Abstract:
An air conditioner comprises: at least one outdoor unit having a compressor and an outdoor heat exchanger; an air process unit including a heat exchanger connected to the outdoor unit by a refrigerant pipe, in which the air is heat exchanged, and a blower fan blowing the heat exchanged air; and a duct having one side connected to the air process unit and another side connected to a plurality of rooms, and introducing to the room, the air blown after heat exchange. Accordingly, the refrigerant pipe is shortened, which reduces a pressure loss and a head loss. Also, oil discharged outside of the compressor together with the compressor refrigerant is easily recovered, and the amount of accumulated refrigerant is reduced, thereby reducing the risk of suffocation due to leakage of a refrigerant.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to an air conditioner, and particularly, to an air conditioner having a relatively short refrigerant pipe so as to reduce the amount of accumulated refrigerant and a pressure loss.  
         [0003]     2. Description of the Background Art  
         [0004]     In general, an air conditioner is designed to control the temperature, the humidity, the air current and the cleanness of the air for the purpose of forming a pleasant indoor environment.  
         [0005]     According to configuration of units, air conditioners are divided into an integrated type air conditioner which has an indoor unit and an outdoor unit in one case, and a separated type air conditioner in which a compressor, a condenser and an evaporator are separately installed such that an outdoor unit includes the compressor and the condenser and an indoor unit includes the evaporator.  
         [0006]     Some of the air conditioners are provided with flow-path switching valves for switching a flow path of a refrigerant, thereby selectively performing cooling and heating. Recently, a so called multi-type air conditioner having a plurality of indoor units is increasingly used, which is able to perform cooling or heating room by room of a building.  
         [0007]      FIG. 1  is a configuration view that illustrates a related art air conditioner. Referring to  FIG. 1 , the related art air conditioner includes an outdoor unit  101  disposed outside and a plurality of indoor units  111  disposed in an interior space (e.g. room) to be cooled or heated.  
         [0008]     The outdoor unit  101  includes a compressor (not shown) for compressing a refrigerant and an outdoor heat exchanger (not shown) performing heat-exchange while contacting with the outdoor air.  
         [0009]     The indoor unit  111  includes an indoor heat exchanger (not shown) connected to the compressor and the outdoor heat exchanger to constitute a cooling cycle.  
         [0010]     A distribution unit  121  is provided between the outdoor unit  101  and the indoor unit  111  so as to distribute to each indoor unit  111 , a refrigerant provided from the outdoor unit  101 . A plurality of connection ports  122  connected to a plurality of refrigerant pipes  123  are formed at the distribution unit  121 .  
         [0011]     However, the related art air conditioner has the following problems.  
         [0012]     If the outdoor unit  101  and the indoor unit  111  are spaced far apart from each other, the related art air conditioner may cause a great pressure loss because of a lengthened refrigerant pipe  123 . Particularly, if a height difference between the outdoor unit  101  and the indoor unit  111  is big, a head loss greatly occurs.  
         [0013]     Also, if the refrigerant pipe  123  is lengthened, oil discharged outside of the compressor together with a compressed refrigerant cannot be recovered.  
         [0014]     Also, if the refrigerant pipe  123  is lengthened, the amount of accumulated refrigerant is increased, and the refrigerant is liable to be leaked. Accordingly, the risk of suffocation is increasing. In order to reduce such risk, a special ventilation system is additionally required, which causes an increase in cost.  
       BRIEF DESCRIPTION OF THE INVENTION  
       [0015]     Therefore, an object of the present invention is to provide an air conditioner having a short refrigerant pipe.  
         [0016]     To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided an air conditioner comprising: at least one outdoor unit having a compressor and an outdoor heat exchanger; an air process unit including a heat exchanger connected to the outdoor unit by a refrigerant pipe, in which the air is heat exchanged, and a blower fan blowing the heat exchanged air; and a duct having one side connected to the air process unit and another side connected to a plurality of rooms, and introducing to the room, the air blown after heat exchange.  
         [0017]     The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]     The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a unit of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.  
