Air duct assembly and air conditioner
Patent Information
- Application Number
- CN202522490201.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-24
- Publication Date
- 2026-10-16
- Estimated Expiration
- 2035-11-24
AI Technical Summary
[0003]相关技术中的一些风道组件中,风道壳体上的冷凝水会积聚在风道壳体上,不能顺利流动到接水盘中,在空调器启动后容易被吹向用户,影响用户体验
[0022] The beneficial effects provided by this utility model embodiment include: This utility model embodiment provides a duct assembly and an air conditioner. The air conditioner includes a duct assembly, which includes a duct housing. The duct housing has two opposite sides along the front-to-back direction, forming an air inlet side and an air outlet side. The duct housing includes a top structure, a bottom structure, and two side structures. The two side structures are spaced apart and located between the top and bottom structures. The bottom structure has a drain groove formed on the side closer to the top structure for communicating with a water collection tray. The top structure has a drain hole communicating with the drain groove. Condensate dripping from the drain hole on the top structure can flow downwards into the drain groove through the connecting part. This reduces the occurrence of condensate blowing onto the user after the air conditioner is turned on, improving the user experience.
Smart Images

Figure CN224860672U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of air conditioning technology, and more specifically, to an air duct assembly and an air conditioner. Background Technology
[0002] In cabinet air conditioners, the air outlet assembly is the main component for air outlet. The air outlet assembly includes structures such as the duct housing, fan blades, and mesh cover. Both the fan blades and the mesh cover are installed on the duct housing.
[0003] In some duct components of related technologies, condensate on the duct housing can accumulate and cannot flow smoothly into the drip tray. When the air conditioner is turned on, it can easily be blown towards the user, affecting the user experience. Utility Model Content
[0004] The purpose of this utility model is to provide a duct assembly and an air conditioner that allows condensate on the duct housing to flow to a drain trough and then to a drip tray, thereby reducing the occurrence of condensate blowing onto the user after the air conditioner is turned on.
[0005] The embodiments of this utility model can be implemented as follows: In a first aspect, this utility model provides a duct assembly, comprising: The air duct housing has two opposite sides along the front-to-back direction, which are the air inlet side and the air outlet side. The air duct housing includes a top structure, a bottom structure and two side structures. The two side structures are spaced apart and located between the top structure and the bottom structure. The bottom structure has a drainage groove on the side closer to the top structure for communicating with the water receiving tray. The top structure has a drainage hole communicating with the drainage groove.
[0006] With the above design, condensate dripping from the drain hole on the top structure can flow downwards through the connection into the drain groove. This reduces the likelihood of condensate blowing onto the user when the air conditioner is turned on, improving the user experience.
[0007] In an optional embodiment, the top structure has a groove, and a drainage hole is provided on the side wall of the groove; And / or, along the direction toward the rear side of the duct housing, the height dimension of the drainage groove gradually decreases.
[0008] With the above-mentioned design, the groove can effectively guide water from the top structure into the groove; or, it can also facilitate the smooth drainage of water in the drainage trough into the water receiving tray.
[0009] In an optional embodiment, the groove includes a flow-guiding bottom wall and two flow-guiding side walls. The arrangement direction of the two flow-guiding side walls is parallel to the arrangement direction of the two side structures. The two flow-guiding side walls are respectively disposed on both sides of the flow-guiding bottom wall. Drainage holes are provided on both flow-guiding side walls. The height dimension of the flow-guiding bottom wall gradually decreases in the direction close to the flow-guiding side walls.
[0010] The above configuration facilitates the flow of water within the groove along the guide wall, which then flows from the drain hole into the drain trough.
[0011] In an optional embodiment, the duct housing further includes a connecting portion, the bottom of which is connected to a bottom structure, and the two sides of which are respectively connected to two side structures. The connecting portion, the top structure, and the two side structures together define an installation cavity for mounting the fan blades. The two side structures divide the drainage channel into a main drainage channel and two side drainage channels. The main drainage channel is located between the two side structures. A first drainage port is provided at the bottom of the connecting part. The main drainage channel is connected to the water receiving tray through the first drainage port. The side drainage channels are located on the side of the side structure away from the main drainage channel. The side drainage channels also have a second drainage port connected to the water receiving tray.
