling the cold. 
     The settings and operation of this “heat for bathing” is basically the same as those of “pre-heat” operation. However, auxiliary heater  22  can be switched between “operate” and “halt” in response to a user&#39;s choice. For instance, when the user feels drawing a draft, and the user thus sets circulating fan  21  to a smaller air volume. Then the user feels a smaller amount of the draft although the refrigerant reduces its heat radiation because the air volume supplied to first heat exchanger  27  is reduced. As a result, the temperature in bathroom  3  lowers, which incurs a loss of the amenity. In such a case, drive of auxiliary heater  22  will further heat the air passed through first heat exchanger  27  to a high temperature, so that the temperature in bathroom  3  can be suppressed to lower. 
     On top of that, when auxiliary heater  22  employs a radiant heater, the heater irradiates radiant heat directly to a human body, who can feel more warmth. The foregoing operation allows users to take a bath comfortably without feeling the cold. 
     During the “heat for bathing” operation, the frost-removal operation similar to that carried out during the “pre-heat” operation is needed for removing the frost attached to second heat exchanger  29 . Since a user exists in bathroom  3  during the “heat for bathing” operation, the “heat” operation is preferably maintained during the “frost removal” operation although during the “pre-heat” operation the “heat” operation is temporarily halted before the “frost removal” operation starts. 
     The “frost removal” operation during the “heat for bathing” operation is demonstrated hereinafter: Ventilating fan  12 , shutter  24 , circulating fan  21 , compressor  26  and flow-path switching valve  30  maintain their workings of the “heat for bathing” operation, although first on-off valve  33  and second on-off valve  34  are switched from the closed states to the open state. The electronic expanding valve of expanding mechanism  28  is set to a full-closed state, and then pre-heater  39  and refrigerant heating device  35  are driven. 
     The settings thus changed as discussed above allows the refrigerant compressed by compressor  26  and in a high pressure and a high temperature state to pass through flow-path switching valve  30  set to the heating cycle, and to branch off toward first heat exchanger  27  and toward bypass circuit  31 , because first on-off valve  33  has been switched to the open state. The refrigerant branched off toward first heat exchanger  27  radiates heat to the air sucked from bathroom  3  by circulating fan  21  and supplied to exchanger  27 . The air heated by the heat radiation from the refrigerant circulates in bathroom  3 , so that the heat operation is maintained. 
     The refrigerant having radiated heat to the supplied air in first heat exchanger flows entirely to bypass circuit  32  and enters into refrigerant heating device  35  because the electronic expanding valve of expanding mechanism  28  is set to the full-closed state and second on-off valve  34  is set to the open state. Refrigerant heating device  35  is equipped with refrigerant heater  40  or refrigerant-hydrothermal exchanger  47 , so that the refrigerant is heated by device  35 , i.e. the refrigerant absorbs heat. 
     On the other hand, the high-temperature and high-pressured refrigerant, which has been discharged from compressor  26  and branched off toward bypass circuit  31 , flows into second heat exchanger  29 . Since ventilating fan  12  in exchanger  29  operates at the strong notch, the air sucked from dressing room  4  and toilet room  5  is supplied to second heat exchanger  29  via exhausting ducts  9  and  11 . This supplied air is heated by pre-heater  39  placed on the upstream side of exchanger  29  before it enters into exchanger  29  at a higher temperature. 
     In second heat exchanger  29 , the high-temperature refrigerant thus flows in the refrigerant conduit, and the high-temperature air heated by pre-heater  39  flows along the conduit surface where frost attaches. The frost attached to second heat exchanger  29  can be thus removed quickly. The refrigerant having melted the frost attached to exchanger  29  flows together with the other refrigerant heated by refrigerant heating device  35 , and returns to compressor  26  via flow-pass switching valve  30 . The air supplied to exchanger  29  radiates heat to the frost attached, and then is evacuated to the outdoors via exhausting duct  7 . 
     As discussed above, the frost-removal of second heater exchanger  29  can be achieved while the “heat for bathing” operation is maintained. When a pipe temperature of exchanger  29  rises to the given value, i.e. when the frost-removal is completed, the operation returns to the regular “heat for bathing” operation so that the “heat” operation can be continuously carried out free from losing user&#39;s comfortable feeling. 
     The structure and working discussed above prove that the ventilating and air-conditioning apparatus for a bathroom in accordance with the first embodiment of the present invention produces the following advantages. 