         [0019]     In the drawings:  
         [0020]      FIG. 1  is a configuration view of the related art air conditioner in accordance with a conventional art;  
         [0021]      FIG. 2  is a configuration view of an air conditioner in accordance with a first embodiment of the present invention;  
         [0022]      FIG. 3  is a configuration view of the air conditioner in accordance with a second embodiment of the present invention; and  
         [0023]      FIG. 4  is a configuration view of the air conditioner in accordance with a third embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0024]     Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.  
         [0025]     The air conditioner in accordance with the first embodiment of the present invention will now be described with reference to the accompanying drawing.  FIG. 2  is a configuration view of the air conditioner in accordance with the first embodiment of the present invention.  
         [0026]     Referring to  FIG. 2 , the air conditioner in accordance with the first embodiment of the present invention includes an outdoor unit  10 , an air process unit  20  and a duct  40 .  
         [0027]     The outdoor unit  10  includes a compressor  11  compressing a refrigerant, and an outdoor heat exchanger  13  disposed at one side of the compressor  11 , in which a refrigerant is heat exchanged by contacting with the outdoor air.  
         [0028]     A flow-path switching valve  15  is installed at a discharge side of the compressor  11  so as to switch a flow path of a refrigerant, and an accumulator  17  is provided at an intake side of the compressor  11  so as to receive a gaseous refrigerant. A port of the flow-path switching valve is connected to the outdoor heat exchanger  13 , and another port is connected to the accumulator  17 . Still another port of the flow-path switching valve is connected to a main refrigerant pipe  29 .  
         [0029]     An outdoor expansion device  16  is installed at one side of the outdoor heat exchanger  13 , and a bypass path  18  having a check valve  19  is formed at one side of the outdoor expansion device  16 .  
         [0030]     A main refrigerant pipe  29  and an auxiliary refrigerant pipe  30  allowing each air process unit  20  and the outdoor unit  10  to be in communication with each other are installed between the outdoor unit  10  and the air process unit  20 .  
         [0031]     One side of the main refrigerant pipe  29  is connected to one side of the outdoor unit  10 , and the other side thereof is connected to the auxiliary refrigerant pipe  30 .  
         [0032]     One side of the auxiliary pipe  30  is connected to the main refrigerant pipe  29 , and its other side is connected to a heat exchanger  23 .  
         [0033]     The air process unit  20  includes a cabinet  22 , a heat exchanger  23 , an indoor expansion device  25  and a blower fan  27 .  
         [0034]     The cabinet  22  is a box having therein a receiving space and forming an exterior of the air process unit  20 .  
         [0035]     The heat exchanger  23  is received in the cabinet  22  and connected to the compressor  1  and the outdoor heat exchanger  13  to constitute a refrigerant circuit.  
         [0036]     The indoor expansion device  25  is disposed at the left side of the heat exchanger  23 , and a refrigerant is decompressed and expanded.  
         [0037]     The blower fan  27  is disposed under the heat exchanger  23 , accelerates heat exchange of the heat exchanger  23  and blows the heat-exchanged air to each room (R).  
         [0038]     In order to improve performance of the air process unit  20 , a humidifier  31 , a filter member  33  and an electric heater  35  are additionally installed.  
         [0039]     The humidifier  31  is installed above the heat exchanger  23  and humidifies the air having passed through the heat exchanger  23 .  
         [0040]     The filter member  33  is installed above the humidifier  31  and removes foreign substances within the air.  
         [0041]     The electric heater  35  is installed above the filter member  33  and heats the air having passed through the heat exchanger  23 , again.  
         [0042]     The installation order and position of the above-mentioned heat exchanger  23 , the blower fan  27 , the humidifier  31 , the filter member  33  and the electric heater  35  may be varied in consideration of the performance of the air process unit  20 .  
         [0043]     The duct  40  is installed at an upper side of the cabinet  22  and goes by way of each room (R). The duct  40  has an air path allowing air heat exchanged in the heat exchanger  23  to flow to each room (R) and a plurality of discharge holes  42  through which the heat exchanged air can be discharged.  
         [0044]     Here, the duct may be divided into an air supply duct (not shown) for transferring to each room (R), the air processed by the air process unit  20 , and a ventilation duct (not shown) provided with a ventilation fan (not shown) for transferring the air of each room (R) to the air process unit  20 .  
         [0045]     The operation of the air conditioner in accordance with the first embodiment of the present invention will now be described.  
