Abstract:
A compact ventilating system having an air purifying function is disclosed, which includes a case having one end buried in a ceiling of a room, and the other end projected toward the inside of the room; an air-supplying passage of communicating the outside of the room, the case, and the inside of the room with one another, to supply an outdoor air to the inside of the room; an air-discharging passage of communicating the inside of the room, the case, and the outside of the room with one another, to discharge an indoor air to the outside of the room; an air-circulating passage of communicating the inside of the room with one point of the air-supplying passage inside the case, to introduce the indoor air to the case, and to re-supply the air to the inside of the room; and a fan provided in the case, for supplying the outdoor air introduced to the case through the air-supplying passage to the inside of the room, or re-supplying the indoor air introduced to the case through the air-circulating passage to the inside of the room.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of Korean Application No. P2004-59268, filed on Jul. 28, 2004, which is hereby incorporated by reference as if fully set forth herein. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a ventilating system, and more particularly, to a compact ventilating system having an air purifying function. 
     2. Discussion of the Related Art 
     In case many people stay in a closed room, such as an office or a vehicle, the closed room is polluted with carbon dioxide, and the like, produced when the people breathe quickly, and the polluted air affects human bodies. Therefore, it is necessary to change the polluted room air with outdoor fresh air, for which a ventilating system is generally used. Such a ventilating system is installed inside a ceiling, for forced discharge of room air and introduction of outdoor air into the room. 
     In order to install the ventilating system, it is necessary to obtain a sufficient room for the ventilating system between a ceiling and a floor of an upper story. Accordingly, a distance between a floor of a lower story and a floor of an upper story, a height of one story, increases, thereby lowering the spatial efficiency and the economical efficiency in a building. 
     In the meantime, currently, for more comfortable room environment, an air purifier as well as the ventilating system is provided in the room, for collecting dust or microbes from the room air, thereby requiring an additional cost for the air purifier. 
     Also, the air purifier is installed on a room floor, for purifying the outdoor air introduced into the room. In this state, it is difficult to improve the efficiency in removing the dust from the room air. Besides, in case the air purifier is installed on the room floor, infants and children can touch the air purifier, so that it may cause safety troubles and damages in the air purifier. 
     Furthermore, since the ventilating system and the air purifier are separately provided in the room, in case of that the outdoor air introduced to the inside of the room is polluted, the polluted outdoor air is directly provided to the inside of the room when ventilating the room air with the ventilating system. As a result, the polluted outdoor air is directly provided to the inside of the room, so that it is impossible to obtain the comfortable room environment. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention is directed to a ventilating system that substantially obviates one or more problems due to limitations and disadvantages of the related art. 
     An object of the present invention is to provide a ventilating system having a modified structure not to increase a distance between a floor of a lower story and a floor of an upper story. 
     Another object of the present invention is to provide a ventilating system having a modified structure of purifying an outdoor air and providing the purified air to the inside of a room when ventilating a room air. 
     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. 
     To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a ventilating system includes a case having one end buried in a ceiling of a room, and the other end projected toward the inside of the room; an air-supplying passage of communicating the outside of the room, the case, and the inside of the room with one another, to supply an outdoor air to the inside of the room; an air-discharging passage of communicating the inside of the room, the case, and the outside of the room with one another, to discharge an indoor air to the outside of the room; an air-circulating passage of communicating the inside of the room with one point of the air-supplying passage inside the case, to introduce the indoor air to the case, and to re-supply the air to the inside of the room; and a fan provided in the case, for supplying the outdoor air introduced to the case through the air-supplying passage to the inside of the room, or re-supplying the indoor air introduced to the case through the air-circulating passage to the inside of the room. 
     At this time, the case is formed in a flat-quadrant shape, for being positioned at a corner of the ceiling in the room. Also, the case has two sides being adhered to the corner of a wall in the room. The case is formed in a flat-quadrate shape, and one side of the case is positioned adjacent to the wall of the room. In addition, the case has a round frontal side for supplying the indoor air or the outdoor air introduced to the inside of the case to the inside of the room. 
