ES2904651T3 - Air duct arrangement for a downdraft smoke extraction device, a furniture plinth as well as a respective downdraft smoke extraction device - Google Patents

Abstract

Air conduction arrangement for a downward draft smoke extraction device with at least two plinth ventilation boxes (1) connected in series one behind the other for mounting on a furniture plinth (100), presenting the plinth ventilation boxes (1) at least one air outlet (2) covered by an exhaust air grille (23) and a first air inlet (3), presenting an inner face (5) of an upper face ( 6) of the plinth ventilation boxes (1) and/or of a lower face (7) of the plinth ventilation boxes (1) opposite the upper face (6) a housing (8) for a support leg (9), the plinth ventilation boxes (1) presenting a second air inlet (3), the first air inlet (3) being arranged in a first plane, the second air inlet (3) in a second plane distanced parallel to the first plane and the air outlet (2) in a third plane located orthogonal to the first and second plane, as well as between the first and second air inlet (3), the plinth ventilation boxes (1) presenting at least one air conduction element (4) housed in the plinth ventilation box (1) , through which the air entering the plinth ventilation box (1) is diverted in the direction of the air outlet (2), conducting a flow of air not diverted by the air conduction element (4) of the respective plinth ventilation box (1) through the second air inlet (3) to the first air inlet (3) of the next plinth ventilation box (1) in the direction of air flow, and leading from the first of the plinth ventilation boxes (1) a part of the air flow to the air outlet (2) of this plinth ventilation box (1) and another part of the air flow to the at least one box plinth ventilation box (1) that follows the first plinth ventilation box (1) in the direction of flow of the air current.

Description

DESCRIPTION

Air duct arrangement for a downdraft smoke extraction device, a furniture plinth as well as a respective downdraft smoke extraction device

The invention relates to an air duct arrangement for a downdraft smoke extraction device with at least two plinth ventilation boxes connected in series for mounting on the plinth of a piece of furniture.

Document DE 102008 033 792 A1 describes a plinth ventilation box for mounting in the plinth of a piece of furniture, the plinth ventilation box having at least one air outlet covered by an air outlet grille and a first air inlet. air, and an inner face of an upper face of the plinth ventilation box and/or of a lower face of the plinth ventilation box opposite the upper face has a receptacle for a support foot. Other similar plinth ventilation boxes are also described in US 3,926,171 A, DE 102015103034 A1, DE 102015103030 A1, DE 102015213471 A1 and DE 102009025038 A1. Plinth ventilation boxes of the type described above are used in particular in so-called downdraft air extraction systems, in which the vapors produced during cooking are sucked directly onto the hob, conducted through the kitchen cabinet kitchen and are expelled, after adequate filtration, as filtered air into the kitchen space through the plinth of the furniture. The filtration generates a considerable loss of pressure inside the plinth ventilation box, so a higher power of the fans is needed, which in turn leads to a high acoustic load, as well as lower energy efficiency. In addition, the conduction of vapors through the plinth area of the kitchen cabinet is sometimes structurally very complicated, since the air conduction system in the plinth can collide with the legs of the kitchen cabinets mounted there , and the air guide system therefore has to be assembled around the legs with corresponding expense of parts. The sometimes bulky plinth ventilation boxes for filtration as well as for exhaust air into the kitchen space cause constructive difficulties.

Therefore, the object of the invention is to improve an air supply arrangement of the type described above in such a way that it has a low pressure loss.

This task is solved by an air duct arrangement with the features of claim 1. Subclaim 14 relates to a corresponding furniture plinth and subclaim 15 to a corresponding downdraft air extraction device. Other advantageous embodiments of the invention are the subject of the dependent claims.

The air conduit arrangement furthermore allows it to be installed, instead of on a possibly existing furniture leg for construction reasons, on the plinth, so that it also takes over the supporting function provided by the furniture leg. For this, at least one support leg can be located in the housing and extend inside the plinth ventilation box between an upper face of the plinth ventilation box and a lower face of the plinth ventilation box. The support leg can preferably be retained in the housing by means of a form-fitting connection.