     In second heat exchanger  29 , the refrigerant absorbs heat from the air which is sucked from dressing room  4  and toilet room  5  and is to be evacuated by ventilating fan  12  to the outdoors. In first heat exchanger  27 , the refrigerant radiates heat to the air circulated by circulating fan  21  in bathroom  3 . A heat pump starts working with a heat source using the air sucked from dressing room  4  and toilet room  5  and to be evacuated to the outdoors, so that bathroom  3  is heated. The air heated by first heat exchanger  27  thus does not leak outside bathroom  3 , which can be thus effectively heated, and the thermal efficiency can be improved. 
     On top of that, the structural elements of refrigerant circuit  25 , i.e. they are compressor  26 , first heat exchanger  27 , expanding mechanism  28 , and second heat exchanger  29 , can be accommodated in ventilating and air-conditioning apparatus  100  installed under the roof of bathroom  3 . This structure allows achieving space-saving and improving the installing work of air-conditioning apparatus  100 . 
     In second heat exchanger  29 , the refrigerant radiates heat to the air sucked from dressing room  4  and toilet room  5  and to be evacuated to the outdoors by ventilating fan  12 . In first heat exchanger  27 , the refrigerant absorbs heat from the air circulating in bathroom  3  by circulating fan  21 . This circulating air works as heat source of the heat pump, which then cools bathroom  3 . The air cooled by first heat exchanger  27  will not leak outside bathroom  3 , which can be thus cooled effectively. The thermal efficiency can be thus improved. 
     The foregoing air circulating in bathroom  3  is absorbed of its heat at the downstream side of decompressing device  38  of first heat exchanger  27 , and then this air radiates its heat at the upstream side of decompressing device  38 , so that bathroom  3  can be dehumidified. As a result, the air dehumidified by first heat exchanger  27  does not leak from bathroom  3 , so that bathroom can be dehumidified effectively. 
     When bathroom  3  is air-conditioned, a greater wind volume can be used than a wind volume used for ventilating the dressing room  4  and toilet room  5 . This increment in the wind volume allows second heat exchanger  29  to absorb or radiate a greater amount of heat, so that a sufficient air-conditioning power can be obtained. 
     The air conditioned by air-conditioner  14  installed outside bathroom  3  is sucked from evacuating ports  8  and  10  and supplied to second heat exchanger  29 , so that the thermal energy produced outside bathroom  3  by air-conditioner  14  can be collected. Further improvement in the thermal efficiency thus can be expected. 
     The presence of ventilation path  23 , which connects bathroom  3  to the suction side of ventilating fan  12 , and shutter  24  which opens or closes ventilation path  23  allows achieving an efficient air-conditioning of bathroom  3  by setting shutter  24  to the closed state for preventing the conditioned air from being exhausted. Setting shutter  24  to the open state allows quick evacuation of the air from bathroom  3 , so that bathroom  3  can be ventilated and dried. 
     In the case of drying bathroom  3 , the refrigerant absorbs heat from the air which flows through ventilation path  23  in second heat exchanger  29  and is to be evacuated to the outdoors, so that the heat radiated to the air of bathroom  3  in first heat exchanger  27  can be collected. As a result, drying efficiency can be improved. 
     Ventilation path  23  can communicate with bathroom  3  via sucking port  17 , so that a sucking section of ventilation path  23  can work also as sucking port  17 . As a result, the number of dust filters can be reduced. 
     Auxiliary heater  22  can heat at least parts of the air blown by circulating fan  21 , so that the heating power in a low-temperature environment can be reinforced. 
     Auxiliary heater  22  disperses its radiant heat in bathroom  3 , thereby reducing the feeling of drawing a draft when a user takes a bath, and increasing the amenity of bathroom  3 . 
     Pre-heater  39  pre-heats the air to be supplied to second heat exchanger  29 , whereby the heating power in the low-temperature environment can be prevented from lowering and the frost can be prevented from attaching to second heat exchanger  29 . This pre-heat is also useful for removing the frost attached to exchanger  29 . 
     When the frost attaches to first heat exchanger  27  or second heat exchanger  29  in the low-temperature environment, flow-path switching valve  30  is switched based on a temperature of the refrigerant for removing the frost. 
     When the frost attaches to second heat exchanger  29  in the low-temperature environment, refrigerant circuit  25  is opened at its high pressure side and its low pressure side via bypass circuit  31  or bypass circuit  32 . This preparation allows the refrigerant at a high-temperature to flow through second heat exchanger  29  or a pressure of the refrigerant in exchanger  29  to be raised for removing the frost. 