         [0046]     When each room (R) is cooled, the flow-path switching valve  15  switches a flow path so as to allow a compressed refrigerant to flow to the outdoor heat exchanger  13 .  
         [0047]     The refrigerant having condensed through the outdoor heat exchanger  13  is distributed to the air process unit  20 , which is in operation, through the main refrigerant pipe  29  and the auxiliary refrigerant pipe  30 , and is decompressed and expanded while passing through the indoor expansion device  25 .  
         [0048]     Then, the refrigerant absorbs latent heat by heat exchange in the heat exchanger  23 , thereby being evaporated.  
         [0049]     The evaporated refrigerant is combined in the main refrigerant pipe  29  and is taken into the compressor  11  via the flow-path switching valve  15  and the accumulator  17 . Such processes are repetitively performed.  
         [0050]     When the blower fan  27  is operated, the air comes in contact with the heat exchanger  23  and is thusly cooled.  
         [0051]     Foreign substances of the cooled air are removed while the air passes through the filter member  33 , and then, the air is discharged to each room (R) through the discharge hole  42  along the duct  40 .  
         [0052]     When each room (R) is heated, the flow-path switching valve  15  switches the flow path to allow the compressed refrigerant to flow to the air process unit  20 .  
         [0053]     The compressed refrigerant is introduced to the heat exchanger  23  of the air process unit  20  through the main refrigerant pipe  29  and the auxiliary refrigerant pipe  30 .  
         [0054]     The refrigerant heat exchanged and condensed in the heat exchanger  23  passes through the main refrigerant pipe  29  and the auxiliary refrigerant pipe  30 , and is depressed and expanded while passing through the outdoor expansion device  16 . Then, the refrigerant absorbs latent heat in the outdoor heat exchanger  13  to be evaporated.  
         [0055]     The evaporated refrigerant is taken into the compressor  11  via the flow-switching valve  15  and the accumulator  17 . Such processes are repetitively performed.  
         [0056]     When the blower fan  27  of the air process unit  20  is operated, the air comes in contact with the heat exchanger  23  to thereby be heated, and is humidified by the humidifier  31 .  
         [0057]     Then, foreign substances of the air are removed while the air passes through the filter member  33 , and the air is heated again by the electric heater  35  when necessary, and is discharged to each room (R) through the discharge hole  42 .  
         [0058]     Due to the above-mentioned related art air process unit  20  and duct  40 , a refrigerant pipe  123  (refer to  FIG. 1 ) does not need to be extended to the related art indoor unit  111  (refer to  FIG. 1 ).  
         [0059]     Namely, when a refrigerant is supplied from the outdoor unit  10  to the pair process unit  20  through the main refrigerant pipe  29  and the auxiliary refrigerant pipe  30 , heat exchanged air, not a refrigerant, is supplied from the air process unit  20  to the room (R) through the duct  40 . Therefore, the refrigerant pipe  123  (refer to  FIG. 1 ) is no longer required.  
         [0060]     Accordingly, a long refrigerant pipe  123  (refer to  FIG. 1 ) for supplying a refrigerant from the outdoor unit  101  (refer to  FIG. 1 ) to the indoor unit  111  (refer to  FIG. 1 ) according to the related art air conditioner is not required. Therefore, the amount of accumulated refrigerant and a pressure loss can be reduced.  
         [0061]     Hereinafter, the air conditioner in accordance with the second embodiment of the present invention will now be described in detail with reference to the accompanying drawing.  FIG. 3  is a configuration view of the air conditioner in accordance with the second embodiment of the present invention. The same reference numerals are designated to the same parts as those of the aforementioned structure, and the detailed description thereon will be omitted.  
         [0062]     Referring to  FIG. 3 , the air conditioner in accordance with the second embodiment of the present invention includes an outdoor unit  10 , an air process unit  20 , a duct  40  and a distribution unit  50 .  
         [0063]     The outdoor unit  10  includes a compressor  11  compressing a refrigerant, and an outdoor heat exchanger  13  disposed at one side of the compressor  11 , in which a refrigerant is heat exchanged by contacting with the outdoor air.  
         [0064]     A flow-path switching valve  14  is installed at a discharge side of the compressor  11  so as to switch a flow path of the refrigerant, and an accumulator  17  is provided at its intake side so as to receive a gaseous refrigerant. A port of the flow-path switching valve  14  is connected to the outdoor heat exchanger  13 , and another port is connected to the accumulator  17 . Still another port of the flow-path switching valve  14  is connected to the distribution unit  50 .  
