EP1450106A2

EP1450106A2 - System for continuously controlling the suction of a kitchen extractor fan

Info

Publication number: EP1450106A2
Application number: EP20040075236
Authority: EP
Inventors: Alvaro Galassi
Original assignee: Faber SpA
Current assignee: Faber SpA
Priority date: 2003-01-31
Filing date: 2004-01-23
Publication date: 2004-08-25
Also published as: ITMI20030167A1

Abstract

System for continuously controlling the suction of a kitchen extractor fan, said extractor fan comprising a control keypad (13), a suction group comprising a motor and a fan (15), a device for adjusting said suction group (115), at least one smoke sensor (16) and at least one temperature sensor (17) and a central processing unit (18).

Description

The present invention refers to a system for continuously controlling, 24 hours per day, the suction of a kitchen extractor fan.
In particular, the present invention refers to a system for controlling the suction of a kitchen extractor fan, in which the suction flow rate of the extractor fan is adjusted.
It is known that, in the state of the art, kitchen extractor fans are provided with a device for sucking in smoke. Such a device comprises an electric motor which rotates a fan which sucks in the air below the lower opening of the extractor fan, conveying it in the direction of the upper suction tube. The management of the adjustment of the suction flow rate of an extractor fan is managed manually by the user, who, generally, activates the extractor fan only when he/she starts normal cooking activities. In such a manual mode it is possible to act upon the adjustment of the lights and of the motor as well as to activate auxiliary functions such as a device for delaying the turning off of the suction device.
Automatic systems for controlling the suction of a kitchen extractor fan are also known in which one or more sensors which detect the presence of smoke send signals to the extractor fan, so as to modulate the suction flow rate. There can also be sensors for automatically adjusting the light intensity emitted by the extractor fan, according to the degree of room lighting.
The Applicant has observed that such control systems are activated only when the sensor(s) receive a perturbation with respect to their by-pass state, which usually occurs during cooking operations or for brief, random moments of concentration of smoke, odours or possibly temperature, in the immediate vicinity of the extractor fan and thus of the sensors. This, for example, refers to the case of a smoker or a heavily perfumed person very close to the extractor fan, or else the case of a leak of a gas that is lighter than air. For the remaining time the suction system remains inactive.
The Applicant has realised a system in which the kitchen extractor fan transforms into an apparatus that is always active, capable of ensuring an adequate exchange of air in the room, not only at the time of cooking but rather uninterruptedly throughout the day, from a still active very low minimum, up to the maximum, through the continuous adjustment of the electronic control, which optimises the flow rate of the ventilator of the extractor fan according to the degree of alteration of the air quality.
Such a requirement is very clear in modern dwellings, increasingly airtight with respect to the outside and increasingly subject to determining uncomfortable and inconvenient living conditions due to the low exchange of air, the formation of mould, condensation, stagnation of residue from the burning of the gas hobs, etc.
For such a purpose, the Applicant has realised a system for controlling the suction of a kitchen extractor fan, which if actuated in automatic mode always remains active, so as to ensure a predetermined suction flow rate for all of the actuation period, for example twenty-four hours per day.
An aspect of the present invention concerns a system for controlling the suction of a kitchen extractor fan, said extractor fan comprising a control keypad, a suction group comprising a motor and a fan, a device for adjusting said suction group, at least one air quality sensor, possibly integrated by at least one temperature sensor and a central processing unit, characterised in that said processing unit, in response to a selection of a button of said control keypad, determines a manual operating mode of the extractor fan and an automatic operating mode in which it receives the signals from the sensors and controls said device for adjusting the suction group, so as to keep said suction group permanently active.
The characteristics and advantages of the system according to the present invention shall become clearer from the following description, given as an example and not for limiting purposes, of an embodiment with reference to the attached figures, in which:
figure 1 represents a front view of a kitchen extractor fan;
figure 2 is a block diagram of the control system for the extractor fan of figure 1 according to the present invention.
With reference to the quoted figures a conventional kitchen extractor fan comprises an upside-down funnel-shaped portion 11, realised in a single body or equivalently connected with an upper suction tube 12, a control keypad 13, a lighting group 14, a suction group comprising a motor and a fan 15.
According to the present invention the system for controlling the suction of a kitchen extractor fan comprises a device for adjusting said suction group 115, at least one air quality sensor 16 and, possibly, at least one temperature sensor 17.
Moreover, said system preferably also comprises a device for adjusting said lighting group 114.
A central processing unit 18 is connected with said adjustment devices with the control keypad and with the sensors. Such a processing unit is, for example, a microprocessor.
The system according to the present invention operates in the following way.
The control keypad 13 is provided with a plurality of buttons, amongst which there is at least one first button 131 for selecting a manual mode or an automatic mode.
The central processing unit, following the reading of a signal coming from said first button, selects the operation of the extractor fan in one of the two modes.
Said manual mode foresees the use of the extractor fan, based upon the commands coming from the other buttons foreseen of the control keypad.
For example, it is possible to foresee a button for switching on the lighting group and manually adjusting its intensity and a button for switching on the suction group and adjusting its intensity.
It is also possible to foresee a button for the delayed switching off of the suction group, and a button for activating an intensive speed. Such a last option allows the suction group to operate at the maximum of its suction capability but only for a limited time period, after which the suction group returns to operation according to the suction mode previously set at the selection of the button of intensive speed.
In automatic mode said sensors send signals to the central unit, which controls the suction group, through said adjustment device of the suction, so as to modulate the suction flow rate according to the degree of alteration of the air quality.
In said automatic mode the suction group remains permanently active, i.e. a minimum suction is ensured throughout the day or for a predetermined time, or rather all the whilst the extractor fan is supplied with electrical energy for example through the electricity mains. The purpose of this is that of ensuring a suitable exchange of air in the room, not only at the time of cooking, but rather uninterruptedly throughout the day, from a still active very low minimum, up to the maximum, through the continuous adjustment of the suction group, which optimises the flow rate of the fan according to the degree of alteration of the air quality.
Moreover, such a central unit can advantageously control the lighting adjustment device in order to modulate the light emitted by the lighting group according to the lighting of the surrounding environment.
Such a requirement is very clear in modern dwellings, increasingly airtight with respect to the outside and increasingly subject to determining uncomfortable and inconvenient living conditions due to the low exchange of air, the formation of mould, condensation, stagnation of residue from the burning of the gas hobs, etc.
A purpose of the present invention is that of characterising the extractor fan as an intelligent ventilation system, aimed for the maximum comfort of the kitchen and of other communicating rooms. To do this it is sufficient to activate, through suitable commands, the automatic operating mode with continuous exchange of air.
After such activation, the user no longer has to worry about the adjustment of the suction flow rate of the extractor fan which shall be managed completely automatically.
Preferably, in normal conditions the extractor fan always works, 24 hours per day, at the continuous ventilation flow rate (for example about 100 m³/h) ensuring an adequate exchange of air in the room and outside with unnoticeable noise and extremely low energy consumption. By doing so, the extractor fan contributes to avoiding the formation of mould and condensation on the walls and to extracting polluted air from the room drawing in clean air from the ventilation openings made by law on the walls or on the window or simply through each non-sealed air inlet. This adjustment system is useful in all seasons of the year; in winter, when the kitchen walls are colder, the continuous exchange introduces fresh air with a lower relative humidity level, helping to avoid the formation of condensation and mould on the walls. In summer, when the humidity level is generally high, a correct ventilation allows the typical uncomfortable sensation due to the stillness of the air inside living areas to be reduced.
The activation of said sensors, due for example to an increase in the humidity levels and/or odours generated during cooking, modulates the suction flow rate of the extractor fan according to the real need for air evacuation, so as to ensure at all times the minimum noise and low energy consumption together with the capture and extraction of undesired pollutants.
The high level of safety ensured by the system of the present invention against possible gas leaks should also be highlighted. Indeed, the air quality sensor can detect an anomalous presence of gas an automatically and immediately activate the fan at high flow rates, evacuating the gas mixture to the outside and drawing in unpolluted air from the outside with the effect of keeping the mixture itself very diluted and harmless, until the intervention of the user.
Advantageously, for this purpose, it is possible to foresee that the sensor, as well as activating the inner fan of the extractor fan, can act at the same time on an electro-valve arranged along a supply piping of the gas in the room (kitchen) so as to close said valve and thus block the flow of gas to the room itself, eliminating any danger at the source.
It should also be highlighted that the continuous operation of the inner fan of the extractor fan at the continuous exchange speed, for example 100 m³/h, makes the intervention of the extractor fan possible also in cases of leaks of gases heavier than air, since the continuous flow towards the extractor of the extractor fan manages to very quickly transport a sufficient amount of gas heavier than air that is sufficient to trigger the highest speeds and the possible simultaneous closing of the supply valve of the gas towards the sensor(s).
The system, therefore, combines comfort and safety in a domestic kitchen environment in the best possible of ways.