[0012] With the above configuration, the condensate on the inner side of the side structure can be directly drained into the side drainage trough along the inner side of the side structure, and the water in the side drainage can also be discharged into the water receiving tray through the second drainage port.
[0013] In an optional embodiment, a drainage channel communicating with a drainage trough is provided on the side of any side structure away from another side structure, and condensate on the side structure can be guided to the drainage trough through the drainage channel.
[0014] The above setup can improve the drainage effect of condensate on the side structure through the drainage channel.
[0015] In an optional embodiment, the side structure includes a first sidewall and two second sidewalls, the two second sidewalls being spaced apart on both sides of the first sidewall in a front-rear direction, and the first sidewall and the two second sidewalls together defining a drainage channel.
[0016] The above settings can reduce the possibility of water splashing onto other areas of the air duct housing.
[0017] In an optional embodiment, the drainage channel is provided with multiple water-guiding ribs, which are inclined and extend toward the bottom structure.
[0018] By using the above-mentioned design, the water guide bar is tilted instead of extending vertically downwards, which can slow down the falling speed of the water and prevent water splashing caused by condensate falling rapidly into the side drain.
[0019] In an optional embodiment, the plurality of water-guiding bars include a first water-guiding bar, and both second sidewalls are provided with a first water-guiding bar and one side of the first water-guiding bar is also connected to the first sidewall. There is a water passage gap between the first water-guiding bars on the two second sidewalls. And / or, the plurality of water-guiding bars also include a second water-guiding bar, the two ends of which are respectively connected to two second side walls, and one side of the second water-guiding bar is also connected to the first side wall.
[0020] Secondly, this utility model provides an air conditioner, including a housing, an electrical control box assembly, and a duct assembly according to any of the aforementioned embodiments. Both the electrical control box assembly and the duct assembly are installed inside the housing. The electrical control box assembly is located below the duct assembly, and the electrical control box assembly has mounting cavities for mounting a wiring board and a PCB board respectively.
[0021] In an optional embodiment, the rear side of the housing has an air inlet and the front side of the housing has an air outlet. The electrical control box assembly includes an electrical control box and a cover, with the cover covering the electrical control box and the opening of the electrical control box facing the air outlet. In the front-to-back direction, the distance from the connection between the electrical control box and the cover to the air inlet is L1, and the distance from the side of the drain trough near the air outlet to the air inlet is L2, where L1 > L2.
[0022] The beneficial effects provided by this utility model embodiment include: This utility model embodiment provides a duct assembly and an air conditioner. The air conditioner includes a duct assembly, which includes a duct housing. The duct housing has two opposite sides along the front-to-back direction, forming an air inlet side and an air outlet side. The duct housing includes a top structure, a bottom structure, and two side structures. The two side structures are spaced apart and located between the top and bottom structures. The bottom structure has a drain groove formed on the side closer to the top structure for communicating with a water collection tray. The top structure has a drain hole communicating with the drain groove. Condensate dripping from the drain hole on the top structure can flow downwards into the drain groove through the connecting part. This reduces the occurrence of condensate blowing onto the user after the air conditioner is turned on, improving the user experience. Attached Figure Description
[0023] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0024] Figure 1 This is a schematic diagram of the air duct assembly provided in an embodiment of the present utility model from a first-view perspective. Figure 2 This is a schematic diagram of the air duct assembly provided in an embodiment of the present utility model from a second perspective. Figure 3 An assembly diagram of the air duct assembly and the electrical control box assembly in an air conditioner provided for an embodiment of this utility model; Figure 4 for Figure 3 A magnified view of a portion of the image.