         [0065]     An outdoor expansion device  16  is installed at one side of the outdoor heat exchanger  13 , and a bypass path  18  provided with a check valve  19  is formed at one side of the outdoor expansion device  16 .  
         [0066]     Unlike the first embodiment, the air process unit  20  in accordance with the second embodiment includes a cooling unit  21   a  and a heating unit  21   b  individually, such that cooling and heating can be performed on each room (R) at the same time.  
         [0067]     The cooling unit  21   a  and the heating unit  21   b  each include a cabinet  22 , a heat exchanger  23 , an indoor expansion device  25 , a blower fan  27 , and a filter member  33 .  
         [0068]     The cabinet  22  is a box having a receiving space therein and forming an exterior of the cooling unit  21   a  and the heating unit  21   b.    
         [0069]     The heat exchanger  23  is received in the cabinet  22  and is connected to the compressor  11  and the outdoor heat exchanger  13  to constitute a refrigerant circuit.  
         [0070]     The indoor expansion device  25  for decompressing and expanding a refrigerant is disposed at the right side of the heat exchanger  23 .  
         [0071]     The blower fan  27  is disposed under the heat exchanger  23 , accelerates heat exchange of the heat exchanger  23 , and blows the heat exchanged air so that the air can be supplied to each room (R).  
         [0072]     The filter member  33  is installed above a humidifier  31 , and removes foreign substances within the air.  
         [0073]     The installation order and position of the above-mentioned heat exchanger  23 , the blower fan  27 , and the filter member  33  may be varied in consideration of the performance of the air process unit  20 .  
         [0074]     The duct  40  is installed at an upper side of the cabinet  22 , and includes a cooling duct  41   a  and a heating duct  41   b.    
         [0075]     The cooling duct  41   a  supplies to each room (R), the air cooled in the cooling unit  21   a.    
         [0076]     The heating duct  41   b  supplies to each room (R), the air heated in the heating unit  21   b.    
         [0077]     A plurality of discharge holes  42  through which the air is discharged to each room (R) are provided at the cooling duct  41   a  and the heating duct  41   b.    
         [0078]     The distribution unit  50  distributes a refrigerant, such that part of the air process unit  20  performs cooling operation and another part thereof performs heating operation. To this end, the distribution unit  50  includes a high-pressure pipe  52 , a low-pressure pipe  54 , a liquid pipe  56 , a high-pressure valve  53  and a low-pressure valve  55 .  
         [0079]     One side of the high-pressure pipe  52  is connected to a discharge side of the compressor  11 , and its other side is connected to the air process unit  20 .  
         [0080]     One side of the low-pressure pipe  54  is connected to an intake side of the accumulator  1 , and its other side is connected to the air process unit  20 .  
         [0081]     One side of the liquid pipe  56  is connected to the outdoor heat exchanger  13 , and its other side is connected to the air process unit  20 .  
         [0082]     The high-pressure valve  53  is installed on the high-pressure pipe  52 , and opens and closes the high-pressure pipe  52 .  
         [0083]     The low-pressure valve  55  is installed on the low-pressure pipe  54 , and opens and closes the low-pressure pipe  54 .  
         [0084]     The operation of the air conditioner in accordance with the second embodiment of the present invention will now be described.  
         [0085]     Cooling dominant operation in which the majority among units of the air process unit  20  perform cooling operation while some few of the units perform heating operation will be described as an example.  
         [0086]     The flow-path switching valve  14  switches a flow path, such that a compressed refrigerant flows to the outdoor heat exchanger  13 .  
         [0087]     The refrigerant having passed through the outdoor heat exchanger  13  flows to the distribution unit  50  along the liquid pipe  56 . Here, a portion of the refrigerant flows to the distribution unit  50  along the high-pressure pipe  52 .  
         [0088]     The refrigerant flowing along the liquid pipe  56  is introduced to the cooling unit  21   a  to perform the cooling operation. Here, the air blown as the blower fan  27  is operated comes in contact with the heat exchanger  23  to thereby be cooled. Also, foreign substances of the air are removed by the filter member  33 , and then the air is discharged to each room (R) through the discharge hole  42  along the cooling duct  41   a.    
