Patent Publication Number: US-2021172627-A1

Title: Humidification and air cleaning apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application claims priority under 35 U.S.C. § 119 to Korean Application No. 10-2019-0162756, filed in Korea on Dec. 9, 2019, whose entire disclosure is hereby incorporated by reference. 
     BACKGROUND 
     1. Field 
     A humidification and air cleaning apparatus is disclosed herein. 
     2. Background 
     Air conditioning apparatuses include air conditioners that control a temperature of air, air cleaners that remove foreign substances from air to maintain air cleanliness, humidifiers that increase humidity in the air, and dehumidifiers that reduce humidity in the air. Typical humidifiers are classified into a vibration type, which atomizes water on a vibrating plate and discharges it into air, and a natural evaporation type which evaporates water in a humidification filter. 
     The natural evaporation type humidifier is classified into a disc type humidifier, which rotates a disc using a drive force and allows water to naturally evaporate from the surface of the disc in the air, and a humidification filter type humidifier which allows water to naturally evaporate from a wet humidification medium by flowing air. 
     Korean Laid-Open Patent Publication No. 10-2017-0051233 (hereinafter referred to as the “related art document”), which is hereby incorporated by reference, discloses an apparatus for both humidification and air cleaning. In the humidification and air cleaning apparatus disclosed in the related art document, humidification housing sprays water by rotating in a water tank. However, the related art document has a problem in that when the humidification housing rotates while spraying water, if a volume of air to be discharged upward increases, droplets sprayed from the humidification housing may also be scattered along with the air to the outside of a discharge port of the water tank. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments will be described in detail with reference to the following drawings in which like reference numerals refer to like elements, and wherein: 
         FIG. 1  is a perspective view of a humidification and air cleaning apparatus according to an embodiment; 
         FIG. 2  is an exploded perspective view of the humidification and air cleaning apparatus of  FIG. 1 ; 
         FIG. 3  is a front cross-sectional view of the humidification and air cleaning apparatus of  FIG. 2 ; 
         FIG. 4  is a perspective view of an air humidification module of  FIG. 2 , from which a top cover assembly is separated; 
         FIG. 5  is an isolated perspective view of the top cover assembly and a discharge humidification medium housing of  FIG. 4 ; 
         FIG. 6  is a cross-sectional view of the air humidification module of  FIG. 4 ; 
         FIG. 7  is a magnified view of a portion G of  FIG. 6 ; 
         FIG. 8  is a front view illustrating an installation state of a humidification housing of  FIG. 4 ; 
         FIG. 9  is a cross-sectional view, taken along line IX-IX of  FIG. 8 ; 
         FIG. 10  is an exploded perspective view of the humidification housing of  FIG. 8 ; 
         FIG. 11  is a front view of  FIG. 10 ; 
         FIG. 12  is a cross-sectional view, taken along line XII-XII of  FIG. 11 ; 
         FIG. 13  is a perspective view of a housing cover of  FIG. 6 ; 
         FIG. 14  is a perspective view of a lower surface of the housing cover of  FIG. 13 ; 
         FIG. 15  is a front cross-sectional view of the lower surface of the housing cover of  FIG. 13 ; 
         FIG. 16  is a partial cross-sectional view of an upper side of a humidification housing, illustrating an arrangement of nozzles and a housing cover; 
         FIG. 17  is a magnified cross-sectional view of a first upper nozzle of  FIG. 16 ; 
         FIG. 18  is a magnified cross-sectional view of a second upper nozzle of  FIG. 16 ; 
         FIG. 19  is an exemplary view of a trajectory of water sprayed through the first upper nozzle; 
         FIG. 20  is an exemplary view of a trajectory of water sprayed through the second upper nozzle; and 
         FIG. 21  is a front cross-sectional view of a humidification housing according to another embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Advantages and features of embodiments and methods of accomplishing the same will be more clearly understood from embodiments described below with reference to the accompanying drawings. However, the embodiments are not limited to the following embodiments but may be implemented in various different forms. The embodiments are provided only to complete disclosure and to fully provide a person having ordinary skill in the art to which embodiments pertains with the category, and embodiments will be defined by the scope of the appended claims. Wherever possible, like reference numerals generally denote like elements through the specification. 
     Hereinafter, embodiments will be described with reference to the accompanying drawings. 
       FIG. 1  is a perspective view of a humidification and air cleaning apparatus according to an embodiment.  FIG. 2  is an exploded perspective view of the humidification and air cleaning apparatus of  FIG. 1 .  FIG. 3  is a front cross-sectional view of the humidification and air cleaning apparatus of  FIG. 2 . 
     Referring to  FIGS. 1 to 3 , an humidification and air cleaning apparatus according to this embodiment may include an air cleaning module  100  and an air humidification module  200  located over the air cleaning module  100 . 
     The air cleaning module  100  may take in and filter external air, and may provide the filtered air to the air humidification module  200 . The air humidification module  200  may be supplied with the filtered air, may humidify the filtered air to provide moisture, and may discharge the humidified air to the outside. 
     The air humidification module  200  may include a water tank  300  that stores water. The water tank  300  may be separated from the air clean module  100  along with the air humidification module  200  when the air humidification module  200  is separated from the air cleaning module  100 . The air humidification module  200  is detachably located over the air cleaning module  100 . 
     A user may upwardly separate the air humidification module  200  upward from the air clean module  100 , and may easily clean the separated air humidification module  200 . Further, the user may clean the interior of the air cleaning module  100 , from which the air humidification module  200  is separated. When the air humidification module  200  is separated, a top surface of the air cleaning module  100  is open to the user. 
     The air cleaning module  100  includes a filter assembly  10 , which will be described hereinafter, and the user may clean the air cleaning module  100  after separating the filter assembly  10  from a base body  110 . 
     The user may supply water into the air humidification module  200 . The air humidification module  200  has a water supply passage  109 , through which water may be supplied from the outside to the water tank  300 . 
     The water supply passage  109  may be formed separately from a discharge passage  107 , through which air is discharged. Air to be discharged may be discharged through the discharge passage  107 , and the discharge of air through the water supply passage  109  may be minimized or blocked. 
     The water supply passage  109  may be formed such that water may be supplied into the water tank  300  at any time. For example, even when the air humidification module  200  is in operation, water may be supplied through the water supply passage  109 . For example, even when the air humidification module  200  is coupled to the air cleaning module  100 , water may be supplied through the water supply passage  109 . For example, even when the air humidification module  200  is separated from the air cleaning module  100 , water may be supplied through the water supply passage  109 . When water is supplied from above through the water supply passage  109 , the water supplied from above may flow into the water tank  300  through the water supply passage  109 . 
     The air cleaning module  100  and the air humidification module  200  may be connected to each other by a connection passage  103 . As the air humidification module  200  is separable, the connection passage  103  may be distributedly provided over the air cleaning module  100  and the air humidification module  200 . It is when the air humidification module  200  is placed over the air cleaning module  100  that a flow passage of the air humidification module  200  and a flow passage of the air cleaning module  100  communicate with each other through the connection passage  103 . 
     The connection passage formed at the air cleaning module  100  may be defined as a cleaning connection passage  104 , and the connection passage formed at the air humidification module  200  is defined as a humidification connection passage  105 . 
     The air cleaning module  100  and the air humidification module  200  will be described hereinafter. 
     The air cleaning module  100  may include base body  110 , filter assembly  10  disposed in the base body  110  and filtering air, and an air blower unit (air blower)  20  disposed in the base body  110  and blowing air. The base body  110  may include an upper body  120  and a lower body  130 . The upper body  120  may be stacked on top of the lower body  130 , and the upper body  120  and the lower body  130  may be assembled to each other. 
     Air may flow into the base body  110 . An intake passage  101  may be disposed at a lower side of the lower body  130 , and a filtering passage  102  may be disposed inside of the lower body  130 , and an air flow passage  108  may be disposed at an upper side of the lower body  130 . 
     In order to form the intake passage  101 , a lower body supporter  190  may be disposed to support the lower body  130  from below. The filtering passage  102  may be disposed in the lower body  130  and pass through the filter assembly  10 . 
     The air flow passage  108  may be disposed at an upper side of the air blower unit  20 . The filtered air, discharged from the air blower unit  20 , may flow into the water tank  300  through an air humidification inlet  31 . 
     The filter assembly  10  may be detachably assembled to the base body  110 . The filter assembly  10  includes the filtering passage  102 , and filters outside air. The filter assembly  10  may be detached from the base body  10  in a horizontal direction. The filter assembly  10  may be disposed to intersect a flow direction of air that flows upstream in the vertical direction. The filter assembly  10  may slide in the horizontal direction and may filter air that flows upstream in the vertical direction. The filter assembly  10  may be disposed in the horizontal direction and may form the filtering passage  102  in the vertical direction. The filter assembly  10  may slide in the horizontal direction with respect to the base body  110 . 
     The air blower unit  20  may be disposed above the filter assembly  10 . The air blower unit  20  generates an air flow. The air blower unit  20  may be disposed inside of the base body  110  and may allow air to flow from a lower side to an upper side. 
     The air blower unit  20  may include a blower housing  150 , a blower motor  22 , and a blower fan (not shown). In this embodiment, the blower motor  22  may be disposed at an upper side of the air blower unit  20 , and the blower fan may be disposed at a lower side thereof. A motor shaft of the blower motor  22  may be disposed to face downward and may be coupled to the blower fan. 
     The blower housing  150  may be disposed inside of the base body  110 . The blower housing  150  may provide a passage for flowing air. The blower motor  22  and the blower fan may be disposed in the blower housing  150 . 
     The blower housing  150  may be disposed above the filter assembly  10  and below the upper body  120 . The blower housing  150  may have the air flow passage  108  formed therein. The blower fan may be disposed in the air flow passage  108 . The air flow passage  108  may connect the filtering passage  102  and the cleaning connection passage  104 . 
     An operating mechanism of the blower fan may be similar to a centrifugal fan, but a discharge direction of the blower fan may be inclined upward. In this embodiment, the blower fan draws in air from below, and then discharges the air outwardly and upwardly in a radial direction. An outer end of the blower fan may be disposed to be directed upward in the radial direction. 
     The blower motor  22  may be disposed above the blower fan to minimize contact with the flowing air. The blower motor  22  may be installed so as to be covered by the blower fan. The blower motor  22  is not located in the air flow passage formed by the blower fan, and does not generate resistance to the air blown by the blower fan. 
     The upper body  120  may form an exterior of the base body  110 , and may be assembled to the upper side of the lower body  130 . The air humidification module  200  may be detachably held in the upper body  120 . 
     The upper body  120  may include an upper outer body  128  forming an exterior of the base body  110  and coupled to the lower body  130 ; an upper inner body  140  disposed inside of the upper outer body  128 , having the water tank  300  inserted therein, and providing the connection passage  103 ; and an air guide  170  that connects the upper inner body  140  and the upper outer body  128  and guides air to the water tank  170 . A water tank insertion space  125  may be formed inside of the upper inner body  140 , and the water tank  300  of the air humidification module  200  may be detachably inserted into the water tank insertion space  125 . 