     The ventilating system further includes a louver provided in the air-circulating passage, for opening and closing the air-circulating passage. In the ventilating system, there is a preheat exchanger provided at an intersection between an air-supplying duct and an air-discharging duct, for indirect heat-exchange of the outdoor air supplied to the inside of the room and the indoor air discharged to the outside of the room. Also, the ventilating system includes a damper provided in the air-supplying passage, for opening and closing the air-supplying passage. In this state, the fan inhales the air at an axis direction, and then discharges the air at a radius direction. 
     The air-supplying passage includes a first port provided in the side of the case; an air-supplying duct connected with the first port, and being in communication with the outside of the room by penetrating the wall; and an air-discharging hole provided in the front of the case. Also, the air-discharging holes are formed at both sides adjacent to the front side of the case. The first port is provided at a lower portion in the side of the case under the ceiling of the room. The air-supplying passage further includes a guide passage slantingly provided from an inner upper portion of the case to the air-discharging hole. 
     The air-discharging passage includes a second inlet provided on the bottom of the case; a second port provided in the side of the case; and an air-discharging duct connected with the second port and being in communication with the outside of the room by penetrating the wall. The second port is provided at a lower portion in the side of the case under the ceiling of the room. 
     The air-circulating passage includes a first inlet provided on the bottom of the case; and an air-discharging hole provided in the front of the case. The air-discharging holes are formed at both sides adjacent to the front side of the case. 
     The case includes a division plate for dividing the inner space of the case into a lower space and an upper space, and an opening provided in the division plate to communicate the lower space of the case with the upper space of the case, and the fan is provided to inhale the air from the lower space of the case and to discharge the inhaled air to the upper space of the case. Also, the case further includes an air guide, for separating the air-supplying passage from the air-discharging passage. The air-supplying passage and the air-discharging passage pass through the case under the ceiling of the room by penetrating the wall of the room. 
     In addition, the ventilating system includes a filter member provided in the case, for purifying the indoor air or the outdoor air introduced to the case, wherein the filter member includes a dust-colleting filter, photo-catalyst, and active carbon, which are provided in the case. The filter member may be formed of an HEPA (High Efficiency Particulate Arrestor) filter which can remove particles and bacteria, larger than 0.3 micron. The filter member may be formed of a ULPA (Ultra Low Penetration Absolute) filter which can remove particles and bacteria, with a size ranging 0.01˜0.1 micron. 
     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 
       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; 
         FIG. 1  is a schematic diagram of illustrating a ventilating system according to the first embodiment of the present invention; 
         FIG. 2  is a cross sectional view along I-I′ of  FIG. 1 ; 
         FIG. 3  is a perspective view of illustrating an air flow when purifying an indoor air with a ventilating system of  FIG. 1 ; 
         FIG. 4  is a perspective view of illustrating an air flow when ventilating a room with a ventilating system of  FIG. 1 ; 
         FIG. 5  and  FIG. 6  are perspective views of illustrating examples of installing a ventilating system of  FIG. 1  to the inside of a room; 
         FIG. 7  is a schematic diagram of illustrating a ventilating system according to the second embodiment of the present invention; 
         FIG. 8  is a perspective view of illustrating an air flow when purifying an indoor air with a ventilating system of  FIG. 7 ; 
         FIG. 9  is a perspective view of illustrating an air flow when ventilating a room with a ventilating system of  FIG. 7 ; and 
         FIG. 10  is an exemplary perspective view of illustrating a ventilating system of  FIG. 7  having a damper at any one discharging hole therein. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. 
     Hereinafter, a ventilating system according to the first embodiment of the present invention will be described with reference to the accompanying drawings. 
       FIG. 1  is a schematic diagram of illustrating a ventilating system according to the first embodiment of the present invention.  FIG. 2  is a cross sectional view along I-I′ of  FIG. 1 .  FIG. 3  is a perspective view of illustrating an air flow when purifying an indoor air with a ventilating system of  FIG. 1 .  FIG. 4  is a perspective view of illustrating an air flow when ventilating a room with a ventilating system of  FIG. 1 .  FIG. 5  and  FIG. 6  are perspective views of illustrating examples of installing a ventilating system of  FIG. 1  to the inside of a room. 
     In a ventilating system according to the related art, a case of the ventilating system is provided to a space between a ceiling and a floor of an upper story. In the meantime, a ventilating system according to the first embodiment of the present invention has a case  100 , wherein one end of the case  100  is projected toward the inside of a room, and the other end is buried in a ceiling. More particularly, as shown in  FIG. 1  and  FIG. 2 , the case  100  has two sides connected with each other for being adhered to the corner of a wall  10 , and one front side being round toward the inside of the room. 
