Ventilation hood

Abstract

The objective is to provide a ventilation hood with a simple configuration that can suppress the soiling of exterior walls caused by contact between the air discharged outdoors and the exterior wall. [Solution] The ventilation grille 32 is provided with a plurality of ventilation openings. The plurality of ventilation openings include at least one exterior wall-side opening 32a and a plurality of outdoor-side openings 32b. The exterior wall-side opening 32a and the plurality of outdoor-side openings 32b are configured such that when air is discharged from the hood body 30 to the outside, the airflow velocity passing through each of the plurality of outdoor-side openings 32b is faster than the airflow velocity passing through the three exterior wall-side openings 32a.

Description

Technical Field

[0001] The present disclosure relates to a ventilation hood.

Background Art

[0002] In a conventional outdoor hood for ventilation, a gallery is provided at an opening in the lower part of the hood body. A plurality of guide plates are provided in the gallery. The middle part of each guide plate is bent at an obtuse angle in a direction away from the outer wall so that the air discharged outdoors through the gallery is separated from the outer wall of the building (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the conventional outdoor hood for ventilation as described above, since a plurality of guide plates are provided in the gallery, the number of parts is large and the configuration becomes complicated.

[0005] The present disclosure has been made to solve the above problems, and an object thereof is to obtain a ventilation hood that can suppress the soiling of the outer wall due to the contact of the air discharged outdoors with the outer wall with a simple configuration.

Means for Solving the Problems

[0006] The ventilation hood according to this disclosure comprises a hood body installed on the outdoor side of the exterior wall of a building, and the lower part of the hood body is provided with a plurality of ventilation openings, the plurality of ventilation openings including an exterior wall side opening located closest to the exterior wall when the hood body is installed on the exterior wall, and a plurality of outdoor side openings located further from the exterior wall than the exterior wall side opening when the hood body is installed on the exterior wall, the exterior wall side opening and the plurality of outdoor side openings are configured such that when air is discharged from the hood body to the outside, the airflow velocity passing through each of the plurality of outdoor side openings is faster than the airflow velocity passing through the exterior wall side opening. [Effects of the Invention]

[0007] According to the ventilation hood of this disclosure, a simple configuration can suppress the soiling of the exterior wall caused by contact between the air discharged to the outside and the exterior wall. [Brief explanation of the drawing]

[0008] [Figure 1] This is a perspective view of the ventilation hood according to Embodiment 1, seen from a diagonal downward angle. [Figure 2] Figure 1 is a perspective view of the ventilation hood, seen from diagonally above. [Figure 3] Figure 1 is an exploded perspective view showing the ventilation hood. [Figure 4] Figure 1 is a bottom view showing the ventilation hood. [Figure 5] Figure 1 is a cross-sectional view of the ventilation hood. [Figure 6] Figure 5 is a magnified view of the main part of the ventilation hood. [Figure 7] This is an explanatory diagram showing the results of an analysis of the airflow discharged from a conventional ventilation hood as a comparative example. [Figure 8] This is an explanatory diagram showing the analysis results of the airflow discharged from the ventilation hood of Embodiment 1. [Figure 9] Figure 8 is an explanatory diagram showing the airflow in the ventilation hood as viewed from directly below the hood. [Figure 10]This is an explanatory diagram that compares the analysis results of the airflow discharged from the ventilation hood of Embodiment 1 with the exhaust pressure loss for cases where angle α in Figure 6 is 50 degrees, 60 degrees, and 70 degrees. [Figure 11] Figure 6 is a graph showing the relationship between angle α and pressure loss. [Figure 12] This is a schematic diagram showing the main parts of the hood body of the ventilation hood according to Embodiment 2. [Modes for carrying out the invention]

[0009] The embodiments will be described below with reference to the drawings. Embodiment 1. Figure 1 is a perspective view of the ventilation hood according to Embodiment 1, seen from diagonally below. Figure 2 is a perspective view of the ventilation hood of Figure 1, seen from diagonally above. Figure 3 is an exploded perspective view of the ventilation hood of Figure 1.

[0010] In the diagram, the exterior wall 11 of the building is provided with ventilation openings (not shown). Furthermore, a ventilation hood 20 is provided on the exterior wall 11 to cover the ventilation openings. The ventilation hood 20 prevents rainwater, insects, etc., from entering the building through the ventilation openings.