     An outer side of the upper inner body  140  may communicate with the air flow passage  108 . The upper inner body  140  may have an upper inlet  121  that passes through the inside and the outside of the upper inner body  140 , and corresponding to the air humidification inlet  31 . The air humidification inlet  31  may be disposed inside of the upper inlet  121 . 
     The upper inlet  121  and the air humidification inlet  31  may allow the inside of the water tank  300  and the air flow passage  108  to communicate with each other. The upper inner body  140  has the water tank insertion space  125  so that the water tank  300  may be inserted therein. 
     As the upper body  120  is disposed to separate the connection passage  103  and the water tank insertion space  125 , it is possible to minimize a flow of water in the water tank  300  into the connection passage  103 . More particularly, the connection passage  103 , divided by the upper inner body  140 , may be disposed outside of a space in which water is stored, such that it is possible to prevent water from flowing into the connection passage  103 . 
     The upper inner body  140  may have an open upper side, through which the water tank  300  may be inserted. The upper inner body  140  may form a portion of the cleaning connection passage  104 , into which the filtered air may flow. 
     The upper inner body  140  may have the upper inlet  121  corresponding to the air humidification inlet  31 . The upper inlet  121  is not an essential component, and may have any shape as long as the upper body  120  to expose the air humidification inlet  31  to the connection passage  103 . 
     The air guide  170  may guide air, supplied through the cleaning connection passage  104 , to the upper inlet  121 . The air guide  170  may collect air inwardly which rises along the outside of the base body  110 . The air guide  170  may change a flow direction of air flowing from a lower side to an upper side. While changing the flow direction of air, the air guide  170  may minimize an angle of change of the flow direction, so as to minimize flow resistance of air. 
     The air guide  170  may cover 360 degrees of the outside of the upper inner body  140  along a circumference of the upper inner body  140 . The air guide  170  may guide air to the water tank  300  in all 360 degrees of directions of the circumference of the water tank  300 . The air guide  170  may collect air inwardly which is guided along the outside of the lower body  130 , and may supply the collected air to the water tank  300 . With this structure, a flow rate of air supplied to the water tank  300  may be sufficiently secured. 
     A handle  129  may be formed at the upper body  120 . As the air humidification module  200  is held in the upper body  120 , the whole humidification and air cleaning apparatus may be lifted up by the handle  129 . 
     The cleaning connection passage (not shown) may be disposed on the outside of the upper inlet  121 , and the water tank insertion space  125  may be disposed on the inside thereof. The air, flowing through the cleaning connection passage  104 , may pass through the upper inlet  121 . When the water tank  300  is held in the water tank insertion space  125 , the filtered air, having passed through the upper inlet  121 , may flow into the water tank  300 . 
     An outer visual body  214  may be coupled to an upper side of the upper body  120 . The outer visual body  214  is a component of a visual body  210 , but in this embodiment, the outer visual body  214  is fixed to the upper body  120 . Alternatively, the outer visual body  214  may also be fixed to the air humidification module  200 . Further, alternatively, the outer visual body  214  may be omitted. 
     The outer visual body  214  may be fixed to the upper body  120 . In this embodiment, the outer visual body  214  may be coupled to the upper outer body  128 . The outer visual body  214  and the outer surface of the upper outer body  128  may form a continuous surface. 
     The outer visual body  214  may be formed of a material, allowing a user to see inside of the outer visual body  214 . The outer visual body  214  may be formed of a transparent or translucent material, for example. 
     A display module (display)  160  may be disposed at at least one of the air cleaning module  100  or the air humidification module  200  to display an operating state to a user. In this embodiment, the display module  160  may be disposed at the base body  110  to display an operating state of the humidification and air cleaning apparatus to a user. 
     The display module  160  may be disposed on an inner surface the outer visual body  214 . The display module  160  may be disposed to be closely adhered to an inner surface of the outer visual body  214 . When viewed from a top, the display module  160  may have a donut shape. The water tank  300  may be inserted into the display module  160 . 
     The display module  160  may be supported by the outer visual body  214 . An inner edge of the display module  160  may be supported by an upper inner body ring  126 . The display module  160  may be integrally formed with a base connector  260 . An inside of the display module  160  may be supported by the upper inner body  140 , and the outside thereof may be supported by the outer visual body  218 . 
     In this embodiment, when viewed from the top, the display module  160  has a ring shape. Alternatively, the display module  160  may have an arc shape. A surface of the display module  160  may be formed of, or coated with, a light-reflective material. 
     Accordingly, when drops of water are formed on the visual body  210 , the water drops formed on the visual body  210  may be projected onto or reflected from the surface of the display module  160 . When the water drops formed on the visual body  210  flow downward, a same effect is also shown on the display module  160 . This effect may give a visual stimulus to a user, such that the user may intuitively recognize that humidification is being performed. The water drop image projected on the display module  160  may have not only an emotional effect of giving a sense of refreshment to a user, but also a functional effect of informing the user of a humidification state. 
     The display module  160  may have an inclined upper surface. The display module  160  may be inclined toward a user, such that a height of the display module  160  is higher on the inside than on the outside. 
     The humidification connection passage  105  may be disposed outside of a side wall of the water tank  300 . The cleaning connection passage  104  may be disposed outside of the upper inner body  150 . 
     Hereinafter, each component of the air humidification module  200  will be described with reference to  FIG. 2  or  FIG. 3 . 
     The air humidification module  200  may include water tank  300  that stores water for humidification and detachably disposed on the air cleaning module  100 ; a water dispensing unit (dispenser)  400  disposed in the water tank  300  and spraying water in the water tank  300 ; a humidification medium  50  wetted with water sprayed from the water dispensing unit  400  and providing moisture to the flowing air; visual body  210  coupled to the water tank  300  and formed of a transparent material allowing a user to see the inside thereof; a top cover assembly (top cover)  230  detachably disposed over the visual body  210  and providing the discharge passage  107 , through which air is discharged, and the water supply passage  109  through which water is supplied; and a discharge vane  1400  disposed below the top cover assembly  230  and covering the discharge passage  107 . 
     The air humidification module  200  provides humidification to the filtered air. The air humidification module  200  may implement a rain view inside of the water tank  300 . The air humidification module  200  may spray and circulate water stored in the water tank  300 . The air humidification module  200  may change the stored water into small droplets, and the scattered droplets may come into contact with the filtered air. Humidification and filtering may be performed while the filtered air is humidified with the scattered droplets. 
     The air humidification module  200  may include the water tank  300 , the water dispensing unit  400 , the humidification medium  50 , the visual body  210 , the top cover assembly  230 , and handle  180 . The handle  180  may be connected to the visual body  210 , rotate in the visual body  210 , and be held in the visual body  210 . A user may simply lift up only the air humidification module  200  by the handle  180 , and the handle  180  may be separated from the air cleaning module  100 . 
     In the humidification and air cleaning apparatus according to this embodiment, a power source may be connected to the air cleaning module  100 , and the air humidification module  200  may be supplied with power from the air cleaning module  100 . As the air humidification module  200  may be separated from the air cleaning module  100 , a separate power supply structure may be provided in which power is provided separately to the air cleaning module  100  and the air humidification module  200 . 
     The air cleaning module  100  and the air humidification module  200  may be detachably assembled in the upper body  120 , such that the base connector  260  for providing power to the air humidification module  200  may be disposed in the upper body  120 . An operation module  240 , which requires power, may be disposed at the top cover assembly  230  of the air humidification module  200 . A top connector  270 , detachably connected to the base connector  260 , may be disposed in the air humidification module  200 . The top connector  270  may be disposed in the top cover assembly  230 . 
     In this embodiment, the top cover assembly  230  may be separated such that the inner surface of the visual body  210  or the inner surface of the water tank  300  may be cleaned in a convenient manner. The top cover assembly  230  may be detachably installed to the visual body  210 . The top cover assembly  230  may be provided with the top connector  270  which may be electrically connected to the base connector  260 . 
     When the top cover assembly  230  is placed on the visual body  210 , the top connector  270  is disposed over the base connector  260 . The top cover assembly  230  is supplied with electricity from the base connector  260  via the top connector  270 . 
     A water level display unit (display)  247  that displays a water level of the water tank  300  may be disposed near the water supply passage  109 . Accordingly, while supplying water, a user may check the water level of the water tank  300  which is not visible. By providing the water level display unit  247  at a position visible to a user while the user supplies water, it is possible to prevent excessive supply of water by the user or prevent overflow of water from the water tank  30 . 
     The water level display unit  247  may be disposed at the top cover assembly  230 . A separate power supply structure of the top connector  270  and the base connector  260  may allow effective supply of water from above. 
     The water tank  300  may be detachably disposed in the upper body  120 . The water dispensing unit  400  may be disposed and rotate inside of the water tank  300 . 
     The water tank  300  may include a water tank body  320  in which water is stored; the air humidification inlet  31  formed to pass through a side wall of the water tank body  320 ; and a water tank body extension part or portion (extension)  380  that extends upward from the water tank body  320  and coupled to the visual body  210 . 
     The water tank body  320  has a bottom surface and a side wall, with an open upper part or portion (opening). The air humidification inlet  31  may pass through the side wall. In this embodiment, the water tank body  320  is formed in a cylindrical shape with an open upper portion. Alternatively, the water tank body  320  may be formed in various shapes. 
     The water tank body extension  380  may extend upward from the water tank  300 . The water tank body extension  380  may form the air humidification inlet  31 . The air humidification inlet  31  may be formed between the water tank body extensions  380 . 
     The air humidification inlet  31  may pass through the side surface of the water tank body  320 . The air humidification inlet  31  may be formed in all 360 degrees of directions of a circumference of the water tank body  320 . 
     The water tank body extension  380  may guide water, flowing down from the inner surface of the visual body  210 , into the water tank  300 . By guiding water flowing down from the visual body  210 , noise of dropping water may be minimized. The water tank body extension  380  may be coupled to a lower end of the visual body  210 . 
     In this embodiment, the visual body  210  and the water tank  300  are manufactured separately and assembled afterwards. Alternatively, the visual body  210  and the water tank  300  may be integrally formed or the water tank  300  may be included in the visual body  210  as a component. For example, a portion of the water tank  300  may be formed of a transparent material by bi-injection molding, in which case the visual body  210  is not manufactured as a separate component. 
     In this embodiment, the air humidification inlet  31  is formed as a component of the water tank body  320 . Alternatively, the air humidification inlet  31  may also be formed by providing the water tank body extension  380  in the visual body  210 . 
     Further, alternatively, the air humidification inlet  31  may be formed in such a manner that some of a plurality of water tank body extensions  380  are disposed in the water tank  380  and the other are disposed in the visual body  210 . In addition, alternatively, the air humidification inlet  31  may be formed as a separate component which is distinguished from the visual body  210  and the water tank  300 . Moreover, alternatively, the visual body  210  may have an apertured surface, on which the air humidification inlet  31  may be formed, and the water tank  300  may also have an apertured surface on which the air humidification inlet  31  may be formed. 
