A ventilation diffuser for an enclosure and a ventilation system for demand-controlled ventilation with such ventilation diffuser

Abstract

The present invention concerns a ventilation diffuser for an enclosure, such as a room in a building, said diffuser comprising a diffuser housing having an upper opening adapted for receiving a supplying airflow and a lower opening, and a front plate mounted in the lower opening of the diffuser housing for directing an airflow from the diffuser housing into the enclosure, wherein airflow adapting means are provided between the diffuser housing and the front plate, wherein the airflow adapting means comprises an airflow regulating plate which is mounted on top of the front plate at a plurality of mounting points, wherein each mounting point comprises an individually length adjustable actuator. The invention further concerns a front plate assembly for such ventilation diffuser and a ventilation system for demand-controlled ventilation (DCV) using such diffuser.

Description

[0001] 84041 PC01

[0002] 1

[0003] A VENTILATION DIFFUSER FOR AN ENCLOSURE AND A VENTILATION SYSTEM FOR DEMAND-CONTROLLED VENTILATION WITH SUCH VENTILATION DIFFUSER

[0004] FIELD OF THE INVENTION

[0005] The present invention relates to a ventilation diffuser for an enclosure, such as a room in a building, said diffuser comprising a diffuser housing having an upper opening adapted for receiving a supplying airflow and a lower opening, and a front plate mounted in the lower opening of the diffuser housing for directing an airflow from the diffuser housing into the enclosure, wherein airflow adapting means are provided between the diffuser housing and the front plate.

[0006] A ventilation diffuser of such kind is known from US 11,187,431 B2 and also from GB 1 325 132.

[0007] BACKGROUND OF THE INVENTION

[0008] In a DCV (Demand-Controlled Ventilation) diffuser, determining the actual airflow rate is essential to assess the air quality in the room and to understand the total airflow rates in the ductwork of the DCV system, which includes all supply diffusers. The airflow rate is calculated based on the area through which the supply air passes (specifically, the space between the airflow regulating plate and the diffuser housing) and the pressure difference across the airflow regulating plate.

[0009] Typically in such traditional ventilation diffusers in DCV systems have airflow adapting means in the form of actuators placed within the duct, near the regulating plate. This causes issues like noise and complications in installation and maintenance of the ventilation system and the ventilation diffusers in the DCV system.

[0010] Accordingly, it is an object to address these problems by offering variable air patterns, reducing noise levels, and simplifying the design and maintenance of DCV systems. 84041 PC01

[0011] 2

[0012] SUMMARY OF THE INVENTION

[0013] This object is achieved in a first aspect of the invention by providing a ventilation diffuser of the initially mentioned kind, wherein the air flow adapting means comprises an airflow regulating plate which is mounted on top of the front plate at a plurality of mounting points, wherein each mounting point comprises an individually length adjustable actuator.

[0014] By the invention it is found advantageous that the diffuser can be installed in a standard supply diffuser commonly used in ventilation systems. This typical diffuser comprises a diffuser housing connected to the ductwork and a demountable front plate that directs airflow within the room.

[0015] The length adjustable actuators sitting on the upper side of the front plate are adapted to provide movement of the airflow regulating plate, whereby the gap size between the upper opening of the diffuser housing and the airflow regulating plate is varied to control the amount of airflow. By length adjustable is meant the length between the motor of the actuator and the airflow regulation plate. Thus, the length adjustable actuators are adjusting the distance between the front plate on which the actuator sits and the airflow regulating plate.

[0016] According to the invention, the front plate (visible from the room) serves as a foundation for a number of actuators, and preferably the actuators are adhesively mounted to the upper side of the front plate. Hereby, the actuators are out of the main airflow and thereby the noise from the actuators is not transferred to the room by the airflow through the ventilation diffuser when air passes the motor in the duct and also vibration from motor is not transferred through the front plate (soft / sound-damping adhesive). Consequently, a DCV ventilation diffuser according to the invention may be provided with a significantly reduced noise level.

[0017] The actuators are operated independently. Each actuator comprises a motor linked to a rotating threaded rod. This rod goes through the airflow regulating plate, which also has matching threads. The matching threads could also be in a nut connected to the airflow regulating plate. As the motor turns the rod, the 84041 PC01

[0018] 3 regulating plate moves up or down, based on the rotation direction. The incoming air flows through the gap between the diffuser housing and the regulating plate. The independent movement of the actuators allows the gap size between the diffuser housing and the regulating plate to vary from one side to the other. This variability enables different air volumes on either side, resulting in adjustable air patterns from the diffuser. Consequently, this innovation allows for precise ventilation control when incorporated into a standard diffuser.