[0025] Icons: 1- Duct assembly; 100- Duct housing; 101- Outlet side; 102- Inlet side; 110- Top structure; 1100- Groove; 1110- Bottom wall of the guide; 1120- Side wall of the guide; 1122- Drain hole; 120- Bottom structure; 121- Drain groove; 1211- Main drain groove; 1212- Side drain groove; 1213- Second drain outlet; 130- Connecting part; 131- First drain outlet; 140- Side structure; 141- First side wall; 142- Second side wall; 200- Water guide rib; 210- First water guide rib; 220- Second water guide rib; 310- Electrical control box; 320- Box cover; 321- Cover body; 322- Flanged edge; 1000- Air inlet. Detailed Implementation
[0026] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.
[0027] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.
[0028] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.
[0029] In the description of this utility model, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the utility model product is usually placed during use, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.
[0030] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.
[0031] It should be noted that, where there is no conflict, the features in the embodiments of this utility model can be combined with each other.
[0032] The following describes in detail, with reference to the accompanying drawings, the specific structure of the air duct component 1 and the air conditioner provided by the present invention, and the corresponding technical effects thereon.
[0033] Please refer to Figures 1-3 This utility model provides an air conditioner, which includes a housing, an electrical control box 310 assembly, an air duct assembly 1, a heat exchange assembly, and other components.
[0034] The air duct assembly 1, the electrical control box 310 assembly, and the heat exchange assembly are all installed inside the housing. The rear side of the housing has an air inlet 1000, and the front side has an air outlet. The air duct assembly 1 includes an air duct housing 100, with an air inlet side 102 and an air outlet side 101 on opposite sides along the front-rear direction. It can be understood that the air inlet side 102 of the air duct housing 100 is closer to the air inlet 1000, i.e., closer to the heat exchange assembly; for example, the air inlet side 102 of the air duct housing 100 is closer to the evaporator, and the air outlet side 101 of the air duct housing 100 is closer to the air outlet of the housing. The air duct assembly 1 also includes fan blades and a face shield, both of which are installed in the air duct housing 100, with the face shield located on the air outlet side 101 of the air duct housing 100.
[0035] The duct housing 100 includes a top structure 110, a bottom structure 120, and two side structures 140. The two side structures 140 are spaced apart and located between the top structure 110 and the bottom structure 120. The bottom structure 120 has a drainage groove 121 for communicating with a water receiving tray on the side near the top structure 110. The top structure 110 has a drainage hole 1122 communicating with the drainage groove 121.
[0036] In other words, condensate on the top structure 110 of the air duct housing 100 can flow downwards along the air duct housing 100 through the drain hole 1122 into the drain trough 121, whereby the drain trough 121 drains the condensate into the drip tray. Of course, since the drain trough 121 is located on the bottom structure 120, condensate generated by the top structure 110 or side structure 140 above the drain trough 121 can also be received by the drain trough 121 and drained into the drip tray. This reduces the occurrence of condensate blowing onto the user after the air conditioner is turned on, improving the user experience.
[0037] It should be noted that the air conditioner in this embodiment can be understood as a cabinet unit, and the fan blades can be axial flow fan blades. The air duct housing 100 also includes a connecting part 130, the bottom of the connecting part 130 is connected to the bottom structure 120, and the two sides of the connecting part 130 are respectively connected to two side structures 140. The connecting part 130, the top structure 110 and the two side structures 140 together define an installation cavity for installing the fan blades.
[0038] Understandably, condensate dripping from the drain hole 1122 on the top structure 110 can flow down through the connection 130 into the drain groove 121.
[0039] Understandably, the water tray is located on the air inlet side 102 of the air duct housing 100. Therefore, in order to facilitate the smooth drainage of water in the drain trough 121 into the water tray, in this embodiment, the height of the drain trough 121 gradually decreases along the direction towards the rear side of the air duct housing 100. That is, the drain trough 121 is inclined downward along the air inlet side 102 so that the water in the drain trough 121 flows towards the rear side and then into the water tray.