     That is, the air humidification inlet  31  may be formed on either the water tank  300  or the visual body  210 . The air humidification inlet  31  may be formed by coupling of the water tank  300  and the visual body  210 . Upon providing the air humidification inlet  31  as a component which is distinguished from the water tank  300  and the visual body  210 , the component may be disposed between the water tank  300  and the visual body  210 . The air humidification inlet  31  may be formed by the coupling of the water tank  300  and the visual body  210 . 
     The visual body  210  may have an upper part or portion and a lower part or portion which is open. When viewed from the top, the open upper portion and the open lower portion of the visual body  210  may have a circular shape. A diameter of the lower opening of the visual body  210  may be smaller than a diameter of the upper opening of the visual body  210 . 
     In this embodiment, the top cover assembly  230  is inserted through the upper opening of the visual body  210 , and is detachably disposed on the inner surface of the visual body  210 . 
     The water dispensing unit  400  has a function of supplying water to the humidification medium  50 . The water dispensing unit  400  has a function of visualizing the humidification process. The water dispensing unit  400  implements a rain view inside of the air humidification module  200 . 
     The water dispensing unit  400  may draw in water stored in the water tank  300  by rotating humidification housing  800 , pump upward the drawn water, and spray the pumped water outwardly in the radial direction. The water dispensing unit  400  may include the humidification housing  800  which draws in water, pumps upward the drawn water, and then sprays the pumped water outwardly in the radial direction. 
     In this embodiment, the humidification housing  800  may rotate to spray water. Alternatively, a nozzle may be used instead of the humidification housing  800  to spray water. As water is sprayed from the nozzle, the water may be supplied to the humidification medium  50  and a rain view may also be similarly implemented. Depending on embodiments, water may be sprayed from the nozzle or the nozzle may rotate. 
     The water sprayed from the humidification housing  800  serves to wet the humidification medium  50 . The water sprayed from the humidification housing  800  may be sprayed toward at least either the visual body  210  or the humidification medium  50 . 
     Water sprayed toward the visual body  210  may be used to implement a rain view. Water sprayed toward the humidification medium  50  may be used to humidify the filtered air. The rain view may be implemented by spraying water toward the visual body  210 , and then water flowing down from the visual body  210  may be used to wet the humidification medium  50 . 
     In this embodiment, a plurality of nozzles having different heights may be provided for the humidification housing  800 . Water discharged from any one of the nozzles may form droplets on the inner surface of the visual body  210  to create a rain view, and water discharged from the other nozzle may wet the humidification medium  50  for use in humidification. 
     The humidification housing  800  may spray water to the inner surface of the visual body  210 , and the sprayed water may flow down along the inner surface of the visual body  210 . Droplets, shown in the form of drops of water, may be formed on the inner surface of the visual body  210 , and a user may see the droplets through the visual body  210 . 
     More particularly, water flowing down from the visual body  210  may wet the humidification medium  50  for use in humidification. The humidification medium  50  may be wetted with water sprayed from the humidification housing  800  and water flowing down from the visual body  210 . 
     The visual body  210  may be coupled to the water tank  300 , and may be disposed above the water tank  300 . At least a portion of the visual body  210  may be formed of a material allowing a user to see the inside thereof. 
     The display module  160  may be disposed outside of the visual body  210 . The display module  160  may be coupled to either one of the visual body  210  or the upper body  120 . 
     The display module  160  may be disposed at a position at which the rain view may be observed by a user. In this embodiment, the display module  160  may be disposed at the upper body  120 . 
     When the air humidification module  200  is placed on the visual body  210 , an outer surface of the visual body  210  is closely adhered to the display module  160 . At least a portion of the surface of the display module  160  may be formed of or coated with a light-reflective material. 
     The droplets formed on the visual body  210  may also be projected onto the surface of the display module  160 . Accordingly, a user may observe motion of droplets at both the visual body  210  and the display module  160 . 
     The water tank  300  may have the air humidification inlet  31  through which air passes. The air humidification inlet  31  may be provided between the connection passage  103  and a humidification passage  106 . The air humidification inlet  31  may be an outlet of the connection passage  103  and an inlet of the humidification passage  106 . 
     The filtered air, supplied from the air cleaning module  100 , may flow into the air humidification module  200  (water tank in this embodiment) through the air humidification inlet  31 . The humidification medium  50  may be disposed at the air humidification inlet  31  and may cover the air humidification inlet  31 . 
     The humidification medium  50  may be disposed at at least one of the following positions: on a same plane as the air humidification inlet  31 , or on the outside or the inside of the air humidification inlet  31 . The humidification medium  50  is wetted with water for humidification, such that the humidification medium  50  is desirably disposed inside the air humidification inlet  31 . That is, the humidification medium  50  is desirably disposed on the inside of the water tank  300 . 
     Water flowing down after wetting the humidification medium  50  is stored in the water tank  300 . The humidification medium  50  humidifies the filtered air passing through the air humidification inlet  31 . 
     The filtered air is humidified by water naturally evaporated from the humidification medium  50 . The term “natural evaporation” means that water evaporates in a state in which separate heat is not applied to the water. Natural evaporation may be promoted as contact with air increases, a flow velocity of air increases, and a pressure in the air decreases. Natural evaporation may also be referred to as “natural vaporization”. 
     The humidification medium  50  may promote the natural evaporation of water. In this embodiment, the humidification medium  50  is wetted with water but is not immersed in the water tank  300 . 
     The humidification medium  50  may be spaced apart from the water stored in the water tank  300 , such that even when water is stored in the water tank  300 , the humidification medium  50  is not always in a wet state. That is, the humidification medium  50  may be in a wet state only during operation of a humidification mode, and during operation of an air cleaning mode, the humidification medium  50  may be maintained in a dry state. 
     The humidification medium  50  may cover the air humidification inlet  31 , and the filtered air may pass through the humidification medium  50  to flow into the water tank  300 . As the filtered air passes through the air humidification inlet  31 , an air flow length may be minimized. 
       FIG. 4  is a perspective view of an air humidification module of  FIG. 2 , from which a top cover assembly is separated.  FIG. 5  is an isolated perspective view of the top cover assembly and a discharge humidification medium housing of  FIG. 4 . 
     The top cover assembly  230  may be detachably placed over the visual body  210 . The top cover assembly  230  may provide not only the discharge passage  107 , but also the water supply passage  109  for supplying water. 
     The top cover assembly  230  may be disposed over the discharge humidification medium  55 . The humidification medium  55  may be disposed in a discharge humidification medium housing  1400 , and the top cover assembly  230  may be disposed over the discharge humidification medium housing  1400 . 
     The discharge humidification medium housing  1400  may be detachably placed over the visual body  210 . The top cover assembly  230  may be detachably placed over the discharge humidification medium housing  1400 . The top cover assembly  230  may be integrally assembled with the discharge humidification medium housing  1400 . The top cover assembly  230  and the discharge humidification medium housing  1400  may be manufactured separately. 
     The top cover assembly  230  may be detachably placed on the visual body  210  and supported by an inner surface of the visual body  210 . The top cover assembly  230  does not apply a load to the discharge humidification medium housing  1400 . The discharge humidification medium housing  1400  may be separately placed on the inner surface of the visual body  210 . 
     The discharge humidification medium housing  1400  may have the discharge humidification medium  55  located therein, and cover an upper side of the visual body  210 . The water supply passage  109  may pass through the discharge humidification medium housing  1400 . 
     The top cover assembly  230  may include a top cover grill  232  forming the discharge passage  107  and the water supply passage  109 ; an operation module  240  installed at the top cover grill  232 ; and top connector  270  providing power or signals to the operation module  240 . The top cover grill  232  may include a grill discharge port  231 , forming at least a portion of the discharge passage  107 , and a grill water supply port  233  forming at least a portion of the water supply passage  109 . The grill discharge port  231  and the grill water supply port  233  may be open in a vertical direction. The grill water supply port  233  may be disposed at a center on an inside of the top cover grill  232 , and the grill discharge port  231  may be disposed outside of the grill water supply port  232 . 
     The top cover grill  232  may be detachably placed on the visual body  210 . The top cover grill  232  may be placed on the inner surface of the visual body  210 . 
     The operation module  240  may be coupled to the top cover grill  232 . The operation module  240  may receive control signals from a user. The operation module  240  may transmit water level information to a user. The water supply passage  109  may be disposed in the operation module  240 . The operation module  240  may be electrically connected to the top connector  270 , and may be supplied with power from the top connector  270 . 
     The operation module  240  may include an operation housing  250  coupled to the discharge grill  232  and having at least a portion of the water supply passage  109  formed therein, an input unit (input)  245  disposed on the operation housing  250 , water level display unit  247  disposed on the operation housing  250 , and an operation controller (not shown) controlling the input unit  245  and the water level display unit  247 . 
     The water supply passage  109  may be formed in the operation module  240 . A portion of the water supply passage  109  may be vertically formed at a center of the operation module  240 . An operation water supply port  241 , forming at least a portion of the water supply passage  109 , may be formed in the operation module  240 . The operation water supply port  241  may be disposed inside of the operation housing  250 , and may be open in a vertical direction. 
     The operation module  240  may further include an upper water supply guide  236 . The upper water supply guide  236  may guide water, supplied from above, into the operation water supply port  241 . A portion of the surface of the operation housing  250  may be inclined to form the upper water supply guide  236 . 
     When supplying water from above, a user may not see the level of water inside of the water tank  300 , but may immediately check a rising level of water through the water level display unit  247  disposed near the operation water supply port  241 . By checking the water level while supplying water from above, the user may adjust an amount of water supplied from above. 
     The water supplied from above may fall into the humidification passage  106  by passing through the discharge humidification medium housing  1400 . More particularly, the water supplied from above may fall down to the top surface of the humidification housing  800  without directly falling down to a water surface in the water tank  300 . 
     When water is supplied from above while the humidification housing  800  rotates, the supplied water falls down to the humidification housing  800  and is scattered by the humidification housing  800  which rotates, thereby separately creating a rain view. That is, the rain view may be created using water sprayed by the water dispensing unit  400 , as well as the water supplied from above. 
       FIG. 6  is a cross-sectional view of the air humidification module of  FIG. 4 ;  FIG. 7  is a magnified view of a portion G of  FIG. 6 ,  FIG. 8  is a front view illustrating an installation state of a humidification housing of  FIG. 4 ;  FIG. 9  is a cross-sectional view, taken along line IX-IX of  FIG. 8 ;  FIG. 10  is an exploded perspective view of the humidification housing of  FIG. 8 ,  FIG. 11  is a front view of  FIG. 10 , and  FIG. 12  is a cross-sectional view, taken along line XII-XII of  FIG. 11 . 
     By rotating, the humidification housing  800  draws in water stored in the water tank  300  and sprays the water outwardly in a radial direction. The humidification housing  800  has a structure for efficiently pumping the water stored in the water tank  300 . 
     The humidification housing  800  rotates by the torque of motor  42 . During rotation, the humidification housing  800  may draw in water stored in the water tank  300  and may pump the water upwardly. The water pumped into the humidification housing  800  may be discharged through a nozzle  410 . 
