Patent Description:
A traditional refrigerator door body generally includes a door housing at an outer side, and a door liner at an inner side, generally a thick foamed layer is further arranged between the door housing and the door liner, and the door liner is further provided with a shelving device such as a bottle holder. Such door body is quite thick and heavy, which is difficult to open and close by a user.

With development of technologies, some composite door structures have emerged in the field of refrigerators. A chamber for storage is formed inside a door body of a refrigerator, and a secondary door is additionally arranged at a front side of the door body to open or close the chamber of the door body. For a refrigerator adopting such composite door technology, double door body layers are arranged and more articles are stored on the door body. Therefore, the door body is thicker and heavier, causing that a user has undesirable experience in opening and closing the door body, and an excessive large thickness of the door body also seriously affects the appearance aesthetics of the refrigerator. <CIT> discloses a freezer glass door comprising a frame, a glass, and a handle part. The frame is made of a rail structure with a predetermined thickness. Each segment of the frame is shaped into a long stick with an L-shaped cross section in order to obtain a rectangular shape after assembling the whole frames. The glass is made of a transparent material in order to enable users to identify the inside of the door from the outside with the naked eye. One part of the handle part is inserted into an uneven part when a curved part is cut. One or more surfaces of the handle part are attached to one side of the glass. The frame is in touch with the other side of the glass to be joined. The other side of the glass is exposed to the outside in order to widen a visual field ratio. <CIT> discloses a thermal insulating glass door including a multi-panel glass panel assembly having a non-structural, protective trim abutting the peripheral edge of the glass panel assembly and extending along the perimeter of the glass panel assembly, and a pair of hinge brackets mounted to one side of said glass panel assembly in spaced relationship, and a handle on the glass panel assembly on the free-swinging side of the door. The non-structural, protective trim, the handle and the hinge brackets are adhesively bonded to the glass panel assembly using double sided adhesive tape. <CIT> discloses a power saving refrigerator having a double-layered door being provided to attach a new heat insulating door to cover a reception part from the exterior, according to the preamble of claim <NUM>.

A purpose of the present invention is to at least overcome one of the above shortcomings existing in the prior art, and to provide a more portable and more beautiful glass door applied to a refrigerator.

Another purpose of the present invention is to provide a refrigerator using the glass door.

A further purpose of the present invention is to make a refrigerator with a composite door structure have a smaller overall thickness.

In one aspect, the present invention provides a glass door applied to a refrigerator, including:.

Optionally, the outer frame includes a vertical frame and two transverse frames that are bent and extend from two ends of the vertical frame in a length direction, so as to cover a vertical side of the glass plate body and some sections of two transverse sides connected to the vertical side.

Optionally, a section, that is not covered by the transverse frame, of one transverse side of the glass plate body includes a handle portion protruding along a vertical direction.

Optionally, a ratio of a length of each transverse frame to a length of the transverse side of the glass door body is <NUM>/<NUM> to <NUM>/<NUM>.

Optionally, the outer frame is provided with a clamping slot with an opening toward the edge of the glass plate body to fixedly clamp the edge of the glass plate body.

Optionally, the glass plate body is made of vacuum glass.

According to the invention, the refrigerator includes a refrigerator body, with a front side opened to define a first chamber; and a door body, installed on the refrigerator body to open and close the first chamber, where the door body defines a second chamber with an opened front side; and the glass door is installed on the door body to open and close the second chamber.

According to the invention, a rear wall of the door body is provided with an air supply port and an air return port that are both in communication with the first chamber and the second chamber. The rear wall is in a hollow shape, inside which a dew removal air duct in communication with the first chamber is defined. A front surface of the rear wall is backwards provided with a plurality of dew removal holes in communication with the second chamber and the dew removal air duct. The refrigerator is configured to be: in a cooling cycle mode in which air in the first chamber enters the second chamber via the air supply port and then returns to the first chamber via the air return port; or in a dew removal mode in which the air in the first chamber enters the dew removal air duct, so that part of an air flow flows to the front surface of the rear wall via the dew removal holes to remove dew formed on the front surface.

Optionally, in a direction from the air supply port to the air return port, an arrangement density of the dew removal holes is gradually reduced.

