Abstract:
An indoor unit for an air conditioner capable of performing cooling and heating, as well as ventilation functions as a single unit is provided. The indoor unit includes a main chassis, a ventilation port, a cross-flow fan, a side fan, and a ventilation duct. The main chassis is installed on a mounting portion and composing its exterior. The ventilation port formed to pass through the main chassis for inletting and exhausting air. The cross-flow fan is installed on one side of the main chassis to blow air in a direction perpendicular to its rotating shaft. The side fan is formed next to the cross-flow fan. The ventilation duct is connected to the ventilation port of the main chassis to ventilate the air forcibly blown by the side fan.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to an air conditioner, and more particularly, to an indoor unit for an air conditioner with an added ventilation feature. More specifically, the present invention relates to a wall mount air conditioner unit that offers users a new level of freshness via an additional ventilation feature.  
         [0003]     2. Description of the Related Art  
         [0004]     An air conditioner is a device for maintaining optimized inside air according to purpose. For example, in the case where inside air becomes high temperature in summer, the air conditioner blows wind of low temperature to cool down the inside. On the contrary, in winter, the air conditioner blows warm wind of high temperature to heat the inside air. Other features of air conditioners include humidity control of interior air, and recently encompasses a variety of features, such as interior air purification.  
         [0005]     The air conditioners are roughly divided into an integral type and a separation type. An integral type air conditioner has one unit as a whole and a separation type air conditioner separately has an indoor unit installed inside a space that needs air-conditioning and an outdoor unit installed in the outside. Particularly, recently, a separation type air conditioner is widely used considering noise and installation environment of an air conditioner.  
         [0006]      FIG. 1  is an exploded perspective view of a separation type air conditioner of a related art and  FIG. 2  is a view illustrating air is sucked into and discharged from an indoor unit of a separation type air conditioner of a related art.  
         [0007]     Referring to the drawings, a main chassis  1  forms a frame of an indoor unit. The main chassis  1  has a front panel  3  formed on a front side thereof to form the outer appearance of the indoor unit. The main chassis  1  having the front panel  3  is mounted on a wall in the inside.  
         [0008]     A space in which parts that will be described below are mounted is formed between the main chassis  1  and the front panel  3 .  
         [0009]     In the meantime, the outer appearance of the indoor unit formed by the main chassis  1  and the front panel  3  is protruded toward the front side as a whole as illustrated in  FIG. 1 .  
         [0010]     A suction panel  7  having a front suction grill  5  is provided on the front of the front panel  3  to form a front appearance of the indoor unit. A hinge member (not shown) is provided at the upper end of the suction panel  7  to allow the suction panel  7  to rotate.  
         [0011]     The front suction grill  5  is a path through which air sucked from a space that needs air-conditioning is sucked into the inside of the indoor unit. The front suction grill  5  is integrally formed with the suction panel  7 . In the meantime, an upper suction grill  3 ′ is formed long left and right on the upper side of the front panel  3 . The upper suction grill  3 ′ is integrally formed with the front panel  3  or separately formed.  
         [0012]     A heat exchanger  9  is installed at the back of the front panel  3 . The heat exchanger  9  allows air sucked through the front suction grill  5  and the upper suction grill  3 ′ to exchange heat while passing through the exchanger  9 . A filter  9 ′ for purifying sucked air is installed on the front of the heat exchanger  9 .  
         [0013]     A cross-flow fan  10  is installed at the back of the heat exchanger. The cross-flow fan  10  sucks air from a space that needs air-conditioning and discharges air back to the space that needs air-conditioning. A fan motor  10 ′ for providing rotational power to the cross-flow fan  10  is installed on the right side of the cross-flow fan  10  and a member for guiding flow created by the cross-flow fan  10  is further integrally formed in the inside of the main chassis  1 .  
         [0014]     In the meantime, air that has heat-exchanged while passing through the heat exchanger  9  is discharged to a space that needs air-conditioning through the cross-flow fan  10 . For that purpose, a discharge grill  11  is installed at the lower end of the main chassis  1  and the front panel  3 .  