     Refrigerant heating device  35  is placed in refrigerant circuit  25  such that device  35  is in series with or in parallel with second heat exchanger  29 . When second heat exchanger  29  lowers its heat absorption power due to, e.g. the frost attaching thereto, this refrigerant heating device  35  is activated, so that the heat absorption power as well as heating power can be maintained. 
     Use of refrigerant heater  40 , which heats the refrigerant with electric heat, as refrigerant heating device  35  allows downsizing device  35 . 
     Use of refrigerant-hydrothermal exchanger  47 , which heats the refrigerant by exchanging heat with the heated water, as refrigerant heating device  35  allows saving electric power. 
     Use of the water heated by a heat-pump type water heater as heated water to be supplied to refrigerant-hydrothermal exchanger  47  allows further saving the electric power of refrigerant heating device  35 . 
     When the water having undergone the heat exchange with the refrigerant is evacuated, use of a drain channel for draining dew water generated on first heat exchanger  27  or second heat exchanger  29  allows not increasing the number of drain channels, so that the installation work can be simplified. 
     When the heat radiating power becomes short particularly in summer, the refrigerant radiates heat to the ordinary-temperature water supplied to refrigerant-hydrothermal exchanger  47 . This structure allows solving the shortage of the heat radiating power and maintaining the cooling power. 
     Embodiment 2 
     A ventilating and air-conditioning apparatus in accordance with the second embodiment of the present invention is demonstrated hereinafter. Similar elements to those used in the first embodiment have the same reference marks thereof, and detailed descriptions thereof are omitted. A living space equipped with the ventilating and air-conditioning apparatus in accordance with this second embodiment is the same one as that used in the first embodiment. 
       FIG. 6  shows an air course structure and a refrigerant circuit of ventilating and air-conditioning apparatus  110  in accordance with the second embodiment of the present invention. As shown in  FIG. 6 , main unit  6  of ventilating and air-conditioning apparatus  110  is installed under the roof of bathroom  3 , which is a first indoor space. Air-conditioning apparatus  110  differs from air-conditioning apparatus  100  of the first embodiment in the following points: 
     Ventilating and air-conditioning apparatus  110  includes temperature sensor  58  around sucking port  17  for sensing a temperature in bathroom  3 . Main unit  6  includes controller  59  therein for controlling circulating fan  21 , ventilating fan  12 , compressor  26  and flow-path switching valve  30 . Controller  59  controls the rpm of circulating fan  21  and ventilating fan  12 , and carries out stopping compressor  26 , switching flow-path switching valve  30  according to an instruction supplied from a remote control (not shown) or based on an indication of temperature sensor  58 . Controller  59  is formed of a control board wired to sensor  58 , fans  21  and  12 , compressor  26  and valve  30  respectively. 
     The working of ventilating and air-conditioning apparatus  110  is demonstrated hereinafter.  FIG. 7  lists the working states of respective work patterns. The list shows the respective work patterns of air-conditioning apparatus  110  in the columns sequentially and working states of major structural elements in response to the work patterns in the rows. Ventilating and air-conditioning apparatus  110  can perform 4 patterns as listed, namely, “around-the-clock ventilation”, “dry”, “cool”, and “heat”. 
     The work pattern of “around-the-clock ventilation” carries out ventilation for 24 hours/day continuously in order to obtain a ventilated amount of air necessary for living space  1 . During this pattern, ventilating fan  12  is set to a weak notch which assures the necessary ventilation amount, and shutter  24  placed in ventilation path  23  is set to “open state”. Other major structural elements including circulating fan  21  and compressor  26  are set to “halt” state. 
     A predetermined amount of air corresponding to a necessary amount of air for ventilation is thus sucked from sucking port  17  open to bathroom  3 , evacuating port  8  open to dressing room  4 , and evacuating port  10  open to toilet room  5  into ventilating fan  12  through ventilation path  23 , and then the air is evacuated to the outdoors. An amount of fresh air corresponding to the amount of the evacuated air is taken into air-supply port  13  open to living room  2 . The air evacuated from living space  1  can be thus replaced with the fresh air, so that living space  1  can be ventilated. 
     Next, the “dry” operation is demonstrated hereinafter. This dry pattern is selected when laundry is hung in bathroom  3  to dry. In the case of carrying out this “dry” operation, ventilating fan  12  is set to a strong notch which gives a greater wind volume than that of the “around-the-clock ventilation”, shutter  24  is set to the open state, and circulating fan  21  is set to a given notch which drives fan  21  at a wind volume set by a user. Then compressor  26  is driven. Flow-path switching valve  30  is set to “heating cycle”. 
