HOME APPLIANCES

Proposed is a home appliance in which each of air inlets and each of air outlets formed on a machine room cover are configured to have flow rates different from each other. Accordingly, a design for the volume of air introduced into a machine room and the volume of air discharged to the outside of the machine room from the inside thereof may be facilitated.

TECHNICAL FIELD

The present disclosure relates to a home appliance having a new type of machine room in which heat dissipation performance can be improved for reduction of power consumption.

BACKGROUND ART

In general, a home appliance refers to an appliance that uses electricity.

As such a home appliance, various apparatuses are provided in which cold air is generated by using the circulation of a refrigerant according to a cooling cycle so as to be used. In this case, the apparatuses may, for example, include a refrigerator, cooling or heating equipment, air conditioner, and air purifier, etc.

A home appliance having the cooling cycle described above is provided with a machine room for installing at least one of a compressor and a condenser.

The machine room is usually located at the rear of a bottom inside an appliance body constituting a home appliance, and is configured to be open at the rear surface of the machine room. In this case, a machine room cover is installed on the open rear surface of the machine room so as to selectively open the inside of the machine room.

In addition, an inlet and an outlet for introducing air into or discharging air from the associated machine room are formed on each wall surface of the machine room (opposite wall surfaces, a bottom surface, and the machine room cover). Accordingly, air circulation is repeated in such a manner that indoor air is introduced into the machine room through the inlet, passes sequentially through the condenser and the compressor to dissipate heat, and then is discharged through the outlet to an indoor space.

Meanwhile, recently, various efforts have been made to reduce power consumption by improving the performance of a home appliance.

For example, heat dissipation performance of the inside of the machine room is improved such that the performance of each of a compressor and a condenser located inside the machine room can be improved.

This is disclosed in Korean Patent Application Publication No. 10-2000-0033353, Korean Patent Application Publication No. 10-2000-0033742, and Korean Patent Application Publication No. 10-2009-0129033.

In a heat dissipation structure for a machine room of each of the prior arts as described above, an air flow is improved so as to improve the heat dissipation performance of the structure.

However, in the case of the above-described prior arts, there is a limit in improving heat dissipation because only a structure for improving air flow is provided, but a design that considers air inflow or outflow volume into the machine room is not made.

For example, in the case of the prior arts, an air inlet and an air outlet formed on a machine room cover are configured to have the shame shapes.

However, considering that air introduced into the air inlet contains a large amount of foreign matter, the air inlet is gradually blocked by such foreign matter, and thus there is a problem in that air inflow flow rate is insufficient.

In addition, in the case of the prior arts, air introduced through an air inlet into a machine room receives flow resistance due to each structure while flowing in the machine room, and thus not all of the introduced air is discharged through an air outlet to the outside of the machine room.

Furthermore, in the case of the prior arts, there were no attempts to reduce a back flow in which high-temperature air discharged to the outside of the machine room is reintroduced into the machine room, and thus it is very difficult to improve heat dissipation performance due to the back flow.

DISCLOSURE OF INVENTION

Technical Problem

The present disclosure has been made to solve various problems occurring in the related art described above, and the present disclosure is intended to improve the heat dissipation performance of the inside of the machine room by reducing a back flow in which high-temperature air discharged to an indoor space after flowing in the machine room is reintroduced directly into the machine room.

Furthermore, the present disclosure is intended to allow air introduced into the machine room to be sufficiently discharged therefrom so as to increase effective air volume, thereby improving heat dissipation performance and reducing power consumption.

Solution to Problem

In order to achieve the above objectives, according to the home appliance of the present disclosure, a machine room cover may include a plurality of air inlets through which air is introduced thereinto, and a plurality of air outlets through which air is discharged therefrom.

According to the home appliance of the present disclosure, each of the air inlets and each of the air outlets formed on the machine room cover may be configured to have flow rates different from each other.

According to the home appliance of the present disclosure, at least any one of the air inlet and the air outlet may be configured as a hole formed through the machine room cover perpendicularly thereto.

According to the home appliance of the present disclosure, at least any one of the air inlet and the air outlet may be configured as a bent louver structure to guide the flow direction of air.

According to the home appliance of the present disclosure, any one of the air inlet and the air outlet may be configured as a hole formed through the machine room cover perpendicularly thereto.