[0011] A ventilation system (not shown) is installed indoors. A ventilation duct (not shown) is provided between the ventilation opening and the ventilation system. The ventilation duct forms an air passage for bringing outside air into the building or for expelling indoor air to the outside. A connecting pipe (not shown) is provided at the end of the ventilation duct on the ventilation opening side. The connecting pipe is inserted into the ventilation opening.

[0012] The ventilation hood 20 comprises a flat base member 21, a cylindrical pipe guide 22, a pair of strip-shaped fixing members 23, and a box-shaped hood body 30.

[0013] The base member 21 is attached to the outer wall 11. A circular base hole is provided in the center of the base member 21.

[0014] The pipe guide 22 is inserted into the base hole and fixed to the base member 21. Further, the pipe guide 22 protrudes from the base member 21 toward the indoor side. Further, the pipe guide 22 is inserted into the connection pipe.

[0015] The pair of fixing members 23 are fixed to both sides in the width direction of the base member 21. Further, it is desirable that each fixing member 23 be fixed to the base member 21 by a method that cannot be easily removed by a donor, a building user, etc., for example, welding. A screw hole 23a is provided at the lower end of each fixing member 23.

[0016] The hood body 30 is provided on the outdoor side of the outer wall 11 so as to protrude from the outer wall 11 to the outside. Further, the hood body 30 covers the ventilation opening so that the ventilation opening is not exposed to the outside. Further, the hood body 30 is attached to the base member 21 via a pair of fixing members 23.

[0017] A plurality of through holes 30a are provided at the lower part of the hood body 30. The hood body 30 is attached to the pair of fixing members 23 by passing each of the plurality of mounting screws 24 through the corresponding through hole 30a and screwing it into the corresponding screw hole 23a. Further, the hood body 30 can be removed from the pair of fixing members 23 by removing each of the plurality of mounting screws 24 from the corresponding screw hole 23a and the corresponding through hole 30a.

[0018] The diameter of each through hole 30a is larger than the screw diameter of the mounting screw 24 and smaller than the head of the mounting screw 24. Further, it is desirable that each screw hole 23a be provided in the fixing member 23 by a processing method that can withstand repeated attachment and detachment of the mounting screw 24, such as tapping or burring. Thereby, the hood body 30 can be easily replaced.

[0019] It is desirable that the plurality of screw holes 23a and the plurality of through holes 30a be provided at positions where tools such as a driver can be easily applied.

[0020] The hood body 30 has a housing 31 and a ventilation grille 32. The housing 31 covers the ventilation opening. The housing 31 has a front portion 31a, a pair of side portions 31b, and a top portion 31c integrally formed.

[0021] The front portion 31a faces the base member 21. Furthermore, the front portion 31a is curved such that its middle section in the width direction slightly protrudes away from the base member 21.

[0022] The pair of side portions 31b protrude toward the base member 21 from both ends in the width direction of the front portion 31a. Furthermore, the pair of side portions 31b face each other.

[0023] The top surface portion 31c protrudes from the upper end of the front surface portion 31a toward the base member 21. The top surface portion 31c also closes the upper end of the space enclosed by the front surface portion 31a, the pair of side surfaces 31b, and the base member 21. Furthermore, the top surface portion 31c is gently sloped downwards as it moves away from the base member 21.

[0024] The ventilation grille 32 is fixed to the lower end of the housing 31 so as to seal the lower end of the space inside the housing 31. The ventilation grille 32 is also fixed to the front portion 31a and the pair of side portions 31b in a way that prevents it from being easily removed, such as by spot welding.

[0025] Figure 4 is a bottom view showing the ventilation hood 20 of Figure 1. Figure 5 is a cross-sectional view of the ventilation hood 20 of Figure 1. Figure 6 is an enlarged view of the main part of the ventilation hood 20 of Figure 5.

[0026] The ventilation grille 32 is provided with multiple ventilation openings. Specifically, the multiple ventilation openings are located at the bottom of the hood body 30. The multiple ventilation openings include at least one exterior wall-side opening 32a and multiple outdoor-side openings 32b.

[0027] The exterior wall-side opening 32a is the ventilation opening that is closest to the exterior wall 11 among the multiple ventilation openings when the hood body 30 is installed on the exterior wall 11. In Figure 4, each of the three ventilation openings closest to the exterior wall 11 is an exterior wall-side opening 32a.

