EP4368899A1

EP4368899A1 - Fume extraction system and method for operating an extraction device

Info

Publication number: EP4368899A1
Application number: EP22207131.8A
Authority: EP
Inventors: Frank Benold; Nikolai SCHNEIDER
Original assignee: Electrolux Appliances AB
Current assignee: Electrolux Appliances AB
Priority date: 2022-11-14
Filing date: 2022-11-14
Publication date: 2024-05-15

Abstract

The present invention concerns a fume extraction system comprising an extraction device (14) for removing air from an area above a cooking hob (12) and an air guiding and/or channelling element. The extraction device (14) comprises an air inlet opening (24), an air conveying means (36) for aspirating air from the area above the cooking hob (12) through the air inlet opening (24), and an exhaust opening (30) for exhausting air from the extraction device (14). The air guiding and/or channelling element is connected to or cooperates with or is configured to be connected to or to cooperate with the exhaust opening (30) of the extraction device (14). According to the invention, the air guiding and/or channelling element comprises an air distributing and/or diffusing means (72), which is configured to split the air up, which flows along or inside the air guiding and/or channelling element, and/or to enlarge the contact area of the flowing air with a wall surface (66). Additionally or alternatively, an insulating means (86) is arranged or arrangeable between a wall element (74) or wall section of the air guiding and/or channelling element, which is arranged outside of a housing (28) of the extraction device (14), and a building wall (66) or a furniture wall (62).Further disclosed is a method for operating an extraction device (14) .

