WO2015057072A1

WO2015057072A1 - Kitchen air extraction canopy having a cavity with air guiding and directing delimiting wall

Info

Publication number: WO2015057072A1
Application number: PCT/NL2014/050725
Authority: WO
Inventors: Hendrikus Joseph Vianen
Original assignee: Randolph Beleggingen B.V.
Priority date: 2013-10-17
Filing date: 2014-10-17
Publication date: 2015-04-23

Abstract

A kitchen air extraction canopy (1) comprises an extraction area (10) for extracting air from a kitchen space (200), especially from a space above cooking equipment (100), away through the extraction area; and a cavity (20) for collecting air drawn from the kitchen space through an open downward facing side (21) of the cavity into the cavity towards the extraction area (10), the extraction area being arranged in a wall of the cavity. The cavity comprises a guiding delimiting wall (22) configured such that air within the cavity is guided along the guiding delimiting wall and directed by the guiding delimiting wall in a direction substantially along the open downward facing side (21) of the cavity. Preferably, the guiding delimiting wall is configured such that air is guided in a laminar flow condition along the guiding delimiting wall. The canopy further allows introduction of additional air into the cavity (20) adjacent to and along the guiding delimiting wall (22) such as to provide an additional air flow along the guiding delimiting wall.

Description

KITCHEN AIR EXTRACTION CANOPY HAVING A CAVITY WITH AIR

GUIDING AND DIRECTING DELIMITING WALL

FIELD OF THE INVENTION

The invention relates to a kitchen air extraction canopy comprising an extraction area arranged for extracting air from a kitchen space, especially from a space above cooking equipment, away through the extraction area; and a cavity arranged for collecting air drawn from the kitchen space through an open downward facing side of the cavity into the cavity towards the extraction area, the extraction area being arranged in a wall of the cavity.

BACKGROUND OF THE INVENTION

Kitchen air extraction canopies are generally known and especially applied above cooking stoves to draw away any fumes and vapor from cooking pans heated on the stove. It is intended to not have such fumes and vapor enter the kitchen area. To achieve so the air extraction capacity can be set at a high level, which requires high capacity ventilators in the canopy and drawing large volumes of air from the kitchen area.

This is quite inefficient from at least two points of view. It takes a large electrical power to drive the canopy ventilators with associated costs. Further, the air that is drawn away and exhausted through the canopy mostly has been brought to a required temperature by heating or cooling and may generally have been air-conditioned.

Exhausted thus treated air from the kitchen environment implies that it has to be replaced by air that is again to be heated, cooled and/or air-conditioned, which again consumes power and associated costs. It also requires that any heating, cooling and/or air-conditioning equipment should have a larger capacity.

Additionally, operating the canopy at large extraction capacity will cause a draught in the kitchen area, which is uncomfortable. Operating the canopy and its ventilators at high capacity will also induce high noise levels, which is extremely unpleasant.

Air extraction canopies draw air towards the canopy to extract it from the kitchen area into an extraction duct arrangement. However, more air may be drawn towards the canopy than actually can be extracted into the duct arrangement and part of the air flow generally rebounds again into the kitchen area, which greatly reduce the efficiency of the extraction canopy.

GB 1 545 217 and US 4,085,736 disclose extraction canopies for drawing air from a kitchen space. The extraction canopies have a cavity with an internal shape intended to create a vortex in an air flow drawn from the kitchen area to improve the extraction efficiency of the canopies.

SUMMARY OF THE INVENTION

It is an objective of the invention to provide a kitchen air extraction canopy that efficiently removes fumes and vapor from a kitchen area.

It is another or alternative objective of the invention to provide a kitchen air extraction canopy that removes fumes and vapor from the kitchen area at limited extraction capacity.

It is yet another or alternative objective of the invention to provide a kitchen air extraction canopy that operates at low noise levels.

It is yet another or alternative objective of the invention to provide a kitchen air extraction canopy that prevents rebound of fumes and vapors by the canopy into the kitchen area.