[0019] Preferably, the front plate is detachably mounted to the lower opening at one or more peripheral points, preferably such that when the diffuser housing is provided in a ceiling the front plate is substantially parallel, such as flush, with said ceiling. The detachably mounting may include one or more mounting solutions, such as click-on, screws, a spring function, a key-hole, insertion of a lock, magnets, etc. In one preferred embodiment, the diffuser housing is conical in shape and having a wider lower opening in which the front plate is mounted compared to the upper opening. The airflow regulation plate may also be conical or bulb-shaped lifted / pointing upwards. The regulation plate may also be provided with an air- permeable layer on top of the plate or with brushes at the periphery substantially oriented in radial direction to further dampen any noise.

[0020] The ventilation diffuser according to a preferred embodiment of the invention comprises a demountable front plate with three independently operated actuators. Each actuator comprises a motor connected to a rotating threaded rod passing through a regulating plate with matching threads. The actuators are governed by a diffuser control unit. The movement of the regulating plate, controlled by the rotation of the rod, varies the gap size between the upper opening of the diffuser housing and the regulating plate. This allows for adjustable air patterns, enabling precise control of ventilation. Preferably the motors are adhesively mounted to the upper side of the front plate.

[0021] The diffuser may comprise a diffuser control unit, which is adapted to control the length adjustable actuators to regulate the air flow through the diffuser. In addition, it is found advantageous that one or more sensors are provided to deliver one or more measurements of room air conditions to the diffuser control unit. Hereby, the ventilation diffuser can be operated as a "stand alone" unit since 84041 PC01

[0022] 4 the sensors can provide the necessary input to the control unit for regulating the airflow through the diffuser and into the enclosure / room. In another embodiment, the diffuser control unit may be adapted to receive data input from an external control source, e.g. adapted for controlling a plurality of ventilation diffusers, either in addition to the sensors in the diffuser or as an alternative to the diffuser mounted sensors. By the invention it is further realised that there are several sensor options. Accordingly, the sensor may be provided on the control unit, for instance integrated in the electronics of the control unit. The sensors may be in wired connection to the control unit or in a wireless connection to the control unit.

[0023] In one embodiment, the front plate is perforated for inducing air from the enclosure into the diffuser, e.g. so that said induced air passes the one or more sensors registering one or more parameters of said induced airflow. Accordingly, the sensors may include one or more of a room temperature sensor, humidity sensor for measuring the humidity in the room, CO2 sensor for measuring the CO2 level in the room, and / or a VOC sensor for measuring the volatile organic compounds (VOC) level in the air from the enclosure, a pressure sensor for measuring pressure difference across the airflow regulating plate, a supply air temperature sensor for measuring supply air temperature, a pressure sensor for measuring pressure in the enclosure, i.e. the room and / or a presence sensor through a hole in the front plate.

[0024] In one preferred embodiment of the invention, said diffuser control unit is provided on the upper side of the front plate. Hereby, the control unit can be provided without being visible from the enclosure / room.

[0025] In one embodiment of the invention, three individually length adjustable actuators are provided, preferably substantially equally spaced apart along the peripheral region of the airflow regulating plate. However, it is realised by the invention that both the number of actuators as well as the position of the mounting points may be varied and chosen according to the circumstances.

[0026] In one series of embodiments, the three individually length adjustable actuators are operated with individual displacement for tilting the airflow regulating plate. In another series of embodiments of the invention, the individually length adjustable 84041 PC01

[0027] 5 actuators are operated with identical displacement for raising or lowering the airflow regulating plate and thereby maintaining the regulating plate substantially parallel with the front plate.

[0028] In a second aspect of the invention there is provided a ventilation system for demand-controlled ventilation (DCV) comprising one or more ventilation diffusers of the type according to the first aspect. Preferably, the plurality of ventilation diffusers are provided, each having a diffuser control, which is adapted to receive data input from one common external control source. This data exchange may for instance be provided by wireless communication. The external control source may be for instance a room controller or a building management system.

[0029] As an alternative, it is by the invention realised that a ventilation system for demand-controlled ventilation (DCV) with a plurality of ventilation diffusers according to the first aspect of the invention, may advantageously be operated as a number of stand-alone diffusers, each having their own diffuser control unit, which is self-regulating based on room air conditions from measurements of the one or more sensors.