According to the home appliance of the present disclosure, the remaining one of the air inlet and the air outlet may be configured as a bent louver structure to guide the flow direction of air.

According to the home appliance of the present disclosure, the air inlet may be configured as a hole formed through the machine room cover perpendicularly thereto.

According to the home appliance of the present disclosure, the air outlet may be configured as a bent louver structure to guide the flow direction of air.

According to the home appliance of the present disclosure, the air outlet of the louver structure may be bent such that air inside the machine room is discharged to the outside of the machine room toward a direction opposite to a side toward which the air inlet is located.

According to the home appliance of the present disclosure, the air outlet of the louver structure may be configured to protrude toward the inside of the machine room.

According to the home appliance of the present disclosure, the air outlet of the louver structure may be configured to have an introduction opening into which air flowing in the machine room is introduced.

According to the home appliance of the present disclosure, the air outlet of the louver structure may be configured to have an exit opening through which air of the inside of the machine room introduced through the introduction opening is discharged to the outside of the machine room.

According to the home appliance of the present disclosure, the air outlet of the louver structure may include a connection part connecting the introduction opening with the exit opening.

According to the home appliance of the present disclosure, at least a portion of the connection part constituting the air outlet having a louver structure may be configured to be round.

According to the home appliance of the present disclosure, the air inlet may be configured to have a larger open area than the air outlet.

According to the home appliance of the present disclosure, the air inlet and the air outlet may be configured to have open areas having sizes different from each other.

According to the home appliance of the present disclosure, the air inlet may be configured to have a larger flow rate than the air outlet.

According to the home appliance of the present disclosure, the air outlet may be configured such that air discharged to the outside of the machine room flows toward a side opposite to a direction in which the air inlet is formed.

According to the home appliance of the present disclosure, each of at least some air outlets of the air outlets may be configured as a bent louver structure to guide the flow direction of air.

According to the home appliance of the present disclosure, each of at least some air outlets of each of the air outlets may be configured as a hole formed through the machine room cover perpendicularly thereto.

According to the home appliance of the present disclosure, the air outlet having the louver structure may be located to be more adjacent to the air inlet than the hole-shaped air outlet.

According the home appliance of the present disclosure, the sum of open areas provided by all of the air outlets of the machine room cover may be larger than the sum of open areas provided by all of the air inlets of the machine room cover.

According the home appliance of the present disclosure, each of the air inlets and each of the air outlets may be configured to have shapes different from each other.

Advantageous Effects of Invention

As described above, the home appliance of the present disclosure may have the following effects.

According to the home appliance of the present disclosure, each of the air inlets and each of the air outlets formed on the machine room cover may be configured to have flow rates different from each other, thereby facilitating design for the volume of air introduced into the machine room and the volume of air discharged to the outside of the machine room from the inside thereof.

According to the home appliance of the present disclosure, at least any one of the air inlet and the air outlet formed on the machine room cover may be configured as a hole, thereby maximizing the amount of air flowing in the machine room.

According to the home appliance of the present disclosure, at least any one of the air inlet and the air outlet formed on the machine room cover may be configured as a louver structure so as to give directionality to the inflow or outflow of air, thereby reducing an air back flow.

According to the home appliance of the present disclosure, each of the air inlets formed on the machine room cover may be configured as a hole, and each of the air outlets may be configured as a louver structure, thereby increasing the volume of air and preventing an air back flow.

MODE FOR THE INVENTION

Prior to description, a home appliance of the present disclosure may be a product having a cooling cycle, and more specifically, a product having a structure in which some of devices constituting the cooling cycle are disposed in the machine room.

In an embodiment below, the home appliance is a refrigerator as an example, and the machine room of the home appliance is a machine room of the refrigerator as an example.

Hereinafter, the exemplary embodiment of the home appliance of the present disclosure will be described.

In the home appliance of the present disclosure, each of air inlets and each of air outlets formed on a machine room cover may be configured to have flow rates different from each other. Accordingly, effective air volume may be increased so as to improve heat dissipation performance and reduce power consumption.

This will be described in more detail with reference toFIGS.1to18hereinbelow.

FIG.1is a perspective view illustrating the front state of a home appliance according to the embodiment of the present disclosure,FIG.2is a perspective view illustrating the rear state of the home appliance according to the embodiment of the present disclosure, andFIG.3is a side sectional view illustrating the internal structure of the home appliance according to the embodiment of the present disclosure.