         [0015]     In the meantime, a discharge port  13  for guiding air that has passed through the cross-flow fan  10  to a space that needs air-conditioning is formed in the inside of a discharge grill  11 .  
         [0016]     A vane  15  for vertically controlling the direction of discharged air and a louver for horizontally controlling the direction of discharged air are installed in the inside of the discharge port  13 . The louver  16  is provided in plurals and the louvers  16  are connected to each other by a link  17  to operate simultaneously.  
         [0017]     Also, a display part  19  for displaying an operation state of an air conditioner is provided at an about center on the lower portion of the front panel  3 .  
         [0018]     Description will be made for the air conditioner having the above-described construction and operating in a cooling mode.  
         [0019]     When the air conditioner operates, air for air-conditioning is sucked into the inside of an indoor unit by the cross-flow fan  11 . That is, air is sucked into the inside of the indoor unit through the front suction grill  5  and the upper suction grill  3 ′ to pass through the heat exchanger  9 .  
         [0020]     The air that has passed through the heat exchanger  9  exchanges heat with working fluid flowing in the inside of the heat exchanger  9 .  
         [0021]     The air that has exchanged heat with the heat exchanger  9  becomes relatively low temperature and is sucked into the cross-flow fan  10 . The air sucked into the cross-flow fan  10  is discharged to the lower direction and guided to the side of the discharge port  13 .  
         [0022]     The air guided to the inside of the discharge port  13  changes a discharging direction thereof using the vane  15  and the louver  16  installed inside the discharge port  13  and is discharged to a space that needs air-conditioning through the discharge grill  13 . At this point, since the vane  15  and the louver  16  allow the discharged air to be distributed vertically and horizontally, the air is uniformly discharged to the space that needs air-conditioning.  
         [0023]     To fix the heat exchanger  9 , a fixing bracket  8  is provided to the left of the main chassis  1  and a fixing end  8 ′ that corresponds to a screw-coupling end  9   a  of the heat exchanger  9  is provided to the right of the main chassis  1 . A screw-coupling hole  8 ″ should be punched in the inside of the fixing end  8 ′.  
         [0024]     A receiving groove  8   a  for receiving a left end of the heat exchanger  9  is formed on the front side and the upper side of the fixing bracket  8 . Hookers  8   b  for hooking and fixing a left hairpin  9   c  of the heat exchanger  9  are protruded in the inside of the receiving groove  8   a.    
         [0025]     A screw through hole  9   b  that corresponds to the screw-coupling hole  8 ″ is punched in the inside of the screw-coupling end  9   a  of the heat exchanger  9 .  
         [0026]     The heat exchanger  9  is fixed by fixing the fixing bracket  8  in the left of the main chassis  1  using a screw S. At this point, the receiving groove  8   a  of the fixing bracket  8  is open toward the right side.  
         [0027]     When the hairpin  9   c  of the heat exchanger  9  is inserted into the receiving groove  8   a  of the fixing bracket  8 , the hairpin  9   c  is hooked at and fixed in the hooker  8   b  of the inside of the receiving groove  8   a . At this point, the left end of the heat exchanger  9  is fixed first.  
         [0028]     After that, the right side of the heat exchanger  9 , more specifically, the screw-coupling end  9   a  is closed attached to the fixing end  8 ′ of the main chassis  1  and the screen through hole  9   b  is coupled to the screw-coupling hole  8 ″ using a screw S, so that the heat exchanger  9  is fixed to the main chassis  1 .  
         [0029]     However, related art indoor units have the following problems.  
         [0030]     First, because related art air conditioners cool or heat closed indoor spaces for a long durations, the air confined in the spaces becomes stale. In other words, because air from the outside is not drawn in and interior air is not expelled out, while a desired indoor temperature can be obtained using the air conditioner, clean air cannot. Moreover, a separate ventilation unit needs to be installed to ventilate the stale air. Installing such a ventilator alongside an air conditioner involves added cost and use of additional interior space.  