The plinth ventilation box has at least one air guide element housed in the plinth ventilation box, the air entering the plinth ventilation box through the air guide element being diverted in the direction of the air outlet. air.

Both the upper face and the lower face can be provided with at least one housing of the type described above. Respectively one of the receptacles of the upper part and of the lower part can be aligned oppositely. In this case, the support leg can be inserted with the first of its opposite ends in the first of the housings and with an end opposite to the first end in the second of the housings.

The plinth ventilation box can be supported with its underside on a base, for example on the floor of a building. In addition, a bottom element of a piece of furniture can also be supported on the upper face of the plinth ventilation box.

If a height compensation is necessary, for example, between the upper face of the plinth ventilation box and a bottom element of a piece of furniture, it can be foreseen that on the outer face of the upper face it is arranged, aligned with the support leg, a spacer, in particular a spacer sleeve, on whose support face opposite the outer face the bottom element is placed and supported. In a direction perpendicular to the upper face of the plinth ventilation box, the spacer advantageously has a dimension that exactly corresponds to the distance to be bridged between the upper face and the bottom element. The base element can be supported on the base by means of the spacer, the upper face of the plinth ventilation box, the support leg and the lower face of the plinth ventilation box. The support leg and/or the spacer can be adjusted in terms of height or length.

The upper face of the plinth ventilation box may be formed by an upper part and the lower face of the plinth ventilation box may be formed by a lower part which are joined together through a connection point, in particular an adhesive connection. The top and bottom can be injection molded plastic parts. In particular, the upper part and the lower part can be specially configured as identical parts.

The upper part and the lower part can have at least one opposed arcuate groove on their respective inner faces, into which the air guide element penetrates with opposite longitudinal edges.

The second air inlet can also take over the function of a second air outlet, for example when in a situation where several plinth ventilation boxes are aligned, the air enters through a first air inlet of a first ventilation box. plinth and from the first plinth ventilation box partly through the air outlet with the exhaust air grille and partly through the second "air inlet", to enter through the air inlet from a second plinth vent box into a second plinth vent box. The upper part and the lower part may have on their inner face a first pair and a second pair of opposite arcuate slots, the first pair of arcuate slots leading from the air outlet to the first air inlet and the second pair of arcuate slots from the air outlet to the second air inlet. In order to vary the conduction of air inside the plinth ventilation box, provision can be made in particular for the upper part and the lower part to have on their inner faces several pairs of opposing arched slots conducted from the air outlet to the same air inlet, but at a distance from each other. The distance can be extended along the development of the slots from the air outlet in the direction of the air inlet. If the upper part and the lower part are also identical parts, the assembly can be carried out regardless of the direction of flow and, after pre-assembly of the housing in the plinth area, it is only necessary that the air guide elements be inserted , as needed, into the corresponding pairs of slots.

The upper part and the lower part can present on their inner faces two curved slots configured as slots in the shape of a parabola.

The geometry of curvature of the different pairs of arcuate slots can be identical, so that the same air guide element with the same geometry of curvature as the arcuate slots can optionally be inserted into any pair of opposite arcuate slots through their opposite longitudinal edges. The plinth ventilation box may have a notched shape with a wide part supporting the exhaust air grille and having at least a first width corresponding to the width of the filter, and with a part adjacent to the wide part having a second width less than the width of the filter, the at least one air inlet being arranged on an outer face of the narrow part arranged in the widthwise direction of the narrow part. When the plinth ventilation box is provided with two air inlets or one air inlet and one air outlet, these can be arranged in the widthwise direction of the narrow part on the outer faces of the narrow part. Due to its notched shape, the plinth ventilation box occupies a particularly small space.

According to another aspect, a furniture plinth is described in which a plinth ventilation box of the type described above is mounted, placing a free edge of the lower face of the plinth ventilation box oriented towards the outer face of the furniture plinth further back with respect to a front alignment of the furniture plinth, and a sealing lip being arranged on a lower edge of the exhaust air grille between the free edge and the front alignment of the furniture plinth, whereby it fits snugly airtight to a base of the furniture plinth, especially to the floor of a building.