[0040] In detail, in this embodiment, the top structure 110 is provided with a groove 1100, and a drain hole 1122 is provided on the side wall of the groove 1100. It can be understood that the groove 1100 can effectively guide the water of the top structure 110 into the groove 1100, and then the condensate flows into the drain trough 121 through the drain hole 1122, and then the water is led to the water receiving tray through the drain trough 121.
[0041] In detail, the groove 1100 includes a flow-guiding bottom wall 1110 and two flow-guiding side walls 1120. The arrangement direction of the two flow-guiding side walls 1120 is parallel to the arrangement direction of the two side structures 140. The two flow-guiding side walls 1120 are respectively disposed on both sides of the flow-guiding bottom wall 1110. Drainage holes 1122 are provided on both flow-guiding side walls 1120. The height dimension of the flow-guiding bottom wall 1110 gradually decreases in the direction close to the flow-guiding side wall 1120.
[0042] Understandably, the bottom guide wall 1110 can guide the condensate in the direction of the guide side wall 1120, thereby facilitating the discharge of the condensate through the drain hole 1122. Moreover, the guide side wall 1120 can also guide the condensate downwards, so that the condensate can enter the groove 1100 and be discharged into the drain trough 121 through the drain hole 1122.
[0043] In this embodiment, a drainage channel communicating with the drainage trough 121 is provided on the side of any side structure 140 away from the other side structure 140, and the condensate on the side structure 140 can be guided to the drainage trough 121 through the drainage channel.
[0044] Specifically, the two side structures 140 divide the drainage trough 121 into a main drainage trough 1211 and two side drainage troughs 1212. The main drainage trough 1211 is located between the two side structures 140. A first drainage port 131 is provided at the bottom of the connecting part 130. The main drainage trough 1211 can be connected to the water receiving tray through the first drainage port 131. The water in the main drainage trough 1211 can flow to the rear air intake side 102 channel, and then flow to the rear through the first drainage port 131, and then flow into the water receiving tray.
[0045] The side drainage trough 1212 is located on the side of the side structure 140 away from the main drainage trough 1211. A connecting hole is provided at the bottom of the side structure 140. The side drainage trough 1212 is connected to the main drainage trough 1211 through the connecting hole. The side drainage trough 1212 also has a second drain outlet 1213 that is connected to the water receiving tray.
[0046] Understandably, in this embodiment, the condensate inside the side structure 140 can be directly drained into the side drain trough 1212 along the inner side of the side structure 140. A portion of the water in the side drain trough 1212 can enter the main drain trough 1211 through the connecting hole, and then be discharged into the water receiving tray through the main drain trough 1211. The remaining water in the side drain can be directly discharged into the water receiving tray through the second drain outlet 1213. Understandably, the second drain outlet 1213 of the side drain trough 1212 is located above the water receiving tray.
[0047] In detail, to facilitate better water drainage from the side structures 140, in this embodiment, a drainage channel communicating with the drainage trough 121 is provided on the side of any one side structure 140 away from the other side structure 140. Condensate on the side structures 140 can be led to the drainage trough 121 through the drainage channel. Furthermore, the condensate on the side structures 140 can be led to the side drainage trough 1212 through the drainage channel, which better guides the water flow downwards.
[0048] Specifically, the side structure 140 includes a first sidewall 141 and two second sidewalls 142. The two second sidewalls 142 are spaced apart on both sides of the first sidewall 141 in the front-back direction. The first sidewall 141 and the two second sidewalls 142 together define a drainage channel. It can be understood that by enclosing the drainage channel in a roughly U-shape with the first sidewall 141 and the two second sidewalls 142, the possibility of water splashing into other areas of the air duct housing 100 can be reduced.
[0049] In detail, the drainage channel is equipped with multiple water guide ribs 200. The water guide ribs 200 are inclined and extend towards the bottom structure 120. It can be understood that the water guide ribs 200 are inclined rather than extending vertically downward, which can slow down the falling speed of the water flow and avoid water splashing caused by the rapid falling of condensate into the side drainage trough 1212.