This will be described in more detail with reference to the illustrated contents of each drawing.

First, the home appliance (a refrigerator) according to the embodiment of the present disclosure may include an appliance body1.

The appliance body1may be a component constituting the exterior of the home appliance.

A storage compartment11may be provided in the appliance body1. The storage compartment11which is a storage space for storing items may include at least one storage compartment11provided in the appliance body1.

As illustrated inFIG.1, the storage compartment11may be opened and closed by a door1a.

Furthermore, the machine room100may be provided in the appliance body1. The machine room100may be space provided to install some devices constituting a cooling cycle.

In this case, devices constituting the cooling cycle may include at least one compressor21, a condenser22, an expander (not shown), and an evaporator23.

Such a machine room100may be configured to have space partitioned from the storage compartment11.

In addition, the machine room100may be located at the lower end of the appliance body1. More specifically, as illustrated inFIG.2, the machine room100may be located on the rear of the lower end of the appliance body1.

Of course, although not shown, the machine room100may be located on a front or side of the lower end of the appliance body1, an entire lower end thereof, or a portion of the upper end of the appliance body1.

FIG.4is a perspective view illustrating the internal structure of the machine room of the home appliance according to the embodiment of the present disclosure,FIG.5is a top plan view illustrating the internal structure of the machine room of the home appliance according to the embodiment of the present disclosure, andFIG.6is a rear view illustrating the internal structure of the machine room of the home appliance according to the embodiment of the present disclosure.

As illustrated in these drawings, at least one of the compressor21, the condenser22, and a cooling fan24may be provided in the machine room100of the home appliance according to the embodiment of the present disclosure. Specifically, the compressor21, the condenser22, and the cooling fan24may together be provided in the machine room100.

Here, the compressor21and the condenser22may be sequentially disposed in the longitudinal direction of the machine room100(in opposite-side directions when viewed from the front surface of the home appliance).

The compressor21may function to compress refrigerant of the cooling cycle, and the condenser22may function to condense refrigerant compressed by the compressor21. The cooling fan24may function to generate the flow of air outside the machine room100such that the air is heat-exchanged with the condenser while passing through the condenser.

In this case, the cooling fan24may be located between the compressor21and the condenser22and may be configured to function to lower the temperature of the compressor21while air passing through the condenser22passes through the compressor21.

Furthermore, the machine room100may include a rear surface, opposite side surfaces, and a bottom surface. In this case, the rear surface of the machine room100may be configured to be open, and the machine room cover110may be provided on the open rear surface of the machine room100. That is, the machine room cover110may substantially constitute the rear surface of the machine room100.

Furthermore, as illustrated inFIGS.4to7, a plurality of air inlets120,130, and160and a plurality of air outlets140and150may be formed on at least one wall surface of the machine room100.

The air inlets120,130, and160may be parts configured such that air of the outside (for example, an indoor space) of the machine room is introduced into the machine room100.

Air inlets120of the plurality of air inlets120,130, and160described above may be formed on any one side surface of the machine room100. That is, air outside the machine room may be introduced into the machine room100through the air inlets120formed on any one side surface of the machine room100.

In this case, any one side surface on which the air inlets120are formed may be a wall surface of a side at which the condenser22is located relative to the center of the inside of the machine room.

In addition, air inlets130of the plurality of air inlets120,130, and160may be formed on the rear surface of the machine room100. That is, the air inlets130may be formed on the machine room cover110constituting the rear surface of the machine room100, and air outside the machine room may be introduced through the air inlets130formed on this manner into the machine room100.

The air inlets130formed on the machine room cover110may be formed on a side at which the condenser22is located in the opposite side portions of the machine room cover110. Accordingly, air introduced into the machine room100through the air inlets130due to the operation of the cooling fan24may first pass through the condenser22, pass through the cooling fan24, and then may flow to the compressor21.

The air inlets160of the plurality of air inlets120,130, and160may be formed on the bottom surface of the machine room100. In this case, it may be preferable that the air inlets160are formed at a side at which the condenser22is located.

In addition, the air outlets140and150may be parts configured such that air of the inside of the machine room100is discharged to the outside of the machine room therethrough.

The air outlets140of the plurality of air outlets140and150may be formed on the bottom surface of the machine room100. That is, a plurality of air outlets140may be formed on the bottom surface of the machine room100, and air inside the machine room100may be discharged through the air outlets140formed on this manner to the outside.