     For example, the case  100  is formed at a predetermined thickness. In this state, as shown in  FIG. 1 , the case  100  has a quadrant shape formed by dividing a circular shape into four parts. The case  100  has the two sides positioned at the corner of the wall  10  for being adhered to the wall  10 , an upper end being buried in the ceiling, and a lower end being projected toward the inside of the room. 
     In this way the case  100  is positioned, some of the case  100  corresponding to a first height H 1  (H 1  of  FIG. 2 ) is provided in a space between the ceiling and the bottom of the upper story, and the remaining of the case  100  corresponding to a second height H 2  (H 2  of  FIG. 2 ) is provided in an inside space of the room under the ceiling. 
     Accordingly, the ventilating system according to the present invention may be easily installed to a building having a small distance between a floor of a lower story and a floor of an upper story, that is, a small height of one story. If using the ventilating system according to the present invention, it is possible to decrease a height of one story when constructing a new building. 
     The ventilating system according to the present invention has an air supplying passage of providing an outdoor air to the inside of the room, an air discharging passage of discharging an indoor air to the outside of the room, and an air circulating passage of circulating the indoor air, wherein each passage flows through the case  100 . 
     Hereinafter, the air passages will be described in detail. 
     Through the air supplying passage, the outside of the room, the case  100 , and the inside of the room are in communication with one another. 
     In case of the ventilating system according to the related art, after the air supplying passage of providing the outdoor air to the inside of the room flows through the space provided between the ceiling and the floor of the upper story, the air supplying passage is connected to the case  100 . 
     Meanwhile, in case of the ventilating system according to the present invention, the air supplying passage penetrates the wall  10  without passing through the space provided between the ceiling and the floor of the upper story, and then the air supplying passage is directly connected with the side of the case  10  under the ceiling  20 . 
     For example, the air supplying passage is comprised of a first port  101  provided in side of the case  100 , an air-supplying duct  300  connected with the first port  101 , and an air-discharging hole  130  provided in the case  100 . The first port  101  is provided at any one side of the two sides of the case  100 , for being positioned under the ceiling  20 . Also, the air-supplying duct  300  is provided to penetrate the wall  100 , wherein one end of the air-supplying duct  300  is connected with the outside of the room, the other end of the air-supplying duct  300  is connected with the first port  101  under the ceiling  20 , and the air-discharging hole  130  is provided in the front of the case  100 . 
     At this time, the first port  101  is provided at a lower portion in the side of the case  100 , and the air-discharging hole  130  is provided at a central portion or an upper portion in the front of the case  100  under the ceiling  20 . Also, as shown in  FIG. 2 , a guide passage  160  is provided in the case  100 , wherein the guide passage  160  is slantingly provided from the inner upper portion of the case  100  to the air-discharging hole  130 . In addition, as shown in  FIG. 2 , a flow-direction guide  131  may be additionally provided in the air-discharging hole  130 , for controlling the flow direction of the air discharged to the inside of the room. 
     Accordingly, the outdoor air, introduced to a lower part of the case  100  through the air-supplying duct  300 , moves to an upper part of the case  100 , and then is discharged to the inside of the room through the guide passage  160  and the air-discharging hole  130 . At this time, the air supplied to the inside of the room is discharged to a lower space of the room by the guide passage  160 , and the air-supplying direction is determined by the flow-direction guide  131 . In the meantime, for example, an air-supplying fan  320  may be provided in the air-supplying duct  300 , as shown in  FIG. 1 , wherein the air-supplying fan  320  supplies the outdoor air to the inside of the room. 
     Through the air discharging passage, the inside of the room, the case  100 , and the outside of the room are in communication with one another. 
     In the related art ventilating system, after the air discharging passage of discharging the indoor air to the outside of the room flows through the space formed between the ceiling and the floor of the upper story, the air discharging passage is connected to the case  100 . 
     In the meantime, in case of the ventilating system according to the present invention, the air discharging passage penetrates the wall  10  without passing through the space formed between the ceiling and the floor of the upper story, and then the air discharging passage is directly connected with the case  100  under the ceiling  20 . 