     The settings discussed above allow the refrigerant, compressed by compressor  26  and in a high temperature and a high pressure state, to flow through flow-path switching valve  30  set to the heating cycle, and then the refrigerant arrives at first heat exchanger  27 . In first heat exchanger  27 , circulating fan  21  works at the given notch, so that the air sucked from bathroom  3  through sucking port  17  into main unit  6  is supplied to first heat exchanger  27 . In first heat exchanger  27 , the refrigerant exchanges heat with the supplied air, i.e. the refrigerant radiates heat for heating the air, which is then blown out from blowout port  18  to bathroom  3 . 
     The refrigerant having radiated the heat in first heat exchanger  27  passes through expanding mechanism  28 , i.e. capillary tube, where the refrigerant is decompressed and expands, and then the refrigerant arrives at second heat exchanger  29 . Since ventilating fan  12  works at the strong notch in second heat exchanger  29 , the air in dressing room  4  and toilet room  5  is supplied to second heat exchanger  29  via exhausting ducts  9  and  11 . Since shutter  24  is set to the open state, the air sucked from bathroom  3  via sucking port  17  travels through ventilation path  23  and arrives at second heat exchanger  29 . 
     The refrigerant absorbs heat from the air supplied from bathroom  3 , dressing room  4  and toilet room  5 . The refrigerant having absorbed the heat in second heat exchanger  29  returns to compressor  26  via flow-path switching valve  30 , so that the refrigerant resultantly circulates through refrigerant circuit  25 . The air supplied to second heat exchanger  29  is absorbed the heat by the refrigerant, thereby reducing its enthalpy, and is finally evacuated to the outdoors through exhausting duct  7 . 
     The laundry is hung in bathroom  3  during the dry operation discussed above, then the air heated to a high temperature by first heat exchanger  27  circulates in bathroom  3  and promotes evaporation of water from the laundry. The air in bathroom  3  traps the water evaporated from the laundry and is sucked into main unit  6  by ventilating fan  12 , and then collected its heat by second heat exchanger  29  before the air is evacuated to the outdoors. On top of that, second heat exchanger  29  receives a greater amount of air than the air amount supplied thereto during the around-the-clock ventilation operation, so that the refrigerant can absorb a greater amount of heat. As a result, the refrigerant can radiate a greater amount of heat, thereby drying the laundry quickly. 
     Next, the “cool” operation is demonstrated hereinafter. The “cool” pattern is selected when a user in bathroom  3  wants to lower a high temperature, e.g. in summer, for cooling bathroom  3  in order to take a bath pleasantly, or to clean bathroom  3  lightly. 
     In the case of carrying out this “cool” operation, circulating fan  21  is set to the given notch at which fan  21  produces a wind volume set by a user. Shutter  24  is set to the closed state. Then compressor  26  is driven. Flow-path switching valve  30  is set to “cooling cycle”, and the air volume of ventilating fan  12  is set according to a value sensed by temperature sensor  58 . Control of fan  12  will be detailed later. 
     The settings discussed above allow the refrigerant compressed by compressor  26  and in a high temperature and a high pressure state to flow through flow-path switching valve  30  set to the cooling cycle, and then the refrigerant arrives at second heat exchanger  29 . In second heat exchanger  29 , since ventilating fan  12  works at a given notch set according to the value sensed by temperature sensor  58  discussed later, the air in dressing room  4  and toilet room  5  is supplied to second heat exchanger  29  through exhausting ducts  9  and  11 , and the refrigerant radiates heat to the supplied air. The temperature of the air supplied from dressing room  4  and toilet room  5  rises due to the heat radiation from the refrigerant, and then the air is evacuated to the outdoors through exhausting duct  7 . 
     The refrigerant having radiated the heat in second heat exchanger  29  arrives at expanding mechanism  28 , and when the air passes through the capillary tube, the refrigerant is decompressed and expands. The refrigerant then arrives at first heat exchanger  27 . In first heat exchanger  27 , circulating fan  21  works at the given notch, so that the air sucked from bathroom  3  through sucking port  17  to main unit  6  is supplied to first heat exchanger  27 , and the refrigerant absorbs heat from this supplied air. The refrigerant having absorbed the heat then returns to compressor  26  via flow-path switching valve  30 . The refrigerant thus resultantly circulates through refrigerant circuit  25 . 