According to yet another aspect, a downward draft smoke extraction device is described with at least two plinth ventilation boxes of the aforementioned type, in which the plinth ventilation boxes with the air outlet open towards the face. outside of the furniture plinth and in which the plinth ventilation boxes as well as a downdraft smoke extractor are connected to an air duct arrangement. Through the downdraft smoke extractor, the steam from the hob located on an upper face of a piece of furniture placed on the plinth of the piece of furniture is introduced into the air ducting arrangement, it is led through the ducting arrangement of air and is exhausted through the at least two ventilation boxes in the plinth of the air duct arrangement.

For installation, the plinth ventilation box can be inserted from the front into the furniture plinth and then fastened to the plinth strips. As described above, the plinth ventilation box has a housing for the positioning of a support leg. This housing can be, in particular, a positive-fit housing on the inside face of the upper part or the lower part of the plinth ventilation box. The support leg can be optionally inserted to provide stability to the superimposed structure. The support leg can, for example, replace a factory-fitted kitchen cabinet leg. For fixing the support leg, it can be inserted into the described receptacle and fixed by adjusting the height, in particular by adjusting the length of the support leg through prestressing between the upper face and the lower face. of the plinth ventilation box.

Inside the plinth ventilation box there are guide bodies that direct part of the flow towards the air outlet, thus reducing the pressure loss in the plinth ventilation box. The length of the guide body can depend on the respective position of the plinth ventilation box. As for the flow, Plinth vent boxes may be connected in series using flexible tubing or the like. In the plinth ventilation box, which is the last in flow direction, (virtually) the entire remaining flow can be diverted in the direction of the air outlet of the corresponding plinth ventilation box.

The air conduction elements can be fastened inside the plinth ventilation box between the upper face and the lower face of the plinth ventilation box, preferably establishing a detachable connection between the air conduction elements and the faces. upper and lower, so that, if necessary, the air guide elements can be removed and repositioned. In particular, it is also possible to use several air guide elements, possibly with different curvatures, in a plinth ventilation box. The air guide elements can have a constant or variable cross-section in the flow direction.

The plinth ventilation box can have, located in the direction of flow in front of the air outlet, a condensed vapor retention edge that prevents the condensate from leaving the plinth ventilation box. For the connection of the plinth ventilation box to a flexible tube or to a ventilation pipe, an adapter can be provided, which is attached to the plinth ventilation box, for example, via a clip connection. The flexible tube can be slid over the adapter and fixed fluid-tight with the aid of a clamp or the like. If the plinth ventilation box has several air inlets, it can be provided that an unneeded air inlet can optionally be closed with the aid of a cover. In the case of an arrangement of several plinth ventilation boxes connected in series, as described above, it is possible that, in particular, the last plinth ventilation box viewed in the direction of air flow has an air inlet. closed by a lid.

The plinth vent box can be notched so that the described tube adapters do not protrude excessively from the sides. This allows assembly, even when the distance between the furniture legs is very small, without the need to remove the furniture legs.

The surface of the air outlet can be covered with activated carbon filter, and the filter surface can be curved once or multiple times. Compared to a straight filter, the filter surface is increased and the flow rate through the filter fluid is reduced due to the higher flow resistance, thus increasing the filtration effect. The curvature of the filter has the advantage that air always flows through filter layers that are first stretched and then compressed. This increases the exchange of substances between activated carbon and odor particles and intensifies the filtration effect.

An air outlet grille of the plinth ventilation box may consist of sheets of aerodynamic configuration, the activated carbon filter and the ventilation grill forming a unit. The two elements can be fixed on respective supports located respectively on the left and on the right of the unit. It can be envisaged that the unit is inserted and fixed in the plinth fan box by means of a magnetic connection.

The sheets can be inserted individually into the holder and mounted or removed at any time by means of a clip connection. A bottom sheet can be distinguished from the others by the fact that it is designed to rest with its bottom edge on a base, for example on the floor of a building, presenting for this purpose an additional joint, for example a sealing lip.