     For example, the air discharging passage is comprised of a second inlet  120  provided on the bottom of the case  100 , a second port  102  provided in the side of the case  100 , and an air-discharging duct  400  connected with the second port  102  and being in communication with the outside of the room. At this time, as shown in  FIG. 1  to  FIG. 3 , the second inlet  120  may be formed of a plurality of slots. 
     For example, as shown in  FIG. 1  to  FIG. 3 , the second inlet  120  may be formed of a plurality of slots. Also, for example, the second port  102  is provided in parallel with the first port  101  at the lower portion in the side of the case  100 . Accordingly, the indoor air introduced to the case  100  through the second inlet  120  is discharged to the outside of the room through the air-discharging duct  400 . 
     In more detail, as shown in  FIG. 1 , the air-discharging duct  400  may have an additional air-discharging fan  410  for discharging the introduced indoor air to the outside of the room. Furthermore, as shown in  FIG. 1 , another air-discharging fan  411  may be provided in the air-discharging duct  400 , for improvement the efficiency in discharging the air. 
     Through the air circulating passage, the inside of the room is in communication with one point of the air supplying passage inside the case  100 . 
     The air circulating passage introduces the indoor air to the case  100 , and again supplies the introduced air to the inside of the room. For example, the air circulating passage is comprised of a first inlet  110  provided on the bottom of the case  100 , and the air-discharging hole  130  provided in the front of the case  100 . At this time, as shown in  FIG. 1  to  FIG. 3 , the first inlet  110  may be formed of a plurality of slots, wherein the first inlet  110  is provided in parallel with the second inlet  120  on the bottom of the case  100 . 
     The air circulating passage meets with the air supplying passage in the case  100 . Accordingly, the indoor air introduced to the case  100  through the air circulating passage and the outdoor air introduced to the case  100  through the air supplying passage are supplied to the inside of the room through the air-discharging hole  130 . 
     In the ventilating system according to the present invention, a preheat exchanger  500  may be additionally provided at an intersection of the air supplying passage and the air discharging passage, and more specifically, at an intersection of the air-supplying duct  300  and the air-discharging duct  400 . 
     The preheat exchanger  500  includes a plurality of first passages for the flow of the outdoor air, and a plurality of second passages for the flow of the indoor air, wherein the second passages are provided in-between the first passages. Then, a plate is provided between each of the first passages and each of the second passages. As a result, the outdoor air supplied to the inside of the room through the air-supplying duct  300  is indirectly heat-exchanged with the indoor air discharged to the outside of the room through the air-discharging duct  400  in the preheat exchanger  500 . 
     In the meantime, as shown in  FIG. 2 , a fan  210  is provided in the case  100 , wherein the fan  210  supplies the air introduced to the case  100  through the air supplying passage or the air circulating passage to the inside of the room. The fan  210  supplies the outdoor air introduced to the inside of the case  100  through the air-supplying duct  300  connected with the lower portion in the side of the case  100  to the inside of the room. Also, the fan  210  supplies the indoor air flowing into the case  100  through the first inlet  110  formed on the bottom of the case  100  to the inside of the room, again. For example, the fan  210  may be formed of a cross flow fan of inhaling the air at an axis direction, and discharging the inhaled air at a radius direction. In this case, it is possible to obtain compactness in the case  100 , and to improve the efficiency in the fan  210 . 
     As shown in  FIG. 2 , a division plate  150  may be provided in the case  100 , wherein the division plate  150  divides the inside space of the case  100  into a lower space and an upper space. Also, an opening  151  is provided in the division plate  150 , for communication between the lower space and the upper space of the case  100 . As shown in  FIG. 2 , the fan  210  is positioned in the opening  151 . 
     Accordingly, the air introduced to the lower space of the case  100  through the first inlet  110  or the air-supplying duct  300  is provided to the lower side of the fan  210  through the opening  151 , and then is discharged to the upper space of the case  100 . After that, the air discharged to the upper space of the case  100  moves along the guide passage  160  inclined toward the inside of the case  100 , and then the air is provided to the inside of the room through the air-discharging hole  130  provided at the lower portion in the front of the case  100 . 