[0028] Each outdoor-side opening 32b is a ventilation opening located further from the outer wall 11 than the multiple outer wall-side openings 32a when the hood body 30 is installed on the outer wall 11. In Figure 4, all ventilation openings except for the three outer wall-side openings 32a are outdoor-side openings 32b.

[0029] The three exterior wall-side openings 32a and the multiple outdoor-side openings 32b are configured such that when air is discharged from the hood body 30 to the outside, the airflow velocity passing through each of the multiple outdoor-side openings 32b is faster than the airflow velocity passing through each exterior wall-side opening 32a.

[0030] Specifically, although no clear difference is shown in Figure 4, the opening area of ​​each of the multiple outdoor-side openings 32b in Embodiment 1 is smaller than the opening area of ​​each outer wall-side opening 32a.

[0031] Furthermore, although no clear difference is shown in Figure 4, the multiple outdoor openings 32b in Embodiment 1 are configured such that when air is discharged from the hood body 30 to the outside, the airflow velocity passing through each of the multiple outdoor openings 32b gradually increases from the side closer to the outer wall 11 to the side further away.

[0032] Specifically, the opening area of ​​each of the multiple outdoor openings 32b gradually decreases from the side closer to the exterior wall 11 to the side further away.

[0033] Furthermore, the ventilation grille 32 is provided with multiple flat guide sections 32c. That is, multiple guide sections 32c are provided on the lower part of the hood body 30.

[0034] Multiple guide sections 32c protrude diagonally from the edges of the ventilation openings on the outer wall 11 side, moving downwards and away from the outer wall 11. As a result, the multiple guide sections 32c straighten the jets entering or leaving the hood body 30.

[0035] As shown in Figure 6, the side of each guide section 32c opposite to the outer wall 11 forms an angle α with respect to the bottom surface of the hood body 30. The angle α is an acute angle between 50 degrees and 70 degrees.

[0036] Figure 7 is an explanatory diagram showing the analysis results of the airflow discharged from a conventional ventilation hood 50 as a comparative example. Figure 8 is an explanatory diagram showing the analysis results of the airflow discharged from the ventilation hood 20 of Embodiment 1. Figure 9 is an explanatory diagram showing the airflow in the ventilation hood 20 of Figure 8 as viewed from directly below the ventilation hood 20.

[0037] In the comparative example shown in Figure 7, the airflow velocity of the air discharged from the ventilation hood 50 is particularly high in the region in contact with the outer wall 11. In contrast, as shown in Figures 8 and 9, in the ventilation hood 20 of Embodiment 1, the velocity of the jet from the ventilation hood 20 gradually increases as it moves away from the outer wall 11.

[0038] Due to the Bernoulli effect, the pressure of a fluid decreases as the fluid velocity increases, so the pressure on the atmospheric side becomes lower than that on the outer wall 11 side. This pressure difference pulls particulate matter contained in the exhaust from the outer wall 11 side towards the atmosphere, thus suppressing the adhesion of particulate matter to the outer wall 11.

[0039] In this way, by intentionally creating a pressure difference as a change in flow velocity within the jet in the same flow field, it is possible to suppress contact of fine particles contained in the air discharged from the ventilation hood 20 with the outer wall 11.

[0040] Therefore, without complicating the shape of the ventilation grille 32 or increasing the number of parts, it is possible to control the jet flow from the ventilation grille 32, and with a simple configuration, it is possible to suppress the soiling of the outer wall 11 by contact of the discharged air with the outer wall 11.

[0041] Furthermore, by making the opening area of ​​each of the multiple outdoor-side openings 32b smaller than the opening area of ​​each outer wall-side opening 32a, the flow velocity of the jet from the outdoor-side openings 32b can be made faster than the flow velocity of the jet from the outer wall-side openings 32a with a simpler configuration. This also helps to avoid complicating the mold used when manufacturing the ventilation grille 32.

[0042] Furthermore, the ventilation hood 20 is composed of a base member 21, a pipe guide 22, a pair of fixing members 23, and a hood body 30. This simplifies the overall structure of the ventilation hood 20, making assembly and installation on the exterior wall 11 easier.

[0043] Furthermore, the hood body 30 is composed of a housing 31 and a ventilation grille 32. This simplifies the structure of the hood body 30 and facilitates its manufacture.