     The temperature of the air supplied to first heat exchanger  27  lowers due to the heat absorption by the refrigerant, and returns to bathroom  3  through blowout port  18 . The air circulation discussed above is repeated, thereby lowering the temperature in bathroom  3 , which is thus cooled. Shutter  24  is set to the closed state, so that the air cooled to a low temperature in circulation path  20  cannot be evacuated to the outside of bathroom  3 . The foregoing mechanics thus prevents an air-conditioning efficiency from lowering. 
     Next, the “heat” operation is demonstrated hereinafter. This pattern is selected for heating bathroom  3  before a user takes a bath. In the heated bathroom  3 , a user washes himself or herself comfortably during a low-temperature season like in winter without feeling the cold. 
     In the case of carrying out this “heat” operation, circulating fan  21  is set to the given notch at which fan  21  produces a wind volume set by a user. Shutter  24  is set to the closed state. Then compressor  26  is driven. Flow-path switching valve  30  is set to “heating cycle”, and the air volume of ventilating fan  12  is set according to a value sensed by temperature sensor  58 . Control of fan  12  will be detailed later. 
     These settings allow the refrigerant compressed by compressor  26  and in a high pressure and a high temperature state to pass through flow-path switching valve  30  and arrives at first heat exchanger  27 . Since circulating fan  21  is driven at the given notch in first heat exchanger  27 , the air sucked from bathroom  3  through sucking port  17  into main unit  6  is supplied to first heat exchanger  27 . The refrigerant radiates heat to the supplied air and raises the temperature of the air. This high-temperature air returns to bathroom  3  via blowout port  18 . This air circulation is repeated, whereby the temperature is raised in bathroom  3 , which is thus heated. 
     The refrigerant having radiated heat in first heat exchanger  27  arrives at expanding mechanism  28 , and when it passes through the capillary tube, the refrigerant is decompressed and expands, and then the refrigerant arrives at second heat exchanger  29 . Since ventilating fan  12  works at a notch set according to a value sensed by temperature sensor  58  which is detailed later, the air in dressing room  4  and toilet room  5  is supplied to second heat exchanger  29  via exhausting ducts  9  and  11 . The refrigerant absorbs heat from the air supplied from dressing room  4  and toilet room  5 . The refrigerant having absorbed the heat in second heat exchanger  29  returns to compressor  26  via flow-path switching valve  30 , so that the refrigerant resultantly circulates through refrigerant circuit  25 . 
     The heat in the air supplied to second heat exchanger  29  is absorbed by the refrigerant, thereby reducing its enthalpy, and is finally evacuated to the outdoors through exhausting duct  7 . Since shutter  24  is set to the closed state, the air heated to a high temperature in circulation path  20  cannot be evacuated outside bathroom  3 , so that the efficiency of air-conditioning is prevented from lowering. 
       FIG. 8  shows timing charts illustrating relations between an indication of temperature sensor  58  and an air volume of ventilating fan  12  during the “cool” operation. The horizontal axis represents the time and the vertical axis represents an indication (sensed value)  60  of temperature sensor  58  and also set air-volume  61  of ventilating fan  12 . 
     Temperature sensor  58  is placed around sucking port  17  of main unit  6 . During the “cool” operation circulating fan  21  and ventilating fan  12  suck the air from bathroom  3  through sucking port  17 , so that temperature sensor  58  senses the air in bathroom  3  and outputs indication  60 . 
     In the timing chart shown in  FIG. 8 , the “cool” operation starts at time “X 0 ” marked on the horizontal axis. A user sets a temperature to his or her taste, and pushes a start button for starting the “cool” operation. Indication  60  indicating the temperature in bathroom  3  starts lowering gradually from the initial value T 0 , e.g. 35° C., marked on scale  62  of the vertical axis. Ventilating fan  12  is halted before the “cool” operation starts. Air volume  61  of fan  12  is set correspondingly to the halt state indicated by scale  63 . When the “cool” operation starts, controller  59  issues a command to fan  12 , which then works at the strong notch indicated on scale  64  of the vertical axis. 
     Assume that a target temperature of the “cool” operation is set at temperature TS, e.g. 20° C., marked on scale  65  of the vertical axis. Temperature TS is greatly lower than the initial temperature T 0  in bathroom  3 , and the temperature in bathroom  3  lowers gradually following the continuous “cool” operation, so that the difference between set-temperature TS and the temperature in bathroom  3  becomes smaller step by step. The cooling load of bathroom  3  thus decreases step by step. 