     In addition, an air guide  140  may be additionally provided in the case  100 , for separating the air supplying passage from the air discharging passage. As shown in  FIG. 2 , for example, the air guide  140  is provided to the lower space of the case  100 , for separation of the first inlet  110  and the second inlet  120 . Accordingly, the air guide  140  guides the air introduced to the case  100  through the air-supplying duct  300  or the first inlet  110  toward the air-discharging hole  130 , and guides the air introduced to the case  100  through the second inlet  120  toward the air-discharging duct  400 . 
     Also, at least one louver  111  is provided in the air circulating passage, for opening and closing the air circulating passage. For example, as shown in  FIG. 2  and  FIG. 3 , the louver  111  is provided for opening and closing the first inlet  110 . In this case, the first inlet  110  is provided with a plurality of slots, whereby the several louvers  111  are provided for opening and closing the respective slots. 
     Also, when the outdoor air is introduced to the inside of the room through the air supplying passage with the ventilating system, the louver  111  closes the first inlet  110 . In the meantime, when circulating the indoor air by using the air circulating passage with the ventilating system, the louver  111  opens the first inlet  110 . 
     Furthermore, a damper  310  may be provided in the air supplying passage, for opening and closing the air supplying passage. For example, as shown in  FIG. 1 ,  FIG. 3  and  FIG. 4 , the damper  310  is provided to open and close the first port  101 . That is, the damper  310  opens the first port  101  when supplying the outdoor air to the inside of the room through the air supplying passage with the ventilating system. In the meantime, the damper  310  closes the first port  101  when circulating the indoor air by using the air circulating passage with the ventilating system. 
     Then, a filter member  600  may be provided in the case  100 . For example, the filter member  600  is positioned under the fan  210 , wherein the filter member  600  purifies the outdoor air introduced to the inside of the case  100  through the air-supplying duct  300  and the indoor air introduced to the inside of the case  100  through the first inlet  110 . 
     At this time, the air purified by the filter member  600  in the case  100  is provided to the room space through the air-discharging hole  130 . Accordingly, when ventilating and circulating the room air with the ventilating system according to the present invention, it is possible to provide the purified clean air to the room space since the filter member  600  is provided in the ventilating system. 
     As shown in  FIG. 2 , for example, the filter member  600  is provided with a dust-collecting filter  610 , photo-catalyst  620 , and active carbon  630 . The dust-collecting filter  610  filters dust from the air, and the photo-catalyst  620  and the active carbon  630  are carbon having a strong adsorption capability, and absorb odor from the air. 
     The dust-collecting filter  610  may be used of an HEPA (High Efficiency Particulate Arrestor) filter, or an ULPA (Ultra Low Penetration Absolute) filter. At this time, the HEPA filter can remove particles, such as dust, bacteria, virus, and the like, larger than 0.3 micron, up to 99.97%, and the ULPA filter, having a better performance than the HEPA filter, can remove particles, such as fine dust, bacteria, dandruff, mold, pollen, radon-decay product, smoke, and the like, with a size ranging 0.1˜0.01 micron, up to 99.999%. Also, the photo-catalyst  620  is one kind of catalysts, wherein catalysis is performed with light energy. At this time, the photo-catalyst  620  may be used of TiO 2 , ZnO, CdS, ZrO 2 , SnO 2 , V 2 O 2 , or WO 3 . 
     Referring to  FIG. 5  and  FIG. 6 , the aforementioned ventilating system according to the present invention may be installed in various positions according to the structure of the building. 
     For example, as shown in  FIG. 5 , if it is convenient to provide the air-supplying duct  200  and the air-discharging duct  300  connected with the inside of the room by penetrating the right-side wall  10 , the case  100  is positioned at the right-side corner of the room. Thus, the air-supplying duct  200  and the air-discharging duct  300  are connected with the right side of the case  100 . 
     In the meantime, if it is convenient to provide the air-supplying duct  200  and the air-discharging duct  300  connected with the inside of the room by penetrating the left-side wall  10 , the case  100  is positioned at the left-side corner of the room. Thus, the air-supplying duct  200  and the air-discharging duct  300  are connected with the left side of the case  100 . 
     The ventilating system according to the first embodiment of the present invention is operated as a first operation mode for circulating and purifying the indoor air, and a second operation mode for ventilating the room air by introducing the outdoor air to the inside of the room. 