At least one of these objectives is achieved by a kitchen air extraction canopy comprising

- an extraction area arranged for extracting air from a kitchen space, especially from a space above cooking equipment, away through the extraction area; and

- a cavity arranged for collecting air drawn from the kitchen space through an open downward facing side of the cavity into the cavity towards the extraction area, the extraction area being arranged in a wall of the cavity,

wherein the cavity comprises a guiding delimiting wall that is configured such that air within the cavity is guided along the guiding delimiting wall and directed by the guiding delimiting wall in a direction substantially along the open downward facing side of the cavity, and

wherein the canopy is constructed such as to allow introduction of additional air into the cavity adjacent to and along the guiding delimiting wall such as to provide an additional air flow along the guiding delimiting wall, which additional air flow is directed by the guiding delimiting wall in a direction substantially along the open downward facing side of the cavity.

Such configuration of the guiding delimiting walls directs the air such that it will better remain within the inner cavity of the kitchen canopy such that it will be more efficiently be extracted by the ventilator(s) into an extraction arrangement associated with the ventilator(s). Air flowing into the cavity and not immediately extracted through the extraction surface(s) is guided and redirected such as to remain inside the cavity. The additional air flow entrains air within the inner cavity along the guiding delimiting wall. Having the additional air flow introduced along the guiding delimiting wall efficiently induces or at least improves the vortex within the cavity in the air flow drawn from the kitchen space. A good vortex in the air flow within the cavity improves the extraction efficiency of the canopy and the additional air flow proves to enhance such efficiency. A layer of air in contact with the guiding delimiting surface(s) further establishes to some extent an air screen along the open downward facing side of the cavity. The air screen will additionally act to keep air other than within the air layer inside the cavity.

Such embodiment proves more efficient when the canopy is constructed such as to allow injection of pressurized additional air into the cavity adjacent to and along the guiding delimiting wall such as to provide an additional air flow along the guiding delimiting wall, which additional air flow is directed by the guiding delimiting wall in a direction substantially along the open downward facing side of the cavity, which provides a well-directed flow of air along the guiding delimiting wall. The injected air can be provided with a sufficient flow velocity and momentum to have a well-defined air screen along the open downward facing side of the cavity, which assists in keeping air trapped within the cavity.

In an embodiment additional air openings (which can also be referred to as air outlets) are provided in the guiding delimiting wall for the introduction of additional air into the cavity adjacent to and along the guiding delimiting wall. In another

embodiment additional air openings are provided in the guiding delimiting wall for the introduction of pressurized additional air into the cavity, adjacent to and along the guiding delimiting wall.

Preferably, the additional air openings are configured and/or shaped such as to direct additional air introduced through the additional air openings along the guiding delimiting wall such as to provide an additional air flow along the guiding delimiting wall, which additional air flow is directed by the guiding delimiting wall in a direction substantially along the open downward facing side of the cavity.

In another embodiment the additional air openings are distributed over at least a portion of the guiding delimiting wall, so that an additional air flow is created at multiple locations for improved entrainment of air within the cavity and improved vortex creation.

In an efficient embodiment, in operation, additional air is introduced into the cavity from a plenum adjacent the cavity. In an embodiment the plenum is separated from the cavity by the guiding delimiting wall.

Preferably, the guiding delimiting wall is configured such that air is guided in a laminar flow condition along the guiding delimiting wall, which prevents occurrence of turbulence in the air flow. Having turbulence within the cavity enhances the risk of air to escape again from the cavity, which is suppressed by having a laminar air flow along the guiding wall(s).

In an embodiment the guiding delimiting wall is configured in a continuous, semi-continuous or substantially continuous configuration, which enhances formation of a laminar flow condition of air guided along the guiding delimiting wall.

In a preferred embodiment an edge region of the guiding delimiting wall adjacent to the open downward facing side of the cavity is directed essentially parallel to the open downward facing side of the cavity, which efficiently directs an air flow guided by the guiding delimiting wall(s) along the open downward facing side of the cavity.

In an embodiment a region of the guiding delimiting wall is configured such that air is guided in an outward direction with respect to the canopy.