     A pumping unit may be disposed in the humidification housing  800 . The pumping unit may pump the water in the water tank  300  upwardly. The water in the water tank  300  may be pumped by various methods. Water may be pumped upwardly through friction or mutual interference with water, which occurs when the humidification housing  800  rotates. 
     A structure for pumping water by rotation of the humidification housing  800  is provided. The pumping unit may be a groove  810  which pumps water upwardly through friction or mutual interference with water. 
     The groove  810  as a pumping unit is disposed on the inner surface of the humidification housing  800 . The groove  810  improves pumping efficiency. The groove  810  may protrude from an inner surface of the humidification housing  800 . The groove  810  may be elongated in a vertical direction. The groove  810  may be disposed radially about a motor shaft  43  or power transmission shaft  640 . 
     A lower end of the humidification housing  800  may be spaced apart from a bottom surface of the water tank  300  by a predetermined distance to form a suction gap (H 1 )  801 . Water in the water tank  300  may be drawn into the humidification housing  800  through the suction gap  801 . 
     A water level H 2  of the water tank  300 , at which the humidification housing  800  may spray water, is above the suction gap H 1  and is below the nozzle  410 . The water level H 2  includes a full water level. 
     If the water level H 2  is below the suction gap H 1 , water is not drawn in such that pumping may not be performed. If the water level H 2  is above the nozzle  410 , water pumped to the nozzle  410  may not be sprayed. 
     The humidification housing  800  has an open lower surface, and side and upper surfaces are closed. The humidification housing  800  may have a cylindrical shape with an open lower surface. The humidification housing  800  may have an inverted cup shape. A housing space  805  may be formed inside of the humidification housing  800 . 
     A column  35  of the water tank  300  may be located inside of the humidification housing  800 , and a power transmission assembly  600  may be disposed inside of the column  35 . The humidification housing  800  may be disposed to cover the column  35 . 
     The column  35  may protrude upward from the bottom surface of the water tank  300  and may pass through the lower surface of the humidification housing  800  to be formed therein. The column  35  and the humidification housing  800  may be spaced apart from each other and connected by the power transmission assembly  600 . 
     The humidification housing  800  may be formed such that a horizontal section thereof is gradually expanded in an upward direction. By contrast, the column  35  may be formed such that the horizontal section thereof is gradually reduced in an upward direction. Shapes of the humidification housing  800  and the column  35  are formed to effectively pump water. A capacity of the housing space  805  may gradually increase in an upward direction. 
     When the humidification housing  800  rotates, the drawn water may be closely adhered to an inner circumferential surface of the humidification housing  800  by centrifugal force. The groove  810  formed on the inner circumferential surface of the humidification housing  800  may provide torque to the drawn water. 
     The nozzle  410  for discharging the drawn water to the outside may be disposed in the humidification housing  800 . The nozzle  410  may discharge water in a horizontal direction. The nozzle  410  may pass through the side wall of the humidification housing  800 . 
     When the humidification housing  800  rotates, the water inside of the humidification housing  800  may be discharged to the outside in a radial direction through the nozzle  410 . The water discharged through the nozzle  410  may be sprayed to the visual body  210 . 
     A number of nozzles  410  may vary according to design conditions. In this case, a plurality of nozzles  410  having different heights may be provided in the humidification housing  800 . The nozzles disposed at an upper portion of the humidification housing  800  may be defined as upper nozzles  412  and  413 , and the nozzle disposed at a middle portion of the humidification housing  800  may be defined as a lower nozzle  411 . 
     The water sprayed from the lower nozzle  411  may be used for humidification. The water sprayed from the upper nozzles  412  and  413  may be used for humidification, watering, and rain view. 
     The lower nozzle  411  may be disposed below the upper nozzles  412  and  413 . The lower nozzle  411  may be disposed below the visual body  210 . 
     The upper nozzles  412  and  413  may be disposed within a height of the visual body  210 , and the water sprayed from the upper nozzles  412  and  413  may be seen through the visual body  210 . The water sprayed from the upper nozzles  412  and  413  may be sprayed or scattered to the visual body  210 , and water flowing down along the inner surface of the visual body  210  may wet the water tank humidification medium  51 . 
     The water sprayed from the upper nozzles  412  and  413  hits the visual body  210  and then is scattered to form a rain view. After hitting the visual body  210 , the water sprayed from the upper nozzles  412  and  413  may be changed into fine droplets, which may be used to humidify filtered air. 
     When the humidification housing  800  rotates at a speed higher than or equal to a first rotational speed, water may be sprayed from the lower nozzle  411 . When the humidification housing  800  rotates at a speed higher than or equal to a second rotational speed, water may be sprayed from the upper nozzles  412  and  413 . The second rotational speed may be higher than the first rotational speed. 
     The first rotational speed is a rotational speed of the humidification housing  800 , at which water may be pumped to the inside of the lower nozzle  411 . The second rotational speed is a rotational speed of the humidification housing  800 , at which water may be pumped to the inside of the upper nozzles  412  and  413 . Water may be discharged from the upper nozzles  412  and  413  only when the humidification housing  800  rotates at a high speed. 
     A plurality of upper nozzles may be disposed at the humidification housing  800 . A plurality of lower nozzles may be disposed at the humidification housing  800 . 
     If the humidification housing  800  rotates at a usual rotational speed, the pumped water may rise to a level at least higher than the lower nozzle  411 . If the humidification housing  800  rotates at a high speed, the pumped water may rise to a level equal to or higher than a height of the upper nozzles  412  and  413 . 
     At the second rotational speed, water is pumped up to a lower side of a housing cover  860 . At the second rotational speed, the pumped water is stored at an upper side of an interior of the humidification housing  800 . 
     A plurality of upper nozzles may be disposed in a circumferential direction of the humidification housing  800 . Also, a plurality of lower nozzles may be disposed in a circumferential direction of the humidification housing  800 . 
     If the humidification housing  800  does not rotate, water may not be discharged through the lower nozzle  411 . When a user selects only an air cleaning mode (a mode in which the air cleaning module operates while the air humidification module is stopped), the water dispensing unit  400  does not operate, but only the air blower unit  20  operates. When a user selects a humidification mode, the humidification housing  800  rotates and water is discharged through the nozzle  410 . When a user selects both the air cleaning mode and the humidification mode, water discharged through the nozzle  410  may be sprayed to the inner surface of the visual body  210 . 
     As the humidification housing  800  rotates, the water discharged from the nozzle  410  may hit the inner surface of the visual body  210  and then flow along the inner surface of the visual body  210 . A user may visually check through the visual body  210  that water is sprayed. The spraying of water may indicate that the humidification mode is in operation. By seeing the spraying of water, a user may intuitively check that the humidification mode is in operation. Droplets may be formed on the visual body  210  by the sprayed water, and when a size of the droplets is greater than or equal to a predetermined size, the droplets may flow down. 
     The humidification housing  800  will be described hereinafter with reference to  FIGS. 7 to 12 . 
     The humidification housing  800  may include three parts. Alternatively, the humidification housing  800  may be manufactured with one or two components. 
     A lower end of the humidification housing  800  may be spaced apart from the bottom surface of the water tank  300  by a predetermined distance. The humidification housing  800  may include a first housing  820 , a second housing  840 , housing cover  860 , and a power transmission unit  880 . 
     The humidification housing  800  may be assembled with the power transmission shaft  640  and receives torque from the power transmission shaft  640 . The power transmission unit  880  and the housing cover  860  may be assembled with the power transmission shaft  640 . The humidification housing  800  may be connected to the power transmission shaft  640  at two points and receives torque from the two points. 
     Alternatively, the humidification housing  800  may be connected to the power transmission shaft  640  at one point and may receive torque from the one connected point. Further, alternatively, the humidification housing  800  may receive torque by a method other than the power transmission shaft  640 . For example, the torque of the motor may be delivered by a belt-pulley method. For example, the torque of the motor may be delivered by a gear engagement method. For example, the torque of the motor may be delivered by a chain method. For example, the torque of the motor may be delivered by a clutch method. 
     The power transmission shaft  640  may have a screw thread  643  formed at each of upper and lower ends thereof. The screw thread  643  may be assembled with the housing cover  860 . The lower screw thread may be assembled with a second coupler  620 . A first coupler  620 , coupled to the second coupler  620 , may be disposed on the upper body  120 . 
     The motor  42  may be disposed in the upper body  120 . The motor  42  may provide torque to the humidification housing  800 . 
     A coupler disposed in the air cleaning module  100  and coupled to the motor  42  may be defined as the first coupler  610  (see  FIG. 3 ). A coupler disposed in the air humidification module  200  and detachably coupled to the first coupler  610  may be defined as the second coupler  620  (see  FIG. 3 ). 
     Any one of first coupler  610  or the second coupler  620  may have a male shape, and the other one may have a female shape. In this embodiment, the first coupler  610  has a male shape, and the second coupler  720  has a female shape. Further, the first coupler  610  is inserted into the second coupler  620  to be detachably coupled thereto. Alternatively, the second coupler  620  may be inserted into the first coupler  610  to be coupled thereto. 
     The motor  42  may be installed in the upper body  120 . The motor  42  may be placed over the blower motor  22  and spaced apart from the blower motor  22 . The water tank  300  may be disposed in the upper body  120 . When the water tank  300  is disposed in the upper body  120 , the first coupler  610  and the second coupler  620  may be connected to allow for power transmission. The motor shaft  43  of the motor  42  may be disposed to be directed upward. The first coupler  610  may be disposed at the upper end of the motor shaft  43 . 
     The first housing  820  may have upper and lower sides which are open and the groove  810  formed on the inner surface thereof. A lower end of the first housing  820  may be spaced apart from the bottom surface of the water tank  300  to form the suction gap  801 . 
     The second housing  840  may have upper and lower sides which are open and be assembled with the upper end of the first housing  820 . The housing cover  860  may be coupled to an upper end of the second housing  840  and cover an upper surface of the second housing  840 . Further, the housing cover  860  may close the upper opening of the humidification housing  800 . 
     The power transmission unit  880  may be connected to at least either the first housing  820  or the second housing  840  to receive the torque of the power transmission assembly  600 . In this embodiment, the power transmission unit  880  is connected to the first housing  820 . 
     Alternatively, the first housing  820  and the second housing  840  may be integrally formed with each other. Further, the first housing  820  and the housing cover  860  may be integrally formed with each other. 
     An upper section of the first housing  820  may be larger than a lower section thereof. The first housing  820  may be inclined vertically. The first housing  820  may have a conical shape with a narrow lower section. 
     The first housing  820  may have the groove  810  formed therein. The groove  810  may be formed in a vertical direction. The groove  810  may be disposed radially about the motor shaft  43 . A plurality of grooves  810  may be disposed, which may protrude toward an axial center of the humidification housing  800 . 
     The lower end of the first housing  820  may be spaced apart from the bottom surface of the interior of the water tank  300 , to form the suction gap  801 . The upper end of the first housing  820  may be coupled to the lower end of the second housing  840 . 
