EP2619508B1

EP2619508B1 - Cooker hood and method of ventilating a kitchen

Info

Publication number: EP2619508B1
Application number: EP11767479.6A
Authority: EP
Inventors: Willem Andreas Pieter Van Bruggen; Erwin Cornelis Johannes Slappendel; Jan Willem Dik
Original assignee: Intell Properties BV
Current assignee: Intell Properties BV
Priority date: 2010-09-23
Filing date: 2011-09-23
Publication date: 2018-11-28
Anticipated expiration: 2031-09-23
Also published as: WO2012039618A1; EP2619508A1; NL2005384C2

Description

The invention relates to a cooker hood and a method of ventilating a room using such a cooker hood. It more specifically relates to a cooker hood connectable to a central mechanical ventilation (CMV) system.
Cooker hoods which are connectable to a central mechanical ventilation (CMV) system are known. The capacity of these cooker hoods is limited by the capacity of the CMV system. To improve the capacity, so-called hybrid cooker hoods are designed, which comprise their own mechanical ventilation fan. A problem with these cooker hoods may be that once the mechanical fan is activated, it produces an air flow that cannot be handled by the CMV. This problem is solved by a cooker hood described in patent publication WO 2007/003757 which describes a cooker hood having a separate outlet at the top of the hood for letting out an air flow produced by the fan. The air flow produces by the fan is separated from an air flow generated by a CMV. In this way, part of the exhaust air is re-circulated into the kitchen. The cooker hood comprises several valves for guiding the air flows depending on the mode of operation. If the fan is off, the outlet for re-circulating air is closed and another valve is moved to open a channel to the connected CMV system. It is believed that in this mode of operation a filter present at a central region of the hood is cleaned by the less polluted air going through the filter during periods of non-cooking. The disadvantage of this hood is that the mechanical valve may get polluted by grease and filth and will limit the life time of the hood considerably. Furthermore, the filter is used to clean the air in both operating modes. This means that the filter cannot be too thick because the CMV must be able to suck air through this filter in the non-cooking situation.
It is the object of the present invention to provide a cooker hood which solves at least one of the above mentioned problems.
This object is achieved by providing a cooker hood for ventilating a room, the hood comprising a first and second air inlet, a first air outlet for connecting the hood to a channel of a central mechanical ventilation system, and a second air outlet for recirculation air into the room. Furthermore the hood comprises a first exhaust channel for leading air from the first air inlet to the first air outlet and a second exhaust channel for leading air from the second air inlet to the second air outlet. The second exhaust channel is separate from the first channel. A fan is arranged in the second exhaust channel for creating a flow through the second exhaust channel. The first and second air inlet are arranged at a bottom side of the cooker hood and the first air inlet is arranged in a mid region of the bottom side and the second air inlet is arranged at least partly around the first air inlet.
The cooker hood according to the invention uses two separate channels for exhausting air by means of the CMV and by exhausting air by means of the fan. In this way two air flows are generated leading to a maximal exhaust of air without an overcapacity problem and without the need of moving valves and without disturbing the CMV system.
Furthermore, by arranging the second air inlet at least partly around the first air inlet, an air barrier can be created which prevents air and gasses underneath the cooker hood at the mid region from escaping. In normal operation, the first air inlet is extracting air from underneath the cooker hood, whereby an air column, defined by the barrier, is exhausted to the CMV. This air column comprises relatively more grease and smoke than the air in the air barrier since it originates from pots and pans on the cooking stove which normally is aligned with the cooker hood. So the most polluted air is exhausted to the CMV which will blow the air outside. The less polluted air will be re-circulated. As compared to the state of the art, a thinner filter in the recirculation channel, if any, is needed, while at the same time an air curtain is created to guide the more polluted air towards the CMV inlet. This results in an optimal way of ventilating.
In an embodiment, the first inlet is a rectangular shaped inlet and the second inlet is a slot. By extracting air through this slot, an air curtain will be created to enclose the CMV air column at least partially. The slot can be U-shaped having right angles or round angles as well as being semi oval depending on the design of the bottom of the cooker hood. Other configurations are possible.
In an embodiment the first exhaust channel comprises an inlet filter arranged at the first air inlet. This filter prevents the CMV system from getting polluted with grease and moisture.
In a further embodiment the second exhaust channel comprises a further inlet filter arranged at the second air inlet. This further inlet filter prevents the recirculation system from getting polluted with grease and moisture.
In an embodiment the second exhaust channel comprises an outlet filter arranged at the second air outlet. As a result the air will be cleaned from moisture and odour before it is recirculated.
In an embodiment the first air inlet is substantially rectangular and the second air inlet is substantially U-shaped. Using a U shaped inlet, a curtain is created which, together with a wall at the back completely surrounds the inner air column.
Preferably, there are not any valves or way throughs between the first and second channel. Due to the absence of valves and/or way throughs, less maintenance of the cooker hood is needed saving time and money.
The invention also relates to a method of ventilating a room, such as a kitchen, using a cooker hood as described above.
Further details and advantages of the present invention will become clear to the reader after reading the description of the embodiments described below with reference to the accompanying drawings, in which:

Figure 1 schematically shows a cooker hood 1 according to an embodiment of the invention;
Figure 2 is a schematic cross section of the cooker hood 1 of Figure 1;
Figure 3 shows a cut-out view of the embodiment of Figure 1 showing the components of the cooker hood from a different perspective;
Figure 4 shows a bottom view of the embodiment of Figure 1;
Figure 5 shows a bottom view of a further embodiment showing the two different inlets;
Figure 6 shows a bottom view of another embodiment showing the two different inlets.

Figure 1 schematically shows a cooker hood 1 according to an embodiment of the invention. The cooker hood 1 comprises a box shaped housing 2 and a u-shaped wall 3 surrounding a duct 4. At the top of the duct 4 a first outlet 5 is shown which can be connected to a channel of a central mechanical ventilation (CMV) system, not shown. In the wall 3 a second air outlet 5 is arranged in the form of a plurality of slots. At an opposite side of the cooker hood similar slots are present, not visible in Figure 1.
Figure 2 is a schematic cross section of the cooker hood 1 of Figure 1. Figure 2 shows an inlet filter 10 through which air will be drawn into the duct 4 by the CMV. Behind the duct 4 a fan 12 is installed for re-circulating air back into the kitchen. The re-circulated air enters the hood 1 via an inlet 13. Next, it reaches an inlet filter 14. The air is then sucked by way of the fan 12 upwards into a channel compartment before it reaches an outlet filter 16. Finally it passes through the air outlet slots 7 and is re-circulated into the kitchen. In Figure 2 the recirculated air is indicated by small arrows indicating the direction of the air flow. The larger arrows indicate the air flow going via the CMV channel.
According to the invention, the cooker hood 1 comprises two separate exhaust channels; a first exhaust channel for leading air from the first air inlet 10 to the first air outlet 5, also called the CMV outlet 5, and a second exhaust channel for leading air from the second air inlet 13 to the second air outlet 7 for recirculation.
Figure 3 shows a cut-out view of the embodiment of Figure 1 showing the components of the cooker hood from a different perspective. The inlet filters 10 and 14 may be grease filters made out of aluminium or the like. The outlet filter 16 in the recirculation channel may be an odour filter comprising for example active carbon. The location of the outlet filter can differ from the location stated in the pictures.
Figure 4 shows a bottom view of the embodiment of Figure 1. As can be seen in this view, the air inlet 10 for leading air to the CMV is arranged as a rectangular area at a central part of the bottom of the hood 1. The air inlet 13 for the re-circulated air is arranged at a perimetral part of the bottom of the hood 1. An arrow 20 shows the back side of the cooker hood 1 which is normally in contact with a wall. In this embodiment the air inlet 13 is a u-shaped slot arranged along three edges of the bottom of the hood 1, i.e. the two side edges and the front edge. As can bee seen, the u-shaped slot 13 is spaced from the outer ends of the box shaped housing 2. Typical values for the distance between the outer ends and the slot 13 are between 5-20 cm. Other values are possible.
Instead of a slot at three edges, a slot is conceivable along all four sides of the bottom of the hood, as is shown in Figure 5 . In this case the recirculation inlet 33 is a rectangular slot in the bottom 31 which is completely surrounding the CMV air inlet 32.
In the embodiment of Figure 4, the CMV air inlet 10 is covering approximately half of the region defined by the surrounding slot 13. It should be noted that the CMV air inlet can be as large as to cover almost the complete enclosed region, see air inlet 42 in Figure 6. In Figure 6 reference number 43 indicates the recirculation air inlet in the bottom 41. If the CMV air inlet 10 is chosen too large, the velocity of the air through the CMV inlet may be too low. So, depending on the CMV system present, the dimensions of the CMV channel and the ventilation criteria in the kitchen, the air inlet 42 will have an optimal dimension. The form of the CMV air inlet 10 does not need to be rectangular, other shapes are possible such as a filled oval.
The cooker hood according to the invention can be operated in two modes. If the fan 12 is off, the air is ventilated through the first channel towards the CMV. In this situation, the kitchen is ventilated via the cooker hood. The cooker hood will exhaust air and gasses coming from a cooking stove underneath the hood. If the produced gasses or smoke increases, the fan can be turned on to increase the capacity of the cooker hood. Preferably, the fan can be operated in several modes, such as low, medium, high, and as already mentioned above: "off".
If the fan is turned on, the air is exhausted through both the channels. Underneath the cooker hood 1, air will flow at different rates depending on the region under the hood, and depending on the operating state of the fan 12.
When the fan 12 is fully operating, an air barrier is created at the edges of the cooker hood 1. In Figure 4 the air barrier is indicated by small arrows indicating the direction of the air flow of the recirculated air. The larger arrows indicate the air flow going via the CMV channel. The air barrier itself exhausts air through the filters 14 and 16 so as to recirculate cleaned air back into the kitchen. Furthermore, the air barrier prevents air and gasses underneath the cooker hood at the mid region from escaping. Since the CMV air inlet 10 is continuously extracting air from underneath the cooker hood, an air column defined by the barrier, is exhausted to the CMV. This air column comprises relatively more grease and smoke than air in the air barrier since it originates from pots and pans on the cooking stove which normally is aligned with the cooker hood 1. So the most polluted air is exhausted to the CMV which will blow the air outside. The less polluted air will pass the filter 16 and will be re-circulated. By re-circulating the air entering the hood via the inlet 13, a significant amount of energy is saved as compared to a hood that fully exhaust directly to the outside. Furthermore, the capacity of the hood is significant more than that of a hood that fully exhausts towards a CMV system.
The cooker hood according to the invention comprises two separate channels which have their own mode of operation and their own function. No valves are needed for leading air flows in different ways to different channels and outlets. This will make the configuration as such more robust.
Furthermore, the system works independently of the capacity of the CMV system and the capacity of the CMV system can be fully used.
It is emphasized that the present invention can be varied in many ways, of which the alternative embodiments as presented are just a few examples. These different embodiments are hence non-limiting examples. The scope of the present invention, however, is only limited by the subsequently following claims.