In an embodiment the canopy is constructed such that air drawn from the kitchen space and collected into the cavity in a direction towards a top delimiting wall part of the cavity is guided along the guiding delimiting wall and directed by the guiding delimiting wall in a direction substantially along the open downward facing side of the cavity. Part of the air flow not immediately extracted from the cavity through the extraction surface will be guided by the guiding delimiting wall(s) and become trapped inside the cavity for subsequent efficient removal through the extraction surface. Not all air drawn into the cavity of the canopy may be exhausted immediately through the extraction area into an extraction duct arrangement.

Such embodiment is more efficient when the canopy is constructed such as to allow injection of pressurized air into the cavity adjacent to and along the guiding delimiting wall such as to provide an air flow along the guiding delimiting wall, which air flow is directed by the guiding delimiting wall in a direction substantially along the open downward facing side of the cavity, which provides a well-directed flow of air along the guiding delimiting wall. The injected air can be provided with a sufficient flow velocity and momentum to have a well-defined air screen along the open downward facing side of the cavity, which assists in keeping air trapped within the cavity. In an embodiment air outlets are provided in the guiding delimiting wall for the introduction of pressurized air into the cavity adjacent to and along the guiding delimiting wall.

In an advantageous embodiment the guiding delimiting wall is configured such that air within the cavity is guided along the guiding delimiting wall and directed by the guiding delimiting wall in a direction substantially along the open downward facing side of the cavity so as to provide an air screen along at least part of to the open downward facing side of the cavity. Such configuration can be efficiently manufactured and provides enhanced trapping of air within the cavity by the air screen along its open downward facing side.

In a preferred embodiment the canopy comprises a front side and the cavity comprises a front side region associated with the front side, the front side region of the cavity comprising the guiding delimiting wall such that air guided along the guiding delimiting wall is directed towards a back side of the canopy. Any air from the kitchen area above the cooking stove is thus guided towards a backside of the canopy.

Generally, the canopy is provided with its backside against a wall or against the backside of another canopy, which yields improved entrainment and extraction of air. The air is guided away from the front side of the canopy, which is away from the area where kitchen personnel is working.

Preferably, the extraction area is arranged in a back side region of the cavity, the back side region being associated with the back side of the canopy, which further assists in a backwards directed air flow for better extraction of air from the kitchen area.

Advantageously, the extraction area is arranged in a slanted position, which further improves a well-directed air flow for enhanced extraction of air. Air is both drawn towards the back side and upwards. In an embodiment the canopy comprises opposing longitudinal sides and the cavity comprises longitudinal regions associated with the longitudinal sides, one or both longitudinal regions comprising the guiding delimiting wall such that air guided along the guiding delimiting wall is directed along the open downward facing side of the cavity at one longitudinal side of the canopy towards the opposing longitudinal side. Such canopy is especially suited as a free hanging canopy to be able to assess a kitchen area from both longitudinal sides of the canopy. Air from the kitchen area is directed towards a central position of the canopy for an efficient extraction at reduced or absent rebound of air into the kitchen area again. The air is drawn away from the area where kitchen personnel is working.

In another embodiment the extraction area is arranged in a substantially horizontal position, the extraction area preferably being arranged in a central location of the canopy, which further improves air to be drawn to a central area of the canopy.

In an advantageous embodiment the canopy comprises opposing flank sides and the cavity comprises flank side regions associated with the flank sides, one or both flank side regions of the cavity comprising the guiding delimiting wall such that air guided along the guiding delimiting wall is directed at one flank side of the canopy towards the opposing flank side. Such embodiment provides that air from the kitchen area is directed away from the flank sides to under the canopy for enhanced air extraction.

In another aspect the invention relates to a kitchen air extraction canopy comprising an extraction area arranged for extracting air from a kitchen space, especially from above a space above cooking equipment, away through the extraction area; and a cavity arranged for collecting air drawn from the kitchen space through an open downward facing side of the cavity into the cavity towards the extraction area, the extraction area being arranged in a wall of the cavity.