[0044] Furthermore, the hood body 30 is attached to the fixing member 23 by screwing mounting screws 24 into the screw holes 23a of the fixing member 23. This makes it easy to replace the hood body 30.

[0045] Furthermore, the multiple guide sections 32c protrude diagonally from the edges of the multiple ventilation openings on the outer wall 11 side, moving downwards and away from the outer wall 11. This allows for a more reliable reduction in the flow velocity of the exhaust jet in the area in contact with the outer wall 11. As a result, fouling of the outer wall 11 can be more reliably suppressed.

[0046] Figure 10 is an explanatory diagram comparing the analysis results of the airflow discharged from the ventilation hood 20 of Embodiment 1 with the exhaust pressure loss for cases where the angle α in Figure 6 is 50 degrees, 60 degrees, and 70 degrees. Figure 11 is a graph showing the relationship between the angle α in Figure 6 and the pressure loss.

[0047] As shown in Figures 10 and 11, by setting the angle α to 50 degrees or more and 70 degrees or less, it is possible to more reliably reduce the airflow velocity in the region in contact with the outer wall 11 while suppressing pressure loss.

[0048] When the angle α is greater than 70 degrees, the pressure loss inside the ventilation hood 20 is small because the bend in the exhaust jet is gentler. However, in this case, the angle β that the exhaust jet makes with the outer wall 11 becomes less than 10 degrees, and it is considered that the flow velocity of the exhaust jet in the region in contact with the outer wall 11 cannot be sufficiently reduced.

[0049] Furthermore, if the angle α is less than 50 degrees, the exhaust jet will bend sharply, resulting in a large pressure loss within the ventilation hood 20. Therefore, to ensure the required ventilation volume, it may be necessary to select a model with a larger exhaust capacity, potentially increasing the overall initial and running costs of the ventilation system.

[0050] Furthermore, comparing the case where angle α is 60 degrees with the case where it is 50 degrees, the pressure loss coefficient of the ventilation hood 20 increases by more than 30%, and the difference in ventilation fan airflow becomes larger. From this point of view, it is desirable to exclude configurations where angle α is less than 50 degrees from Embodiment 1.

[0051] Embodiment 2. Next, Figure 12 is a schematic diagram showing the main parts of the hood body 30 of the ventilation hood according to Embodiment 2. The bottom surface of the hood body 30 is provided with a number of ventilation openings, namely a first opening 35a, a second opening 35b, a third opening 35c, and a fourth opening 35d.

[0052] These ventilation openings are arranged in the order of first opening 35a, second opening 35b, third opening 35c, and fourth opening 35d, as they move away from the exterior wall 11. That is, the first opening 35a is an opening on the exterior wall side. The second opening 35b, third opening 35c, and fourth opening 35d are each openings on the exterior side.

[0053] Each ventilation opening is rectangular in shape, with its longer side aligned with the width direction of the hood body 30. Alternatively, each ventilation opening may be divided into multiple sections along the width direction of the hood body 30, as shown in Figure 4.

[0054] Furthermore, the bottom surface of the hood body 30 is provided with multiple guide sections, namely a first guide section 36a, a second guide section 36b, a third guide section 36c, and a fourth guide section 36d.

[0055] The first guide portion 36a protrudes diagonally from the edge of the first opening 35a on the side of the outer wall 11, moving away from the outer wall 11 as it goes downwards. The second guide portion 36b protrudes diagonally from the edge of the second opening 35b on the side of the outer wall 11, moving away from the outer wall 11 as it goes downwards.

[0056] The third guide portion 36c protrudes diagonally from the edge of the third opening 35c on the side of the outer wall 11, moving away from the outer wall 11 as it goes downwards. The fourth guide portion 36d protrudes diagonally from the edge of the fourth opening 35d on the side of the outer wall 11, moving away from the outer wall 11 as it goes downwards.

[0057] Each guide section is formed by punching out and bending the bottom surface of the hood body 30. Therefore, the dimensions of each guide section along the width direction of the hood body 30 are equal to the dimensions of each ventilation opening along the width direction of the hood body 30.

[0058] Furthermore, when the dimension perpendicular to the outer wall 11 in each ventilation opening is defined as the opening width, the opening width of each ventilation opening is equal to the length of the protrusion from the bottom surface of the hood body 30 in the corresponding guide section.