[0030] By the invention it is realised that the ventilation diffuser design can be fitted into standard supply diffusers used in ventilation systems. Accordingly, in a third aspect of the invention, there is provided a front plate assembly for mounting in a lower opening of a diffuser housing of a ventilation diffuser for an enclosure for directing an airflow from the diffuser housing into the enclosure, wherein the assembly comprises a front plate on which airflow adapting means are provided, and wherein the air flow adapting means comprises an airflow regulating plate which is mounted on top of the front plate at a plurality of mounting points, wherein each mounting point comprises an individually length adjustable actuator. Hereby, existing ventilation diffusers may be refurbished and upgraded to a ventilation diffuser according to the first aspect discussed above. Thus, it is realised that the invention can easily be integrated into most existing supply diffusers, converting them into DCV diffusers capable of providing precision ventilation, thus enhancing the efficiency and effectiveness of ventilation systems. 84041 PC01

[0031] 6

[0032] DETAILED DESCRIPTION

[0033] In the following, the invention is described in more detail with reference to the embodiments shown in the accompanying drawings, in which:

[0034] Fig. 1 is a schematic cross-sectional side view of a first embodiment of a ventilation diffuser according to the invention;

[0035] Fig. 2 is a schematic top view of same;

[0036] Fig. 3 is a schematic cross-sectional side view of a second embodiment of a ventilation diffuser according to the invention;

[0037] Fig. 4 is a schematic view of a room having a ventilation system according to the second aspect of the invention; and

[0038] Fig. 5 is a diagram showing the relationship between the opening and the airflow through the ventilation diffuser.

[0039] With reference to figure 1 and 2, a ventilation diffuser according to a first embodiment of the invention is shown. The ventilation diffuser is mounted in the ceiling C of an enclosure, such as a room in a building (see also fig. 3). The ventilation diffuser comprises a diffuser housing 1 which has an upper opening UO adapted for receiving a supplying airflow A and a lower opening LO. A front plate 2 is mounted in the lower opening LO of the diffuser housing 1 for directing the airflow A from the diffuser housing 1 into the enclosure. Airflow adapting means are provided between the diffuser housing 1 and the front plate 2, which comprises an airflow regulating plate 3, which is mounted on top of the front plate 2 at a plurality of mounting points, wherein each mounting point comprises an individually length adjustable actuator 4.

[0040] In an embodiment, a hole (not shown) in the airflow regulation plate 3 is provided. A hose connecting between this hole and a pressure sensor on the control unit 5 is also provided for measuring the pressure difference across the airflow regulating plate 3. Furthermore, below the control unit 5 there may also be provided an opening, where air is induced.

[0041] In the present embodiment three individually length adjustable actuators are provided. This could be any other number depending on the actual installation. 84041 PC01

[0042] 7

[0043] Each of the individually length adjustable actuators comprise a motor 41, which is rotating a threaded rod 42, which is connected to the airflow regulating plate 3. The motors 41 are advantageously adhesively mounted to the upper side of the front plate 2, whereby an adhesive layer 43 is provided which apart from adhering the motor 41 to the front plate 2 also provides a vibration damping so that vibrations and noise from the motors 2 is prevented from being transferred onto the front plate 2.

[0044] In the figures, the airflow regulating plate 3 is shown being flat. However, it is realised that the airflow regulation plate 3 may also be conical or bulb-shaped lifted / pointing upwards. The airflow regulation plate 3 may also be provided with an air-permeable layer 31 on top of the airflow regulation plate 3 and / or with brushes (not shown) at the periphery substantially oriented in radial direction to further dampen any noise.

[0045] The ventilation diffuser also comprises a diffuser control unit 5, which is adapted to control the length adjustable actuators 4 to regulate the air flow through the diffuser. In one embodiment, the diffuser control unit 5 may be adapted to receive data input from an external control source 6. However, as an alternative or as a supplement, the diffuser may be provided with one or more sensors 51 (see fig. 3) to provide one or more measurements of room air conditions to the diffuser control unit 5. Hereby, the ventilation control unit according to the invention may be operating as a stand-alone unit.

[0046] The diffuser control unit 5 may be provided on the upper side of the front plate 2. The front plate 2 may be a solid plate or a perforated plate as shown in fig. 3.