Claims

Cooker hood (1) for ventilating a room, the cooker hood (1) comprising:
- a first air inlet (10) and a second air inlet (13);

- a first air outlet (5) for connecting the hood to a channel of a central mechanical ventilation system;

- a second air outlet (7) for recirculation of air to the room;

- a first exhaust channel (4) for leading air from said first air inlet (10) to said first air outlet (5);

- a second exhaust channel for leading air from said second air inlet (13) to said second air outlet (7), said second exhaust channel being separate from said first exhaust channel (4);

- a fan (12) arranged in said second exhaust channel for creating a flow through said second exhaust channel,
wherein said first (10) and second (13) air inlets are arranged at a bottom side of the cooker hood (1)
characterized in that
said first air inlet (10) is arranged in a mid region of the bottom side and said second air inlet (13) is arranged at least partly around said first air inlet (10).
Cooker hood according to claim 1, wherein said first air inlet (10) is a rectangular shaped inlet and said second air inlet (13) is a slot.
Cooker hood according to any one of the preceding claims, wherein said first exhaust channel (4) comprises an inlet filter arranged at the first air inlet (10).
Cooker hood according to any one of the preceding claims, wherein said second exhaust channel comprises a further inlet filter (14) arranged at the second air inlet (13).
Cooker hood according to any one of the preceding claims, wherein said second exhaust channel comprises an outlet filter (16) arranged at the second air outlet (7).
Cooker hood according to any one of the preceding claims, wherein said first air inlet (10) is substantially rectangular and said second air inlet (13) is substantially U-shaped.
Method of ventilating a room, such as a kitchen, using a cooker hood (1) according to any one of the preceding claims.