EP0943072B1

EP0943072B1 - Space ventilating method and apparatus

Info

Publication number: EP0943072B1
Application number: EP97947991A
Authority: EP
Inventors: Willem Antonius Boekelman
Original assignee: Berli Holding BV
Current assignee: Berli Holding BV
Priority date: 1996-11-27
Filing date: 1997-11-25
Publication date: 2002-03-06
Anticipated expiration: 2017-11-25
Also published as: DE69710920D1; NL1004626C2; DE69710920T2; AU5415298A; WO1998023904A1; EP0943072A1; DK0943072T3

Abstract

A method and a device for ventilating a room, wherein an air passage is opened or closed to a particular degree by means of a ventilation valve in dependence on at least one measurement made by means of at least one sensor (12, 16). Before the measurement is made by means of the sensor (12, 16), the air passage is closed by means of the ventilation valve. Then a predetermined waiting period is preferably observed, and subsequently the measurement is made by means of the sensor present (12, 16) in the room. Following that the ventilation valve is opened or kept in its closed position in dependence on a value ensuing from said measurement.

Description

The invention relates to a method for ventilating a room, wherein an air passage is opened or closed to a particular degree by means of a ventilation valve in dependence on at least one measurement made by means of at least one sensor.
The invention also relates to a device suitable for carrying out such a method.
With such a method, which is known from Dutch patent application NL-A-6615835, the ventilation valve is moved to a particular position, which position depends on a measurement made by means of a sensor and on a value concerning the temperature within the room determined on the basis of said measurement. Each value is associated with a particular position of the ventilation valve. When the room is being ventilated, air flows into and out of the room through the air passage. If the sensor is disposed relatively close to the air passage, there is a danger that the value determined by means of the sensor is based not only on the air present in the room but also or even mainly on the air flowing into the room. As a result of this a reliable measurement cannot be obtained.
The object of the present invention is to provide a method wherein the measurement can be made more accurately.
This objective is accomplished with the method according to the invention in that, prior to making the measurement by means of the sensor(s), the air passage is closed by means of the ventilation valve, and subsequently the measurement is made by means of the sensor(s) present in the room, after which the ventilation valve is opened or kept in its closed position in dependence on a value ensuing from said measurement.
Since the ventilation valve is closed before the measurement is made, the measurement cannot be influenced by air flowing into the room. Also the air that flowed into the room just before the ventilation valve closed is prevented from influencing the measurement, if a waiting period is observed before the measurement is carried out. During the waiting period said air mixes with the air that was already present in the room.
It is also possible to start measuring immediately after said closing for a predetermined period of time or to continue said measuring until a constant measuring value has been reached. The changing measuring values provide information with regard to the "freshening" characteristics of the room. On the basis of this information an estimation may be made as to the start of a next control cycle.
One embodiment of the method according to the invention is characterized in that the position of the ventilation valve that was adjusted after the measurement is maintained for the duration of a predetermined ventilation period, after which the ventilation valve is closed and a next measurement is made, possibly after the waiting period has elapsed.
In this manner a new measurement is carried out automatically after the lapse of the ventilation period. The advantage of this in comparison with the situation wherein a measurement is initiated manually is that a measurement is made at regular intervals, which ensures a better ventilation of the room. The ventilation valve is prevented from remaining opened or closed too long.
Another embodiment of the method according to the invention is characterized in that a measurement is also made outside the room by means of at least one further sensor, whereby the ventilation valve is open or kept in its closed position in dependence on both measurements.
In this manner the ventilation can be attuned to the air conditions both inside and outside the room.
The invention also relates to a device for carrying out the method. It is an object of the present invention to provide a device which can be mounted near an air passage in a simple and compact manner.
This objective is accomplished with the device according to the invention in that the device comprises an adjustable ventilation valve for opening or closing an air passage to a particular degree, at least one sensor disposed near said ventilation valve, a regulating unit comprising said sensor(s), and a drive unit to be controlled by said regulating unit, which is connected to said ventilation valve, whereby the regulation unit comprises means to close the air passage by means of the ventilation valve, prior to making measurement by means of the sensor(s), and to subsequently make the measurement by means of the sensor(s), after which the ventilation valve can be opened or kept in its closed position in dependence on a value ensuing from said measurement.