Claims

System for continuously controlling the suction of a kitchen extractor fan, said extractor fan comprising a control keypad (13), a suction group comprising a motor and a fan (15), a device for adjusting said suction group (115), at least one smoke sensor (16) and at least one temperature sensor (17) and a central processing unit (18), characterised in that said processing unit, in response to a selection of a button of said control keypad, determines a manual operating mode of the extractor fan and an automatic operating mode in which it receives the signals from the sensors and controls said device for continuously adjusting the suction group (115), so as to keep said suction group permanently active.
System according to claim 1, wherein said control keypad comprises at least one button for switching on the suction group and manually adjusting its intensity.
System according to claim 1, wherein said control keypad comprises at least one button for switching on the light group and manually adjusting its intensity.
System according to claim 1, wherein said control keypad comprises at least one button for the delayed switching off of the suction group.
System according to claim 1, wherein said control keypad comprises at least one button for activating an intensive speed of the motor of the suction group.
System according to claim 1, wherein said central processing unit controls an adjustment device (114) of the lighting in order to modulate the light emitted by a lighting group (14) according to the light present in the surrounding area.
System according to claim 1, wherein said central processing unit is connected to an electro-valve arranged along a supply piping of the gas into a room, so as to close said valve and thus block the flow of gas to the room itself.