       SUMMARY OF THE INVENTION  
       [0031]     Accordingly, the present invention is directed to an indoor unit for an air conditioner that substantially obviates one or more problems due to limitations and disadvantages of the related art.  
         [0032]     An object of the present invention is to provide an indoor unit for an air conditioner with a built-in ventilation feature.  
         [0033]     Another object of the present invention is to provide an indoor unit for an air conditioner that controls room temperature having a ventilation feature built into the indoor unit, to provide an optimal indoor atmosphere.  
         [0034]     A further object of the present invention is to provide an indoor unit for an air conditioner that conditions air in terms of temperature and ventilation.  
         [0035]     Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.  
         [0036]     To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, there is provided an indoor unit for an air conditioner including: a main chassis installed on a mounting portion and composing the exterior thereof; a ventilation port formed to pass through the main chassis for inletting and exhausting air; a cross-flow fan installed on one side of the main chassis for blowing air in a direction perpendicular to its rotating shaft; a side fan formed next to the cross-flow fan; and a ventilation duct connected to the ventilation port of the main chassis to ventilate the air blown by the side fan.  
         [0037]     In another aspect of the present invention, there is provided an indoor unit for an air conditioner including: a main chassis having a ventilation port formed in a passing through manner, for inletting and exhausting air; a ventilation door for selectively opening and closing the ventilation port; a first fan installed on one end of the main chassis for blowing air in a direction perpendicular to its rotating shaft; and a second fan disposed next to the first fan, and using a driving device different from that of the first fan, for blowing air sideways.  
         [0038]     In a further aspect of the present invention, there is provided an indoor unit for an air conditioner including: a main chassis having a ventilation port; a ventilation duct connected to the ventilation port and exhausting outdoors; a first fan connected to one end of the main chassis for circulating interior air; and a second fan disposed next to the first fan for ventilating air.  
         [0039]     The indoor unit for an air conditioner as described above not only adjusts indoor air temperature, but also provides a convenient ventilation feature that ventilates indoor spaces. Because cooling and heating is in conjunction with ventilation, a user will be able to derive satisfactory air conditioning results in a wide variety of circumstances.  
         [0040]     It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0041]     The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings:  
         [0042]      FIG. 1  is an exploded perspective view of an indoor unit of an air conditioner according to the related art;  
         [0043]      FIG. 2  is a side view illustrating an air flow in an indoor unit of an air conditioner according to the related art;  
         [0044]      FIG. 3  is an exploded perspective view of an indoor unit of an air conditioner according to the present invention;  
         [0045]      FIG. 4  is a perspective view of a side fan according to the present invention;  
         [0046]      FIG. 5  is a sectional view explaining the airflow of an indoor unit for an air conditioner according to the present invention while the unit operates in air cooling mode;  
         [0047]      FIG. 6  is a sectional view showing the airflow of an indoor unit for an air conditioner according to the present invention while the unit operates in intake ventilation mode;  
         [0048]      FIG. 7  is a sectional view showing the airflow of an indoor unit for an air conditioner according to the present invention while the unit operates in exhaust ventilation mode; and  
         [0049]      FIG. 8  is a sectional view showing the airflow of an indoor unit for an air conditioner according to the present invention while the unit operates in intake and exhaust ventilation mode. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0050]     Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.  
         [0051]      FIG. 3  is an exploded perspective view of an indoor unit of an air conditioner of the present invention.  
         [0052]     Referring to  FIG. 3 , the indoor unit of the air conditioner includes a main chassis  110  and a front panel  130 , which constitute an appearance.  
         [0053]     The main chassis  110  serves as a basic element of the indoor unit of the air conditioner, has a quadrangular space subsiding in a front side thereof, and has a backside fixed on an inside, i.e., a wall surface of a space that needs air-conditioning.  