     The first housing  82  and the second housing  840  may be assembled with or disassembled from each other. The first housing  820  and the second housing  840  may be assembled via screw coupling. The first housing  820  may have a screw thread  822  formed on an outer circumferential surface of an upper side thereof, and the second housing  840  may have a screw thread  842  formed on an inner circumferential surface of a lower side thereof. The screw thread  822  formed on the first housing  820  may be defined as a first thread  822 , and the screw thread  842  formed on the second housing  840  may be defined as a second screw thread  842 . 
     A first barrier  823  may be formed below the first thread  822  to restrict movement of the second housing  840 . The first barrier  823  may be formed in a circumferential direction of the first housing  820 . The first barrier  823  may be formed in a strip shape, and protrude outwardly from the first housing  820 . 
     When the first housing  820  and the second housing  840  are assembled, the first barrier  823  may be closely adhered to a lower end of the second housing  840 . The first barrier  823  may protrude outwardly further than the first screw thread  822 . 
     A first packing  825  may be disposed between the first screw thread  822  and the first barrier  823 . The first packing  825  may prevent water from leaking between the first housing  820  and the second housing  840 . The first packing  825  may be formed of an elastic material. The first packing  825  may have a ring shape. 
     A rib  824  may be disposed to fix a position of the first packing  825 . The rib  824  may be disposed on an extension line of the first screw thread  822 . The rib  824  may be a portion of the first screw thread  822 . Accordingly, a plurality of first screw threads  822  may be formed which are distributed discontinuously, and the rib  824  may be one of the first screw threads  822 . 
     The lower nozzle  411  may be disposed in the first housing  820 . In this embodiment, two lower nozzles  411  are disposed, which face in opposite directions. 
     The lower nozzle  411  may allow the inside and outside of the first housing  820  to communicate with each other. In this embodiment, an inner opening area of the lower nozzle  411  is greater than an outer opening area of the lower nozzle  411 . The lower nozzle  411  supplies water to the water tank humidification medium  51  to wet the water tank humidification medium  51 . The lower nozzle  411  may spray water to the water tank humidification medium  51 . 
     A blade  850  may be formed on an outer circumferential surface of the second housing  840 . The blade  850  may allow humidified air to flow. When the humidification housing  800  rotates, the blade  850  may draw in ambient air. The blade  850  may have a function of a rain view creating unit that atomizes droplets, as well as a function of circulating air. 
     Air of the humidification passage  106 , disposed in the humidification housing  800 , mostly flows to the discharge passage  107  by operation of the blower fan  24 , but air around the blade  850  may flow in an opposite direction. The blade  850  may locally form an air flow in the opposite direction to air flow generated by the blower fan  24 . The blade  850  may also form an air flow in the same direction as the air flow generated by the blower fan  24 , according to the shape of the blade  850 . In this case, air around the humidification housing  800  may gather on the surface of the humidification housing  800 . 
     The air flow, generated by the blade  850 , has an effect of allowing water particles around the humidification housing  800  to flow into the water tank  300 . Rotation of the blade  850  has an effect of generating an air volume and drawing in water particles around the humidification housing  800 . Accordingly, the air flow, generated by the blade  850 , may serve to gather falling water into the humidification housing  800  when water drops from the water supply passage  109  to the upper portion of the humidification housing  800 . 
     If water is supplied through the water supply passage  109  when the humidification housing  800  rotates, the water may hit the surface of the humidification housing  800  and scattered irregularly. The air flow generated by the blade  850  may gather water particles, which are scattered during the supply of water, toward the surface of the humidification housing  800 . 
     The second housing  840  has the upper nozzles  412  and  413 . The upper nozzles  412  and  413  spray water toward the visual body  210 . In this embodiment, two upper nozzles  412  and  413  are disposed, one of which is defined as a first upper nozzle  412  and the other is defined as a second upper nozzle  413 . 
     The first upper nozzle  412  and the second upper nozzle  413  may be disposed to face in different directions. For example, the first upper nozzle  412  and the second upper nozzle  413  may be disposed to face in opposite directions. The first upper nozzle  412  and the second upper nozzle  413  may be symmetrical to each other with respect to the power transmission shaft  640 . 
     When viewed from the top, the first upper nozzle  412  and the second upper nozzle  413  form an included angle of 180 degrees. When viewed from the top, the first upper nozzle  412  is disposed between the blades  850 , and the second upper nozzle  413  is also disposed between the blades  850 . 
     When viewed from a front, the first upper nozzle  412  and the second upper nozzle  413  are disposed at a same height as or above the blade  850 . A portion of trajectories S 3  and S 4  of water sprayed from the first upper nozzle  412  and the second upper nozzle  413  may be located within a radius of gyration of the blade  850 . Accordingly, when the humidification housing  800  rotates, a portion of water sprayed from the first upper nozzle  412  and the second upper nozzle  413  is scattered by hitting the blade  850 . 
     In this embodiment, the first upper nozzle  412  and the second upper nozzle  413  have a predetermined height difference. The first upper nozzle  412  and the second upper nozzle  413  are not disposed a same height. 
     As the first upper nozzle  412  and the second upper nozzle  413  have different heights, positions of water hitting the visual body  210  may be set differently, such that when the humidification housing  800  rotates, water sprayed from the first upper nozzle  412  and water sprayed from the second upper nozzle  413  may pass through different paths. The trajectory S 3  of water hitting the inner surface of the visual body  210  from the second upper nozzles  412  and  413  may be defined as a spray line. The spray line may be a continuous water stream. A spray line formed by the first upper nozzle  412  may be defined as a first spray line L 1 , and a spray line formed by the second upper nozzle  413  may be defined as a second spray line L 2 . 
     The spray line formed in the visual body  210  may not only be a straight line. The spray line may also be a curved line according to an angle at which water is discharged from the nozzle. 
     Further, a thickness of the spray line may vary according to a diameter of the nozzle. That is, when a diameter of the nozzle is large, the spray line may be thick, and when a diameter of the nozzle is small, the spray line may be thin. 
     In this embodiment, after a lapse of a predetermined period of time when water sprayed from the first upper nozzle  412  passes through any one location of the visual body  210 , water sprayed from the second upper nozzle  413  may pass through another location having a different height. That is, two spray lines L 1  and L 2  may be formed on the inner surface of the visual body  210 , and this visual effect may allow a user to recognize spraying of water more effectively. 
     When water is discharged from two upper nozzles disposed at a predetermined height, only one spray line is formed. When the humidification housing  800  rotates at a high speed, even if the first and second upper nozzles  412  and  413  are disposed in opposite directions, a very short phase difference may be formed, thereby causing a user to mistakenly think that water flows down from one spray line. 
     In addition, when two spray lines are formed, water hits different locations, such that different sounds are generated by the hitting water. That is, the sound generated from the first spray line is different from the sound generated by the second spray line. By this sound difference, a user may acoustically recognize rotation of the humidification housing  800 . 
     When only one spray line is formed, the same sound is generated continuously, such that a user may not recognize the sound or may mistake the sound as simply noise. 
     The different sounds generated from the plurality of spray lines may have an effect of allowing people with low vision or hearing loss to effectively recognize operating circumstances. Further, even in a dark environment with no light, a user may easily recognize that the humidification and air cleaning apparatus is in operation. 
     At least one of the upper nozzles  412  and  413  may be partially covered by the housing cover  860 . In this embodiment, the first upper nozzle  412  is fully open, and the second upper nozzle  413  is partially overlapped and covered by the housing cover  860 . 
     The housing cover  860  may be disposed in front of the second upper nozzle  413 . The housing cover  860  may partially cover an upper part or portion of the second upper nozzle  413 . In this embodiment, when the housing cover  860  is coupled to the second housing  840 , the housing cover  860  overlaps a portion of the second upper nozzle  413 . 
     Water sprayed from the second upper nozzle  413  may interfere with a diffusion member, such that a spray angle and width may be changed. The water interfering with the diffusion member may be pulled toward the diffusion member by surface tension. 
     The spray line discharged from the first upper nozzle  412  has a similar diameter to that of the nozzle. Water discharged from the second upper nozzle  413  overlaps with the housing cover  860 , such that water may be scattered to a wider range than the diameter of the second upper nozzle  413 . 
     A trajectory of water sprayed from the first upper nozzle  412  is defined as S 3 , and a trajectory of water sprayed from the upper nozzle  413  is defined as S 4 . The second upper nozzle  413  is disposed slightly above the first upper nozzle  412 . Droplets sprayed from the second upper nozzle  412  may be smaller than droplets sprayed from the first nozzle  412 . The trajectory S 4  of droplets sprayed from the second upper nozzle  413  is located above the trajectory S 3  of droplets sprayed from the first upper nozzle  412 . The droplets sprayed from the second upper nozzle  413  are sprayed more widely than droplets sprayed from the first upper nozzle  412 . Accordingly, the spray line L 2  formed by the overlapped second upper nozzle  413  has a wider width than the spray line L 1  formed by the first upper nozzle  412 . 
     In addition, the blade  850  may allow air around the humidification housing  800  to flow, and may atomize water sprayed from the nozzle  410  into fine particles. Water sprayed from the upper nozzles  412  and  413  may hit the blade  850  to be atomized into fine particles. The blade  850  may atomize water into a mist form. 
     The blade  850  may not atomize all water sprayed from the upper nozzles  412  and  413 . A portion of water sprayed from the upper nozzles  412  and  413  may hit the blade  850 . 
     Water sprayed from the upper nozzles  412  and  413  forms the predetermined trajectory S 3 , and the rotating blade  850  collides with water on the trajectory S 3 . That is, a portion of water sprayed from the upper nozzles  412  and  413  hits the blade  850  to be scattered, and the remaining water hits the inner surface of the visual body  210  without hitting the blade  850 . 
     Water hitting the blade  850  is widely scattered in the visual body  210 , rather than being scattered in a specific direction. For example, water scattered from the blade  850  may wet the discharge humidification medium  55 . Water scattered from the blade  850  may form water drops on the visual body  210 . Water scattered from the blade  850  may float into the water tank  300 . 
     Water atomized by the blade  850  may be effective in creating a rain view. The atomized droplets may be shown in the form of small droplets on the inner surface of the visual body  210 . 
     Further, a rain view created in the humidification passage  106  may generate negative ions by the Lenard effect. The Lenard effect refers to a phenomenon in which large amounts of negative ions are generated when water is atomized by a large external force. When the droplets are scattered and hit to create a rain view, large amounts of negative ions are generated in the process. 
     When water sprayed from the lower nozzle  411  hits a structure, negative ions may be generated by the Lenard effect. Further, when water sprayed from the upper nozzles  412  and  413  hits the visual body  210 , negative ions may be generated by the Lenard effect. Also, when water sprayed from the upper nozzles  412  and  413  hits the blade  850 , negative ions may be generated by the Lenard effect. In addition, when water is supplied from above, droplets scattered from the housing cover  860  hit various structures, negative ions may be generated by the Lenard effect. 
     As described above, in this embodiment, droplets formed in various sizes for creating a rain view may have an effect of generating negative ions. The generated negative ions may be discharged to an indoor space through the discharge passage  107 . 