In a preferred embodiment the canopy comprises an air jet arrangement constructed and arranged at one or more sides of the canopy such as to provide one or more air jet streams below and along the open downward facing side of the cavity, the air jet stream(s) being directed to an opposing side, and the one or more sides comprising at least one of a front side, flank sides and longitudinal sides of the canopy. Having the air jet streams improves guiding of air to under the canopy from the kitchen area and along the open downward facing side of the cavity of air within the cavity for improved extraction and guiding and trapping of air.

Advantageously, the air jet arrangement is constructed and arranged such that the air jet stream(s) provide an air screen below and along the open downward facing side of the cavity. Having an air screen along the open side improves the trapping capability of air within the cavity of the kitchen canopy and thus enhances the extraction efficiency.

In a preferred embodiment the air jet arrangement comprises an air outlet constructed for ejected the air jet stream and an air jet guiding surface above the air outlet, the air jet guiding surface being directed parallel to the open downward facing side of the cavity. The guiding surface for the air jet stream provides a sharply defined top surface of the air jet stream and/or air jet screen to provide an efficient barrier for keeping air within the cavity of the kitchen canopy. Air trapped within the barrier will be reflected from the smooth top surface of the air jet streams and/or air jet screens and not mix.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages of the invention will become apparent from the description of the invention by way of non-limiting and non-exclusive embodiments. These embodiments are not to be construed as limiting the scope of protection. Various other embodiments can be envisioned within the scope of the invention. Embodiments of the invention will be described with reference to the accompanying drawings, in which like or same reference symbols denote like, same or corresponding parts, and in which

Figure 1 shows a cross sectional view of a first embodiment of a kitchen air extraction canopy according to the invention;

Figures la and lb show a schematic view of variations of the embodiment of figure 1;

Figure 2 shows a cross sectional view of a kitchen area with the extraction canopy of figure 1 ;

Figure 3 a shows a cross sectional view of a second embodiment of a kitchen air extraction canopy according to the invention;

Figure 3b shows a longitudinal sectional view of the second embodiment of figure 3 a; and Figures 4a and 4b shows cross sectional views of other embodiments of a kitchen air extraction canopy according to the invention.

DETAILED DESCRIPTION OF EMBODIMENTS

A kitchen air extraction canopy 1 is shown in figures 1 and 2 in a cross sectional view. Figure 2 shows the canopy provided in a kitchen space 200. The canopy is generally provided above cooking equipment 100, such as a cooking stove, to extract any fumes and vapors from the kitchen area, especially from above the cooking stove. A front side la of the canopy 1 faces to a space where kitchen personnel will be standing while working at the cooking stove and a back side lb is provided against a wall 250 of the kitchen space 200. In an alternative arrangement, which is not shown in the figures, two extraction canopies are provided back-to-back above, for instance, a cooking stove that is more centrally provided in the kitchen space. A bottom side lc of the canopy faces downwards towards the cooking equipment. The fumes and vapors from pans, such as cooking or frying pans, on the cooking stove are to be extracted from the kitchen space to keep a good working environment without excess humidity from cooking vapors and any odors and grease from fumes escaping from the pans. The fumes and vapors will be extracted by the canopy together with other air from the kitchen space, which all will be generally referred to as air. This air will thus contain any fumes, vapors and further gases that are to be extracted and drawn away by the canopy from the kitchen space.

The extraction canopy 1 comprises a housing 2 in which an extraction area 10 is provided. The extraction area 10 is connected to an extraction channel 15 in which a fan 16 is arranged to extract and draw away the air in the direction of the arrow indicated in the extraction channel in the figures. The extraction area 10 has one or more openings through which the air is drawn away and generally comprises a filter 11 to separate out any contaminants, such as, for instance, grease particles. Grease separated out of the air extracted will have fluid components that are collected in a grease collector tray 3. Tray 3 can be taken out and emptied regularly. A filter 11 is known as such.

The extraction area 10 is provided in a wall of a cavity 20 in the housing 2 of the canopy 1. Air extracted from the kitchen space, which is indicated by arrows 210, 210a, 210b and 210c, is first collected into the cavity 20, which cavity may also be referred to as a buffer or buffer cavity, through its open downward facing side 21. Part of the air flow 201a is then immediately drawn away through the extraction area 10 into the extraction channel 15. Another part of the extracted air flow 210b impinges on a top delimiting wall of the cavity 20. The top delimiting wall is part of a guiding delimiting wall 22 of cavity 20. The air flow 210b impinging on the top delimiting wall of the cavity and moving towards an outward direction with respect to the canopy, which is the right-hand side in figures 1 and 2, will be guided along the guiding delimiting wall and gradually change direction.