The exhaust air can be supplied to the plinth ventilation boxes through a flexible tube or a rigid channel by means of a fan, for example, a downdraft smoke extractor. Due to the installation situation, the channel can preferably have a rectangular cross-section. The air can be conducted through one or several series-connected plinth ventilation boxes of the type described above, the number of plinth ventilation boxes being selectable depending on the situation. Due to the pressure loss and the cleaning effect of activated carbon filters, two to three plinth ventilation boxes can preferably be used, depending on the case of application.

The air outlet grille can be connected inside to a filter insert. The filter insert can have a flat or curved filter substrate or one with several curves. The arched or multi-curved filter substrate can be fixed via its opposite ends in the exhaust air grille. In order to further increase the effective cross-section of the filter substrate, provision can be made for the curved or multi-curved filter substrate to be arranged around the at least one support leg.

Other details of the invention are explained in view of the following figures. These show in the:

Figure 1 a first embodiment of a plinth ventilation box mounted on a plinth ventilation box, in a perspective view;

Figure 2 a perspective view on the inside face of an upper part or a lower part of a plinth ventilation box according to an embodiment of the invention;

FIG. 3 a perspective view of an air inlet of a plinth ventilation box according to an embodiment of the invention;

Figure 4 a perspective view of a plinth ventilation box according to an embodiment of the invention with the upper part removed;

FIG. 5 a cross-sectional view of a mounting situation of a plinth ventilation box in a schematic representation;

Figure 6 an air duct arrangement in the plinth of a piece of furniture using several plinth ventilation boxes according to an embodiment of the invention;

FIG. 7 another embodiment of a plinth ventilation box mounted on the plinth of a piece of furniture, in a perspective view and

FIG. 8 is a further embodiment of a plinth ventilation box mounted on the plinth of a piece of furniture, in a perspective view.

Figure 1 shows, by way of example, an embodiment of a plinth ventilation box 1 mounted on a furniture plinth 100 with an exhaust air grille 23 removed and a filter insert 18 fixed inside it. the grid. The plinth ventilation box 1 is inserted into the plinth 100 through an opening in the front face of the plinth 100, so that the plinth ventilation box 1 is located in the furniture plinth 100 below a piece of furniture. kitchen, for example. The plinth ventilation box 1 has an air outlet 2 as well as two air inlets 3. One of the air inlets 3 is closed by a cover 20. Through the other unclosed air inlet 3, the box Plinth 1 vent can be connected to a downdraft fume extractor. A corresponding downdraft smoke extraction device is known, for example, from DE 102015103034 A1 and will not be described in detail here.

The plinth ventilation box 1 has an upper part 13 and a lower part 14, which can essentially be configured as equal parts. The upper part 13 and the lower part 14 are connected to each other through a connection point 19, for example an adhesion point. The upper part 13 and the lower part 14 can be configured, for example, as injection molded parts of plastic material. The upper part 13 and the lower part 14 have a housing 8 on their inner face 5, respectively. The housings 8 are arranged opposite and aligned. In particular, the housings 8 can consist of a positive connection housing for the reception in drag in the form of a support leg (not shown), in order to support the upper part 13 in front of the lower part 14, so that the plinth vent box 1 can take over the functions of a furniture leg. In order to avoid an off-center loading of the plinth ventilation box outside the housings 8, the housing 8 formed on the inner face 5 of the upper part 13 can also be seen on the outer face 10 of the upper part 13 which forms the face top 6 of the plinth ventilation box 1.

An edge 16 of the lower part 14 of the plinth ventilation box oriented towards the front face of the plinth 1 is arranged further back compared to a front line of the furniture plinth 100 in the front part of the base 10. What is indicated by the two arrows pointing towards each other. In the case of the exhaust air grille 23 and the filter insert 18 mounted on the air outlet 2, a sealing lip 17 is arranged in the area between the edge 16 and the front line of the furniture plinth 100, which can sealing the exhaust air grille 23 against a base of the plinth ventilation box 1, for example, the floor of a building.