     Hereinafter, the respective operation modes of the ventilating system according to the first embodiment of the present invention will be described with reference to  FIG. 3  and  FIG. 4 . 
     Referring to  FIG. 3 , on the first operation mode, the damper  310  closes the first port  101 , and the louver  111  opens the first inlet  110 . Although not shown, on the first operation mode, air-discharging fans  410  and  411  are not driven. Accordingly, the indoor air is not discharged to the outside of the room through the air-discharging duct  400 . With operation of the fan  210  in the case  100 , the polluted indoor air is introduced to the lower space of the case  100  through the first inlet  110  formed on the bottom of the case  100 . 
     After that, the polluted air introduced to the lower space of the case  100  passes through the filter member  600  and the fan  210 , and then the filtered clean air is discharged to the upper space of the case  100 . At this time, the filter member  600  is provided with the dust-colleting filter  610 , the photo-catalyst  620 , and the active carbon  630 , which remove the foreign matters from the polluted air, thereby purifying the air. Thereafter, the purified clean air is introduced to the upper space of the case  100 , and then is provided to the room space through the air-discharging hole  130 . 
     During this process, the damper  310  closes the first port  101 , so that the outdoor air is not introduced to the case  100  through the air-supplying duct  300 . As a result, only the indoor air flows into the case  100 , and the indoor air is purified in the case  100 . After that, the purified air is discharged to the room space. Thus, the ventilating system according to the present invention continuously circulates and purifies the indoor air. 
     Next, as shown in  FIG. 4 , on the second operation mode, the damper  310  opens the first port  101 , and the louver  111  closes the first inlet  110 . As operating the air-supplying fan  320  inside the air-supplying duct  300 , and the fan  210  inside the case  100 , the outdoor air flows into the lower space of the case  100  through the air-supplying duct  300  and the first port  101 . Then, as the outdoor air provided to the lower space of the case  100  passes through the filter member  600 , the outdoor air is purified. After that, the purified air moves to the upper space of the case  100 , and then is provided to the room space through the air-discharging hole  130 . As described above, during this process, the louver  111  closes the first inlet  110 , whereby the indoor air is not provided to the case  100  through the first inlet  110 . 
     In the meantime, as the air-discharging fans  410  and  411  are operated, the indoor air is supplied to the inside of the case  100  through the second inlet  120 , and more particularly, to the lower space of the case  100  through the second inlet  120 . At this time, the first inlet  110  and the second inlet  120  are separated from each other by using the air guide  140 . Accordingly, the indoor air introduced to the case  100  through the second inlet  120  is not mixed with the outdoor air introduced to the case  100  through the air-supplying duct  300 . The indoor air introduced to the case  100  through the second inlet  120  is discharged to the outside of the room through the second port  102  and the air-discharging duct  400 . 
     Herein, the preheat exchanger  500  indirectly heat-exchanges the outdoor air flowing through the air-supplying duct  300  with the indoor air flowing through the air-discharging duct  400 . That is, when ventilating the room air, the outdoor air introduced to the inside of the room is heated or cooled by the indoor air discharged to the outside of the room, and then the heated or cooled air is provided to the room space, thereby preventing the rapid change on the inside temperature of the room space. 
     In the aforementioned description, the louver  111  is provided in the first inlet  110 . However, it is not limited to this, that is, the louver  111  may not be provided. In this case, when ventilating the room air, the outdoor air is provided to the case  100  through the first port  101 , and the indoor air is provided to the case  100  through the first inlet  110 . 
     Accordingly, the ventilating system according to the present invention continuously introduces the outdoor air to the inside of the room, and simultaneously circulates the indoor air. In this state, the outdoor air introduced to the inside of the room and the circulating indoor air are purified by the filter member  600  of the case  100 , and then the purified air is provided to the room space. 
     In the meantime,  FIG. 7  is a schematic diagram of illustrating a ventilating system according to the second embodiment of the present invention.  FIG. 8  is a perspective view of illustrating an air flow when purifying an indoor air with a ventilating system of  FIG. 7 .  FIG. 9  is a perspective view of illustrating an air flow when ventilating a room with a ventilating system of  FIG. 7 . 
     Hereinafter, the ventilating system according to the second embodiment of the present invention will be described with reference to  FIG. 7 ,  FIG. 8  and  FIG. 9 . 