The glass door applied to a refrigerator in the present invention includes a glass plate body and an outer frame that are fixedly connected, and the outer frame is hinged to other members (for example, a refrigerator body or a door body) of the refrigerator. In comparison with a traditional door body, the glass door is thinner, and more beautiful in appearance. In addition, according to the present invention, the outer frame is not a complete square frame, but is of a half-frame structure that covers only part of the edge of the glass plate body. On the premise of guaranteeing a connection strength, the outer frame is enabled to be smaller in total length, lighter in weight, cheaper in cost, and more unique in appearance. In addition, according to the present invention, the glass plate body is made of vacuum glass, so that the glass plate body has a better heat insulation property.

Further, the glass door provided by the present invention is especially applicable to a composite door type refrigerator, of which a door body is provided with a second chamber, and the second chamber is opened and closed through the glass door. The glass door is lighter and thinner, and therefore the second chamber is easier to open and close. In addition, such structure enables the overall door body (including the door body and the glass door) of the composite door type refrigerator to be not too thick or too heavy. In this way, the overall door body is easier to open and close. Moreover, the outer frame of the glass door used is of a half-frame structure, so that a user can have a wider view and can observe more details inside the second chamber, and thus the product grade is increased.

Further, according to the present invention, the door body is specially designed to effectively remove dew on an inner wall of the second chamber. Specifically, according to the present invention, the rear wall of the door body is specially designed in a hollow shape to define a dew removal air duct, and the front surface of the rear wall is backwards provided with a plurality of dew removal holes. When normal refrigeration is required in the second chamber, the refrigerator runs in a cooling cycle mode, so that air in the first chamber normally enters the second chamber via the air supply port so as to implement refrigeration in the second chamber. When dew generated on a rear wall surface of the second chamber (namely the front surface of the rear wall of the door body) is to be removed, the refrigerator runs in a dew removal mode, so that air in the first chamber enters the dew removal air duct inside the rear wall of the door body, and thus part of the air flow flows to the front surface of the rear wall via the dew removal holes. The air in the dew removal air duct must have a lower relative humidity than the original air flow at the front surface of the rear wall of the door body (the air close to dew must have a quite high relative humidity). Therefore, introduction of low-humidity air in the dew removal air duct can promote evaporation of the dew.

In addition, when the refrigerator provided by the present invention runs in the dew removal mode, a traditional way of electrically heating the rear wall or introducing hot air is not adopted. Instead, cold air in the first chamber is used to remove dew, and a dew removal process has no influences on normal refrigeration of the second chamber, realizing a quite ingenious structural design.

Specific embodiments of the present invention are described below in detail with reference to the accompanying drawings, and persons skilled in the art can more clearly understand the above and other purposes, advantages and features of the present invention.

Some specific embodiments of the present invention are described below in detail in an exemplary and unlimited way with reference to the accompanying drawings. The same or similar components or parts are indicated by the same reference numerals in the drawings. Persons skilled in the art should understand that these drawings are not necessarily drawn to scale. In the drawings:.

A refrigerator and a glass door thereof according to embodiments of the present invention are described with reference to <FIG>. The orientations or positional relationships indicated by "front", "rear", "up", "down", "top", "bottom", "inside", "outside", "transverse" and the like are based on the orientations or positional relationships shown in the accompanying drawings. Such terms are intended merely for the ease and brevity of description of the present invention without indicating or implying that the apparatuses or components mentioned must have specified orientations or must be constructed and manipulated in the specified orientations, and therefore shall not be construed as any limitation on the present invention.

An embodiment of the present invention provides a glass door applied to a refrigerator. The glass door is installed on a refrigerator body or a door body of the refrigerator to open and close a corresponding storage chamber.

<FIG> is a schematic structural diagram of a glass door applied to a refrigerator according to an embodiment of the present invention, and <FIG> is a schematic exploded view of the glass door shown in <FIG>. As shown in <FIG> and <FIG>, the glass door <NUM> applied to a refrigerator according to this embodiment of the present invention may generally include a glass plate body <NUM> and an outer frame <NUM>. The glass plate body <NUM> is shaped as a flat plate and constitutes a main body part of the glass door <NUM>. The glass plate body <NUM> may be made of vacuum glass so as to improve a heat insulation property thereof.