     Further, a water curtain inhibiting rib  870  may be disposed in the second housing  840  to inhibit a water curtain rotating flow. The water curtain rotating flow may refer to a rotating flow along the inner surface of the humidification housing  800 . 
     As more water stays in the second housing  840 , vibrations of the humidification housing  800  may increase. Water pumped up to the second housing  840  is required to be sprayed rapidly through the upper nozzles  412  and  413 , in order to minimize eccentricity of the humidification housing  800 , and thus, to minimize vibrations thereof. 
     The water curtain inhibiting rib  870  may protrude from an inner surface of the second housing  840 . In this embodiment, the water curtain inhibiting rib  870  protrudes toward the power transmission shaft  640 . The water curtain inhibiting rib  870  is formed in a direction intersecting the water curtain rotating flow. 
     The power transmission unit  880  transmits torque of the power transmission shaft  640  to the humidification housing  800 . In this embodiment, the power transmission unit  880  is connected to the second housing  840 . Alternatively, the power transmission unit  880  may be connected to the first housing  820 . 
     In this embodiment, the power transmission unit  880  is integrally formed with the second housing  840 . Alternatively, the power transmission unit  880  may be manufactured separately from the second housing  840 , and then may be assembled thereto. 
     The power transmission unit  880  may include a bushing installation part or portion  882  located at an axial center of the humidification housing  800 , and a connection part or portion (connector)  884  that connects the bushing installation portion  882  and the housing  800 . In this embodiment, the bushing installation portion  882 , the connection portion  884 , and the second housing  820  may be integrally formed by injection-molding, for example. 
     The connection portion  884  may be formed in a rib shape. The connection portion  884  may be disposed radially about the axial center, and a plurality may be provided. 
     In this embodiment, the connection portion  884  is integrally formed with the water curtain inhibiting rib  870 . The connection portion  884  and the water curtain inhibiting rib  870  are connected to each other. 
     The power transmission shaft  640  may be installed so as to penetrate the bushing installation portion  882 . The bushing installation portion  882  may have an open lower side. A bushing  90  may be inserted through an open lower side of the bushing installation portion  882 . 
     The bushing installation portion  882  and the bushing  90  may be separated from each other in a vertical direction. The bushing installation portion  882  and the bushing  90  may be engaged with each other in a rotational direction. 
     A bushing engaging portion  93  may be formed on any one of the bushing installation portion  882  and the bushing  90 , and a bushing engaging groove  883  may be formed on the other one thereof. In this embodiment, the bushing engaging portion  93  may be formed on the bushing  90 , and the bushing engaging groove  883  may be formed on the bushing installation portion  882 . 
     The bushing engaging groove  883  may be formed on the inner surface of the bushing installation part  882  and have a concave shape. The bushing engaging portion  93  may be formed on an outer surface of the bushing  90  and have a convex shape. The busing engaging portion  93  may be inserted and fitted into the bushing engaging groove  882 . 
     Alternatively, the bushing installation portion  882  and the bushing  90  may be integrally formed with each other. The bushing  90  may be formed of a metallic material, such that by placing the bushing  90  in the mold when the second housing  840  is manufactured, the bushing  90  may be integrally formed by injection-molding a material of the second housing  840 . 
     The bushing  90  may be coupled to the power transmission shaft  640  of the power transmission assembly  600 . The bushing  90  may be coupled to the power transmission shaft  640  to receive torque. The bushing  90  may be formed of a metallic material. If the bushing  90  is not formed of a rigid metallic material, abrasion may occur, which causes vibrations. 
     The bushing  90  may have a bushing axis hollow that passes through the bushing  90  in a vertical direction. The power transmission shaft  640  may be inserted into the bushing axis hollow. 
     The bushing  90  may reduce vibrations occurring when the humidification housing  800  rotates. The bushing  90  may be located on the power transmission shaft  640 . In this embodiment, the bushing  90  may be located at a center of gravity of the humidification housing  800 . As the bushing  90  is located at the center of gravity of the humidification housing  800 , the bushing  90  may significantly reduce the vibrations of the humidification housing  800  during rotation. 
     The bushing  90  and the power transmission shaft  640  are assembled with each other through fitting. The bushing  90  is supported by the power transmission shaft  640 . 
     In order to support the bushing  90 , the power transmission shaft  640  may include a shaft support end  642 . A diameter at an upper side of the power transmission shaft  640  may be smaller than a diameter at a lower side based on the shaft support end  642 . 
     The bushing  90  may be inserted onto the upper end of the power transmission shaft  640 . In order to minimize abrasion, the shaft support end  642  may be formed in a tapered, chamfered, or rounded shape. When the shaft support end  642  has a right-angled shape, abrasion may occur during an assembly process or operation process. 
     When the shaft support end  642  is abraded, the bushing  90  may be moved, which causes vibrations. Also, when the shaft support end  642  is abraded, the bushing  90  may be inclined or moved, such that misalignment with the power transmission shaft  640  may occur. In addition, when misalignment between the bushing  90  and the power transmission shaft  640  occurs, eccentricity may occur during rotation, thereby causing vibrations. 
       FIG. 13  is a perspective view of a housing cover illustrated in  FIG. 6 .  FIG. 14  is a perspective view of a lower surface of the housing cover of  FIG. 13 .  FIG. 15  is a front cross-sectional view of the lower surface of the housing cover of  FIG. 13 .  FIG. 16  is a partial cross-sectional view of an upper side of a humidification housing, illustrating an arrangement of nozzles and a housing cover.  FIG. 17  is a magnified cross-sectional view of a first upper nozzle illustrated in  FIG. 16 .  FIG. 18  is a magnified cross-sectional view of a second upper nozzle illustrated in  FIG. 16 . 
     Referring to  FIGS. 13 to 18 , the housing cover will be described hereinafter. 
     The housing cover  860  may be coupled to an upper side of the second housing  840  and seal the upper side of the second housing  86 . In this embodiment, the housing cover  860  may be coupled to the second housing  840  by screw coupling. 
     The housing cover  860  is assembled with the power transmission assembly  600 . Alternatively, the housing cover  860  may be separated from the power transmission assembly  600 . 
     When the housing cover  860  is coupled to the power transmission shaft  640 , eccentricity and vibration of the humidification housing  800  may be reduced more effectively. 
     The housing cover  860  may include a top wall  862  that covers an upper opening of the second housing  840 ; a side wall  863  that extends downwardly from the top wall  862  and covers an upper end of the second housing  840 ; an inner rib  864  disposed under the top wall  862  and spaced apart from the side wall  863  by a predetermined distance; a shaft fixing part or portion  866  disposed under the top wall  862  and fixed to the power transmission shaft  640 ; a reinforcing rib  868  that connects the shaft fixing portion  866  and the inner rib  864 ; and a shield  890  that extends downwardly from the side wall  863  and spaced apart from the outer surface of the second housing  840 . 
     When viewed from the top, the top wall  862  may have a circular shape. A diameter of the top wall  862  may be greater than a diameter of the second housing  840 . 
     Alternatively, it is also possible that the top wall  862  has a shape other than the circular shape, when viewed in a top plan view. Also, the humidification housing  800  is not limited to a specific shape, when viewed in top plan view. 
     The side wall  863  may form an edge of the top wall  862 . The side wall  863  may extend downwardly from the edge of the top wall  862 . 
     The side wall  863  may have a ring shape and be integrally formed with the top wall  862 . The side wall  863  may have a plurality of protrusions  861  formed on an outer surface thereof, and the protrusions  861  may be formed in a circumferential direction of 360 degrees. The protrusions  861  may provide a grip feeling for a user when the housing cover  860  is separated. 
     Further, the protrusions  861  may effectively scatter water when supplied from above. Water supplied from above falls down to the housing cover  860  and flows to the side wall  863  by rotation of the humidification housing  800 . Then, water may be separated from the protrusions  861  in the form of water drops, to be scattered to the inner surface of the visual body  210 . The protrusions  861  may effectively scatter water supplied from above. 
     The inner rib  864  may be located inside of the side wall  863  and spaced apart from the side wall  863  by a predetermined distance. A second packing  865  may be disposed between the side wall  863  and the inner rib  864 . When viewed from the bottom, the inner rib  864  may be formed in a ring shape and spaced apart from the inner surface of the side wall  863 , and form a packing installation space which is downwardly open. The second packing  865  may be installed in the packing installation space. 
     The second packing  865  may seal a space between the housing cover  860  and the second housing  840 . The first packing  825  and the second packing  865  may prevent leakage of water of the housing space  805 , and pressure of water discharged from the nozzle  410  may be maintained constant. 
     If water leaks between the first housing  820  and the second housing  840  or between the second housing  840  and the housing cover  860 , there is difficulty in maintaining a constant pressure of water discharged from the nozzle  410  and in providing the spray line in the form of a continuous water stream. That is, when water leakage occurs in the humidification housing  800 , water may not be sprayed from the nozzle  410  even by rotation of the humidification housing  800 . 
     The side wall  863  and the second housing  840  may be screw-coupled. In this embodiment, the housing cover  860  and the second housing  840  may be coupled to each other by forced fitting. The housing cover  860  and the power transmission shaft  640  may be maintained in a coupled state, such that even when the humidification housing  800  rotates, the housing cover  860  and the second housing  840  may be maintained in a coupled state. 
     The shaft fixing portion  866  may be assembled with the power transmission shaft  640  and receive torque from the power transmission shaft  640 . The shaft fixing portion  866  and the power transmission shaft  640  may be screw-coupled to each other. A screw thread  643  for screw coupling with the housing cover  860  may be formed on an outer circumferential surface of an upper end of the power transmission shaft  640 . 
     A screw thread  843  for assembling with the power transmission shaft  640  may be formed on the shaft fixing portion  866 . In this embodiment, a shaft fixing member  867  may be disposed on the shaft fixing portion  866 , and the shaft fixing member  867  may be integrally formed with the shaft fixing portion  866  by double injection-molding. In this embodiment, a nut may be used for the shaft fixing member  867 . 
     Unlike the housing cover  860 , the shaft fixing member  867  may be formed of a metallic material. As the power transmission shaft  640  is formed of a metallic material, a portion screw-coupled to the power transmission shaft  640  also needs to be made of a metallic material to prevent abrasion or damage during coupling. 
     When the entire housing cover  860  is formed of a metallic material, or when the shaft fixing portion  866  is formed of a metallic material, a screw thread may be formed on the shaft fixing portion  866  itself. 
     The housing cover  860  may have a diameter greater than a diameter of the second housing  840 . When viewed from the top, only the housing cover  860  may be exposed, without exposing the second housing  840  and the first housing  820 . 
     Accordingly, a portion of water supplied to the water supply passage  109  may fall down to the housing cover  860 . When the humidification housing  800  rotates, the water falling down to the housing cover  860  may be sprayed outwardly in a radial direction from the surface of the housing cover  860 . 
     The housing cover  860  which rotates may spray the supplied water in a rotational direction and may produce an effect as if water drops from an umbrella. More particularly, drops of water may be separated from the plurality of protrusions  861  disposed in a circumferential direction of the housing cover  860 . The droplets scattered in the rotational direction of the housing cover  860  may collide with the inner surface of the visual body  210 , thereby creating a rain view. 