Observing figures 1 and 2 together, it can be seen that on the inner face 5 a first elevation 21 and a second elevation 23 have been configured, positioned further back with respect to the edge 16. The elevation 26, which in relation to the edge 16 is the first, it is a fixing elevation with the help of which the filter insert 18, and thus also the exhaust air grille 23, are held and sealed in the air outlet 2 in their mounting position.

The elevation 21, displaced parallel to the fixing elevation 26 towards the interior of the base ventilation box 1, is a condensate retention edge that extends uninterruptedly between the opposite partition walls 27 of the upper part and the lower part. lower 13, 14.

In figure 2 it can also be seen that the housing 18 can be configured fundamentally as an annular elevation on the inner face 5 of the upper part 13 or of the lower part 14, which can correspond to the outer diameter of a support leg ( not shown), so that the housing 8 forms a form-locking housing for the support leg.

The upper part 13 or the lower part 14 also has a plurality of slots 15 on its inner face 5 which can serve to receive an air conduction element (not shown). As can be seen, two slots 15 have been configured that extend from the air outlet 2 in the direction of the first of the two air inlets 3, and another two slots 15 that extend from the air outlet 2 in the direction of the second of the air inlets 3. The two slots 15 extending towards the same air inlet 3 run respectively from an edge area of the air outlet 2 to different areas of the respective air inlet 3. Depending on the which of the two slots 15 extending in the direction of the same air inlet 3 an air guide element is inserted, a different division of the air flow occurs, for example to adapt the plinth ventilation box 1 to a situation of alignment of several plinth ventilation boxes (compare figure 6).

Figure 3 shows an embodiment of a plinth ventilation box 1, in which one of the two air inlets 3 is closed by a cover 20. The upper part 13 and the lower part 14 of the plinth ventilation box plinth 1 shown in figure 3 can be configured according to the upper part 13 and the lower part 14 shown in figure 2. As can be seen in figure 3, both slots 15, which extend between the air outlet 2 and the open air inlet 3, have been inserted into both air conduction elements 4, therefore that the air stream entering through the open air inlet 3 continuously deflects from the inlet direction perpendicular to the cross section of the air inlet to the outlet direction perpendicular to the air outlet 2, whereby turbulence inside the plinth ventilation box and thus pressure losses are reduced.

Further details of the arrangement according to Figure 3 are shown in Figure 4, which also allows one to recognize that the exhaust air grille 23 is arranged, in its illustrated mounting position, with respect to the furniture plinth 100 such that the grille air outlet 23 is aligned with the outer face of the furniture plinth 100. To connect the plinth ventilation box 100 to a channel system of an air duct arrangement, the open air inlet 3 has a pipe adapter hose 22 that can be inserted into the air inlet 3 and that has an outer contour that allows a hose to be attached, for example with the aid of a hose clamp.

Figure 5 schematically shows, by way of example, an arrangement in which a cabinet bottom 300 rests, via a plinth ventilation box 1 according to the invention, on a base 200, for example on the floor of a building. For this, the plinth ventilation box 1 has on its inner faces 5 of the upper face 6 and of the lower face 7 respectively a housing 8, between which a support leg 9 extends located with the first of its opposite ends in the housing 8 of the inner face 5 of the upper face 6, and with the second of its ends opposite the first end, in a housing formed in the inner face 5 of the lower face 7, with which it supports the upper face 6 in front of the lower face 7. In alignment with the housings 8 and the support leg 9, a spacer 11 is arranged on the outer face 10 of the upper face 6, which saves a distance between the outer face 10 of the upper face 6 and the bottom of the cabinet 300, so that finally the bottom of the cabinet 300 rests through the spacer 11, the upper face 6, the support leg 9 and the lower face 7 on the base 2.

In this way, the plinth ventilation box 1 is not only an integral component of an exhaust air system with a corresponding air-guiding function. Rather, according to the invention, it fulfills a double function, since in addition to its function of conducting air it is prepared to support the piece of furniture, on whose plinth 100 the plinth ventilation box 1 has been mounted. This allows a leg The cabinet provided by the manufacturer at the bottom of the cabinet 300 can be removed and replaced by the arrangement shown in Figure 5 without reducing the stability of the cabinet.