[0050] Optionally, the plurality of water-guiding ribs 200 include a first water-guiding rib 210, and both second sidewalls 142 are provided with first water-guiding ribs, and one side of the first water-guiding rib 210 is also connected to the first sidewall 141, and there is a water passage gap between the first water-guiding ribs 210 on the two second sidewalls 142.
[0051] Optionally, the plurality of water-diverting bars 200 include a second water-diverting bar 220, the two ends of which are respectively connected to two second sidewalls 142, and one side of the second water-diverting bar 220 is connected to a first sidewall 141 in the sea area.
[0052] It should be noted that in this embodiment, the first water guide rib 210 is located above the second water guide rib 220. Both second sidewalls 142 are provided with the first water guide rib 210, which can improve the water guiding efficiency of condensate in the drainage channel. After flowing through the water gap, the water passes through the second water guide rib 220, which can slow down the downward flow speed and reduce the splashing of condensate in the drainage channel.
[0053] It should be noted that in this embodiment, the electrical control box 310 assembly is located below the air duct assembly 1, and the electrical control box 310 assembly has mounting cavities for mounting the junction box and the PCB board respectively. That is to say, the electrical control box 310 assembly in this embodiment integrates the functions of the junction box and the electrical control box 310, making the structure more compact.
[0054] Please refer to Figures 3-4 In detail, in this embodiment, the electrical control box 310 assembly includes an electrical control box 310 and a cover 320. The cover 320 covers the electrical control box 310, and the opening of the electrical control box 310 faces the air outlet. The distance from the connection between the electrical control box 310 and the cover 320 to the air inlet 1000 is L1, and the distance from the side of the drain trough 121 near the air outlet to the air inlet 1000 is L2, where L1 > L2. That is, the connection between the electrical control box 310 and the cover 320 is further forward than the drain trough 121. This can prevent water from the drain trough 121 inside the air duct housing 100 of the air duct assembly 1 from accidentally entering the electrical control box 310, and can also reserve more space on the rear side of the electrical control box 310 for the installation of other modules.
[0055] Specifically, in this embodiment, the cover 320 includes a cover body 321 and a flange 322. The flange 322 surrounds the outer periphery of the cover body 321 and is opposite to the outer peripheral wall of the electrical control box 310. The cover body 321 covers the electrical control box 310. Due to the action of the flange 322, water in the drain groove 121 can be prevented from accidentally flowing out and soaking into the electrical control box 310.
[0056] Moreover, in this embodiment, the projection of the front side of the drain trough 121 in the vertical direction falls on the flange 322 of the cover 320, which can further prevent water in the drain trough 121 from accidentally flowing out and soaking into the electrical control box 310.
[0057] In summary, this utility model provides a duct assembly 1 and an air conditioner. The air conditioner includes the duct assembly 1, which includes a duct housing 100. The duct housing 100 has two opposing sides along its front-to-back direction: an air inlet side 102 and an air outlet side 101. The duct housing 100 includes a top structure 110, a bottom structure 120, and two side structures 140. The two side structures 140 are spaced apart and located between the top structure 110 and the bottom structure 120. The bottom structure 120 has a drain groove 121 on the side closest to the top structure 110 for communication with a drip tray. The top structure 110 has a drain hole 1122 communicating with the drain groove 121. Condensate dripping from the drain hole 1122 on the top structure 110 can flow downwards through the connecting part 130 into the drain groove 121. This reduces the occurrence of condensate blowing onto the user after the air conditioner is turned on, improving the user experience.
[0058] The above description is only a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model.
Claims
1. A duct assembly (1), characterized in that, include: The duct housing (100) has an air inlet side (102) and an air outlet side (101) on opposite sides in the front-rear direction. The duct housing (100) includes a top structure (110), a bottom structure (120) and two side structures (140). The two side structures (140) are spaced apart and located between the top structure (110) and the bottom structure (120). The bottom structure (120) has a drainage groove (121) on the side near the top structure (110) for communicating with a water receiving tray. The top structure (110) has a drainage hole (1122) communicating with the drainage groove (121).