         [0054]     A left discharge hole  112  for guiding air discharged by a left discharge fan  420  that will be described later is formed on the left side of the main chassis  110  and a right discharge hole  114  for guiding air discharged by a right discharge fan  430  that will be described later is formed on the right side of the main chassis  110 .  
         [0055]     Ventilation ports  120  and  123  are formed in a pair on the main chassis  110  to pass from the front to the rear of the main chassis. That is, the ventilation ports  120  and  123  consist of a left ventilation port  120  and a right ventilation port  123  formed on the respective ends of the main chassis  110 .  
         [0056]     In addition, disposed respectively at one end of the ventilation ports  120  and  123  are ventilation doors  122  and  121  for selectively opening and closing the ventilation ports  120  and  123 . Namely, to the right of the left ventilation port  120  is a left ventilation door  122  formed to open and close over the ventilation port  120 , and to the left of the right ventilation port  123  is a right ventilation door  121  formed to open and close over the ventilation port  123 . The left and right doors  122  and  121  open and shut by pivoting on a respective hinge (h) formed thereon, and open the ventilation port  120  and  123  during ventilation mode.  
         [0057]     Furthermore, ventilation motors  124  and  125  are respectively disposed at the ventilation ports  120  and  123  for providing power to open and close the ventilation doors  122  and  121 . Specifically, a left ventilation motor  124  is disposed to the right of the left ventilation door  122  to open and close the same, and a right ventilation motor  125  is disposed to the left of the right ventilation door  121  to open and close the same. In order to open and close the ventilation doors  122  and  121 , the ventilation motors  124  and  125  can rotate the hinges (h) on the doors, or a variety of other methods.  
         [0058]     Ventilation ducts  126  and  127  extend rearward from the ventilation ports  120  and  123 . The ventilation ducts  126  and  127  pass through to the outside of the building from the indoor space. A left ventilation duct  126  is connected to the left ventilation port  120 , and a right ventilation duct  127  is connected to the right ventilation port  123 . Accordingly, air flows through the ventilation ducts  126  and  127  between the indoor space and the outside.  
         [0059]     Parts such as a heat exchanger and a cross-flow fan that will be described later are installed between the main chassis  110  and the front panel  130 . In the meantime, the appearance of the indoor unit formed by the main chassis  110  and the front panel  130  is protruded to round on the whole toward the front side as illustrated.  
         [0060]     A suction panel  150  having a front suction grill  155  is installed on the front of the front panel  130 . The front suction grill  155  is a path through which air sucked from a space that needs air-conditioning is sucked into the inside of the indoor unit. For that purpose, the front suction grill  155  passes through the suction panel  150 . Also, an upper suction grill  156  is formed on the upper side of the front panel  130  to allow air of the upper portion of the space that needs air-conditioning to be sucked into the inside of the indoor unit. A filter  160  is provided between the front panel  130  and the suction panel  150 . The filter  160  filters air sucked through the front suction grill  155 .  
         [0061]     A heat exchanger holder  200  for fixing the left of the heat exchanger to the main chassis  110  is fixed at the left end of the inside of the main chassis  110  by a screw (S). A right holder  210  in which the right of the heat exchanger is fixed is protruded on the right of the inside of the main chassis  110 .  
         [0062]     In detail, the heat exchanger holder  200  includes a frame part  201  to which the left end of the heat exchanger is closely attached and a hairpin guide  203  punched in an edge of the frame part  201 . The size and the number of the hairpin guides  203  correspond to a hairpin of the heat exchanger that will be described later.  
         [0063]     The frame part  201  serves as a basic element forming the heat exchanger holder  200  and has a predetermined thickness. The reason the frame part  201  is formed to have a predetermined thickness is that the frame part  201  should substantially support the weight of the heat exchanger.  