The outer frame <NUM> is configured to be hinged to a refrigerator body or a door body of the refrigerator. As shown in <FIG>, upper and lower ends of the outer frame <NUM> are each provided with a hinge shaft <NUM> to realize being hinged to the refrigerator body or the door body. The outer frame <NUM> extends along an edge of the glass plate body <NUM> and is fixedly connected to the edge of the glass plate body <NUM>. In other words, the outer frame <NUM> covers only part of the edge of the glass plate body <NUM>, so that a main part of the glass plate body <NUM> is not shielded, thus making good use of its advantage of transparency. The outer frame <NUM> covers part of the edge of the glass plate body <NUM>. That is, the remaining edge of the glass plate body <NUM> is exposed outside.

In this embodiment of the present invention, in comparison with a traditional door body, the glass door <NUM> is thinner, and more beautiful in appearance. In addition, according to this embodiment of the present invention, the outer frame <NUM> is not a complete square frame, but is of a half-frame structure that covers only part of the edge of the glass plate body <NUM>. On the premise of guaranteeing a connection strength, the outer frame <NUM> is enabled to be smaller in total length, lighter in weight, cheaper in cost, and more unique in appearance. The existing glass door bodies of some furniture or other products are generally a totally-sealed outer frame structure, so that all edges of glass are covered, which lacks novelty. However, this embodiment of the present invention breaks through the constraint of such a design habit and creates a totally new glass door design concept.

In some embodiments, as shown in <FIG> and <FIG>, the outer frame <NUM> includes a vertical frame <NUM> and two transverse frames <NUM> that are bent and extend from two ends of the vertical frame <NUM> in a length direction (the overall outer frame <NUM> is in a "U" shape with an opening toward an open side of the glass door <NUM>), so as to cover a vertical side of the glass plate body <NUM> and some sections of two transverse sides connected to the vertical side. Such shape of the outer frame <NUM> facilitates arrangement of a hinging structure, and also meets a strength requirement of the outer frame <NUM>. With such shape, the outer frame <NUM> has the simplest structure and the lightest weight, thus more material costs are reduced.

Further, a ratio of a length of each transverse frame <NUM> to a length of the transverse side of the glass door <NUM> body may be <NUM>/<NUM> to <NUM>/<NUM>, so as to realize optimal combination of strength and portability.

In some embodiments, as shown in <FIG> and <FIG>, the outer frame <NUM> may be provided with a clamping slot <NUM> with an opening toward the edge of the glass plate body <NUM> to fixedly clamp the edge of the glass plate body <NUM>, thereby realizing fixed connection of the outer frame <NUM> and the glass plate body <NUM>. Such fixation manner realizes a simple structure and a quite firm connection. Certainly, in some alternative embodiments, the two may be connected in other manners, for example, in an adhesion manner.

In some embodiments, as shown in <FIG> and <FIG>, a section, that is not covered by the transverse frame <NUM>, of one transverse side of the glass plate body <NUM> may include a handle portion <NUM> protruding along a vertical direction. For example, the handle portion <NUM> (a position indicated by a dotted box in <FIG> is the handle portion <NUM>) protruding downwards is formed in a right section of a lower edge of the glass plate body <NUM>. In this embodiment, the handle portion <NUM> is formed based on the shape of the glass plate body <NUM> without additionally arranging a handle made of plastic or another material on the surface of the glass, thus the glass plate body <NUM> has a simpler overall structure.

An embodiment of the present invention further provides a refrigerator, including the glass door <NUM> according to any one of the above embodiments. A structure of the refrigerator is not additionally limited in this embodiment of the present invention. The refrigerator can perform refrigeration through a vapor compression refrigeration circulation system, a semiconductor refrigeration system, or other ways. According to differences of refrigeration temperatures, chambers inside the refrigerator may be divided into a refrigeration chamber, a freezing chamber and a variable-temperature chamber. For example, a temperature in the refrigeration chamber is generally controlled between <NUM> and <NUM>, preferably between <NUM> and <NUM>. A temperature in the freezing chamber is generally controlled between -<NUM> and -<NUM>. A temperature in the variable-temperature chamber may be adjusted between -<NUM> and <NUM> so as to realize a temperature variation effect. Different types of objects should be stored at different optimal storage temperatures, and also should be stored in different storage chambers. For example, fruit and vegetable foods are suitable for being stored in a refrigeration chamber, while meat foods are suitable for being stored in a freezing chamber.