     The shield  890  serves to prevent water, sprayed from the upper nozzles  412  and  413 , from being sprayed or scattered beyond the upper nozzles  412  and  413 . The shield  890  may extend outwardly in a radial direction from the side wall  863  and be spaced apart from an outer surface of the second housing  840 . The shield  890  may be disposed outside of an upper opening of the humidification housing  800 . 
     With respect to the power transmission shaft  640 , the shield  890  include a shield portion  892 , which protrudes outwardly in a radial direction from the side wall  863  and is inclined downwardly, and a scatter portion  894  which protrudes outwardly in a radial direction from the shield portion  892 . In this embodiment, the first upper nozzle  412  and the second upper nozzle  413  have different heights, such that relative heights of the shield portion  892  and the upper nozzles  412  and  413  may be different from each other. 
     The shield portion  892  may be inclined downwardly and spaced apart from the outer surface of the second housing  840 . An upper end of the shield portion  892  may be connected to a lower end of the side wall  863 , and a lower end of the shield portion  892  may be spaced apart from the side wall  863 . A horizontal section of the shield portion  892  may have a ring shape and a diameter which increases from an upper side toward a lower side. 
     An outer surface  891  and an inner surface  893  of the shield portion  892  may form an inclined surface. The outer surface  891  may be formed as an inclined surface facing outwardly and downwardly in a radial direction. The outer surface  891  may form a predetermined included angle A with the scatter portion  894 . The included angle A between the outer surface  891  and the scatter portion  894  may be greater than 90 degrees and less than 180 degrees. Water may be guided to the scatter portion  894  along the outer surface  891 . In this embodiment, the included angle A is 115 degrees. 
     Unlike the outer surface  891 , the inner surface  893  may form a rounded surface. A center of curvature of the rounded surface may be located toward the inside of the humidification housing  800 . An upper end of the rounded surface may be disposed lower than an upper end of the inclined surface, and a lower end of the rounded surface may be disposed lower than a lower end of the inclined surface. The lower end of the rounded surface may be connected to a lower surface of the scatter portion  894 . 
     The inner surface  893  may be formed as a groove being recessed upwardly from the bottom side. The inner surface  893  may be open downwardly and toward the center of the humidification housing  800 . 
     The scatter portion  894  may extend in a lateral direction, in this embodiment horizontally. The scatter portion  894  may protrude outwardly in a radial direction from the shield portion  892 . When viewed from the top, the scatter portion  894  may have a ring shape and be disposed radially outside of the shield portion  892 . 
     A lower surface  894   b  of the scatter portion  894  may be connected to a lower end of the inner surface  893 . An upper surface  894   a  of the scatter portion  894  may be connected to a lower end of the outer surface  891 . The included angle A may be formed between the upper surface  894   a  of the scatter portion  894  and the outer surface  891 . 
     An outer surface  894   c  of the scatter portion  894  may be formed to extend in the upward-downward or vertical direction, and in this embodiment is formed in the vertical direction. The outer surface  894   c  of the scatter portion  894  may connect the upper surface  894   a  and the lower surface  894   b.    
     In this embodiment, a protruding length of the scatter portion  894  is 1.5 mm. More specifically, a protruding length of the upper surface  894   a  is 1.5 mm, and a protruding length of the lower surface  894   b  may be longer than that of the upper surface  894   a.  The protruding length of the outer surface  894   c  is 1.5 mm, which is equal to the protruding length of the upper surface  894   a.    
     In this embodiment, by minimizing a vertical length of the outer surface  894   c,  a width of the scattered droplets may be minimized. As the protruding length of the scatter portion  894  increases, deformation may occur during rotation, and vibrations may also increase. More particularly, the shield  890  collides with water sprayed from the upper nozzle, such that it is important to minimize vibrations by minimizing the protruding length of the scatter portion  894 . 
     The shield  892  prevents spray lines S 3  and S 4  from being sprayed upward at a predetermined angle or more. A spray angle of the spray lines S 3  and S 4  may be slightly changed according to a rotational speed of the humidification housing  800 . For example, the spray lines S 3  and S 4  may be sprayed more horizontally when the humidification housing  800  rotates at a high speed, compared to a case in which the humidification housing  800  rotates at a low speed. Further, when the air blower unit  20  generates a strong air flow, the spray lines  3  and S 4  may be changed to be directed upward by the pressure of air flowing from the lower side toward the upper side. 
     In this embodiment, the shield portions  892  are disposed at a same height, and the first upper nozzle  412  and the second upper nozzle  413  are disposed at different heights. Accordingly, a relative height between the shield  890  and the first upper nozzle  412  is different from a relative height between the shield  890  and the second upper nozzle  413 . 
     In this embodiment, the first upper nozzle  412  is disposed at the same height as or below the shield portion  892 , and the second upper nozzle  413  is disposed above the shield portion  892 . In this embodiment, the first upper nozzle  412  is disposed at the same height as or below the scatter portion  894 , and the second upper nozzle  413  is disposed above the scatter portion  894 . 
     A correlation between the shield  890  and the first upper nozzle  412  will be described hereinafter. 
     The scatter portion  894  of the shield  890  may be disposed at a same height as or above the first upper nozzle  412 . The first upper nozzle  412  may be disposed below the side wall  863 . The first upper nozzle  412  may be disposed inside of the shield portion  892 . In this embodiment, the height of the scatter portion  894  and the height of the first upper nozzle  412  may overlap each other. 
     More specifically, the lower surface  894   b  may be located within the height of the first upper nozzle  412 . The lower surface  894   b  may be disposed at the same height as that of the first upper nozzle  412 , such that exposure of the first upper nozzle  412  may be minimized when seen from a user&#39;s point of view. That is, the shield  890  has an effect of hiding the first upper nozzle  412 . 
     Water sprayed from the first upper nozzle  412  forms the spray line S 3 , comes into contact with the shield  890 , and is sprayed to the inner surface of the visual body  210 . The water forming the spray line S 3  forms a parabola which opens downwards due to self-weight of the water, such that even when the scatter portion  894  of the shield  890  and the first upper nozzle  412  are disposed at the same height, they may not come into contact with each other. 
     A correlation between the shield  890  and the second upper nozzle  413  will be described hereinafter. 
     The second upper nozzle  413  may be disposed at a level higher than the first upper nozzle  412 . The second upper nozzle  413  and the first upper nozzle  412  may be disposed on opposite sides with respect to the power transmission shaft  640 . The second upper nozzle  413  may be disposed inside of the side wall  863 . The side wall  863  and the second upper nozzle  413  may face each other and be spaced apart from each other by a predetermined distance in a horizontal direction. The second upper nozzle  413  may be completely hidden by the housing cover  860 . 
     Water, sprayed from the second upper nozzle  413 , may be discharged outside of the second housing  840  through the space between the second upper nozzle  413  and the side wall  863 . Water discharged through the second upper nozzle  413  may be discharged between the shield  980  and the outer surface of the second housing  840 , and then may immediately fall down into the water tank  300 . In this case, the scattered water may wet the water tank humidification medium  51 . In addition, water discharged through the second upper nozzle  413  may move along the inner surface  893  of the shield  890 . 
     A space between the inner rib  864  and the side wall  863  may be greater than a thickness of the second housing  840 , such that a predetermined gap is formed between the second housing  840  and the side wall  863 . The gap may be downwardly open. 
     The inner surface of the second housing  840  may be closely adhered to an outer surface of the inner rib  864 . The upper end of the second housing  840  may be disposed above a lower end of the inner rib  864 . Accordingly, water sprayed through the second upper nozzle  413  may be sprayed downwardly through the gap between the outer surface of the second housing  840  and the inner surface of the side wall  863 . In this case, water sprayed through the gap flows outwardly in a radial direction along the shield portion  892  due to surface tension and centrifugal force occurring during rotation of the humidification housing  800 . 
     More specifically, water sprayed from the second upper nozzle  413  flows outwardly in a radial direction along the inner surface  893  of the shield portion  892 , and then are formed as droplets on the scatter portion  894 . Then, the water is scattered outwardly in a radial direction from the scatter portion  894  by the centrifugal force occurring during rotation of the humidification housing  800 . By minimizing a length of the outer surface  894   c  of the scatter portion  894 , a scattering range of the scattered droplets may be minimized. 
     That is, by adjusting the length of the outer surface  894   c  of the scatter portion  894 , a spray range of the spray line S 4  may be minimized. By minimizing a scattering range of droplets according to the spray line S 4 , it is possible to minimize droplets scattered to the upper side of the housing cover  860  and to prevent droplets from being directly scattered to the grill discharge port  231  by wind velocity of the air blower unit  20 . 
     If the droplets pass through the grill discharge port  231  along with air discharged upward, a problem occurs in that the droplets may be scattered into the indoor space. By minimizing a thickness (length of the outer surface) of the scatter portion  894  of the housing cover  860  according to this embodiment, a problem of the scattered droplets, which is caused by strong airflow generated by the air blower unit  20 , may be solved easily. 
     In addition, a space is formed inside of the inner surface  893  of the shield portion  892 , such that a predetermined amount of water may be temporarily stored during rotation of the humidification housing  800 , and scattering of water sprayed from the second upper nozzle  413  may be delayed by a predetermined period of time. More particularly, an upper end of the inner surface  893  may be formed in a horizontal direction, such that water sprayed from the second upper nozzle  413  may be easily guided to the inside of the shield portion  892 . Further, a lower end of the inner surface  893  may be directed downward in a vertical direction, thereby allowing a portion of water flowing into the inside of the shield portion  892  to vertically fall down. 
     If a centrifugal force is greater than a force in the direction of gravity, water flows to the scatter portion  894 , but if a force in the direction of gravity is greater than a centrifugal force, water may fall downwardly from the inner surface  893 . 
       FIG. 19  is an exemplary view of a trajectory of water sprayed through a first upper nozzle.  FIG. 20  is an exemplary view of a trajectory of water sprayed through a second upper nozzle. 
     A rain view created in the air humidification module  200  will be described hereinafter. 
     The rain view refers to an effect that looks like raindrops falling outside a window, and an effect that appears as if raindrops are formed. In this embodiment, the rain view creates an effect that looks like raindrops falling inside the visual body  210  or an effect that appears as if raindrops are formed on the inner surface of the visual body  210 . 
     When the rain view is created, various sizes of droplets are formed. The blade  850 , the lower nozzle  411 , the first upper nozzle  412 , the second upper nozzle  413 , the housing cover  860 , the protrusions  861 , and the blower fan  24 , which generate the flow of air, may serve as a rain view creating unit for generating droplets. 
     The lower nozzle  411 , the first upper nozzle  412 , and the second nozzle  413  are used to spray water pumped by water dispensing unit  400 . The rain view may be created with water sprayed from the lower nozzle  411 , the first upper nozzle  412 , and the second upper nozzle  413 . 
     The housing cover  860  or the protrusions  861  may create a rain view by scattering water which falls when the water is supplied from above. 