         [0064]     A hairpin guide  203  is punched in the frame part  201 . The hairpin guide  203  is a kind of through hole for receiving a fixing the hairpin of the heat exchanger and formed along the outer edge of the frame part  201 . The hairpin guide  203  corresponds to the hairpin of the heat exchanger. Therefore, when the heat exchanger has one step or two-step bending shape, the hairpin guides  203  have an about “U” shape.  
         [0065]     The heat exchanger holder  200  may be fixed to the main chassis  100  through a screw S as a separate member or may be integrally formed with the main chassis  100 . A left guide hole  202  through which air discharged by the left discharge fan  420  passes is formed on the rear end of the heat exchanger holder  200 .  
         [0066]     The right holder  210  is intended for fixing the right end of the heat exchanger. A coupling hole  211  that corresponds to a through hole of the fixing end of the heat exchanger is punched in one side of the right holder  210 . Also, a right guide hole  212  through which air guided by the right discharge fan  430  on the right is formed in a passing through manner on the center of the right holder  210 .  
         [0067]     A control box seat part  230  on which a control box is installed is formed between the right holder  210  and the right end of the main chassis  100 .  
         [0068]     In the meantime, the heat exchanger  300  is installed at the rear side of the front panel  130 , more specifically, in a space formed between the main chassis  110  and the front panel  130 .  
         [0069]     The heat exchanger  300  allows air to exchange heat while the air sucked through the front suction grill  155  and the upper suction grill  156  passes therethrough and includes coolant tubes  310  and cooling pins  330 .  
         [0070]     The coolant tube  310  is a path through which working fluid flowing through a heat exchange cycle, namely, a coolant flows and has the cooling pins  330  fitted therein with a predetermined interval. With such a construction, the coolant flowing through the coolant tube  310  cools down the cooling pin  330 . Therefore, the air sucked through the front suction grill  155  and the upper suction grill  156  is cooled down while passing through the cooling pin  330 .  
         [0071]     In the meantime, the coolant tube  310  runs between left and right of the heat exchanger several times and has an about ‘U’-shaped hairpin  311  formed on the end thereof, i.e., the portion returning back to the opposite side. The hairpins  311  are protruded on both sides as the coolant tube  310  runs between left and right several times and inserted into the hairpin guide  203  of the heat exchanger holder  200 .  
         [0072]     A cross-flow fan  400  is installed in the rear of the heat exchanger  300 , more specifically, between the heat exchanger  300  and the main chassis  100 .  
         [0073]     The cross-flow fan  400  sucks air for air-conditioning and discharges the air downward. That is, the cross-flow fan  400  discharges the heat-exchanged air to the lower direction perpendicular to the rotational axis of the cross-flow fan  400 .  
         [0074]     Generally, the cross-flow fan has straight-line type wings. That is, since the cross-flow fan has wings bent in the rotational direction, a suction/discharge flow to an axial direction is not generated but suction/discharge flow is generated within a plane perpendicular to the axis of the cross-flow fan.  
         [0075]     The cross-flow fan  400  is smaller compared to the width of the heat exchanger  300 , and a fan motor  410  to its right provides power to spin the cross-flow fan  400 .  
         [0076]     A left motor  416  is installed to the left of the cross-flow fan  400  along an imaginary extension of its shaft, and a left fan  420  is installed to the left of the left motor  416 . That is, a left motor shaft  417  passes through the center of the left motor  416 , and the left fan  420  is installed on the left end of the left motor shaft  417 . Accordingly, the left motor  416  provides power to spin the left fan  420 . The air in the inside of the indoor unit is discharged to the left side by the left fan  420 . The left fan  420  is formed on an imaginary rotational axis of the cross-flow fan  400 , so that the inner construction of the air conditioner can be compact even more.  
         [0077]      FIG. 4  is a perspective view of a side fan according to the present invention. Referring to  FIG. 4 , it is preferable that the left fan  420  is a shaft-type chi-fan. Specifically, the fan is formed of a cylindrical rotating body  422  and a plurality of fan blades  424  on the outer surface of the rotating body  422 . The fan blades  424  spiral helically on the outer surface of the rotating body  422 , and push air along an axial direction when rotating.  