The glass door <NUM> provided by the present invention is especially applicable to a composite door type refrigerator. <FIG> is a schematic diagram of an assembling structure for a door body and a glass door <NUM> in a refrigerator according to an embodiment of the present invention, and <FIG> is a schematic diagram of a refrigerator in a cooling cycle mode according to an embodiment of the present invention.

As shown in <FIG> and <FIG>, the refrigerator is a composite door refrigeration, and specifically the refrigerator includes a refrigerator body <NUM>, a door body <NUM> and a glass door <NUM>. A front side of the refrigerator body <NUM> is opened to define a first chamber <NUM>. The door body <NUM> is installed on the refrigerator body <NUM> to open and close the first chamber <NUM>, and the door body <NUM> defines a second chamber <NUM> with an opened front side. The glass door <NUM> is installed on the door body <NUM> to open and close the second chamber <NUM>. The first chamber <NUM> of this embodiment of the present invention is preferably a refrigeration chamber. The front side of the door body <NUM> may be provided with a sealing strip <NUM> to seal between the door body and a rear surface of the glass door <NUM>. The front side of the door body <NUM> may be further provided with a magnet <NUM> for attracting another magnet on the glass door <NUM>, so that the glass door <NUM> is closed more tightly, and thus leakage of cold air is reduced.

The door body <NUM> may be rotatably installed on the refrigerator body <NUM> at the front side of the refrigerator body <NUM>; the front side of the door body <NUM> is opened to define the second chamber <NUM>, and the glass door <NUM> is rotatably installed on the door body <NUM> at the front side of the door body <NUM>. When the door body <NUM> is opened, a user stores or gets objects in the first chamber <NUM>. When the door body <NUM> is closed and the glass door <NUM> is opened, a user can store or get objects in the second chamber <NUM>.

According to this embodiment of the present invention, the second chamber <NUM> is opened and closed through the glass door <NUM>. The glass door <NUM> is lighter and thinner, and therefore the second chamber <NUM> is easier to open and close by a user. In addition, the overall door body (including the door body <NUM> and the glass door <NUM>) of the composite door type refrigerator is not too thick or too heavy, making it easier to open and close the overall door body. Moreover, the outer frame <NUM> of the glass door <NUM> used is of a half-frame structure, so that a user can have a wider view and can observe more details inside the second chamber <NUM>, and thus the product grade is increased.

<FIG> is an enlarged view of a location A in <FIG>; <FIG> is a schematic diagram of a state of the refrigerator shown in <FIG> in a dew removal mode; <FIG> is an enlarged view of a location B in <FIG>; and an air direction is indicated by an arrow in each figure.

In an existing composite door type refrigerator, the problem of condensation on the inner wall of the chamber (the second chamber <NUM> in the present invention) of the door body often occurs. The inventors have realized that the rear wall <NUM> of the door body <NUM> is close to the first chamber <NUM>, and can transfer heat with the air in the first chamber <NUM> via heat conduction. Therefore, the temperature at the front surface of the rear wall <NUM> is lower than the temperature at the other wall surfaces of the second chamber <NUM>, and it is easier to generate dew.

On the basis of the above concept, in this embodiment of the present invention, the door body <NUM> is specially designed, and dew removal is specially performed for the front surface of the rear wall <NUM> of the second chamber <NUM>. Specifically, the rear wall <NUM> of the door body <NUM> is provided with an air supply port <NUM> and an air return port <NUM> that are both in communication with the first chamber <NUM> and the second chamber <NUM>. In addition, the rear wall <NUM> of the door body <NUM> is in a hollow shape, inside which a dew removal air duct <NUM> in communication with the first chamber <NUM> is defined. That is, a hollow space of the rear wall <NUM> forms the dew removal air duct <NUM>. The front surface of the rear wall <NUM> is backwards provided with a plurality of dew removal holes <NUM> in communication with the second chamber <NUM> and the dew removal air duct <NUM>. The refrigerator is configured to be: in a cooling cycle mode in which the air in the first chamber <NUM> enters the second chamber <NUM> via the air supply port <NUM> and then returns to the first chamber <NUM> via the air return port <NUM>, so as to refrigerate the second chamber <NUM> with the cold air in the first chamber <NUM>, as shown in <FIG> and <FIG>. Alternatively, the refrigerator runs in a dew removal mode in which the air in the first chamber <NUM> enters the dew removal air duct <NUM>, so that part of an air flow flows to the front surface of the rear wall <NUM> via the dew removal holes <NUM> to remove dew formed on the front surface of the rear wall, as shown in <FIG> and <FIG>.