Description

The present invention relates to an extraction device for removing air, specifically cooking vapours, from an area above a cooking hob according to the preamble of claim 1. The present invention further relates to a method for operating an extraction device according to the preamble of claim 14.
In order to support persons in performing domestic work, household appliances of different kinds are known. In particular, cooking processes are performed using cooking appliances. For example, cooking hobs comprise cooking zones for placement of cookware receiving the food to be cooked. The cooking zones are generally arranged on a cooktop, in particular a glass ceramic cooktop, which forms an upper wall of the cooking hob. During cooking processes under use of such cooking hobs, cooking vapours are generated, which are distributed over the cooking area. In order to avoid these cooking vapours to be spread throughout the entire kitchen space, it is common to arrange an extraction hood above the cooking area for an aspiration of these fumes. Moreover, there are also cooking hobs known, in which a cooking vapours extraction functionality is integrated. More specifically, such kind of a combination appliance comprises a cooking hob and an integrated downdraft extraction device with an extraction opening in the cooktop of the cooking hob. With this combination of a cooking hob and an extraction device, a compact solution is provided. Extraction hood or extraction device can be operated in parallel to the cooking hob, thereby sucking in those cooking vapours in order to filter out particles and tiny droplets and/or to blow the cooking vapours to the outside of the building.
It is quite common for domestic extraction devices to operate with recirculating air, which means that the extracted air is not released outside of the installation room or building, but is blown out into a kitchen cabinet or directly into the ambient air after it has been filtered. This extracted air is regularly loaded with humidity, so that in those cases, in which the extraction device is installed next to a building wall, especially an external building wall, condensation of the air humidity particularly at low outside temperatures and poorly insulated building walls occurs and may cause damages to the wall, e. g. resulting from mould formation.
It is an object of the present invention to provide a fume extraction system as well as a method for operating an extraction device, with which bad impact on a wall, in particular a building wall and/or a furniture wall, as a result of a condensation effect stemming from the humidity load of the exhaust air of the operated extraction device can be prevented.
The object is achieved for a fume extraction system according to the preamble of claim 1 by the features of the characterizing part of claim 1.
The fume extraction system according to the present invention comprises an extraction device for removing air, specifically cooking vapours, from an area above a cooking hob, as well as an air guiding and/or channelling element. The extraction device is in particular a downdraft extraction appliance and/or forms a combination appliance in combination with the cooking hob. In that case, the extraction device of the combination appliance is preferably arranged below the cooking hob. The extraction device comprises an air inlet opening, air conveying means for aspirating air from the area above the cooking hob through the air inlet opening, and an exhaust opening for exhausting air from the extraction device. The air inlet opening is preferably arranged at or below a cutout or a recess of a worktop, particularly of a cooktop or glass plate of the cooking hob. The air conveying means may be a fan. The air is particularly aspirated through the cutout or recess of the worktop, more specifically through the cutout or recess of the cooktop or glass plate. The air released from the exhaust opening is particularly passed on into the ambient air, more particularly into room air. The extraction device preferably further comprises a filter element, which may comprise an odour filter and/or a carbon filter for removing odours from the aspirated air. In addition or as an alternative to the odour and/or grease filter elements, the extraction device may further comprise an electrostatic filter for removing particles, which are based on the electrostatic principle, from the aspirated air. The air guiding and/or channelling element is connected to or cooperates with the exhaust opening of the extraction device, or, as an alternative, the air guiding and/or channelling element is configured to be connected to or to cooperate with the exhaust opening of the extraction device.
According to a first aspect of the invention, the air guiding and/or channelling element comprises an air distributing and/or diffusing means. The air guiding and/or channelling element may further comprise an air deflecting wall and/or may be arranged outside of a housing of the extraction device. Moreover, the air distributing and/or diffusing means is configured to split the air up, which air flows along or inside the air guiding and/or channelling element. Additionally, or as an alternative to its characteristic of splitting the air up, the air distributing and/or diffusing means is configured to enlarge the contact area of the flowing air with a wall surface. Said wall surface, or the related wall or wall section comprising said wall surface, is particularly arranged or arrangeable next to or adjacent to a building wall, especially an external building wall, or a furniture wall.
According to a second aspect of the invention, which may be considered in addition or as an alternative to the first aspect above, an insulating means is arranged or arrangeable between a wall element or a wall section of the air guiding and/or channelling element and a building wall, especially an external building wall, or a furniture wall. In that sense, the insulating means may be sandwiched between the wall element or wall section and the building wall or furniture wall. Said insulating means is in particular an insulating layer. Moreover, the air guiding and/or channelling element may be arranged outside of a housing of the extraction device.
The present invention is favourable in view of a reduction of the risk of damages to a wall behind the extraction device, specifically a wall facing the exhaust opening of the extraction device. The fact that the airflow leaving the exhaust opening is distributed over a surface that is particularly enlarged in comparison with the area of the exhaust opening, with the effect of preventing a punctual focusing of the airflow with affecting a specifically limited area of the wall surface by a high concentration of moisture-laden air, a wall section staying moist over a longer period with a resulting mould formation is avoided.
Another advantage achieved by the present invention is founded in the fact of having an optimization, i. e. essentially a reduction, of the noise of the airflow. By a, so to speak, fanning out the airflow particularly directly downstream of the exhaust opening with a respective diffusion of the airflow, particularly resulting in an at least partial or sectional reduction of flow velocity, the noise generated by the guided airflow is reduced.
The extraction device may alternatively be an extraction hood, which may be installed in a household kitchen, but an arrangement in an industrial or canteen kitchen may be possible as well. The sucked or aspirated air, which is or shall be removed from the cooking hob, specifically includes cooking vapours, which notably arise during cooking with uncovered cookware.
The cooking hob being the source for the aspirated cooking vapours may be of any type including electric or gas cooking hobs. In particular, the electric cooking hob is an induction cooking hob. The cooking hob may further be an autarkic cooking appliance, particularly integrated in a countertop of kitchen furniture, or it may be part of a stove.
A top surface of the cooktop or glass plate, which is accessible to a user, may be used for putting cookware thereon, specifically in order to perform a cooking process. To this end, the cooking hob preferably comprises at least one heating element defining a cooking zone on the cooktop or glass plate, which is favourably made out of glass ceramics.
A preferred embodiment of the present invention provides for a filter element, which is arranged upstream of the air conveying means and removable through the air inlet opening, in particular through the cutout or recess of the worktop.