2. The air duct assembly (1) according to claim 1, characterized in that: The top structure (110) has a groove (1100), and the drain hole (1122) is provided on the side wall of the groove (1100); And / or, along the direction toward the rear side of the air duct housing (100), the height dimension of the drainage groove (121) gradually decreases.
3. The air duct assembly (1) according to claim 2, characterized in that: The groove (1100) includes a flow-guiding bottom wall (1110) and two flow-guiding side walls (1120). The arrangement direction of the two flow-guiding side walls (1120) is parallel to the arrangement direction of the two side structures (140). The two flow-guiding side walls (1120) are respectively disposed on both sides of the flow-guiding bottom wall (1110). The drainage hole (1122) is provided on both flow-guiding side walls (1120). The height dimension of the flow-guiding bottom wall (1110) gradually decreases in the direction close to the flow-guiding side wall (1120).
4. The air duct assembly (1) according to claim 1, characterized in that: The duct housing (100) further includes a connecting part (130), the bottom of which is connected to the bottom structure (120), and the two sides of which are respectively connected to two side structures (140). The connecting part (130), the top structure (110), and the two side structures (140) together define an installation cavity for the fan blades. The two side structures (140) divide the drainage channel (121) into a main drainage channel (1211) and two side drainage channels (1212). The main drainage channel (1211) is located between the two side structures (140). A first drain outlet (131) is provided at the bottom of the connecting part (130). The main drainage channel (1211) is connected to the water receiving tray through the first drain outlet (131). The side drainage channels (1212) are located on the side of the side structure (140) away from the main drainage channel (1211). The side drainage channels (1212) also have a second drain outlet (1213) connected to the water receiving tray.
5. The air duct assembly (1) according to claim 1, characterized in that: Each of the side structures (140) has a drainage channel connected to the drainage trough (121) on the side away from the other side structure (140), and the condensate on the side structure (140) can be guided to the drainage trough (121) through the drainage channel.
6. The air duct assembly (1) according to claim 5, characterized in that: The side structure (140) includes a first sidewall (141) and two second sidewalls (142). The two second sidewalls (142) are spaced apart on both sides of the first sidewall (141) in the front-back direction. The first sidewall (141) and the two second sidewalls (142) together define a drainage channel.
7. The air duct assembly (1) according to claim 6, characterized in that: The drainage channel is provided with a plurality of water guide bars (200), which are inclined and extend toward the bottom structure (120).
8. The air duct assembly (1) according to claim 7, characterized in that: The plurality of water-guiding bars (200) include a first water-guiding bar (210), both of the two second sidewalls (142) are provided with the first water-guiding bar (210) and one side of the first water-guiding bar (210) is also connected to the first sidewall (141), and there is a water passage gap between the first water-guiding bars (210) on the two second sidewalls (142); And / or, the plurality of water-guiding bars (200) further include a second water-guiding bar (220), the two ends of which are respectively connected to the two second sidewalls (142), and one side of the second water-guiding bar (220) is also connected to the first sidewall (141).
9. An air conditioner, characterized in that, The device includes a housing, an electrical control box (310) assembly, and a duct assembly (1) as described in any one of claims 1-8. The electrical control box (310) assembly and the duct assembly (1) are both installed inside the housing. The electrical control box (310) assembly is located below the duct assembly (1). The electrical control box (310) assembly has mounting cavities for mounting a wiring board and a PCB board, respectively.
10. The air conditioner according to claim 9, characterized in that: The rear side of the housing has an air inlet (1000), the front side of the housing has an air outlet, and the electrical control box (310) assembly includes an electrical control box (310) and a box cover (320). The box cover (320) covers the electrical control box (310), and the opening of the electrical control box (310) faces the air outlet. In the front-to-back direction, the distance from the connection between the electrical control box (310) and the cover (320) to the air inlet (1000) is L1, and the distance from the side of the drain trough (121) near the air outlet to the air inlet (1000) is L2, where L1 > L2.