In this embodiment of the present invention, the refrigerator is usually in the aforementioned cooling cycle mode. However, when a lot of dew appears on the front surface of the rear wall <NUM> of the door body <NUM> due to introduction of wet air as the door is opened and closed or storage of a high-humidity object, the refrigerator may be controlled to run in the aforementioned dew removal mode, so that the air in the first chamber <NUM> enters the dew removal air duct <NUM> inside the rear wall <NUM> of the door body <NUM>, and thus part of the air flow flows to the front surface of the rear wall <NUM> via the dew removal holes <NUM>. The air in the dew removal air duct <NUM> must have a lower relative humidity than the original air flow at the front surface of the rear wall <NUM> of the door body <NUM> (the air close to the dew must have a quite high relative humidity). Therefore, introduction of low-humidity air in the dew removal air duct <NUM> can promote evaporation of the dew to complete a dew removal process. After dew is removed, the refrigerator can be controlled to switch to the cooling cycle mode.

The timing for switching the cooling cycle mode to the dew removal mode may be automatically controlled by the refrigerator, for example, a running mode of the refrigerator is periodically switched or automatically switched according to a detection result of a humidity sensor. Alternatively, the running mode of the refrigerator may be manually controlled, for example, the running mode of the refrigerator may be manually controlled when a user needs to remove dew or needs to stop removing dew.

When the refrigerator provided by this embodiment of the present invention runs in the dew removal mode, a traditional way of electrically heating the rear wall <NUM> or introducing hot air is not adopted. Instead, cold air in the first chamber <NUM> is used to remove dew, and a dew removal process has no influences on normal refrigeration of the second chamber <NUM>, realizing a quite ingenious structural design.

In some embodiments, as shown in <FIG> and <FIG>, the dew removal air duct <NUM> may include an inlet <NUM> and an outlet <NUM> that are in communication with the first chamber <NUM>, so that an air path circulation is formed between the dew removal air duct <NUM> and the first chamber <NUM>. Thus, the air flow for removing dew is prevented from being accumulated in the dew removal air duct <NUM> and near the dew removal holes <NUM>, so as not to affect a dew removal effect. In addition, the refrigerator is further configured to make the inlet <NUM> and the outlet <NUM> in a closed state and an open state respectively when in the cooling cycle mode; and make the inlet <NUM> and the outlet <NUM> both in an open state when in the dew removal mode. In other words, when the refrigerator runs in the cooling cycle mode, only the inlet <NUM> of the dew removal air duct <NUM> needs to be closed. When the refrigerator runs in the dew removal mode, the inlet <NUM> of the dew removal air duct <NUM> is opened. Since the opening and closing of the dew removal air duct <NUM> have been controlled by opening and closing the inlet <NUM> and the outlet <NUM> thereof, the outlet <NUM> of the dew removal air duct <NUM> needs not to be controlled. Under the two modes, the outlet <NUM> of the dew removal air duct <NUM> is in a normally open state and needs not to be controlled, so as to simplify the structure and control of the refrigerator.

In some embodiments, as shown in <FIG> and <FIG>, the inlet <NUM> of the dew removal air duct <NUM> may be in communication with the air supply port <NUM> by penetrating through a sidewall of the air supply port <NUM>. That is, the dew removal air duct <NUM> is in communication with the first chamber <NUM> via the air supply port <NUM>, and there is no need to form another opening in the rear wall <NUM>. Also, the outlet <NUM> of the dew removal air duct <NUM> may be in communication with the air return port <NUM> by penetrating through a sidewall of the air return port <NUM>. That is, the dew removal air duct <NUM> is in communication with the first chamber <NUM> via the air return port <NUM>, and there is no need to form another opening in the rear wall <NUM>. The structure designed in this way is quite ingenious, and a perforated structure of the rear wall <NUM> of the door body <NUM> is simplified, so that only the air supply port <NUM> and the air return port <NUM> need to be directly formed in the rear surface of the rear wall <NUM> of the door body <NUM>.