According to embodiments, the air guiding and/or channelling element is or comprises a diffusor plate, the diffusor plate being arranged downstream of the air conveying means and facing the exhaust opening. The diffusor plate particularly comprises at least one air guiding rib or blade, but preferably a plurality of air guiding ribs or blades is provided. Said at least one air guiding rib or blade is configured for distributing the airflow in an upward direction and/or in a downward direction and/or in a sideways direction. The distribution direction is preferably configurable depending on a user's preference or installation conditions. For example, a rotatable plate or another rotatable means is provided for the modification and/or adaptation of the distribution direction.
The air guiding and/or channelling element, in particular the diffusor plate, may be configured to be attached to the building wall and/or to the furniture wall. The attachment may particularly be performed by gluing, wherein a thermally insulating glue layer may be applicable.
According to another embodiment, a diffusor means is arranged at an outlet opening of the air guiding and/or channelling element. The diffusor means is rigidly designed or, alternatively, designed as an adjustable element configured for an adjustment of the direction of distribution by a user of the fume extraction system.
The extraction device according to the present invention may be characterized in that the air guiding and/or channelling element, in particular the diffusor plate, comprises an oleophobic and/or hydrophobic coating. A material with rapid water-absorbing and subsequent water-releasing characteristics, in particular silica gel, may be included in the air guiding and/or channelling element supplementarily to or as a substitute for the oleophobic and/or hydrophobic coating.
In some implementations, the air guiding and/or channelling element, in particular the diffusor plate, comprises an odour absorbing material or characteristic. This may be an alternative to an odour filter element, or it may further increase the odour reducing capacity of the extraction device.
The air guiding and/or channelling element, in particular the diffusor plate, may also comprise mechanical means for collecting condensed water, in particular water drops. For example, a collection trough or gutter may be provided.
According to embodiments, the air guiding and/or channelling element, in particular the diffusor plate, is U-shaped in a cross-section. More specifically, the U-shaped air guiding and/or channelling element is open towards the exhaust opening. With such U-shaped design, the open side thereof facing the exhaust opening and being arranged in such way as to receive the air that is discharged from the exhaust opening, a fume extraction system is provided, with which the amount of air that will get uncontrolled to the reverse side of a kitchen cabinet, in which the extraction device is installed, is significantly reduced.
The air guiding and/or channelling element is advantageously an exhaust channel. Said exhaust channel comprises two opposing U-shaped channel elements, which interlock and form a depth-adjustable pipe. That way, an adaptation to the installation conditions for the fume extraction system, more specifically to a distance between a rear wall of the related kitchen cabinet and the room or building wall, is enabled.
According to a specific embodiment, at least one sensor means is arranged downstream of the exhaust opening. The sensor means is configured to measure the temperature and/or the humidity of the air. Additionally, or alternatively, the sensor means may detect or measure type and/or concentration of organic compounds, in particular volatile organic compounds, comprised in the air. The at least one sensor means is particularly arranged in flow direction, which the air takes when passing through the exhaust opening. The at least one sensor means is particularly arranged at a surface of the air guiding and/or channelling element, specifically at the diffusor plate.
One specific embodiment of the fume extraction system including the at least one sensor means is characterized in that the at least one sensor means is connected to a control unit of the extraction device, which control unit is configured to modify an operating program of the extraction device based on data received from the at least one sensor means. In particular, the operating program is or comprises a breeze function with low airflow speed, which may be modifiable.
More specifically, the air guiding and/or channelling element, in particular the diffusor plate, is provided in different sizes. This allows for the air guiding and/or channelling element for being assignable to the width of the extraction device, which in particular has a width of at least approximately 60 cm, 68 cm, 80 cm or 90 cm. Moreover, the distance between exhaust opening and a rear wall of the air guiding and/or channelling element, in particular the diffusor plate, may be between 10 and 180 mm, preferably between 25 and 115 mm.
The air guiding and/or channelling element, in particular the diffusor plate, may also comprise purification means for a cleaning of the exhausted air. Said purification means are preferably formed by an antibacterial coating, in particular including silver ions, which coating may be arranged at a surface of the air guiding and/or channelling element.
The object is further achieved for a method for operating an extraction device according to the preamble of claim 14 by the features of the characterizing part of claim 14.
A method for operating an extraction device, which removes air, specifically cooking vapours, from an area above a cooking hob is provided. The extraction device at least comprises an air inlet opening, an air conveying means for aspirating air from an area above a cooking hob through the air inlet opening, and an exhaust opening for exhausting air from the extraction device. The air inlet opening is preferably arranged at or below a cutout or a recess of a worktop, particularly of a cooktop or glass plate of the cooking hob. The air is particularly aspirated by a fan, more particularly through the cutout or recess of the worktop. The air may be passed on into the ambient air, more particularly into room air, which is for example the ambient air in a kitchen, in which the extraction device is arranged. The extraction device is particularly included in the fume extraction system as herein disclosed, more specifically as previously described. According to the invention, the extraction device is operated based on data from at least one sensor means arranged downstream of an exhaust opening of the extraction device. The at least one sensor means is in particular arranged at a surface, more specifically a wall surface, which faces the exhaust opening, and/or transmits data related to temperature conditions and/or humidity conditions and/or concentration of organic compounds, which may be volatile organic compounds.
The extraction device may be operated with a sensor-based operating program based on humidity data transmitted from a humidity sensor. More specifically, the operating program comprises a breeze function. In addition, or as an alternative, the extraction device may be operated with a sensor-based function or operating program based on temperature data transmitted from a temperature sensor.
In particular, the conveying velocity of the airflow and/or the duration of the sensor-based operating program is/are modified depending on the humidity data and/or depending on the temperature data.
By means of such particular operating method and e. g. with the help of a humidity sensor, excess humidity at a building wall or furniture wall over a longer period and resulting mould formation is avoided by the fact that any condensed air humidity is treated with an airflow of reduced or low humidity with sufficient air volume, following an operating program with extracted cooking vapours.
On the other hand, when receiving data from a temperature sensor, any temperature data exceeding a predetermined temperature level may point to a fire risk, so that the air conveying means of the extraction device can be switched off and other security measure, such as switching off the cooking hob, may be triggered.
Novel and inventive features of the present invention are set forth in the appended claims.
The present invention will be described in further detail with reference to the drawings, in which