         [0089]     The refrigerant having performed the cooling operation passes through the opened low-pressure valve  55  and then is taken into the accumulator  17  along the low-pressure pipe  54 .  
         [0090]     The refrigerant flowing along the high-pressure pipe  52  is introduced to the heating unit  21   b  through the opened high-pressure valve  53 , to thereby perform the heating operation. Here, the air blown as the blower fan  27  of the heating unit  21   b  is operated comes in contact with the heat exchanger  23  to thereby be heated. Then, foreign substances of the air are moved by the filter member  33 , and the air is discharged to each room (R) along the heating duct  41   b.    
         [0091]     Due to the air process unit  20 , the distribution unit  50  and the duct  40 , a related art refrigerant pipe  123  (refer to  FIG. 1 ) does not need to be extended to the related art indoor unit  111  (refer to  FIG. 1 ).  
         [0092]     Namely, if a refrigerant is supplied from the outdoor unit  10  to the air process unit  20  through the distribution unit  50 , heat exchanged air, not the refrigerant, is supplied from the air process unit  20  to the room (R) through the duct  40 , Therefore, the refrigerant pipe  123  (refer to  FIG. 1 ) is no longer required.  
         [0093]     Accordingly, a long refrigerant pipe like the one of the related art, for supplying a refrigerant from the related art outdoor unit  101  (refer to  FIG. 1 ) to the related art indoor unit  111  (refer to  FIG. 1 ), is not required. Thusly, the amount of accumulated refrigerant and a pressure loss can be reduced.  
         [0094]     The air conditioner in accordance with the third embodiment of the present invention will now be described with reference to the accompanying drawing.  FIG. 4  is a configuration view of the air conditioner in accordance with the third embodiment of the present invention. The same reference numerals are designated to the same parts as those of the aforementioned structure, and the detailed description thereon will be omitted.  
         [0095]     Referring to  FIG. 4 , the air conditioner in accordance with the third embodiment of the present invention includes an outdoor unit  10 , a heat exchange unit  60  and a fan coil unit  65 .  
         [0096]     The outdoor unit  10  includes a compressor  11  for compressing a refrigerant, and an outdoor heat exchanger  13  disposed at one side of the compressor  11 , in which a refrigerant is heat exchanged by contacting with the outdoor air.  
         [0097]     A flow-path switching valve  15  is installed at a discharge side of the compressor  11  so as to switch a flow path of a refrigerant, and an accumulator  17  is provided at an intake side thereof so as to take in a gaseous refrigerant. A port of the flow-path switching valve  15  is connected to the outdoor heat exchanger  13 , and another port is connected to an accumulator  17 . Still Another port of the flow-path switching valve  15  is connected to a main refrigerant pipe  29 .  
         [0098]     An outdoor expansion device  16  is installed at one side of the outdoor heat exchanger  13 , and a bypass path  18  provided with a check valve  19  is formed at one side of the outdoor expansion device  16 .  
         [0099]     A main refrigerant pipe  29  and an auxiliary refrigerant pipe  30  allowing the outdoor unit  10  and the heat exchange unit  60  to be in communication with each other are installed between the outdoor unit  10  and the heat exchange unit  60 .  
         [0100]     One side of the main refrigerant pipe  29  is connected to the outdoor unit  10 , and its other side is connected to the auxiliary refrigerant pipe  30 .  
         [0101]     One side of the auxiliary refrigerant pipe  30  is connected to the main refrigerant pipe  29 , and its other side connected to the heat exchanger  23 .  
         [0102]     The heat exchange unit  60  includes a water storage tank  62  and a heat exchanger  23 .  
         [0103]     The water storage tank  62  has therein a heater  64  for heating stored water. A water pipe  63  is connected to one side of the water storage tank  62  so as to allow the water to circulate to the fan coil unit  65  disposed at each room (R).  
         [0104]     A circulation pump  67  allowing water to circulate is installed on the water pipe  63 .  
         [0105]     The heat exchanger  23  is received in the water tank  62  and is connected to the compressor  11  and the outdoor heat exchanger  13 .  