Such a device is relatively simple and can be disposed near an air passage. The device may form part of a window casing or a window.
The invention will be explained in more detail with reference to the drawings, in which:
Figures 1A and 1B show a longitudinal section and a cross-section respectively of a first embodiment of a device according to the invention;
Figures 2A, 2B, 2C and 2D show a longitudinal section, a rear view, a front view and a side view respectively of a second embodiment of a device according to the invention; and
Figure 3 shows a control diagram of the device shown in Figures 2A-2D.
Like parts are numbered alike in the figures.
Figures 1A and 1B show a longitudinal section and a cross-section respectively of a first embodiment of a device 1 according to the invention. Device 1 comprises a rectangular housing 2, in which a shaft 3 is rotatably supported in bearings 4. Shaft 3 is connected to a ventilation valve (not shown). Shaft 3 is also connected to a lever 5, which is connected to a shifting mechanism 7 with one end, via a pivot 6, and which lever abuts against a leaf spring 9 with an end 8 remote-from said first end. Elongated leaf spring 9 is connected with its ends to opposing walls 10 of housing 2. Shifting mechanism 7 comprises electrically excitable coils and a pin 11, which is capable of movement within said coils and which is pivotally connected to pivot 6 with one end. Pin 11 comprises a soft-iron portion, which can be attracted by the coils. Shifting mechanism 7 is flexibly connected, via a spring, to the walls of housing 2 at and end remote from pivot 6. Device 1 furthermore comprises a sensor 12, a battery holder 13 with a battery present therein, and a loudspeaker 14, which are mounted on a wall 15 of housing 2, which wall is directed towards a room to be ventilated during operation. Device 1 furthermore comprises a sensor 16, which is mounted on a bottom wall 10 of housing 2. During operation sensor 16 is disposed outside the room to be ventilated. Device 1 furthermore comprises a solar cell 17, which is mounted on a wall 18 opposite wall 15. Sensors 12, 16, battery holder 13, loudspeaker 14 and solar cell 17 are electrically connected to a printed circuit board 19 provided with electronic components.
The operation of device 1 is as follows. In the position of shaft 3 shown in Figures 1A and 1B the air inlet (not shown) is closed by means of the ventilation valve connected to the shaft. A regulating unit built up of electronic components is present on the printed circuit board, by means of which the sensors are controlled to make a measurement. Sensors 12 and 16 may for example be used to measure the air humidity, the temperature, the pressure or the CO₂-content of the air inside and outside the room to be ventilated. Furthermore it is possible to detect the presence of persons in the room to be ventilated by means of sensor 12. Depending on the measurement made by means of the sensors a value is determined, which is compared with a reference value stored on printed circuit board 19. When the reference value is exceeded, the regulating unit will deliver a signal to shifting mechanism 7, which causes pin 11 to be moved in a direction indicated by arrow P1. Lever 5 thereby pivots in a direction indicated by arrow P2, and leaf spring 9 is bent outwards against spring force in a direction indicated by arrow P3. When lever 5 pivots in the direction indicated by arrow P2, pivot 6 is moved over a relatively small distance in a direction opposed to the direction indicated by arrow P3. Shifting mechanism 7 makes a slight pivoting movement about the spring thereby. Pin 11 is moved in the direction indicated by arrow P1 until lever 5 has been pivoted through an angle of 90°. In this position leaf spring 9 urges lever 5 under spring force in a direction opposed to the direction-indicated by arrow P3. Spring leaf 9 prevents lever 5 from returning to the position shown in Figure 1B, which would be undesirable. When lever 5 pivots in the direction indicated by arrow P2, also the ventilation valve connected to shaft 3 is moved from a closed position to a fully open position. With the device 1 shown in Figures 1A and 1B, the ventilation valve can only be moved between these two positions. After a ventilation period stored on printed circuit board 19 has elapsed, shifting mechanism 7 is excited again, after which pin 11 is moved in a direction opposed to the direction indicated by arrow P1, and lever 5 returns to the position shown in Figure 1B and the ventilation valve is closed again. Following that a new measurement may be made. The power supply of printed circuit board 19 and shifting mechanism 7 takes place by means of solar cell 18 and/or the battery present in battery holder 13. The battery may be charged by means of the solar cell. The moment the battery is nearly flat, loudspeaker 14 delivers an acoustic signal, which informs a person present in the room that the battery is running down. Device 1 can be mounted in a window casing in a simple manner. Since the energy supply takes place by means of solar cells and batteries, device 1 can be installed at a random location in a building. It is also possible, of course, to connect device 1 to a 220 V power supply, but this has the drawback that separate power supply wires are necessary.