The guiding is such that the air flow along the guiding delimiting wall 22 is in a laminar flow condition. To achieve so the guiding delimiting wall is configured an a continuous configuration as is shown in the figures. In alternative embodiments the guiding delimiting wall is configured in a semi continuous or substantially continuous configuration as schematically shown in figures la and lb. The guiding delimiting wall 22 in figures la and lb comprises segments enclosing large angles. The segments can be straight or slightly curved.

An edge region 22a of the guiding delimiting wall adjacent the open downward facing side 21 of the cavity 20 is directed essentially parallel to the open downward facing side 21 such that the air flow 210b is guided along the guiding delimiting wall and directed by the guiding delimiting wall 22 in a direction substantially along, at least part of, the open downward facing side of the cavity, which is indicated by reference numeral 211. A radius of curvature of a part of the guiding delimiting wall adjacent its top part is in the range of 350 - 400 mm and a radius of curvature of a part of the guiding delimiting wall at and adjacent the edge region 22a is in the range of 60 - 70 mm in the embodiment shown in figures 1 and 2. These values are examples only and dependent on the dimensions of the canopy. Other values for the radii of curvature can be employed as well. The embodiment of figures 3a and 3b, for instance, has a smaller radius of curvature in the guiding delimiting wall. Larger values can be used as well.

When leaving the edge region 22a of the guiding delimiting wall 22 and passing along the open downward facing side 21 of cavity 20 the air flow 211 is approximately parallel to the open downward facing side 21. Having an air flow, which preferably forms an air screen, along the open downward side 21 better traps air within the cavity for subsequent extraction through the extraction area 10. It both directs an air flow along the guiding delimiting wall 22 to remain within the cavity and traps air within the cavity through a barrier action of the air flow along the open downward facing side 21. An upward air flow 210c near the front side of the extraction canopy will be guided backwards by interaction with the air flow 211 and eventually mix with air flow 211 and other upward air flows to be drawn into and collected within the cavity 20.

The extraction area 10 of the extraction canopy 1 shown in figures 1, la, lb and 2 is arranged in a backside region of the cavity, which backside region is associated with the back side lb of the canopy, and is arranged in a slanted position. Any air extracted from the kitchen area 200 and also air collected in the cavity 20 is therefore drawn backwards and upwards towards the extraction area into the extraction channel 15, which assists in an efficient extraction of air from the kitchen space.

The canopy 1 shown in figures 1 and 2 also provides for an air jet stream 220 along a bottom side of the open downward facing side 21 of the cavity 20. The air jet stream is provided through air outlets 41 from an enclosed space 40 within the housing 2 of the canopy 1. The air jet stream 220 from multiple air outlets 41 is directed towards the back side of the canopy to provide an air flow, which preferably forms an air screen, along and below, at least part of, the open downward facing side 21 of the cavity 20. The air jet screen 220 forms another barrier for trapping air within the cavity 20 and it further functions to entrain air from the kitchen space towards the back side of the canopy. Air is introduced inside the enclosed space 40 by a fan 45 arranged in a top side of the canopy. The fan 45 draws air from a top region of the kitchen space into the enclosed space to provide an overpressure in the enclosed space 40. The overpressure in the enclosed space is, in use, such that air jets are provided through the multiple air outlets 41 in the enclosed space 40.

The air outlets 41 are arranged along a front side la of the canopy. Further air outlets 42 from enclosed space 40 are arranged along flank sides of the extraction canopy 1, which air outlets 42 are shown in figure 1. Air jet streams 220 from the front side air outlets 41 and flank side air outlets 42 cooperate to form an air stream and/or air screen below the open downward facing side of the cavity, which is very effective along the front and flank sides of the canopy to keep air trapped within the cavity 20 and to entrain air from the kitchen space to under the canopy and towards a backside of the canopy.