In addition, the air outlets150of the plurality of air outlets140and150may be formed on the rear surface of the machine room100. That is, the air outlets150may be formed on the machine room cover110constituting the rear surface of the machine room100, and air inside the machine room100may be discharged through the air outlets150formed on this manner to the outside.

The air outlets150formed on the machine room cover110may be formed on a side at which the compressor21is located in the opposite side portions of the machine room cover110. Accordingly, air introduced into the machine room100due to the operation of the cooling fan24may sequentially pass through the condenser22, the cooling fan24, and the compressor21and then may be discharged to the outside of the machine room100.

Meanwhile, in the embodiment of the present disclosure, each of the air inlets130and each of the air outlets150formed on the machine room cover110may be configured to have flow rates different from each other.

For an example, any one of the air inlet130and the air outlet150may be configured as a hole formed through the machine room cover110perpendicularly thereto.

For example, as illustrated inFIG.8, the air inlet130may be configured as a hole. That is, a simple hole may have a larger opening and less air resistance than a non-hole shape, and thus a greater flow rate of air may be introduced and clogging caused by foreign matter may be reduced.

In this case, the hole may be a circular through hole, or may be an oval or a long slot in one direction, such as a track type. Of course, the hole may be configured as a polygonal slot or a polygonal through hole. In addition, the hole may include holes configured to form a plurality of vertical columns, or to form a plurality of horizontal rows.

For another example, any one of the air inlet130and the air outlet150may be configured as a louver structure formed by being bent from the machine room cover110.

In this case, the louver structure may be a structure configured such that the associate portion of the machine room cover110is bent by punching and pressing the machine room cover110. For example, as illustrated inFIG.7, the louver structure may be configured as a structure having a D-shaped outer surface. Due to such a louver structure, the flow direction of air passing through the associated portion may be guided.

For example, as illustrated inFIG.9, the air outlet150may be configured as a louver structure. That is, in a process in which air inside the machine room100is discharged through the air outlet150to the outside, the flow of the air may be guided in a direction other than a portion toward which the air inlet130of the machine room cover110is formed. Accordingly, a back flow in which the discharged air is reintroduced directly through the air inlet130into the machine room may be prevented or minimized.

Due to the prevention or minimization of such a back flow, air having an increased temperature while passing through the compressor21may be prevented from being reintroduced into the air inlet130, and accordingly, a heat exchange defect and the deterioration of a heat exchange performance caused by high-temperature air supplied to the condenser22may be prevented.

For another example, each of the air inlets130and each of the air outlets150formed on the machine room cover110may be configured to have shapes different from each other.

For example, any one of the air inlet130and the air outlet150may be configured as a hole formed through the machine room cover110perpendicularly thereto, and the remaining one thereof may be configured as a louver structure formed by being bent from the machine room cover110.

Here, it may be advantageous that the shape of the hole can secure the maximum flow rate of air passing through the hole, and the shape of the louver structure can guide an air flow in a desired direction.

Preferably, the air inlet130may be configured as a hole and the air outlet150may be configured as a louver structure. That is, the flow rate of air introduced into the air inlet130may be increased, and the air inlet130may be prevented from being clogged, and the reintroduction of air discharged to the outside through the air outlet150into the air inlet130may be prevented or minimized so as to improve cooling performance such that power consumption can be reduced and heat dissipation performance can be improved.

The graph ofFIG.10illustrates a power consumption reduction rate and a back flow rate according to the shapes of the air inlet130and the air outlet150. As can be seen from this, when the air inlet130of the machine room cover110is configured as a hole and the air outlet150is configured as a louver structure, power consumption and a back flow may be reduced.

In addition, as can be seen from the graph ofFIG.11, when the air inlet130of the machine room cover110is configured as a hole and the air outlet150is configured as a louver structure, a sufficient discharge area may be secured, and as can be seen from the graph ofFIG.12, the standard of noise generated during an air flow may be satisfied by a conventional structure (O/O type structure).

Particularly, as for an effective air volume excluding a backflow air volume from a total air volume flowing into the machine room100, when the air inlet130is configured as a hole and the air outlet150is configured as a louver structure, the effective air volume may have the highest rise rate. This can be seen through the graph ofFIG.13. That is, the overall effective air volume may be increased by reducing a flow resistance on an air inlet side and reducing a back flow on an air outlet side.