         [0106]     The fan coil unit  65  is installed in each room (R) and is connected to the heat exchange unit  60  by the water pipe  63 . An opening and closing valve  69  for opening and closing a flow path is provided at one side of the fan coil unit  65 .  
         [0107]     The operation of the air conditioner in accordance with the third embodiment of the present invention will now be described.  
         [0108]     When the room (R) is cooled, the flow-path switching valve  15  switches a flow path so as to allow a compressed refrigerant to flow to the outdoor heat exchanger  13 .  
         [0109]     The refrigerant heat exchanged in the heat exchanger  23  passes through the main refrigerant pipe  29  and the auxiliary refrigerant pipe  30 , and then passes through the indoor expansion device  25  of the heat exchange unit  60  to be decompressed and expanded.  
         [0110]     Here, a refrigerant is evaporated by absorbing latent heat in the heat exchanger  23 . Also, water circulated by the circulation pump  67  is cooled by the heat exchanger  23 , and the cooled water is introduced to the fan coil unit  65  along the water pipe  63  to perform the cooling operation.  
         [0111]     When the room (R) is heated, the flow path switching valve  15  switches a flow path so as to allow a compressed refrigerant to flow toward the heat exchange unit  60 .  
         [0112]     The refrigerant introduced to the heat exchanger  23  of the heat exchange unit  60  after passing through the main refrigerant pipe  29  and the auxiliary refrigerant pipe  30  is heat exchanged with water flowing along the water pipe  63  to thereby condensed.  
         [0113]     The condensed refrigerant is decompressed and expanded while passing through the outdoor expansion device  16 , is evaporated upon absorbing latent heat in the outdoor heat exchanger  13 , and is taken into the compressor  11  via the accumulator  17 .  
         [0114]     Water circulated by the circulation pump  67  is heat exchanged with the heat exchanger  23  and is heated by the heater  64  when necessary, and is introduced to the fan coil unit  65  along the water pipe  63 , thereby performing heating operation.  
         [0115]     Due to the heat exchange unit  60  and the fan coil unit  65 , the related art refrigerant pipe  123  (refer to  FIG. 1 ) does not need to be extended to the related art indoor unit  111  (refer to  FIG. 1 ).  
         [0116]     Namely, when a refrigerant is supplied from the outdoor unit  10  to the heat exchange unit  60  through the main refrigerant pipe  29  and the auxiliary refrigerant pipe  30 , heat exchanged water moves along the water pipe  63  from the heat exchange unit  60  to the fan coil unit  65  installed at the room (R), thereby performing heat and cooling operation.  
         [0117]     Accordingly, a long refrigerant pipe  123  (referring to  FIG. 1 ) for supplying a refrigerant from the outdoor unit  101  (referring to  FIG. 1 ) to the indoor unit  111  (referring to  FIG. 1 ) according to the related art air conditioner is not required. Therefore, the amount of accumulated refrigerant and a pressure loss can be reduced.  
         [0118]     In the second embodiment described and illustrated with reference to  FIG. 3 , the case where only the filter member  33  is provided at the heating unit  21   b  is taken as an example. However, the humidifier  31  and the electric heater  35  shown in  FIG. 3  may be further provided at the heating unit  21   b.    
         [0119]     In the third embodiment described and illustrated with reference to  FIG. 4 , the case where cooling or heating operation is made upon switching a flow of a refrigerant is taken as an example. However, the distribution unit  50  shown in  FIG. 3  may be further provided such that part of the heat exchange unit  60  performs the cooling operation and another part performs the heating operation.  
         [0120]     In the aforedescribed embodiments, the case where only one outdoor unit  10  is provided is taken as an example. However, a plurality of outdoor units  10  may be provided.  
         [0121]     As so far described, the air conditioner in accordance with the embodiments of the present invention has the following advantages. First, a pressure loss and a head loss can be reduced because of its short refrigerant pipe. Secondly, oil having been discharged outside the compressor together with a compressor refrigerant can be easily recovered. Thirdly, as the amount of accumulated refrigerant is reduced, the risk of suffocation due to the leakage of refrigerant is reduced. Also, because a special ventilation system for preventing suffocation is not required, a cost can be reduced.  
         [0122]     As the present invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the metes and bounds of the claims, or equivalence of such metes and bounds are therefore intended to be embraced by the appended claims.