     The ventilating system according to the second embodiment of the present invention is similar in structure to the ventilating system according to the first embodiment of the present invention, so that the detailed explanation for the structure of the ventilating system according to the second embodiment of the present invention will be omitted. That is, the differences between the first embodiment and the second embodiment will be described in chief. 
     In the same way as the ventilating system according to the first embodiment of the present invention, the ventilating system according to the second embodiment of the present invention has a case  100 , wherein an upper end of the case  100  is buried in a ceiling, and a lower end of the case  100  is projected toward the inside of a room. 
     In the ventilating system according to the first embodiment of the present invention, the case is formed in the flat-quadrant shape. In the meantime, in case of the ventilating system according to the second embodiment of the present invention, the case  100  is formed in a flat quadrate shape, as shown in  FIG. 8  and  FIG. 9 . 
     Also, in the ventilating system according to the first embodiment of the present invention, the air-discharging hole  130  is provided in the front of the case  100 , for discharging the air to the room space. However, in the ventilating system according to the second embodiment of the present invention, air-discharging holes  130  are provided at both sides of the case  100  as well as the front side of the case  100 . Accordingly, in case of the ventilating system according to the second embodiment of the present invention, one side of the case  100  is adhered and fixed to a wall of the room, and the air is provided to the inside of the room through the air-discharging holes  130  formed in the front side and the both sides of the case  100 , as shown in  FIG. 8  and  FIG. 9 . 
     The ventilating system according to the second embodiment of the present invention may have one side being adhered and fixed to the wall of the room, as shown in  FIG. 8  and  FIG. 9 . 
     However, the ventilating system according to the second embodiment of the present invention may be installed at a corner of a ceiling in the room. In this case, the two sides of the case  100  are adhered to the wall of the room, so that any one of the two air-discharging holes  130  formed on the two sides adjacent to the front side of the case  100  is positioned close to the wall of the room. Thus, the air discharged through any one air-discharging hole  103  comes into collision with the wall of the room, thereby generating turbulent air and noise. 
     In order to prevent this problem, as shown in  FIG. 10 , a damper  135  is provided to the air-discharging hole  130  adjacent to the wall, for closing the air-discharging hole  130 . Thus, the air inside the case  100  is discharged to the room space through the two air-discharging holes  130  of the case  100 , as shown in  FIG. 10 . 
     As described above, the ventilating system according to the second embodiment of the present invention is very similar to the ventilating system according to the first embodiment of the present invention in the shape of the case  100 , the position of the air-discharging holes  130 , and the damper  135  provided in the air-discharging hole  130 , as shown in  FIG. 7  to  FIG. 10 . Accordingly, the detailed explanation for the structure and function of the ventilating system according to the second embodiment of the present invention will be omitted. 
     As described above, the ventilating system according to the present invention has the following advantages. 
     In the ventilating system according to the present invention, it is possible to perform two functions of circulating the indoor air and the purifying the indoor air with one unit, thereby decreasing the cost in purchasing the device of ventilating and purifying the air. 
     Also, the air-supplying duct and the air-discharging duct are connected to one side of the case, so that it is possible to lower a height of the ventilating system at a degree corresponding to a height in each duct. Also, one end of the case is buried in the ceiling of the room, and the other end of the case is projected toward the room space. In this sate, the air-supplying duct and the air-discharging duct are in direct connection with the case under the ceiling. As a result, there is no requirement for obtaining a large space between the ceiling and the bottom of the upper story. That is, it is possible to decrease the distance between the ceiling and the bottom of the upper story, thereby decreasing the initial cost in constructing the building. Also, the number of stories increases, for improvement of the spatial efficiency. 
     Also, each duct may be connected with one side from the two sides of the case. Thus, each duct may be selectively connected with one side of the two sides of the case, in due consideration of the structure of outer walls for installing the ventilating system. 
     Furthermore, the filter member is provided in the case, so that the purified clean outdoor air and indoor air is provided to the room space, thereby obtaining the more comfortable room environment. 
     In addition, the cross flow fan is provided to forcibly inhale the indoor air and the outdoor air, so that it is possible to prevent the decrease in the air supplying amount, generated by the increase in the loss of pressure, even in case of the high-performance dust-collecting filter is provided in the filter member. 
     It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. 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.