An air guiding surface 43 is provided near and above the air outlets 41 and 42. The air guiding surface is directed parallel to the open downward facing side 21 of the cavity 20. It is effective in providing a smooth upper surface of the air jet streams and/or air jet screens from the air outlets 41, 42, which prevents mixing of the air flow 21 1 within the cavity 20 above and along the open downward facing side and the air flow 220 below and along the open downward facing side 21 of the cavity.

Experiments have shown that the efficiency of an air extraction canopy having a cavity with guiding and directing delimiting wall 22 as disclosed requires a much reduced extraction air flow velocity through the exhaust channel as compared to a canopy having a cavity without such wall. Also the air flow velocity of the air jet stream below the open downward facing side of the cavity can be set at much lower values, which all shows that the overall efficiency of the inventive air extraction canopy is much improved.

Figures 1 and 2 further show a light 30, especially LEDs, arranged in a top wall of the cavity for lighting the cooking equipment 100 below the canopy 1.

The extraction canopy 1 shown in figures 3a and 3b is designed to be provided above cooking equipment that is accessible from all sides. The canopy of figures 3a and 3b is not provided against a wall but is suspended from a ceiling 260 by its extraction channels 15. The extraction canopy 1 comprises extraction areas 10 provided with filters 11 and comprises a cavity 20 with open downward facing side 21 and guiding delimiting walls 22 as described with respect to the embodiment of figures 1 and 2. Part of the air extracted from the kitchen space 200 will extracted directly through the extraction area 10 into the extraction channel 15. Another part of the air extracted from the kitchen space will be guided again along the guiding delimiting wall as has been described above for the embodiment of figures 1 and 2.

The canopy 1 of figures 3a and 3b is also provided with an enclosed space or plenum 40 that can be brought at overpressure by a fan 45 with air from the kitchen space. The enclosed space is provided with additional air openings or outlets 46 adjacent the guiding delimiting walls 22 such that additional air is introduced adjacent and along the guiding delimiting walls from the plenum 40. The additional air flow from the openings 46 is guided along the guiding delimiting walls and directed by the guiding delimiting walls in a direction along the open downward facing side 21 of the cavity 20 towards an opposing side of the canopy. This results in additional air flows 212 along the open downward facing side 21 of the cavity, which preferably form an air screen 212. The air flows and/or air screen 212 again function to trap air within the cavity 20 and to entrain air from the kitchen space towards a central position underneath the canopy for enhanced extraction. An air flow 211 equivalent to the one as described with reference to figures 1 and 2 may also form, but will may mix with air flow 212 to form one air flow.

Since the air in enclosed space or plenum 40 is pressurized a faster additional air flow or even jets will result along the guiding delimiting wall and also a faster air flow and/or air screen 212 along the open downward facing side 21 of the cavity will result, which enhances trapping and entraining of air. The optimum overpressure will result on the configuration of the extraction canopy.

The embodiment of figures 3a and 3b comprises opposing longitudinal sides, which figure 3b shows in a cross sectional view. The cavity comprises longitudinal regions associated with these longitudinal sides. Both longitudinal regions comprise a guiding delimiting wall 22 and associated air outlet(s) 46. The air flow guided and directed by one of those guiding delimiting walls is directed from the associated longitudinal side to the opposing longitudinal side.

Equivalently, the embodiment of figures 3a and 3b comprises opposing flank sides, which figure 3a shows in a longitudinal sectional view. The cavity comprises flank side regions associated with these flank sides. Both flank side regions comprise a guiding delimiting wall 22 and associated air outlet(s) 46. The air flow guided and directed by one of those guiding delimiting walls is directed from the associated flank side to the opposing flank side.

The embodiment of figures 3 a and 3b has its extraction area arranged in a substantially horizontal position and a central position of the canopy, which both extracts air towards a central position of the canopy and upwards for an efficient air extraction from the kitchen space.