Figures 2A, 2B, 2C and 2D show a longitudinal section, a rear view, a front view and a side view respectively of a second embodiment of a device 20 according to the invention. Device 20 comprises a housing 2 disposed near an air passage, in which a shaft 3 is supported in bearings, which shaft is connected to a tiltable ventilation valve (not shown) with one end. Shaft 3 is connected to a motor 22 via a transmission 21. Transmission 21 is provided with a gear 24, which is coupled to an outgoing shaft 23 of motor 22, which gear is in mesh with a gear 25, which is bearing-mounted on shaft 3. Gear 25 is rigidly connected to a gear 26, which is likewise bearing-mounted on shaft 3, which gear is in mesh with a gear 28, which is rotatable about a shaft 27. Gear 28 is rigidly connected to gear 29, which is in mesh with a gear 30, which is rigidly connected to shaft 3. Device 20 comprises sensors 12, which are directed towards the room to be ventilated, as well as sensors 16, which are disposed outside the room to be ventilated. Device 20 is provided with a solar cell 18 on a side located outside the room. Housing 2 is provided on a bottom side with a flange 31, which comprises a U-shaped section 32. An edge of a double-glass window pane 33 can be clamped down in said U-shaped section 32. Sensors 12, 16, solar cell 18, battery 13 and motor 22 are electrically connected to a printed circuit board 19, which inter alia comprises a regulating unit. Stored in said regulating unit is inter alia the control diagram shown in Figure 3, by means of which device 20 is controlled.
The operation of the device 20 shown in Figures 2A-2D will be explained in more detail with reference to Figure 3. The regulating unit comprises a control unit 34, by means of which a closing command 36 is transmitted to motor 22 after a ventilation period 35 stored in the regulating unit has elapsed. Motor 22 is activated, whereby shaft 3 is pivoted by means of motor 22, in such a manner that the ventilation valve is moved to a closed position. The moment said closed position is reached, a closed position signal 37 is transmitted to a time measuring unit 38. After the lapse of a waiting period 39 stored in the regulating unit, time measuring unit 38 delivers a signal to control unit 34, after which measuring commands 40 are delivered to sensors 12, 16 from control unit 34. The values 41 measured by sensors 12, 16 are delivered to control unit 34 and forwarded to a control position unit 42. Stored in said control position unit 42 are tables or formulas, on the basis of which a position of the ventilation valve associated with the measuring data determined by means of the sensors is determined. Motor 22 is controlled on the basis of the desired position of the ventilation valve, as a result of which the ventilation valve is pivoted to the desired position by means of shaft 3. The moment the desired position is reached, a signal 43 is delivered, which signal is supplied to time measuring unit 38. After receipt of said signal 43, the ventilation valve remains open for the duration of the ventilation period 35. After the lapse of the ventilation period 35 a signal is transmitted to control unit 34 by time measuring unit 38 again, after which the cycle is repeated again.
The ventilation period may have a fixed value, but a ventilation period may also be adjusted in dependence on the measuring data 41 determined by means of sensors 12, 16. If one of the sensors 12 is a motion sensor, it is possible to lengthen/shorten the ventilation period if the presence of a person in the room to be ventilated is detected, and to shorten/lengthen the ventilation period if such presence is not detected.
It is also possible to measure the sound level inside and outside the room to be ventilated. If the sound level in the room is higher than would be expected on the basis of the sound level outside the room, this signifies that sound is being produced inside the room. This is an indication that the room is being used by persons. In this way it is possible to establish that the room is being used without having to use motion detectors. This is of importance in particular if sensors are mounted on the window casing, with curtains hanging in front of the window casing, which make it impossible to use a motion sensor.
It is also possible to continue measuring the conditions in the room to be ventilated after the closing of the ventilation valve until the measured values remain constant for a predetermined period. As soon as these values remain constant during said predetermined period, said values will be the measuring values to be used.
Furthermore it is possible to open the ventilation valve only partially, in order to prevent draught. In addition this makes it possible to eliminate small increases in for example the CO₂ level by additional ventilation.
Furthermore it is possible to measure the pressures inside and outside the room. In the event that the pressure inside a room is higher than the pressure outside the room, for example as a result of the flow of the wind, it will not be necessary to close the ventilation valve prior to making a measurement, because the air flow will be directed outward in that case and there will be hardly any influencing of the measurement by the outside air.