Fig. 1: is a perspective view of a combination appliance comprising a cooking hob and a downdraft extraction device installed in a kitchen cabinet according to a first embodiment;
Fig. 2: is a cross-sectional perspective view of the disassembled combination appliance of Fig. 1 with a frontal surface cut away;
Fig. 3: is a rear view of the combination appliance of Fig. 2;
Fig. 4: is a schematic side view of a combination appliance similar to Figs. 1 to 3 arranged in a kitchen cabinet, but with a different air exhaustion;
Fig. 5: is a schematic side view of the combination appliance similar to Figs. 1 to 3 arranged in a kitchen cabinet, but with an air duct positioned outside of the kitchen cabinet;
Fig. 6: is a schematic cross-sectional view of the arrangement of the combination appliance in the kitchen cabinet, as indicated in Fig. 5 by VI - VI;
Fig. 7: is a schematic cross-sectional view of the air duct of the combination appliance towards the rear wall of the air duct, as indicated in Fig. 6 by VII - VII;
Fig. 8: is a flow chart for an operating program of the extraction device using humidity and temperature data; and
Fig. 9: is a flow chart for a safety function of the extraction device and for a corresponding cooking hob using temperature data.

In all figures the same or equivalent part are marked with the same reference numbers.
Figs. 1 to 3 illustrate a general construction and installation of a combination appliance 10, which comprises a cooking hob 12 and a downdraft extraction device 14 installed in a kitchen cabinet 16, as it is already known in the prior art. The cooking hob 12 is implemented in a cutout of a kitchen countertop 18 forming a top cover plate of the kitchen cabinet 16. The downdraft extraction device 14 is configured to take away cooking vapours occurring during cooking processes, in particular when cooking with uncovered cookware. The cooking hob 12 comprises cooking regions 20a, 20b arranged on a left half and a right half of a cooktop 22 of the cooking hob 12, which left and right halves are separated from each other by a suction opening 24 for an intake of the cooking vapours, the suction opening 24 being arranged alongside a cooktop centreline. The suction opening 24 is covered by a cover grid 26 for preventing items, e. g. cookware, to fall into the suction opening 24. Instead of the cover grid 26 a lid may be used for entirely covering the suction opening when the extraction device 14 is out of use, but for the operation of the extraction device 14 the lid is pivotable into an upright open position.
A casing 28 of the extraction device 14 is shown in Fig. 1 in transparent illustration. Said casing 28 provides a closed outer shell or first channel for a flow of the sucked-in cooking vapours on their way from the suction opening 24 to an exhaust opening 30 in a base area 32 of the kitchen cabinet 16. Said exhaust opening 30 is also covered, namely by an outlet grille 34.
The flow of the sucked-in cooking vapours through the extraction device 14 is driven by the operation of an extraction fan 36 arranged inside of the casing 28. Said extraction fan 36 comprises a bottom-sided intake opening 38 for sucking the cooking vapours from the interior space of the casing 28.
As illustrated by Fig. 3, which is a rear view of the combination appliance 10, a rear-sided fan outlet 40 is arranged for a horizontal exit of the air blown out backwards from the extraction fan housing 42. The fan outlet 40 is connected to a first end of an air duct 44 designed as a rectangular tube and forms a second channel arranged downstream of the above-mentioned first channel. Directly at the passage from the fan outlet 40 to the air duct 44, an air duct bending by 90 degrees is implemented, which redirects the airflow from horizontal to vertical downwards. The air duct 44 is guided alongside a rear side of the kitchen cabinet 16 and is bent again by 90 degrees close to a rear lower edge of the kitchen cabinet 16 in order to direct the airflow towards exhaust opening 30 in the base area 32 of the kitchen cabinet 16. Accordingly, the second end of the air duct 44 is connected to the exhaust opening 30.
The course of the cooking vapours from the cooking area through the extraction device 14 to a re-entry into ambient air is illustrated in Fig. 1 by dotted arrows 46¹ to 46⁵. On their way through the extraction device 14, the cooking vapours pass through a filter assembly 48, which is arranged downstream directly behind the suction opening 24 for providing a purification of the conveyed air. Said filter assembly 48 includes a filter carrier 50 supporting a filter element (not shown) that is usually configured for filtering out grease particles and droplets.
The cross-sectional view of Fig. 2 further shows two power boards 54, one for the left cooking region 20a and one for the right cooking region 20b, the power boards 54 providing cooking zones in the left and right cooking regions 20a, 20b with electrical power. In the present embodiment, the cooking hob 12 is an induction cooking hob and the cooking zones are defined by induction coils (not shown) that are arranged below the cooktop 22 of the cooking hob 12. Attached to the bottom side of the power board 54 assigned to the right cooking region 20b, a further circuit board is arranged forming a control electronics 56 for the combination appliance 10.
Fig. 4 illustrates, by a schematic presentation, a combination appliance 10 similar to that one of Figs. 1 to 3 installed in a kitchen cabinet 16, which further comprises two kitchen drawers 60 arranged underneath the combination appliance 10. In contrast to the arrangement according to Fig. 1, this embodiment of a combination appliance 10 enables full utilization of the entire depth of the kitchen cabinet 16, i. e. there is no need to install drawers 60 with lower depth. Moreover, in further contrast to the arrangement according to Fig. 1, the extraction device 14 of the combination appliance 10 blows the air out backwards into the atmosphere through an exhaust opening 30 arranged at the rear of the extraction device 14. To this end, the fan outlet 40 of the extraction device 14 is immediately followed by an outlet duct 58 replacing the air duct 44 and its air duct bending of the embodiment according to Fig. 1. Consequently, rather than to convey the air through the interior of the kitchen cabinet 16 inside of the air duct 44, an immediate rearward air exhaustion shortly after the fan outlet 40 through the outlet duct 58 and, thereafter, through the exhaust opening 30 on the rear side of the exhaustion device 14 is provided. To this end, a rear wall 62 of the kitchen cabinet 16 is provided with a cutout 64 in order to enable the exhaust air to be blown out towards a building wall 66, where the exhaust air spreads over the gap between rear wall 62 and building wall 66. However, as indicated in Fig. 4 by water droplets 68, which are created as a result of condensation of the humidity contained in the air that leaves the extraction device 14 through the exhaust opening 30, due to the focused airflow towards the building wall 66, which airflow is formed by the tubular outlet duct 58, condensation occurs at the focused area at the building wall 66 due to the high concentration of humid air, particularly when this area is cold, e. g. in the winter period. The water droplets 68, which may also be created at the reverse side of the rear wall 62 of the kitchen cabinet 16, flow down at building wall 66 and cabinet rear wall 62 and may be collected on the kitchen floor 70.