[0047] The front plate 2 is detachably mounted to the lower opening LO of the diffuser housing 1 at one or more peripheral points, such that when the diffuser housing 1 is provided in a ceiling the front plate 2 is substantially parallel, such as flush, with said ceiling C. The three individually length adjustable actuators 4 are preferably provided substantially equally spaced apart along the peripheral region of the airflow regulating plate 3 as shown in fig. 2. 84041 PC01

[0048] 8

[0049] To ensure effective operation of the diffusers, the end positions may be detected for the open and closed states at each intersection point of the threaded rod 42 and the regulating plate 3. The degree of opening (between the diffuser housing 1 and the periphery of the regulating plate 3) is calculated e.g. by counting the rotations of the threaded rod from the closed position, considering the movement of the regulating plate 3.

[0050] As mentioned above, the front plate 2 may be a solid plate as shown in fig. 1 or a perforated plate as shown in fig. 3. When the airflow passes through the gap opening between the diffuser housing 1 and the periphery of the regulating plate 3 and induction effect is occurring. If the front plate 2 is perforated (see fig. 3) this means that air from the room is drawn into the space above the front plate 2 as indicated by the arrows RA. This allows the sensors 51 to measure room air conditions. The sensors 51 may also be provided on the control unit 5, and the sensors 51 may be integrated in the control unit 5, in wired connection to the control unit 5, or in a wireless connection to the control unit 5.

[0051] In the following the induction is further explained:

[0052] The total pressure is the sum of static and dynamic pressure.

[0053] The dynamic pressure equals pv2 / 2, where p is density (kg / m3) and v is air speed (m / s). The high air speed created at the opening between the airflow regulating plate and the diffuser housing generates a low static pressure in the space between the airflow regulating plate and the front plate due to the high dynamic pressure. This lower static pressure can induce air from the enclosure through any opening in the front plate.

[0054] The induced air can be used for sensing temperature, CO2, and VOC and humidity levels when passing through the diffuser control via a hole in the front plate.

[0055] The induced air can also mix the colder supply air with warmer air from the enclosure through holes in the front plate, resulting in a higher airflow with an increased temperature from the diffuser into the enclosure, improving the indoor climate. 84041 PC01

[0056] 9

[0057] The following sensors may be included in the diffuser control unit 5:

[0058] - Pressure sensor for measuring pressure difference across the airflow regulating plate;

[0059] - Supply air temperature sensor for measuring supply air temperature;

[0060] - Presence sensor for detecting presence in the enclosure;

[0061] - Room temperature sensor for measuring enclosure air temperature;

[0062] - humidity sensor for measuring enclosure air humidity;

[0063] - CO2 sensor for measuring CO2 level in the air from the enclosure;

[0064] - VOC (Volatile Organic Compounds) sensor for measuring VOC level in the air from the enclosure.

[0065] The pressure sensor and supply air temperature sensor are measuring conditions related to the supply air flow preferably with the help of a hose connected from the air flow regulating plate to the diffuser control.

[0066] Enclosure air temperature sensor, enclosure air humidity sensor, CO2 sensor and VOC sensor are positioned on the diffuser control in a way that they protrude through a hole in the front plate or are close to a hole in the front plate, to measure conditions in the enclosure air induced through the hole in the front plate.

[0067] Presence sensor can be installed on the diffuser control protruding through a hole in the front plate.

[0068] The flow rate of the airflow can be calculated using two parameters:

[0069] - The pressure difference across the airflow regulating plate, and

[0070] - the opening between the airflow regulating plate and the diffuser housing.

[0071] The opening between the airflow regulating plate 3 and the diffuser housing 2 is a function of the positions of the individual adjustable actuators 4. 84041 PC01

[0072] 10

[0073] Zero position is the position where the airflow regulating plate 3 touches the housing 1.

[0074] The position of each actuator 4 can be defined for example based on the number of steps from the zero position (step motor) or the time duration of power supply from the zero position (DC motor).

[0075] To be able to measure the position correctly, it is possible to detect and calibrate the zero position. The calibration may be done by an adaption process to determine the right values, for example by measuring changes in the electric current.

[0076] The relationship is presented in fig. 5 in a form of a diagram showing the relationship between the flow rate (in m3 / s), the pressure difference across the airflow regulating plate 3, and the opening (in m2) between the airflow regulating plate 3 and the diffuser housing 1.

[0077] In general, when directional terms like "upper" and "lower" or similar directional references are used in the present disclosure, these terms are meant to be understood as relative terms e.g. where the term "upper" refers to a direction essentially opposite to the "lower", but it is realised that the planar assembly when in use can be positioned with any orientation.