The air outlet150having a louver structure may include an introduction opening151into which air flowing in the machine room100is introduced.

The air outlet150of the louver structure may include an exit opening152through which air of the inside of the machine room100is discharged to the outside of the machine room100.

The air outlet150having the louver structure may include a connection part153connecting the introduction opening151with the exit opening152.

Particularly, as described above, in the case in which the air outlet150is configured as a louver structure, the connection part153of the air outlet150of the louver structure may be configured to be bent such that air inside the machine room100is discharged to the outside of the machine room100in a direction opposite to a side toward which the air inlet130is located. In this case, the bending may include inclining, at least partially rounding, or entirely rounding.

That is, air discharged to the outside of the machine room100by the guidance of the connection part153constituting the air outlet150may flow in a direction opposite to a side toward which the air inlet130is located, and thus may be prevented from mixing with air introduced into the machine room100through the air inlet130.

Of course, even if the air outlet150is not configured as a louver structure, each of the air outlets150is preferably configured to guide air flowing through the associated air outlet150such that the air flows toward a side opposite to a direction in which the air inlet130is formed.

When the air inlet130is configured as a louver structure, the air inlet130is preferably configured in a direction opposite to a portion toward which the air outlet150is formed.

In addition, the air outlet150having the louver structure may be configured to protrude toward the inside of the machine room100. Accordingly, a distance between the machine room cover110and a wall surface of an indoor space may further be secured, so the difficulty of the installation of the machine room cover or the flow resistance of air flowing between the machine room cover110and the wall surface of the indoor space may be decreased.

For another example, each of the air inlets130and each of the air outlets150may be configured to have open areas having sizes different from each other.

For example, the open area (an individual inlet area (IIA)) of the air inlet130may be formed to be larger than the open area (an individual outlet area (IOA)) of the air outlet150.

Accordingly, the clogging of the air inlet130by foreign matter such as dust contained in air introduced through the air inlet130formed on the machine room cover110may be reduced. Additionally, the amount of air introduced through the machine room cover110into the machine room may be sufficiently secured.

Here, the individual outlet area (IOA) of the air outlet150may be preset as the open area of the exit opening152. That is, the opening of a side through which the air is discharged may determine the amount of air discharged through the air outlet150.

Of course, even without increasing the individual inlet area (IIA), each of the air inlets130may be configured to have a larger flow rate than each of the air outlets150.

For example, although not shown, the air inlet may be configured to have a larger flow rate than the air outlet by additionally forming a separate guide in each of the air inlets130or by forming the shape of the air inlet130differently from the shape of the air outlet150.

Meanwhile, it may be preferable that the sum of individual outlet areas (IOA) provided by all of the air outlets150of the machine room cover110is larger than the sum of individual inlet areas (IIA) provided by all of the air inlets130of the machine room cover110.

That is, air introduced through the air inlet130into the machine room100may hit each device (for example, the compressor, the condenser, the cooling fan, and a circuit part, etc.) located inside the machine room100while passing through the inside of the machine room100, so a sufficient amount of the air may not be discharged to the outside. Accordingly, the cover total outlet area (CTOA) of the machine room cover110is preferably formed to be larger than the cover total inlet area (CTIA) of the machine room cover110such that the loss of an air outflow rate due to a dead zone can be compensated and an effective air volume can be increased.

Hereinbelow, the heat dissipation process of the machine room100of the home appliance according to the embodiment of the present disclosure described above will be described in more detail with reference toFIGS.14to16.

First, when the operating conditions of the cooling cycle provided in the home appliance are satisfied and the cooling cycle is operated, the compressor21in the machine room100may operate to circulate refrigerant.

In this case, repeated is a refrigerant flow in which refrigerant compressed by the operation of the compressor21is condensed while passing through the condenser22, continuously passes sequentially through the expander (not shown) and the evaporator23, and then is returned to the compressor21.

Furthermore, when the operation of the compressor21described above is performed, the cooling fan24inside the machine room100may also be operated and thus air suction force may be generated in space in which the air inlet130is located.

Accordingly, as illustrated inFIGS.14and15, air outside the machine room100may be introduced into the machine room100through the air inlets130formed on the machine room cover110.