In order to avoid such focused area at the building wall 66 receiving the airflow blown out from the exhaust opening 30, a distribution means effecting the airflow to spread across an enlarged area is provided by a diffusor plate 72 leaned against the building wall 66. As indicated by Figs. 5 to 7, this diffusor plate 72 is designed shell-like with a rectangular bottom plate 74, with which the diffusor plate 72 leans against the building wall 66. In this upright orientation, the upper rim section 76 of the shell-like diffusor plate 72 may touch the reverse side of the rear wall 62 of the kitchen cabinet 16 in order to avoid the airflow to be redirected upwards. Instead, a redirection downwards is established, so that the airflow is guided towards the base area 32 of the kitchen cabinet 16, also guided by the lateral rim sections 78 of the diffusor plate shell, which also may touch the reverse side of the rear wall 62 of the kitchen cabinet 16. That way, the airflow is channelled between the interior of the shell-like diffusor plate 72 and the rear wall 62 of the kitchen cabinet 16. At the bottom end of the diffusor plate 72, the lower rim section 80 takes care of a further redirection of the airflow into horizontal direction, so that the air flowing out of the interior of the shell-like diffusor plate 72 can be distributed over the entire base area 32 of the kitchen cabinet 16. Said lower rim section 80, on the one hand, and the rear lower edge 82 of the kitchen cabinet 16, on the other hand, form an outlet opening 84 for the exhaust air into the ambient air of the base section 32 of the kitchen cabinet 16.
As also illustrated by Fig. 5, in order to avoid the humid air to get into contact with a cold surface, not only the diffusor plate 72 is made of plastic material, which has thermal insulation characteristics, but also an insulating layer 86 is arranged between the bottom plate 74 of the diffusor plate 72 and the inner surface of the building wall 66. That way, a sufficient thermal insulation is provided and it is not necessary for the installer of the combination appliance 10 to care about this question.
On the other hand, in order to keep the airflow nearly completely away from the rear wall 62 of the kitchen cabinet 16, also this rear wall 62 is protected, namely by means of a backwall cover 88, which may also be made of plastic, and which leans against, in particular is glued on, the rear wall 62 of the kitchen cabinet 16. As shown in the cross-sectional presentation according to Fig. 6, said backwall cover 88 is slightly reduced in width compared to the diffusor plate 72 and is also U-shaped in cross-section, in the same way as the diffusor plate 72. Due to the fact that diffusor plate 72 and backwall cover 88 are arranged in that their U-shapes open in opposite directions, their lateral rim sections 78, 78' interlock and form a circumferentially closed air channel. Moreover, the lateral rim sections 78, 78' both of the diffusor plate and of the backwall cover are configured to slide along each other, hence forming a depth-adjustable channel formation, which allows an adaptation to installation conditions of the respective installation location. It is to be noted that also the backwall cover 88 may be attached at the rear wall 62 of the kitchen cabinet 16 by an intermediated insulating layer (not shown), which may not only be for reasons of thermal insulation, but also provides an acoustic baffle reducing flow noises.
In addition to its previously mentioned insulating characteristic, the diffusor plate 72 is also configured to spread the air moving along it. To this end, at the interior side of the bottom plate 74 of the diffusor plate 72 diffusor ribs 90 are arranged, particularly integrally moulded. These diffusor ribs 90 are configured to distribute the air at the bottom end of the diffusor plate 72 to the entire width of the diffusor plate 72. The height of the diffusor ribs 90 is selected by the same dimensional extension as the lateral rims 78 of the diffusor plate 72, which allows a maximum utilization of the depth adjustment of the channel formation.
The combination appliance 10 specifically described herein does not only comprise mechanical means for avoiding damages to the building wall 66 and/or the furniture wall, i. e. the rear wall 62 of the kitchen cabinet 16. In addition to the previously described mechanical means, or as an alternative to these mechanical means, the combination appliance 10, more specifically the extraction device 14 of the combination appliance 10, comprises or cooperates with sensor means (not shown), which provide data input to a control unit of the extraction device 14 and/or of the cooking hob 12 and/or of the entire combination appliance 10. The sensor means of the specifically described and illustrated embodiment include at least one temperature sensor, which measure(s) the temperature of the airflow and/or the temperature of the building wall 66, alternatively of the diffusor plate 72, and at least one humidity sensor, which provides information related to the moisture concentration of the airflow downstream of the exhaust opening 30. In other embodiments additional or alternative sensor means detecting the concentration of organic compounds (VOC / TVOC sensor) may be used. Said sensor means, at least a temperature sensor detecting the temperature of the building wall 66, may be positioned at the diffusor plate 72 opposite the exhaust opening 30. Another temperature sensor for measuring the temperature of the airflow, as well as a humidity sensor and/or a VOC / TVOC sensor may be arranged in the space between the building wall 66 or diffusor plate 72 and the rear wall 62 of the kitchen cabinet 16 or backwall cover 88.