In some embodiments, as shown in <FIG> and <FIG>, the air supply port <NUM> and the air return port <NUM> are located at a top and a bottom of the rear wall <NUM>, respectively. When the refrigerator runs in the cooling cycle mode, after cold air flows from the air supply port <NUM> into the second chamber <NUM>, the cold air sinks due to a relatively large density and flows down to sequentially refrigerate regions at all heights of the second chamber <NUM>, and the air flows back to the first chamber <NUM> via the air return port <NUM> at the bottom of the second chamber <NUM> after its temperature rises gradually. In this way, smoother air path circulation is formed, which improves a refrigeration effect of the second chamber <NUM>. When the refrigerator runs in the dew removal mode, cold air enters the dew removal air duct <NUM> from the top of the dew removal air duct <NUM>, which is more favorable for downward flowing of the cold air, achieves better flowing in the dew removal air duct <NUM> and accelerates a dew removal process.

As shown in <FIG> and <FIG>, the refrigerator may further include a damper <NUM>, where the damper <NUM> is installed at the air supply port <NUM>, and is configured to controllably move to a cooling state (as shown in <FIG>) in which the inlet <NUM> is closed and the air supply port <NUM> is turned on, or move to a dew removal state (as shown in <FIG>) in which the inlet <NUM> is opened and the air supply port <NUM> is closed. This embodiment makes effective use of the advantage of communication between the inlet <NUM> and the air supply port <NUM>, and the air supply port <NUM> and the inlet <NUM> are controlled by one damper <NUM> at the same time, simplifying air input and output control and achieving an ingenious design.

Specifically, as shown in <FIG> and <FIG>, one end of the damper <NUM> is rotatably installed at a front edge of the inlet <NUM>, so that the damper <NUM> can rotate to the cooling state (as shown in <FIG>) or the dew removal state (as shown in <FIG>). In this embodiment of the present invention, complex movement mechanism and control logic are not needed, and the running mode of the refrigerator can be switched by controlling rotation of one damper <NUM>, greatly simplifying the structure and control.

In some embodiments, as shown in <FIG> and <FIG>, the refrigerator further includes a fan <NUM>, where the fan <NUM> is located at the air supply port <NUM> to promote the air in the first chamber <NUM> to flow to the air supply port <NUM>, thus accelerating cooling circulation. Certainly, for a solution in which the inlet <NUM> is in communication with the air supply port <NUM>, the fan <NUM> is also configured to promote the air in the first chamber <NUM> to flow to the dew removal air duct <NUM>.

Claim 1:
A refrigerator, comprising:
a glass door (<NUM>);
a refrigerator body (<NUM>), with a front side opened to define a first chamber (<NUM>); and
a door body (<NUM>), installed on the refrigerator body (<NUM>) to open and close the first chamber (<NUM>), wherein the door body (<NUM>) defines a second chamber (<NUM>) with an opened front side;
wherein the glass door (<NUM>) is installed on the door body (<NUM>) to open and close the second chamber (<NUM>);
wherein the glass door (<NUM>) comprises:
a glass plate body (<NUM>); and
an outer frame (<NUM>), configured to be hinged to the refrigerator body (<NUM>) or the door body (<NUM>) of the refrigerator, wherein the outer frame (<NUM>) extends along an edge of the glass plate body (<NUM>) and is fixedly connected to the edge of the glass plate body (<NUM>);
characterized in that
the outer frame (<NUM>) covers part of the edge of the glass plate body (<NUM>); wherein
a rear wall (<NUM>) of the door body (<NUM>) is provided with an air supply port (<NUM>) and an air return port (<NUM>) that are both in communication with the first chamber (<NUM>) and the second chamber (<NUM>); the rear wall (<NUM>) is in a hollow shape, inside which a dew removal air duct (<NUM>) in communication with the first chamber (<NUM>) is defined; a front surface of the rear wall (<NUM>) is backwards provided with a plurality of dew removal holes (<NUM>) in communication with the second chamber (<NUM>) and the dew removal air duct (<NUM>); and the refrigerator is configured to be:
in a cooling cycle mode in which air in the first chamber (<NUM>) enters the second chamber (<NUM>) via the air supply port (<NUM>) and then returns to the first chamber (<NUM>) via the air return port (<NUM>); or
in a dew removal mode in which the air in the first chamber (<NUM>) enters the dew removal air duct (<NUM>), so that part of an air flow flows to the front surface of the rear wall (<NUM>) via the dew removal holes (<NUM>) to remove dew formed on the front surface.