Figures 4a and 4b show the embodiment of figures 1 and 2 with two variations of additional air openings 46. The embodiment of figure 4a comprises an additional air opening 46 from the enclosed space or plenum 40. The additional air opening 46 is provided within the cavity 20 adjacent the guiding delimiting wall 22 such that an additional air flow adjacent to and along the guiding delimiting wall results as has been described with reference to the embodiment of figures 3a and 3b, which provides an additional air flow 212 along the open downward facing side 21 of the cavity in addition to the air flow 21 1 along the downward side 21 of the cavity. In practice, both air flows 211 and 212 with just provide one air flow. Having an additional air flow from air outlets 46 along the guiding delimiting wall indices or enhances guiding and directing the air flow 210b of air extracted from the kitchen space 200 into the cavity. The number and opening area of the additional air openings 46 is dependent on the configuration of the extraction canopy. The additional air openings may be distributed over at least a portion of the guiding delimiting wall. The air flow through air outlets 41 and additional air openings 46 is provided by pressurized air which is introduced into enclosed space or plenum 40 by a fan 45. Fan 45 draws air from the kitchen space into the enclosed space 40.

Figure 4b shows a variation to the embodiment of figure 4a in which an air flow 212 through additional air openings 46 adjacent the guiding delimiting wall 22 is provided by a dedicated fan 47 in a plenum 40a. Fan 45 provides pressurized air into plenum 40 which induces air jet streams 220 from air outlets 41. The air flow in the air jet streams 220 from air outlets 41, and also from air outlets 42 as shown in figure 1, can therefore be regulated by controlling the speed of fan 45. Fan 47 provides for an air flow through only additional air openings 46 in the embodiment of figure 4b. The additional air flows through additional air openings 46 and air outlets 41, 42 can therefore be controlled and regulated independently, which provides for a more efficient control of the kitchen air extraction canopy.

Claims

1. A kitchen air extraction canopy (1) comprising

- an extraction area (10) arranged for extracting air from a kitchen space (200), especially from a space above cooking equipment (100), away through the extraction area; and

- a cavity (20) arranged for collecting air drawn from the kitchen space through an open downward facing side (21) of the cavity into the cavity towards the extraction area (10), the extraction area being arranged in a wall of the cavity,

wherein the cavity comprises a guiding delimiting wall (22) that is configured such that air within the cavity is guided along the guiding delimiting wall and directed by the guiding delimiting wall in a direction substantially along the open downward facing side (21) of the cavity, and

wherein the canopy is constructed such as to allow introduction of additional air into the cavity (20) adjacent to and along the guiding delimiting wall (22) such as to provide an additional air flow along the guiding delimiting wall, which additional air flow is directed by the guiding delimiting wall in a direction substantially along the open downward facing side (21) of the cavity (20).

2. The canopy according to the preceding claim, wherein the canopy is constructed such as to allow injection of pressurized additional air into the cavity (20) adjacent to and along the guiding delimiting wall (22) such as to provide an additional air flow along the guiding delimiting wall, which additional air flow is directed by the guiding delimiting wall in a direction substantially along the open downward facing side (21) of the cavity (20).

3. The canopy according to anyone of the preceding claims, wherein additional air openings (46) are provided in the guiding delimiting wall (22) for the introduction of additional air into the cavity (20) adjacent to and along the guiding delimiting wall.

4. The canopy according to anyone of the preceding claims, wherein additional air openings (46) are provided in the guiding delimiting wall (22) for the introduction of pressurized additional air into the cavity (20) adjacent to and along the guiding delimiting wall.

5. The canopy according to any one of claims 3 and 4, wherein the additional air openings (46) are configured and/or shaped such as to direct additional air introduced through the additional air openings along the guiding delimiting wall (22) such as to provide an additional air flow along the guiding delimiting wall, which additional air flow is directed by the guiding delimiting wall in a direction substantially along the open downward facing side (21) of the cavity (20).

6. The canopy according to any one of claims 3 to 5, wherein the additional air openings (46) are distributed over at least a portion of the guiding delimiting wall.

7. The canopy according to anyone of the preceding claims, wherein, in operation, additional air is introduced into the cavity (20) from a plenum (40, 40a) adjacent the cavity.