By detection and processing the wall temperature and the humidity of the airflow, the dew point of water , i. e. when condensation at the building wall 66 or the diffusor plate 72 takes place, can be determined. By means of this information, transmitted to the control means, specifically using in addition transmitted data from the temperature sensor for measuring the airflow temperature, the control means or a process control application is enabled to determine a duration of a breeze function or program, working as a drying function for the building wall 66 or the diffusor plate 72, respectively, and/or the rear wall 62 of the kitchen cabinet 16 or the backwall cover 88, respectively, after finalizing the operating program for the extraction of cooking fumes.
A further function of the temperature sensor for temperature measurement of the wall, may be provided by warning a user of the combination appliance 10 in case of low outdoor temperature. E. g. with a display of a message "Wall too cold", the user may be advised to not run the extraction device 14 at the present time. In addition, the sensor data may be used to determine how long it will take to dry the wall, which estimated information may be given to the user in a display means of the combination appliance 10.
Information about the concentration of organic (e. g. carbon-based) compounds may be determined, too. This enables a determination of the concentration of odour-causing components in the exhaust air. By this means, i. e. any information about purity of the exhaust air, knowledge about any saturation of filter elements of the extraction device 14, indicating any need for a cleansing, may be perceived.
The sensor data may also be used for a sustainable operation of the extraction device 14. For example, if a warm wall, no humidity in the exhaust air, a sufficiently warm exhaust air and/or no organic compounds in the exhaust air may be detected, the extraction device 14 may be operated with a minimum amount of energy necessary to prevent mould growth, i. e. damage to the kitchen or house. Moreover, the user may actively be informed about such low-energy consumption and/or the user may determine the right time for a change of filter elements.
Finally, Figs. 8 and 9 show specific flow charts for the extraction device using the described sensor data.
Referring to Fig. 8, the flow chart illustrates an operating program for the extraction device 14 using humidity and temperature data. Input data are provided to a control unit, by operation box 100, transmitting temperature information from a temperature sensor attached to the diffusor plate 72, which has physical contact to the building wall 66 behind the kitchen cabinet 16, in which the combination appliance 10 is installed. Further data are provided by 120 transmitting air humidity information from a humidity sensor positioned in the airflow downstream of the exhaust opening 30. By operation box 110, the dew point of the water of the cooking fumes in the airstream is determined using Mollier-h-x-diagram information. If the temperature of the wall is too cold, decision box 130, a message is displayed, e. g. "room temperature is too cold" as well as a recommendation to not use the extraction device 14 until sufficient room temperature is reached, see operation box 140. In case of a sufficient room temperature is measured, operation box 150, normal operation is allowed. As long as during the operation of the extraction device 14 no relevant humidity increase is detected, decision box 160, the operation is continued by operation box 170, without any amendment to operational parameters. If humidity increase, by operation box 160, is measured, with respective sensor information from operation box 120, by next decision box 180, determination takes place if the diffusor plate 72 is already humid, i. e. whether already condensation effect occurs. If this is not the case, no specific action takes place, by operation box 190, and the extraction device 14 operation continues without any modification. Otherwise the extraction device 14 will be operated on a low level, i. e. with reduced fan speed, which brings the diffusor plate 72 into a condition to dry off, because of being fed with a reduced amount of humid air, operation box 200. Said low-level operation is continued and, by decision box 210, a repeated investigation of the drying stage of the diffusor wall 72 is performed, and, by operation box 220, the low-level operation is continued. Otherwise, by operation box 230, either the normal operation is resumed, if there are still cooking fumes to be extracted, or a breeze function of the extraction device 14 is terminated, if the cooking process on the related cooking hob 12 has been already finalized and the normal extraction operation of the extraction device 14 would have been terminated in parallel, too.
The flow chart according to Fig. 9 illustrates a safety function for the extraction device 14 and any impact on a corresponding cooking hob 12 und use of temperature data. Input data are provided to a control unit, by operation box 300, transmitting temperature information from a temperature sensor positioned in the airflow downstream of the exhaust opening 30. If the air temperature in the airflow is substantially higher than an expected level that corresponds to a user's normal cooking behaviour, decision box 310, the danger of fire generation is growing, so that the combination appliance 10 will shut down all operations, i. e. all heating units of the cooking hob 12 will be switched off and the operation of the extraction device 14 will be terminated, operation box 330. Otherwise, no safety action is required, operation box 320, and the extraction device 14 as well as the cooking hob 12 are operated as configured by the user, and the safety monitoring is continued until the combination appliance 10 is entirely switched off.
Although illustrative embodiments of the present invention have been described herein with reference to the accompanying drawings, it is to be understood that the present invention is not limited to these precise embodiments, and that various other changes and modifications may be affected therein by one skilled in the art without departing from the scope or spirit of the invention. All such changes and modifications are intended to be included within the scope of the invention as defined by the appended claims.