     When indication  60  of temperature sensor  58  reaches first given temperature T 1 , e.g. 30° C., indicated on scale  66 , controller  59  changes air-volume  61  from the present strong notch to a medium notch marked on scale  67  lower than the strong notch. This change prompts ventilating fan  12  to reduce the air volume, so that an amount of the air to be evacuated through exhausting ducts  9  and  11  to the outdoors decreases, which entails a decrease in an amount of fresh air to be taken into air-supply port  13 . The air-conditioning load of living room  2  applied to air-conditioner  14  thus lowers and air-conditioner  14  can reduce its air-conditioning energy. As a result, the loss in air-conditioning energy of entire living space  1  can be reduced. 
     The “cool” operation goes on working, and when indication  60  of temperature sensor  58  reaches second given value T 2 , e.g. 25° C., indicated on scale  68 , controller  59  changes set air-volume  61  from the medium notch to a weak notch marked on scale  69  lower than the medium notch. This weak notch indicates the same air volume as that produced during the “around-the-clock ventilation” operation, so that a ventilation amount necessary for living space  1  is taken in, while energy of cooled air is collected from the conditioned air evacuated through exhausting ducts  9  and  11 . As a result, the “cool” operation achieves an extremely high level of energy saving. 
     As discussed above, during the “cool” operation, when the temperature in bathroom  3  lowers to a temperature lower than the second given temperature, ventilating fan  12  is controlled such that its set air volume decreases step by step. To be more specific, an amount of exhausted air, i.e. the heat source, is controlled in response to the cooling load of bathroom  3 . The cooling environment in bathroom  3  can be maintained while an amount of fresh air flowing into living room  2  through air-supplying port  13  is reduced for lowering the loss in air-conditioning energy used for living room  2 . As a result, entire living space  1  can be efficiently ventilated and air-conditioned. 
       FIG. 9  shows timing charts illustrating relations between an indication of temperature sensor  58  and an air volume of ventilating fan  12  during the “heat” operation. The horizontal axis of the timing chart in  FIG. 9  represents the time, and the vertical axis represents indication  60  of temperature sensor  58  and set air-volume  61  of ventilating fan  12 . 
     Temperature sensor  58  is placed around sucking port  17  of main unit  6 . During the “heat” operation, circulating fan  21  and ventilating fan  12  suck the air from bathroom  3  through sucking port  17 , so that temperature sensor  58  senses the temperature of the air in bathroom  3  and outputs indication  60 . 
     In the timing chart shown in  FIG. 9 , the “heat” operation starts at time “X 0 ” marked on the horizontal axis. A user sets a temperature to his or her taste, and pushes a start button for starting the “heat” operation. Indication  60  indicating the temperature in bathroom  3  starts rising gradually from the initial value T 0 , e.g. 15° C., marked on scale  70  of the vertical axis. Ventilating fan  12  is halted before the “heat” operation starts. Air volume  61  of fan  12  is set correspondingly to the halt state indicated at scale  72 . When the “heat” operation starts, controller  59  issues a command to fan  12 , which then works at the strong notch indicated on scale  72  of the vertical axis. 
     Assume that a target temperature of the “heat” operation is temperature TS, e.g. 40° C., marked on scale  73  of the vertical axis. Temperature TS is greatly higher than the initial temperature T 0  in bathroom  3 , and the temperature in bathroom  3  rises gradually following the continuous “heat” operation, so that the difference between set-temperature TS and the temperature in bathroom  3  becomes smaller gradually. The heating load of bathroom  3  thus gradually decreases. 
     When indication  60  of temperature sensor  58  reaches second given temperature T 2 , e.g. 25° C., indicated on scale  74 , controller  59  changes air-volume  61  from the present strong notch the medium notch marked on scale  75  lower than the strong notch. This change prompts ventilating fan  12  to reduce its air volume, so that an amount of the air to be evacuated through exhausting ducts  9  and  11  to the outdoors decreases, which entails a decrease in an amount of fresh air to be taken into air-supply port  13 . The air-conditioning load of living room  2  thus lowers and air-conditioner  14  reduces its air-conditioning energy. As a result, the loss in the air-conditioning energy for entire living space  1  can be reduced. 
     The “heat” operation goes on working, and when indication  60  of temperature sensor  58  reaches first given value T 2 , e.g. 35° C. indicated on scale  76 , controller  59  changes set air-volume  61  from the medium notch to a weak notch marked on scale  77  lower than the medium notch. This weak notch indicates the same air volume as that produced during the “around-the-clock ventilation” operation, so that a ventilation amount necessary for living space  1  is taken in, while the heat is collected from the conditioned air evacuated through exhausting ducts  9  and  11 . As a result, the “heat” operation achieves an extremely high level of energy saving. 