Of course, air outside the machine room100may be introduced into the machine room100even through the air inlets120and160formed on other wall surfaces of the machine room100, and air introduced in this manner and air introduced through the air inlet130of the machine room cover110may be heat-exchanged with the condenser22while passing through the condenser22.

In this case, the air inlet130formed on the machine room cover110may be configured as a simple hole, and thus air outside the machine room100may efficiently pass through the air inlet130, and foreign matter contained in the air outside the machine room100may be prevented from being accumulated in the air inlet.

In addition, air heat-exchanged with the condenser22may pass through the cooling fan24and may be discharged to the compressor21to dissipate heat of the compressor21and then may be discharged to the outside of the machine room100through the air outlet150formed on the machine room cover110. Of course, the air by which the heat of the compressor is dissipated may be discharged to the outside of the machine room100even through the air outlet140formed on the bottom surface of the machine room100.

Particularly, the air outlet150of the machine room cover110may be configured as a louver structure, and thus as illustrated inFIG.16, by the guidance of the curve or inclination of the connection part153, air discharged through the air outlet150may flow toward a side opposite to a side toward which the air inlet130of the machine room cover110is located.

Accordingly, a back flow in which the discharged air is reintroduced into the air inlet130may be prevented or only minimally performed.

Furthermore, in the home appliance according to the embodiment of the present disclosure, the total outflow area (CTOA) of the machine room cover110may be larger than the total inflow area (CTIA) of the machine room cover110, and thus even if external air introduced into the machine room100has flow resistance by hitting each device while passing through the inside of the machine room100, a sufficient amount of the external air may be discharged to the outside of the machine room.

Accordingly, since the loss of an air outflow rate due to a dead zone is compensated, an effective air volume may be increased, and since the effective air volume is increased even with the same power, power consumption efficiency may be improved.

Meanwhile, all of the air outlets150formed on the machine room cover110of the present disclosure may not be required to be formed to have the same shapes.

As an example, only a portion of at least one of the air inlet130and the air outlet150may be configured as a hole and the other portion thereof may be configured as a louver structure.

More specifically, as illustrated inFIG.17, a portion151of the air outlets150may be configured as a louver structure formed by being bent from the machine room cover110, and the other portion152of the air outlets150may be configured as a hole formed through the machine room cover110perpendicularly thereto. That is, the air outlet150may be configured to have a structure in which an air outflow rate and backflow rate are simultaneously considered.

In this case, the air outlet151having the louver structure may be located to be more adjacent to the air inlet130than the hole-shaped air outlet152. That is, the air outlet151having the louver structure may be disposed at a side at which the air inlet130is formed such that an air back flow can be prevented and an air flow volume through the hole-shaped air outlet152can be secured.

In the case of the above-described structure (the air outlet is a structure in which a hole shape and a louver shape are mixed), the air inlet130may be configured as a hole formed through the machine room cover110perpendicularly thereto so as to secure the suction flow rate.

On the other hand, according to the home appliance of the present disclosure, as illustrated inFIG.18, the air inlet130formed on the machine room cover110may be configured as a louver structure, and the air outlet150may be configured to have a hole shape.

Of course, the structure may have a higher back flow rate, a lower power consumption reduction rate, and a lower effective air volume than a structure in which the air outlet150formed on the machine room cover110is configured as a louver structure and the air inlet130is configured as a hole. This is illustrated inFIGS.10and13.

As described above, according to the home appliance of the present disclosure, each of the air inlets130and each of the air outlets150formed on the machine room cover110may be configured to have flow rates different from each other, so design for the volume of air introduced into the machine room100and the volume of air discharged to the outside of the machine room100from the inside thereof may be facilitated.

Furthermore, according to the home appliance of the present disclosure, at least any one of the air inlet130and the air outlet150formed on the machine room cover110air outlet150may be configured as a hole, so the amount of air flowing in the machine room100may be maximized.

Furthermore, according to the home appliance of the present disclosure, at least any one of the air inlet130and the air outlet150formed on the machine room cover110may be configured as a louver structure so as to give directionality to the inflow or outflow of air, so an air back flow may be reduced.

Furthermore, according to the home appliance of the present disclosure, each of the air inlets130formed on the machine room cover110may be configured as a hole, and each of the air outlets150may be configured as a louver structure, so the volume of air may be increased and an air back flow may be prevented.