     The sprayed or scattered droplets may be fragmented into smaller droplets by the air pressure or air volume generated by the blower fan  24 . The air blown by the air blower unit  20  may pass through the water tank humidification medium  51  to cause the droplets to be further broken up into fine droplets. 
     The air blown by the air blower unit  20  may cause air falling from the humidification passage  106  to be broken up into fine streams. The air blown by the air blower unit  20  moves in an opposite direction to the direction of gravity, such that the air falling due to self-weight may collide with the falling droplets to be broken into fine streams. 
     The droplets generated by the rain view creating unit may flow or float along the humidification passage  106 . Droplets in the humidification passage  106  may humidify the flowing air, or may be formed on the inner surface of the visual body  210  in the form of water drops. The water drops formed on the inner surface of the visual body  210  may move along a slope of the inner surface of the visual body  210 . 
     The visual body  210  may be inclined toward the water tank  300 . The visual body  210  may be wide at top and narrow at bottom, thereby allowing a longer stay time of droplets flowing along the visual body  210 , and a longer showing time of the rain view. In addition, the shape of the visual body  210  may inhibit the formed droplets from flowing down the slope of the visual body  210 . The droplets may be maintained on the visual body  210  by surface tension of the droplets. In addition, the air flow generated by the air blower unit  20  may inhibit droplets from flowing downward. 
     Further, the inner surface of the visual body  210  may be coated with a water repellent. Wide spreading of the droplets and formation droplets in a more circular shape may be prevented by the water repellent coating. 
     When water drops are formed on the visual body  210 , the water drops formed on the visual body  210  may be projected onto or reflected from the surface of the display  160 . When the water drops formed on the visual body  210  flow down, the same effect is also shown on the display  160 . 
     Actual droplets may move from an upper side to a lower side and from an outer side to an inner side along the slope of the visual body  210 . Droplets reflected from the surface of the display  160  may move from a lower side to an upper side and from an outer side to an inner side in opposition to the slope of the display  160 . Accordingly, at a boundary where the visual body  210  meets the display  160 , actual droplets may join reflected droplets. This joining may allow a user to recognize a rain view more effectively. 
       FIG. 21  is a front cross-sectional view of a humidification housing according to another embodiment. In the humidification housing  800  according to this embodiment, the first upper nozzle  412  and the second upper nozzle  413 ′ are disposed at a same height, and a portion of the side wall forming the housing cover  1860  extends downwardly to cover the second upper nozzle  413 ′. 
     In this embodiment, as seen in the front cross-sectional view, the housing cover  1860  is bilaterally asymmetrical. Accordingly, a correlation between the first upper nozzle  412  and the shield  890  in this embodiment is the same as the correlation of the previous embodiment. Further, a correlation between the second upper nozzle  413 ′ and a shield  1890  is also the same as the correlation of the previous embodiment. 
     However, as the first upper nozzle  412  and the second upper nozzle  413 ′ are disposed at the same height, the shield  1890  covering the second upper nozzle  413 ′ is disposed below the shield  890  disposed at the first upper nozzle  412 . 
     In this embodiment, a side wall  1863  that covers the second upper nozzle  413 ′ extends downwardly further than the side wall  863  disposed outside of the first upper nozzle  412 . Accordingly, when viewed from the side, the shield  1890  disposed outside of the second upper nozzle  413 ′ is disposed below the shield  890  disposed outside of the first upper nozzle  412 . 
     Other components of this embodiment are the same as those of the previous embodiment, and thus, detailed description thereof has been omitted. 
     The humidification and air cleaning apparatus according to embodiments has at least one or more of the following advantages. 
     Firstly, the shield disposed at the housing cover may prevent water, discharged from the upper nozzle, from being scattered upward, thereby preventing droplets from being scattered to the discharge port which is open to the upper side of the water tank. Secondly, as an included angle is formed between the shield portion and the scatter portion of the shield, water may easily flow to the scatter portion. 
     Thirdly, even when the air blower unit rotates at a high speed generating a strong air flow, droplets may be scattered to the visual body without being directly moved to the discharge port, through which the droplets scattered from the scatter portion are discharged. 
     Fourthly, the first upper nozzle may be disposed below the second upper nozzle, and the shield may be disposed below the second upper nozzle, such that any one of the spray lines may be scattered with a predetermined width, and a height of the scattered water may be lower than the nozzle. Fifthly, the first upper nozzle and the second upper nozzle may be disposed at the same height, and the shield may be disposed below the second upper nozzle, such that a spray line discharged from the second upper nozzle may be scattered with a predetermined width, and a height of the scattered water may be lower than the nozzle. Sixthly, the side wall may be disposed outside of the second upper nozzle to cover the second upper nozzle, and the side wall and the second upper nozzle may be spaced apart from each other by a predetermined distance, such that the discharged water may be changed into droplets. 
     Seventhly, the shield may be disposed below the second upper nozzle, such that water discharged from the second upper nozzle may be changed into droplets at the shield. Eighthly, the shield may be disposed at the same height as or above the first upper nozzle and may be disposed below the second upper nozzle, such that a spray line sprayed from the first upper nozzle hits the visual body in the form of a water stream, and the spray line sprayed from the second upper nozzle is changed into droplets, to be scattered with a predetermined width. 
     Ninthly, the scatter portion protrudes outwardly in a radial direction from the lower end of the shield portion, such that a width of the spray line may be minimized. Tenthly, the scatter portion is disposed below the second upper nozzle, such that a spray direction of the spray line, being changed into droplets, may be guided downwardly, thereby preventing droplets from being directly moved to the discharge port. Eleventhly, the scatter portion is disposed at the same height as or above the first upper nozzle, such that the first upper nozzle, forming the spray line in the form of a water stream, may be hidden. 
     Embodiments disclosed herein provide a humidification and air cleaning apparatus capable of minimizing scattering of water, sprayed from a humidification housing, to a discharge port disposed at an upper side thereof. Embodiments disclosed herein further provide a humidification and air cleaning apparatus capable of preventing water, sprayed from the housing assembly, from being scattered upward. Embodiments disclosed herein furthermore provide a humidification and air cleaning apparatus, in which when the sprayed water is scattered from the surface of the humidification housing, an area of the scattered water may be narrow in width. 
     The advantages of embodiments are not limited to the aforementioned advantages and other advantages not described herein will be clearly understood by those skilled in the art from the description. 
     A shield disposed at the housing cover prevents water, discharged from an upper nozzle, from being scattered upward, thereby preventing droplets from being scattered to a discharge port which is open to the upper side of a water tank. An included angle is formed between a shield portion and a scatter portion of the shield, such that water may easily flow to the scatter portion. Even when an air blower unit rotates at a high speed generating a strong air flow, droplets may be scattered to a visual body without being directly moved to the discharge port, through which the droplets scattered from the scatter portion are discharged. 
     Embodiments disclosed herein provide a humidification and air cleaning apparatus that may include a housing having an upper opening and a lower opening; a first upper nozzle passing through an inside and an outside of the housing; a second upper nozzle passing through the inside and outside of the housing; a housing cover closing an upper surface of the housing; and a shield disposed at an outer edge of the housing and spaced apart from an outer surface of the housing. The shield may be disposed below either the first upper nozzle or the second upper nozzle. 
     The first upper nozzle may be disposed below the second upper nozzle, and the shield may be disposed below the second upper nozzle, such that any one of spray lines may be scattered with a predetermined width, and the height of the scattered water may be lower than the nozzle. The first upper nozzle and the second upper nozzle may be disposed at the same height, and the shield may be disposed below the second upper nozzle, such that a spray line discharged from the second upper nozzle may be scattered with a predetermined width, and the height of the scattered water may be lower than the nozzle. 
     The housing cover may include a top wall that covers the upper opening of the housing, and a side wall that extends downwardly from the top wall and covering an upper end of the housing. The shield may extend downwardly from a lower end of the side wall. 
     The side wall may be disposed outside of the second upper nozzle to cover the second upper nozzle, and the side wall and the second upper nozzle may be spaced apart from each other by a predetermined distance, such that discharged water may be changed into droplets. The shield may be disposed below the second upper nozzle, such that water discharged from the second upper nozzle may be changed into droplets at the shield. 
     The shield may be disposed at the same height as or above the first upper nozzle, and may be disposed below the second upper nozzle, such that a spray line, sprayed from the first upper nozzle, may hit a visual body in the form of a water stream, and a spray line, sprayed from the second upper nozzle, may be changed into droplets to be scattered with a predetermined width. 
     The humidification and air cleaning apparatus may further include an inner rib disposed under the top wall and spaced apart from the side wall by a predetermined distance. The upper end of the housing may be disposed between the inner rib and the side wall. The second upper nozzle may be disposed between a lower end of the inner rib and an upper end of the shield, such that a discharge pressure of water to be supplied to the second upper nozzle may be easily achieved. 
     The shield may include a shield portion spaced apart from the outer surface of the housing; and a scatter portion that protrudes outwardly in a radial direction from the shield portion. With respect to a rotational axis of the housing, the shield portion may protrude outwardly in a radial direction from the side wall and may be inclined downwardly. 
     The scatter portion may protrude outwardly in a radial direction from a lower end of the shield portion, such that a width of the spray line may be minimized. The scatter portion may be disposed below the second upper nozzle, such that a spray direction of the spray line, being changed into droplets, may be guided downwardly, thereby preventing the droplets from being directly moved to the discharge port. 
     The scatter portion may be disposed at the same height as or above the first upper nozzle, such that the first upper nozzle, forming the spray line in the form of a water stream, may be hidden. An outer surface of the shield portion and the scatter portion may form an included angle of greater than 90 degrees and less than 180 degrees. 
     An inner surface of the shield portion may be open downwardly and toward the rotational axis, such that water supplied to the shield portion may be temporarily stored. The inner surface of the shield portion may have a rounded shape which is recessed upwardly from a bottom side. 
     While embodiments have been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that embodiments are not limited to those exemplary embodiments and various changes in form and details may be made therein without departing from the scope and spirit as defined by the appended claims and should not be individually understood from the technical spirit or prospect. 
     It will be understood that when an element or layer is referred to as being “on” another element or layer, the element or layer can be directly on another element or layer or intervening elements or layers. In contrast, when an element is referred to as being “directly on” another element or layer, there are no intervening elements or layers present. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. 
     It will be understood that, although the terms first, second, third, etc., may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another region, layer or section. Thus, a first element, component, region, layer or section could be termed a second element, component, region, layer or section without departing from the teachings of the present invention. 
     Spatially relative terms, such as “lower”, “upper” and the like, may be used herein for ease of description to describe the relationship of one element or feature to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation, in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “lower” relative to other elements or features would then be oriented “upper” relative to the other elements or features. Thus, the exemplary term “lower” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. 
     Embodiments are described herein with reference to cross-section illustrations that are schematic illustrations of idealized embodiments (and intermediate structures). As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, embodiments should not be construed as limited to the particular shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. 
     Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which embodiments belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. 
     Any reference in this specification to “one embodiment,” “an embodiment,” “example embodiment,” etc., means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with any embodiment, it is submitted that it is within the purview of one skilled in the art to effect such feature, structure, or characteristic in connection with other ones of the embodiments. 
     Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.