     As discussed above, during the “heat” operation, when the temperature in bathroom  3  rises to a temperature higher than the first given temperature, ventilating fan  12  is controlled such that its set air volume decreases step by step. To be more specific, an amount of exhausted air, i.e. the heat source, is controlled in response to a heating load of bathroom  3 . The heating environment in bathroom  3  can be maintained while an amount of fresh air flowing into living room  2  through air-supplying port  13  is reduced for lowering the loss in air-conditioning energy used for living room  2 . As a result, entire living space  1  can be efficiently ventilated and air-conditioned. 
     The structure and working discussed above prove that the air-conditioning apparatus of a bathroom in accordance with the second embodiment of the present invention produces the following advantages. 
     In second heat exchanger  29 , the refrigerant absorbs heat from the air which is sucked from dressing room  4  and toilet room  5  and is to be evacuated to the outdoors by ventilating fan  12 . In first heat exchanger  27 , the refrigerant radiates heat to the air circulated in bathroom  3  by circulating fan  21 . A heat pump starts working with a heat source using the air sucked from dressing room  4  and toilet room  5  and to be evacuated to the outdoors, so that bathroom  3  is heated. The air heated by first heat exchanger  27  thus does not leak outside bathroom  3 , which can be thus efficiently heated, and the thermal efficiency can be improved. 
     On top of that, the structural elements of refrigerant circuit  25 , i.e. compressor  26 , first heat exchanger  27 , expanding mechanism  28 , and second heat exchanger  29 , can be accommodated in ventilating and air-conditioning apparatus  110  installed under the roof of bathroom  3 . This structure allows achieving space-saving and improving the installing work of air-conditioning apparatus  110 . 
     In second heat exchanger  29 , the refrigerant radiates heat to the air sucked from dressing room  4  and toilet room  5  and to be evacuated to the outdoors by ventilating fan  12 . In first heat exchanger  27 , the refrigerant absorbs heat from the air circulated in bathroom  3  by circulating fan  21 . This circulating air works as heat source of the heat pump, which then cools bathroom  3 . The air cooled by first heat exchanger  27  will not leak outside bathroom  3 , which can be thus cooled efficiently. The thermal efficiency can be thus improved. 
     When bathroom  3  is air-conditioned, a greater wind volume can be used than a wind volume used in ventilating the dressing room  4  and toilet room  5 . This increment in the wind volume allows second heat exchanger  29  to absorb or radiate a greater amount of heat, so that sufficient air-conditioning power can be obtained. 
     The air conditioned by air-conditioner  14  installed outside bathroom  3  is sucked from evacuating ports  8  and  10  and supplied to second heat exchanger  29 , so that the thermal energy produced outside bathroom  3  by air-conditioner  14  can be collected. Further improvement in the thermal efficiency thus can be expected. 
     The presence of ventilation path  23 , which connects bathroom  3  to the suction side of ventilating fan  12 , and shutter  24 , which opens or closes shutter  24 , allows achieving an efficient air-conditioning of bathroom  3  by setting shutter  24  to the closed state for preventing the conditioned air from being exhausted. Setting shutter  24  to the open state allows quick evacuation of the air from bathroom  3 , so that bathroom  3  can be ventilated and dried. 
     In the case of drying bathroom  3 , the refrigerant absorbs heat from the air which flows through ventilation path  23  in second heat exchanger  29  and is to be evacuated to the outdoors, so that the heat radiated to the air of bathroom  3  in first heat exchanger  27  can be collected. As a result, drying efficiency can be improved. 
     During the “heat” operation, when the temperature in bathroom  3  rises to a temperature higher than the first given temperature, ventilating fan  12  reduces its blowing air-volume so that the loss in air-conditioning energy can decrease. 
     During the “heat” operation, ventilating fan  12  is controlled such that its blowing air-volume decreases step by step, whereby an air-volume (heat source) to be evacuated can be controlled in response to the heating load of bathroom  3 . The loss in air-conditioning energy produced by ventilation can be reduced. 
     During the “heat” operation, when the temperature in bathroom  3  rises to a temperature higher than the first given temperature, ventilating fan  12  is controlled to work solely so that a blowing air-volume of ventilating fan  12  can decrease to a similar volume to the air-volume necessary for ventilating the indoor spaces to which exhausting ports  8  and  10  are open. This control allows collecting heat from the air evacuated from exhausting ports  8  and  10 , and also allows heating bathroom  3  while an air-volume necessary for ventilating living space  1  is taken in. The heat operation thus can achieve an extremely high level of energy saving. 