         [0078]     Referring to  FIG. 3 , the left fan housing  425  is installed on the outer side of the left fan  420 . The left fan housing  425  guides the air forcibly blown by the left fan  420  and has a discharge guide hole (not shown) formed therein horizontally in a passing through manner. The discharge guide hole may have a size that corresponds to the outer diameter of the rotational wing  424  of the left fan  420 .  
         [0079]     The left fan housing  425  has a cylindrical shape and a center whose diameter is relatively small compared with both side ends. That is, the diameter of the center has a diameter relatively smaller than that of both side ends and is rounded inward.  
         [0080]     To the right of the cross-flow fan  400  is installed a right motor  419 ; and to the right of the right motor  419  is a right fan  430 . Specifically, a right motor shaft  418  runs through the center of the right motor  419 , with the right fan  430  installed on the right end of the right motor shaft  418 . The right fan  430  is a chi-fan as in the explanation given for the left fan  420 .  
         [0081]     Accordingly, the right motor  419  spins the right fan  430 . The rotational force of the right motor  419  is transferred to the right fan  430  through the right motor shaft  418 . Through the right fan  430 , air is discharged to the inside space from the right side of the unit.  
         [0082]     A right fan housing  435  is installed around the right fan  430 . The right fan housing  435  is formed similarly to the left fan housing  425  explained previously, and forcibly blows air from the right side of the unit.  
         [0083]     The heat exchanged air that passed by the heat exchanger  300  is discharged to the indoor space for air conditioning purposes by the cross-flow fan  400 . To this end, a discharge grill  500  is formed at the lower portions of the main chassis  100  and the front panel  130 .  
         [0084]     Inside the discharge grill  500  a discharge duct  510  is formed for guiding the air conditioning air blown by the cross-flow fan  400  to the indoor space. Also, louvers  530  are formed inside the discharge duct  510  for controlling the direction of the discharged air. The discharge duct  510  is selectively opened and closed by means of discharge vanes  540 .  
         [0085]     In addition, at the approximate center of the suction panel  150  is disposed a display (P) for displaying the operational status of the air conditioner.  
         [0086]     The operation of the indoor unit for an air conditioner will now be explained with reference to  FIGS. 3 through 7 .  
         [0087]      FIGS. 5 through 8  are sectional, horizontal views of an indoor unit for an air conditioner, showing various airflows according to operational mode.  
         [0088]     First, referring to  FIGS. 3 and 5 , the air conditioner will be described during air cooling mode.  
         [0089]     The air conditioner is supplied with power from an external source, which drives the fan motor  410  to spin. The rotational force supplied to the fan motor  410  is relayed via a rotating shaft  412  to a cross-flow fan  400 , a left fan  420 , and a right fan  430 .  
         [0090]     When the cross-flow fan  400  and the left and right fans  420  and  430  spin, airflow is created inside the indoor unit of the air conditioner, thereby sucking in air from the outside. That is, outside air is sucked in through a front intake suction  155  and an upper suction grill  156  and proceeds through a heat exchanger  300  to exchange heat.  
         [0091]     Air that is cooled by passing through the heat exchanger  300  is guided downward and from the sides by the cross-flow fan  400  and the left and right fans  420  and  430 . Specifically, the air guided by the cross-flow fan  400  is discharged downwards from a discharge duct  510  formed at the bottom portion of the main chassis  110 , and the air guided by the left fan  420  passes through a left discharge port to be discharged from the left side of the indoor unit, and the air guided by the right fan  430  passes through a right discharge port  114  to be discharged from the right side of the indoor unit.  
         [0092]     In still further detail, the air that is sucked in through the front and upper suction grills  155  and  156  to be cooled in the heat exchanger  300  is discharged through the lower and side portions of the indoor unit. That is, a portion of the sucked air is discharged via the cross-flow fan  400  downward, and another portion of the air is discharged via the left and right fans  420  and  430  through left and right portions of the indoor unit.  