[0059] That is, when the opening width of the first opening 35a is a1, the protruding length of the first guide portion 36a from the bottom surface of the hood body 30 is also a1. Similarly, when the opening width of the second opening 35b is a2, the protruding length of the second guide portion 36b from the bottom surface of the hood body 30 is also a2.

[0060] Furthermore, when the opening width of the third opening 35c is a3, the protruding length of the third guide portion 36c from the bottom surface of the hood body 30 is also a3. Also, when the opening width of the fourth opening 35d is a4, the protruding length of the fourth guide portion 36d from the bottom surface of the hood body 30 is also a4.

[0061] Furthermore, the relationship a1 > a2 > a3 > a4 opening width holds true. In other words, the opening width gradually decreases as it moves away from the outer wall 11.

[0062] As a result, the opening areas of the first opening 35a, the second opening 35b, the third opening 35c, and the fourth opening 35d gradually decrease as they move away from the outer wall 11.

[0063] Furthermore, the distance from the outer wall 11 side end of the first opening 35a to the outer wall 11 side end of the second opening 35b is defined as b1. Also, the distance from the outer wall 11 side end of the second opening 35b to the outer wall 11 side end of the third opening 35c is defined as b2. The distance from the outer wall 11 side end of the third opening 35c to the outer wall 11 side end of the fourth opening 35d is defined as b3. Also, the distance from the outer wall 11 side end of the fourth opening 35d to the front part of the hood body 30 is defined as b4.

[0064] At this time, distance b1 = distance b2 = distance b3 = distance b4. In other words, each ventilation opening is arranged so that its end on the outer wall 11 side is arranged at equal intervals.

[0065] When air is discharged to the outside from the hood body 30, an airflow rate corresponding to the pitch of each ventilation opening is discharged from each ventilation opening. Furthermore, the airflow velocity of the discharged air is inversely proportional to the opening width. That is, the smaller the opening width, the faster the airflow velocity.

[0066] Therefore, if we denote the air velocity at the first opening 35a as V1, the air velocity at the second opening 35b as V2, the air velocity at the third opening 35c as V3, and the air velocity at the fourth opening 35d as V4, then V1, V2, V3, and V4 can be expressed as follows.

[0067] V1∝b1 / a1

[0068] V2∝b2 / a2

[0069] V3∝b3 / a3

[0070] V4∝b4 / a4

[0071] Here, since a1>a2>a3>a4 and b1=b2=b3=b4, the following relationship holds.

[0072] V1 <V2<V3<V4

[0073] In other words, the airflow velocity passing through each of the multiple ventilation openings gradually increases from the side closer to the exterior wall 11 to the side further away.

[0074] Other configurations in Embodiment 2 are the same as those in Embodiment 1.

[0075] Even with this configuration, a simple design can suppress soiling of the exterior wall 11 caused by contact with the exterior wall 11 when air is discharged outdoors.

[0076] Furthermore, the front shape of the hood body 30 is not limited to a rectangle; depending on the application or design, it may be, for example, round.

[0077] Furthermore, multiple outdoor openings may include two or more outdoor openings that have the same airflow velocity, i.e., the same opening area.

[0078] Although preferred embodiments have been described in detail above, the invention is not limited to the embodiments described above, and various modifications and substitutions can be made to the embodiments described above without departing from the scope of the claims.

[0079] The various aspects of this disclosure are summarized below as an appendix.