     During the “cool” operation, when the temperature in bathroom  3  lowers to a temperature lower than the second given temperature, ventilating fan  12  is controlled such that its blowing air-volume decreases. This control allows reducing the loss in air-conditioning energy produced by ventilation. 
     During the “cool” operation, ventilating fan  12  is controlled such that its blowing air-volume decreases step by step, whereby an air-volume (heat source) to be exhausted can be controlled in response to the cooling load of bathroom  3 . This control allows reducing the loss in air-conditioning energy produced by ventilation. 
     During the “cool” operation, when the temperature in bathroom  3  lowers to a temperature lower than the second given temperature, ventilating fan  12  is controlled to work solely so that the air-volume can decrease to a similar volume to the air-volume necessary for ventilating the indoor spaces, to which exhausting ports  8  and  10  are open. This control allows collecting the energy of cooled air from the air evacuated from exhausting ports  8  and  10 , and also allows cooling bathroom  3  while air-volume necessary for ventilating living space  1  is taken in. The “cool” operation thus can achieve an extremely high level of energy saving. 
     The descriptions discussed previously are only the embodiments, and the present invention is not limited to those embodiments. For instance, in embodiments 1 and 2, the first living space to be air-conditioned is bathroom  3 , and the indoor spaces to which exhausting ports are open are dressing room  4  and toilet room  5 . However, the space to be air-conditioned and the space to which the exhausting ports are open are not necessarily limited to the foregoing rooms, but they can be any spaces partitioned in the living space. In other words, the space to be air-conditioned can be a living room, and the space to which the exhausting port is open can be a bathroom. 
     In embodiments 1 and 2, the exhausting ports are open to dressing room  4  and toilet room  5 ; however, the number and location of the ports are not necessarily limited to this structure. For instance, a single exhausting port can be placed only in a toilet. 
     In embodiments 1 and 2, expanding mechanism  28  employs the capillary tube; however, mechanism  28  can be an electronic expanding valve, or it can be any type as far as it can decompress and expand the refrigerant. 
     In embodiment 1, refrigerant circuit  25  is provided with dual bypass circuits, namely, bypass circuits  31  and  32 ; however, refrigerant circuit  25  can also work with a single bypass circuit. 
     In embodiment 1, refrigerant heating device  35  is placed in parallel with second heat exchanger  29 ; however, device  35  can be placed in refrigerant circuit  25  and in series with second heat exchanger  29 . 
     In embodiment 1, first on-off valve  33  and second on-off valve  34  are switched between the open state and the closed state; however, the on-off valve can be, e.g. an electronic expanding valve, and the on-off valve can be any type as far as it can open or close the bypass circuit. 
     In embodiment 1, refrigerant heating device  35  employs one of two device, namely, refrigerant heater  40  or refrigerant-hydrothermal exchanger  47 ; however device  35  is not necessarily limited to one of these two types, but device  35  can be any type as far as it can heat the refrigerant. 
     In first embodiment 1, refrigerant-hydrothermal exchanger  47  receives hot water from heat-pump type water heater  48  at its water side pipe; however, the water heater is not limited to the heat-pump type, but it can be any type as far as it can supply hot water at a high temperature (e.g. 40-90° C.) or water at an ordinary temperature (e.g. 1-40° C.) to the water side pipe of exchanger  47 . For instance, the water heater can be a gas water heater, electric water heater, oil-burning water heater, or it can employ a structure which circulates water or another structure which supplies tap water, or a structure which circulates the water of a bathtub. 
     In embodiment 2, controller  59  controls ventilating fan  12  such that set air-volume  61  of fan  12  can be changed into three levels based on indication  60  of temperature sensor  58 ; however, the method of controlling the air-volume of ventilating fan  12  is not limited to the foregoing one. For instance, the air volume can be changed into two levels, or into four levels or more than four levels. Fan  12  can be driven by a DC motor, so that the air volume can be changed linearly. 
     INDUSTRIAL APPLICABILITY 
     A ventilating and air-conditioning apparatus of the present invention improves space-saving characteristics and installation work, and reduces the leakage of conditioned air to the outdoors for increasing the thermal efficiency. This ventilating and air conditioning apparatus can be used for ventilating and air-conditioning not only a bathroom but also a living room, bedroom, kitchen, and washroom.