         [0093]     Additionally, airflow that is forcibly created by the left and right fans  420  and  430  are guided by the left and right fan housings  425  and  435  to be respectively discharged from left and right sides. When the air conditioner functions in the above air cooling mode, the ventilation doors  122  and  121  close the ventilation ports  120  and  123 .  
         [0094]     The air conditioner functioning in ventilation mode will now be explained.  
         [0095]     Referring to  FIG. 6 , intake ventilation will be examined. Here, the fan motor  410  does not operate, so the cross-flow fan  400  also does not operate. The left motor  416  spins the left fan  420 , and the right motor  419  spins the right fan  430 .  
         [0096]     The ventilation doors  122  and  121  are opened by the ventilation motors  124  and  125 . That is, the doors move on hinges (h) to open in positions perpendicular to the main chassis  110 , as shown in the diagram. ( FIG. 6  shows the left door  122  opening counter-clockwise and the right door  121  opening clockwise.)  
         [0097]     Consequently, air is sucked in from the outside through the ventilation ports  120  and  123 , and flows in a left and right direction through the side fans  420  and  430 . That is, the air is led through the fan housings  425  and  435  and discharged. Thus, air from the outside is suctioned in and ventilates the indoor space.  
         [0098]      FIG. 7  shows the air conditioner in exhaust ventilation mode. Here, as in the above-explained intake ventilation mode, the fan motor  410 , and thus the cross-flow fan  400  do not operate. The left motor  416  spins the left fan  420 , and the right motor  419  spins the right fan  430 , and the ventilation doors  122  and  121  are opened. However, the right and left fans  430  and  420  rotate in reverse directions from the intake ventilation mode during the exhaust ventilation mode.  
         [0099]     Accordingly, air from the indoor space is suctioned by the left and right fans  420  and  430  through the left and right discharge ports  112  and  114 , and is discharged to the outside through ventilation ducts  126  and  127 . Thus, the indoor space is ventilated by discharging air within to the outside.  
         [0100]     Although the embodiments of the present invention relate to a two-part air conditioning unit, the present invention is not necessarily limited to such applications, and can be varied for use in a wide variety of indoor units.  
         [0101]     Also, although the previous embodiment relates to the air conditioner in either intake or exhaust ventilation mode, the two modes do not have to occur separately and can occur simultaneously.  
         [0102]     For a more detailed explanation, if we refer to  FIG. 8 , one of the two side fans  420  and  430 , the left fan  420  can be used as an exhaust fan, and the other, the right fan  430  can be used as an intake fan, so that intake and exhaust functions occur simultaneously.  
         [0103]     Here, both of the pair of ventilation doors  122  and  121  are opened, and air from the indoor space is suctioned through the left discharge port  112  into the indoor unit and is discharged through the left ventilation port  120  to the outside. Conversely, air from the outside is suctioned through the right discharge port  123  and is discharged through the right discharge port  114  to the indoor space. Thus, intake and exhaust functions are performed simultaneously to ventilate the interior space.  
         [0104]     Furthermore, it is within the scope of the present invention to include an air conditioner that omits the ventilation doors  122  and  121 , but has separate ducts for connecting the ventilation ports  123  and  120  to the side fans  420  and  430 .  
         [0105]     As in the preceding explanation, the indoor unit for an air conditioner according to the present invention has a cross-flow fan inside its central portion and similar fans disposed at either end of the cross-flow fan. Also, the main chassis has a ventilation duct connected to the indoor space, to concentrate components in an effective layout inside a tightly-spaced spaced indoor unit, for cooling and heating as well as ventilating functions.  
         [0106]     Also, the present invention allows for not only cooling and heating of air, but also allows a user to selectively ventilate an indoor space by intaking air from the outside or discharging air to the outside.  
         [0107]     Additionally, the present invention provides an air conditioner having a variety of functions in a single unit that provides a refreshing indoor environment.  
         [0108]     It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.