[0080] (Note 1) Hood body installed on the exterior side of the building's outer wall Equipped with, The lower part of the hood body is provided with multiple ventilation openings. The plurality of ventilation openings include an exterior wall-side opening located closest to the exterior wall when the hood body is installed on the exterior wall, and a plurality of exterior-side openings located further from the exterior wall than the exterior wall-side opening when the hood body is installed on the exterior wall. The ventilation hood is configured such that when air is discharged from the hood body to the outside, the airflow velocity passing through each of the multiple outdoor openings is faster than the airflow velocity passing through the outer wall opening. (Note 2) The ventilation hood described in Appendix 1, wherein the opening area of ​​each of the plurality of outdoor-side openings is smaller than the opening area of ​​the outer wall-side opening. (Note 3) The ventilation hood according to Appendix 1 or Appendix 2, wherein the plurality of outdoor openings are configured such that when air is discharged from the hood body to the outside, the airflow velocity passing through each of the plurality of outdoor openings gradually increases from the side closer to the outer wall to the side further away. (Note 4) The ventilation hood described in Appendix 3, wherein the opening area of ​​each of the multiple outdoor openings gradually decreases from the side closer to the outer wall to the side further away. (Note 5) The ventilation hood according to any one of the appendices 1 to 4, wherein the lower part of the hood body is provided with a plurality of guide portions that project diagonally from the edges of the plurality of ventilation openings on the outer wall side, so as they move downward, they move away from the outer wall. (Note 6) The ventilation hood described in Appendix 5, wherein the surface of each guide section opposite to the outer wall is at an angle of 50 degrees or more and 70 degrees or less with respect to the bottom surface of the hood body. (Note 7) A base member attached to the exterior wall, and Fixing member fixed to the base member Furthermore, The hood body is, A housing that covers the ventilation opening provided in the outer wall, A ventilation grille is attached to the lower part of the housing and has the plurality of ventilation openings provided therein. It has, The ventilation hood described in any one of the appendices 1 to 6, wherein the housing has a front section, a pair of side sections, and a top section integrally formed thereon. (Note 8) The aforementioned fixing member is provided with a screw hole. The hood body is, By screwing a mounting screw into the screw hole, it is attached to the fixing member. The ventilation hood according to Appendix 7, which can be removed from the fixing member by removing the mounting screw from the screw hole. [Explanation of Symbols]

[0081] 11 Exterior wall, 20 Ventilation hood, 21 Base member, 23 Fixing member, 23a Screw hole, 24 Mounting screw, 30 Hood body, 31 Housing, 31a Front part, 31b Side part, 31c Top part, 32 Ventilation grille, 32a Exterior wall side opening (ventilation opening), 32b Outdoor side opening (ventilation opening), 32c Guide part, 35a First opening (ventilation opening, exterior wall side opening), 35b Second opening (ventilation opening, outdoor side opening), 35c Third opening (ventilation opening, outdoor side opening), 35d Fourth opening (ventilation opening, outdoor side opening), 36a First guide part, 36b Second guide part, 36c Third guide part, 36d Fourth guide part.

Claims

1. Hood body installed on the exterior side of the building's outer wall Equipped with, The lower part of the hood body is provided with multiple ventilation openings. The plurality of ventilation openings include an exterior wall-side opening located closest to the exterior wall when the hood body is installed on the exterior wall, and a plurality of exterior-side openings located further from the exterior wall than the exterior wall-side opening when the hood body is installed on the exterior wall. The ventilation hood is configured such that when air is discharged from the hood body to the outside, the airflow velocity passing through each of the multiple outdoor openings is faster than the airflow velocity passing through the outer wall opening.

2. The ventilation hood according to claim 1, wherein the opening area of ​​each of the plurality of outdoor-side openings is smaller than the opening area of ​​the outer wall-side opening.

3. The ventilation hood according to claim 1, wherein the plurality of outdoor openings are configured such that when air is discharged from the hood body to the outside, the airflow velocity passing through each of the plurality of outdoor openings gradually increases from the side closer to the outer wall to the side further away.

4. The ventilation hood according to claim 3, wherein the opening area of ​​each of the plurality of outdoor openings gradually decreases from the side closer to the outer wall to the side further away.

5. The ventilation hood according to claim 1 or any one of claims up to 4, wherein the lower part of the hood body is provided with a plurality of guide portions that protrude diagonally from the outer wall-side edges of the plurality of ventilation openings, so as they move downward, they move away from the outer wall.

6. The ventilation hood according to claim 5, wherein the surface of each guide portion opposite to the outer wall is at an angle of 50 degrees or more and 70 degrees or less with respect to the bottom surface of the hood body.

7. A base member attached to the exterior wall, and Fixing member fixed to the base member Furthermore, The hood body is, A housing that covers the ventilation opening provided in the outer wall, A ventilation grille is attached to the lower part of the housing and has the plurality of ventilation openings provided therein. It has, The ventilation hood according to any one of claims 1 to 4, wherein the housing has a front portion, a pair of side portions, and a top portion integrally formed thereon.

8. The aforementioned fixing member is provided with a screw hole. The hood body is, By screwing a mounting screw into the screw hole, it is attached to the fixing member. The ventilation hood according to claim 7, which is removable from the fixing member by removing the mounting screw from the screw hole.

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