8. The canopy according to the preceding claim, wherein the plenum (40, 40a) is separated from the cavity (20) by the guiding delimiting wall (22).

9. The canopy according to any one of the preceding claims, wherein the guiding delimiting wall (22) is configured such that air is guided in a laminar flow condition along the guiding delimiting wall.

10. The canopy according to any one of the preceding claims, wherein the guiding delimiting wall (22) is configured in a continuous, semi-continuous or substantially continuous configuration.

11. The canopy according to any one of the preceding claims, wherein an edge region (22a) of the guiding delimiting wall (22) adjacent to the open downward facing side (21) of the cavity (20) is directed essentially parallel to the open downward facing side of the cavity.

12. The canopy according to the any one of the preceding claims, wherein a region of the guiding delimiting wall is configured such that air is guided in an outward direction with respect to the canopy.

13. The canopy according to any one of the preceding claims, wherein the canopy is constructed such that air drawn from the kitchen space (200) and collected into the cavity (2) in a direction towards a top delimiting wall part of the cavity is guided along the guiding delimiting wall (22) and directed by the guiding delimiting wall in a direction substantially along the open downward facing side (21) of the cavity (20).

14. The canopy according to any one of the preceding claims, wherein the guiding delimiting wall (22) is configured such that air within the cavity is guided along the guiding delimiting wall and directed by the guiding delimiting wall in a direction substantially along the open downward facing side (21) of the cavity (20) so as to provide an air screen along at least part of to the open downward facing side of the cavity.

15. The canopy according to any one of the preceding claims, wherein the canopy comprises a front side (la) and the cavity comprises a front side region associated with the front side, the front side region of the cavity comprising the guiding delimiting wall (22) such that air guided along the guiding delimiting wall is directed towards a back side (lb) of the canopy.

16. The canopy according to the preceding claim, wherein the extraction area (10) is arranged in a back side region of the cavity, the back side region being associated with the back side (lb) of the canopy.

17. The canopy according to the preceding claim, wherein the extraction area (10) is arranged in a slanted position.

18. The canopy according to any one of the preceding claims, wherein the canopy comprises opposing longitudinal sides and the cavity comprises longitudinal regions associated with the longitudinal sides, one or both longitudinal regions comprising the guiding delimiting wall (22) such that air guided along the guiding delimiting wall is directed along the open downward facing side (21) of the cavity (20) at one longitudinal side of the canopy towards the opposing longitudinal side.

19. The canopy according to the preceding claim, wherein the extraction area (10) is arranged in a substantially horizontal position, the extraction area preferably being arranged in a central location of the canopy.

20. The canopy according to any one of claims 15 to 19, wherein the canopy comprises opposing flank sides and the cavity comprises flank side regions associated with the flank sides, one or both flank side regions of the cavity comprising the guiding delimiting wall (22) such that air guided along the guiding delimiting wall is directed at one flank side of the canopy towards the opposing flank side.

21. A kitchen air extraction canopy (1) comprising

- an extraction area (10) arranged for extracting air from a kitchen space (200), especially from above a space above cooking equipment (100), away through the extraction area; and

- a cavity (20) arranged for collecting air drawn from the kitchen space through an open downward facing side (21) of the cavity into the cavity towards the extraction area (10), the extraction area being arranged in a wall of the cavity.

22. The canopy according to any one of the preceding claims, wherein the canopy comprises an air jet arrangement constructed and arranged at one or more sides of the canopy such as to provide one or more air jet streams below and along the open downward facing side (21) of the cavity (20), the air jet stream(s) being directed to an opposing side, and the one or more sides comprising at least one of a front side (la), flank sides and longitudinal sides of the canopy.

23. The canopy according to the preceding claim, wherein the air jet gement is constructed and arranged such that the air jet stream(s) provide an air screen below and along the open downward facing side (21) of the cavity (20).

24. The canopy according to the preceding two claims, wherein the air jet arrangement comprises one or more air outlets (41, 42) constructed for ejected the air jet stream, and an air jet guiding surface (43) above the air outlet(s), the air jet guiding surface being directed parallel to the open downward facing side (21) of the cavity (20).