List of reference numerals

10: combination appliance
12: cooking hob
14: downdraft extraction device
16: kitchen cabinet
18: kitchen countertop
20a,20b: cooking regions
22: cooktop
24: suction opening
26: cover grid
28: casing
30: exhaust opening
32: base area
34: outlet grille
36: extraction fan
38: intake opening
40: fan outlet
42: fan housing
44: air duct
461 to 5: arrows indicating airflow
48: filter assembly
50: filter carrier
54: power boards
56: control electronics
58: outlet duct
60: kitchen drawers
62: rear wall
64: cutout
66: building wall
68: water droplets
70: kitchen floor
72: diffusor plate
74: bottom plate
76: upper rim section
78,78': lateral rim sections
80: lower rim section
82: rear lower edge
84: outlet opening
86: insulating layer
88: backwall cover
90: diffusor ribs
100...330: flow chart process steps

Y: "yes"
N: "no"

Claims

A fume extraction system comprising an extraction device (14) for removing air, specifically cooking vapours, from an area above a cooking hob (12), and an air guiding and/or channelling element,
wherein the extraction device (14) is in particular a downdraft extraction appliance (14) and/or forms a combination appliance (10) in combination with the cooking hob (12), wherein the extraction device (14) of the combination appliance (10) is preferably arranged below the cooking hob (12), the extraction device (14) comprising
- an air inlet opening (24), which is preferably arranged at or below a cutout or a recess of a worktop (22), particularly of a cooktop or glass plate of the cooking hob (12),

- an air conveying means (36), in particular a fan, for aspirating air from the area above the cooking hob (12) through the air inlet opening (24), in particular through the cutout or recess of the worktop (22),

- preferably a filter element, particularly comprising an odour filter and/or a carbon filter for removing odours and/or grease particles from the aspirated air,

- an exhaust opening (30) for exhausting air from the extraction device (14), the air particularly being passed on into the ambient air, more particularly into room air,

and wherein the air guiding and/or channelling element is connected to or cooperates with or is configured to be connected to or to cooperate with the exhaust opening (30) of the extraction device (14),

characterized in that

the air guiding and/or channelling element comprises an air distributing and/or diffusing means (72) and in particular
- further comprises an air deflecting wall
and/or

- is arranged outside of a housing (28) of the extraction device (14),

the air distributing and/or diffusing means (72) being configured
- to split the air up, which flows along or inside the air guiding and/or channelling element
and/or