[0078] Although the present invention has been described in connection with the specified embodiments, it should not be construed as being in any way limited to the presented examples. The scope of the present invention is set out by the accompanying claim set. In the context of the claims, the terms "comprising" or "comprises" do not exclude other possible elements or steps. Also, the mentioning of references such as "a" or "an" etc. should not be construed as excluding a plurality. The use of reference signs in the claims with respect to elements indicated in the figures shall also not be construed as limiting the scope of the invention. Furthermore, individual features mentioned in different claims, may possibly be advantageously combined, and the mentioning of these features in different claims does not exclude that a combination of features is not possible and advantageous. 84041 PC01

[0079] 11

[0080] Above, the invention is described with reference to some currently preferred embodiments. However, by the invention it is realised that other embodiments and variants may be provided without departing from the scope of the invention as defined in the accompanying claims.

Claims

84041 PC0112CLAIMS1. A ventilation diffuser for an enclosure, such as a room in a building, said diffuser comprising a diffuser housing having an upper opening adapted for receiving a supplying airflow and a lower opening, and a front plate mounted in the lower opening of the diffuser housing for directing an airflow from the diffuser housing into the enclosure, wherein airflow adapting means are provided between the diffuser housing and the front plate, characterised in that the airflow adapting means comprises an airflow regulating plate which is mounted on top of the front plate at a plurality of mounting points, wherein each mounting point comprises an individually length adjustable actuator.

2. A ventilation diffuser according to claim 1, wherein the front plate is detachably mounted to the lower opening at one or more peripheral points, preferably such that when the diffuser housing is provided in a ceiling the front plate is substantially parallel, such as flush, with said ceiling.

3. A ventilation diffuser according to claim 1 or 2, wherein each of the plurality of individually length adjustable actuators comprises a motor which is rotating a threaded rod, which is connected to the airflow regulating plate, and preferably the motors are adhesively mounted to the upper side of the front plate.

4. A ventilation diffuser according to any of the previous claims, wherein the diffuser comprises a diffuser control unit, which is adapted to control the length adjustable actuators to regulate the air flow through the diffuser.

5. A ventilation diffuser according to any of the previous claims, wherein one or more sensors are provided to perform one or more measurements of room air conditions to the diffuser control unit.

6. A ventilation diffuser according to claim 5, wherein the one or more sensors may be provided on the control unit.84041 PC01137. A ventilation diffuser according to any of claims 4 to 6, wherein the diffuser control unit is adapted to receive data input from an external control source.

8. A ventilation diffuser according to any of claims 4 to 7, wherein said diffuser control unit is provided on the upper side of the front plate.

9. A ventilation diffuser according to any of the previous claims, wherein three individually length adjustable actuators are provided, preferably substantially equally spaced apart along the peripheral region of the airflow regulating plate.

10. A ventilation diffuser according to any of the previous claims, wherein the individually length adjustable actuators are operated with individual displacement for tilting the airflow regulating plate.

11. A ventilation diffuser according to any of the previous claims, wherein the individually length adjustable actuators are operated with identical displacement for raising or lowering the airflow regulating plate.

12. A ventilation diffuser according to any of the previous claims, wherein the front plate is perforated for inducing air from the enclosure into the diffuser, e.g. so that said induced air passes the one or more sensors registering one or more parameters of said induced airflow.

13. A ventilation system for demand-controlled ventilation (DCV) comprising at least one ventilation diffuser according to any one of the previous claims.

14. A ventilation system according to claim 13, wherein a plurality of ventilation diffusers are provided, each having a diffuser control unit, which is adapted to receive data input from one common external control source.

15. A ventilation system according to claim 13, wherein a plurality of ventilation diffusers are provided, each having their own diffuser control unit, which is selfregulating based on room air conditions from measurements of the one or more sensors.84041 PC011416. A front plate assembly for mounting in a lower opening of a diffuser housing of a ventilation diffuser for an enclosure for directing an airflow from the diffuser housing into the enclosure, wherein said front plate assembly comprises a front plate on which airflow adapting means are provided, and wherein the air flow adapting means comprises an airflow regulating plate which is mounted on top of the front plate at a plurality of mounting points, wherein each mounting point comprises an individually length adjustable actuator.

17. A front plate assembly according to claim 16 for use in a ventilation diffuser according to any of claims 1 to 12 for use in a ventilation system according to any of claims 13 to 15.

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