Claims

A method for ventilating a room, wherein an air passage is opened or closed to a particular degree by means of a ventilation valve in dependence on at least one measurement made by means of at least one sensor (12, 16), characterized in that, prior to making the measurement by means of the sensor(s) (12, 16), the air passage is closed by means of the ventilation valve, and subsequently the measurement is made by means of the sensor(s) (12, 16) present in the room, after which the ventilation valve is opened or kept in its closed position in dependence on a value ensuing from said measurement.
A method according to claim 1, characterized in that a predetermined waiting period is observed before the measurement is made.
A method according to claim 1 or 2, characterized in that the position of the ventilation valve that was adjusted after the measurement is maintained for the duration of a predetermined ventilation period, after which the ventilation valve is closed and a next measurement is made, possibly after the waiting period has elapsed.
A method according to claim 1, 2 or 3, characterized in that a measurement is also made outside the room by means of at least one further sensor (16), whereby the ventilation valve is open or kept in its closed position in dependence on both measurements.
A method according to any one of the preceding claims, characterized in that the ventilation period is longer than the waiting period.
A method according to any one of the preceding claims, characterized in that the air humidity in the room is measured by means of said sensor.
A method according to any one of the preceding claims, characterized in that the CO₂ level in the room is measured by means of said sensor.
A method according to any one of the preceding claims, characterized in that motion in the room is detected by means of said sensor.
A method according to any one of the preceding claims, characterized in that sound inside and outside the room is measured by means of sensors, after which it is established that the room is being used if the sound level inside the room is higher than would be expected on the basis of the sound level outside the room.
A device (1) suitable for carrying out the method according to any one of the preceding claims, whereby the device (1) comprises an adjustable ventilation valve for opening or closing an air passage to a particular degree, at least one sensor (12, 16) disposed near said ventilation valve, a regulating unit (34-42) comprising said sensor(s), and a drive unit (22) to be controlled by said regulating unit, which is connected to said ventilation valve, characterized in that the regulation unit comprises means (34) to close the air passage by means of the ventilation valve, prior to making measurement by means of the sensor(s), and to subsequently make the measurement by means of the sensor(s) (12, 16), after which the ventilation valve can be opened or kept in its closed position in dependence on a value ensuing from said measurement.
A device according to claim 10, characterized in that said sensor(s), said regulating unit (34-42) and said drive unit are present in a common housing near the ventilation valve.
A device according to claim 10 or 11, characterized in that the device comprises a power source present within said housing.
A device according to any one of the preceding claims 10 - 12, characterized in that said power source comprises a solar cell and/or a battery.
A device according to any one of the preceding claims 10 - 13, characterized in that said device comprises a first sensor, which is present inside the room to be ventilated during operation, and a second sensor, which is present outside the room to be ventilated.
A device according to any one of the preceding claims 10 - 14, characterized in that the device can be mounted near a ventilation opening in a window casing, a wall, a roof or an air duct.