- to enlarge the contact area of the flowing air with a wall surface (74), which is particularly arranged or arrangeable next to or adjacent to a building wall (66), especially an external building wall, or a furniture wall (62),
and/or

an insulating means (86), in particular an insulating layer, is arranged or arrangeable between a wall element (74) or wall section of the air guiding and/or channelling element, which is arranged outside of a housing (28) of the extraction device (14), and a building wall (66), especially an external building wall, or a furniture wall (62).
The fume extraction system according to claim 1,
characterized in that
the air guiding and/or channelling element is or comprises a diffusor plate (72) being arranged downstream of the air conveying means (36) and facing the exhaust opening (30), the diffusor plate (72) particularly comprising air guiding ribs (90) or blades, configured for distributing the airflow in an upward direction and/or in a downward direction and/or in a sideways direction, wherein the distribution direction is preferably configurable depending on user's preference or installation conditions.
The fume extraction system according to claim 1 or 2,
characterized in that
the air guiding and/or channelling element, in particular the diffusor plate (72), is configured to be attached to the building wall (66) and/or the furniture wall (62), particularly by gluing, more particularly using a thermally insulating glue layer.
The fume extraction system according to claim 1,
characterized in that
a diffusor means is arranged at an outlet opening (84) of the air guiding and/or channelling element, the diffusor means being rigidly designed or designed as an adjustable element configured for an adjustment of the direction of distribution by a user of the fume extraction system.
The fume extraction system according to anyone of the preceding claims,
characterized in that
the air guiding and/or channelling element, in particular the diffusor plate (72), comprises
- an oleophobic and/or hydrophobic coating
and/or

- a material with rapid water-absorbing and subsequent water-releasing characteristics, in particular silica gel.
The fume extraction system according to anyone of the preceding claims,
characterized in that
the air guiding and/or channelling element, in particular the diffusor plate (72), comprises an odour absorbing material or characteristic.
The fume extraction system according to anyone of the preceding claims,
characterized in that
the air guiding and/or channelling element, in particular the diffusor plate (72), comprises mechanical means for collecting condensed water, in particular water drops.
The fume extraction system according to anyone of the preceding claims,
characterized in that
the air guiding and/or channelling element, in particular the diffusor plate (72), is U-shaped in a cross-section, the U-shaped air guiding and/or channelling element in particular being open towards the exhaust opening (30).
The fume extraction system according to anyone of the preceding claims,
characterized in that
the air guiding and/or channelling element is an exhaust channel, which comprises two opposing U-shaped channel elements (72, 88), which interlock and form a depth-adjustable pipe.
The fume extraction system according to anyone of the preceding claims,
characterized in that
at least one sensor means is arranged downstream of the exhaust opening (30), in particular arranged at a surface of the air guiding and/or channelling element, in particular at the diffusor plate (72), the sensor means measuring at least one of
- temperature,

- humidity,

- organic compounds, in particular volatile organic compounds,
wherein the at least one sensor means is particularly arranged in flow direction, the air takes when passing through the exhaust opening (30).
The fume extraction system according to claim 10,
characterized in that
the at least one sensor means is connected to a control unit of the extraction device (14), which control means is configured to modify an operating program of the extraction device (14) based on data received from the at least one sensor means, the operating program particularly being or comprising a breeze function with low airflow speed.
The fume extraction system according to anyone of the preceding claims,
characterized in that
the air guiding and/or channelling element, in particular the diffusor plate (72), is provided in different sizes in order to be assignable to the width of the extraction device (14), in particular having a width of at least approximately 60 cm, 68 cm, 80 cm or 90 cm,
and/or

the distance between exhaust opening (30) and a rear wall (74) of the air guiding and/or channelling element, in particular the diffusor plate (72), is between 10 and 180 mm, preferably between 25 and 115 mm.
The fume extraction system according to anyone of the preceding claims,
characterized in that
the air guiding and/or channelling element, in particular the diffusor plate (72), comprises purification means for a cleaning of the exhausted air, the purification means preferably being formed by an antibacterial coating, in particular including silver ions.
A method for operating an extraction device (14), which extraction device (14) removes air, specifically cooking vapours, from an area above a cooking hob (12), the extraction device (14) at least comprising
- an air inlet opening (24), which is preferably arranged at or below a cutout or a recess of a worktop (22), particularly of a cooktop or glass plate of the cooking hob (12),

- an air conveying means (36), in particular a fan, for aspirating air from the area above the cooking hob (12) through the air inlet opening (24), in particular through the cutout or recess of the worktop (22),

- an exhaust opening (30) for exhausting air from the extraction device (14), the air particularly being passed on into the ambient air, more particularly into room air, in particular the extraction device (14) included in the fume extraction system according to any one of the preceding claims,
characterized in that
the extraction device (14) is operated based on data from at least one sensor means arranged downstream of an exhaust opening of the extraction device (14), the at least one sensor means in particular
- being arranged at a surface (74), particularly a wall surface, which surface (74) facing the exhaust opening (30), and/or

- transmitting data related to temperature conditions and/or humidity conditions and/or concentration of organic compounds, in particular volatile organic compounds.
The method according to claim 14,
characterized in that
the extraction device (14) is operated with a sensor-based operating program, the operating program in particular comprising a breeze function, based on humidity data transmitted from a humidity sensor,
and/or

the extraction device (14) is operated with a sensor-based function based on temperature data transmitted from a temperature sensor,
wherein in particular the conveying velocity of the airflow and/or the duration of the sensor-based operating program is/are modified depending on the humidity data and/or the temperature data.