Figure 6 shows, finally, an air duct arrangement according to the invention in which three plinth ventilation boxes 1 have been connected in series. With this use of the plinth ventilation box 100, the air inlet hole 3, which in the plinth ventilation box 1 according to figure 6 is the left, as well as in the central plinth ventilation box 1 is the right, is actually an air outlet, since through the In the same way, the undeflected air flow is led in each case by the air guide element 4 of the respective plinth ventilation box 1 towards the next plinth ventilation box in the flow direction. The plinth ventilation boxes 1 are connected via flexible tubes 25 to an air duct system, for example to a downdraft smoke extraction device, and to each other. The air inlet 3, which in the illustration is on the right and in the flow direction the last, is closed by a cover 20. As described in connection with figure 5, the plinth ventilation box 1, which in the illustration is the center one, it has a support leg 9.

The embodiments shown in FIGS. 7 and 8 differ from the variant according to FIG. 4 in particular in that the arcuate groove 15 is elliptically shaped, thus forming a continuous one-piece groove in which the flow guide element air 4 can optionally be introduced into one of its two halves to divert air from the respective open inlet 3 to outlet 2, depending on which of the inlets 3 is closed by the lid.

While the filter substrate 24 in the variant embodiment according to FIG. 8 is arranged straight and parallel to the exhaust air grille 23, the substrate 24 in the variant embodiment according to FIG. 7 is arranged in the form of arc around the support leg 9, whereby it has a correspondingly larger filter surface and, measured in the direction of air flow, a larger effective thickness.

Reference list:

1 Plinth Vent Box

2 air outlet

3 Air inlet

4 Air guide element

5 Inner face

6 Top face

Underside

Accommodation

support leg

outer face

spacer

support side

Upper part

bottom

Slot

Singing

sealing lip

filter insert

Connection point

Top

Condensate retaining edge Hose adapter Exhaust air grille Filter substrate

Flexible tube

Fixation elevation

partition wall

filter substrate

furniture plinth

Base

background element

Claims (15)

1. Air duct arrangement for a downdraft smoke extraction device with at least two plinth ventilation boxes (1) connected in series one behind the other for mounting on a furniture plinth (100), the plinth ventilation boxes (1) presenting at least one air outlet (2) covered by an exhaust air grille (23) and a first air inlet (3), presenting an inner face (5) of a face (6) of the plinth ventilation boxes (1) and/or of a lower face (7) of the plinth ventilation boxes (1) opposite the upper face (6) a housing (8) for a leg support (9), the plinth ventilation boxes (1) presenting a second air inlet (3), the first air inlet (3) being arranged in a first plane, the second air inlet (3) in a second plane spaced parallel to the first plane and the air outlet (2) in a third plane located orthogonally to the first er and second plane, as well as between the first and second air inlet (3), the plinth ventilation boxes (1) presenting at least one air conduction element (4) housed in the plinth ventilation box (1 ), through which the air entering the plinth ventilation box (1) is diverted in the direction of the air outlet (2), conducting an air flow not diverted by the air conduction element (4) from the respective plinth ventilation box (1) through the second air inlet (3) to the first air inlet (3) of the next plinth ventilation box (1) in the air flow direction, and taking from the first of the plinth ventilation boxes (1) a part of the air flow to the air outlet (2) of this plinth ventilation box (1) and another part of the air flow to the at least one plinth ventilation box (1) that follows the first plinth ventilation box (1) in the direction of air flow. 2. Air conduction arrangement according to claim 1, in which at least one support leg (9) is arranged in the housing (8) and extends inside the plinth ventilation boxes (1) between the upper face (6) of the plinth ventilation box (1) and the lower face (7) of the plinth ventilation box (1) and is preferably retained through a positive connection in the housing (8). 3. Air conduction arrangement according to claim 2, in which both the upper face (6) and the inner face (5) have a housing (8) arranged aligned and opposite each other, with the support leg ( 9) with one of its opposite ends in one of the housings (8) and with an end opposite the first end in the second of the housings (8). Air duct arrangement according to claim 2 or 3, in which the plinth ventilation boxes (1) rest with their underside (7) on a base (200), in particular on the floor of a building , and on whose upper face (6) a bottom element (300) of a piece of furniture rests. 5. Air conduction arrangement according to claim 4, in which a spacer (11) is arranged on an outer face (10) of the upper face (6), aligned with the support leg (9), a spacer sleeve, on whose upper support side (12) opposite the outer face (10) the bottom element (300) rests. 6. Air duct arrangement according to claim 5, in which the bottom element (300) is supported by the spacer (11), the upper face (6), the plinth ventilation box (1), the support leg (9) and the lower face (7) of the plinth ventilation box (1) on the base (200). Air duct arrangement according to one of the preceding claims, in which the upper face (6) of the plinth ventilation box (1) is formed by an upper part (13) and the lower face (7) of the plinth ventilation box (1) is formed by a lower part (14), which are connected to each other through a connection point (19), especially an adhesive connection, the upper part (13) and the lower part being configured (14) preferably as identical pieces. Air duct arrangement according to one of the preceding claims, in which the upper face (6) of the plinth ventilation boxes (1) is formed by an upper part (13) and the lower face (7) of the plinth ventilation box (1) is formed by a lower part (14), presenting the upper part (13) and the lower part (14) on its inner faces (5), and oppositely, respectively, at least one arched slot (15) into which the air conduction element (4) penetrates with opposite longitudinal edges. 9. Air conduction arrangement according to claim 8, in which the upper part (13) and the lower part (14) have on their inner faces (5), in opposite directions, a first and a second pair of arched slots (15), leading the first pair of arcuate slots (15) from the air outlet (2) to the first air inlet or (3) and the second pair of arcuate slots (15) from the air outlet (2 ) to the second air inlet (3). Air duct arrangement according to claim 8 or 9, in which the upper part (13) and the lower part (14) have on their inner faces (5), opposite each other, an arcuate slot (15) configured as a parabolic groove. Air guide arrangement according to claim 9 or 10, in which a curvature geometry of the arcuate slots (15) is identical, so that the same air guide element (4) can be accommodated with the geometry of curvature, through their opposite longitudinal edges, optionally in the first pair of opposed arcuate grooves (15) or in the second pair of opposed arcuate grooves (15). Air duct arrangement according to one of the preceding claims, in which the exhaust air grille (23) is internally connected to a filter insert (18) comprising an arched or multi-curved filter substrate (28). Air duct arrangement according to one of the preceding claims, having a notched shape, with a wide section supporting the exhaust air grille (23) and having at least a first width corresponding to the width of the filter, and with a narrow section adjoining the wide section, which has a second width less than the width of the filter, the at least one air inlet (3) being arranged on an outer face of the narrow area. Furniture plinth (100) with an air duct arrangement according to one of the preceding claims mounted on the furniture plinth (100), with a free edge (16) facing the outside of the furniture plinth (100) of the lower face (7) of the plinth ventilation boxes (1) further back compared to a previous line of the furniture plinth (100), and having a sealing lip (17) on one of the lower edges of the exhaust air grille (23) between the free edge (16) and the front line of the furniture plinth (100), so that it fits a base (200) of the furniture plinth (100), especially the floor of a building, and seal it. Downdraft smoke extraction device with an air duct arrangement according to one of claims 1 to 12 mounted on a furniture plinth (100), in which the plinth ventilation boxes (1) open with the air outlet (2) towards an outer face of the furniture plinth (100), connecting a downdraft smoke extractor to the air conduction arrangement, introducing through the downdraft smoke extractor the vapor sucked from a hob located on the upper face of a piece of furniture mounted on the furniture plinth (100) in the air conduction arrangement, the mist being carried through the air conduction arrangement and being expelled through the air outlet (2) from the plinth ventilation box (1) of the air duct arrangement.