CEILING ISLAND WITH AIR CHANNEL

Abstract

 In a first aspect, the invention relates to a ceiling element for controlling the temperature in an internal space with ceiling, the ceiling element comprising an air channel that is provided at the lower side with an air guide plate, in which that air channel is moreover provided with a plurality of blow openings that are grouped along the length and at both sides of the air channel into successive clusters, in which the clusters of blow openings are arranged alternatively crosswise along both sides of the air channel. In a second aspect, the invention relates to a system comprising one or more of such ceiling elements. In a third aspect, the invention relates to a kit for providing a ceiling element at an internal space with ceiling.

Description

TECHNICAL DOMAIN

[0001] The present invention relates to systems for controlling the temperature in internal spaces with a ceiling. More in particular, the invention relates to a ceiling element, on a system comprising several of such ceiling elements and to a kit for providing such a ceiling element to an internal space with ceiling.

STATE OF THE ART

[0002] Systems for a low-energy control of the temperature in internal spaces, using ceiling elements making use of the thermal capacity of the ceiling structure on top of it, are known in the state of the art.

[0003] EP 2 995 871 describes a flat ceiling element consisting of two parts: an upper part and a lower part. The upper part comprises an upper cooling circuit, which is coupled thermally to the ceiling structure lying on top of it. The lower part comprises a lower cooling circuit, this time coupled thermally to the underlying space. Between both parts, an isolating layer is provided, so that the cooling circuits can be uncoupled. Typically, such a ceiling element is used to withdraw the heat during the day from the underlying space, via the lower cooling circuit. This heat is transported by means of a cooling liquid to the upper cooling circuit and is delivered there to the ceiling structure. At night, this stored heat is withdrawn again. Thereby, the ceiling structure is cooled by the cooler outside air, by means of a cooling liquid circulating through the upper cooling circuit and along a heat exchanger for exchanging heat with the outside air. This withdrawing of heat that was stored in the ceiling structure during the day, is also called "resetting" of that ceiling structure. Since the upper and the lower part are uncoupled thermally, there is no risk of overcooling of the underlying space when resetting the ceiling structure. A disadvantage of this system is however that the ceiling element does not sufficiently use the thermal capacity of the ceiling structure. Indeed, there is only a thermal coupling with the ceiling structure, at the place where the upper cooling circuit overlaps. Another disadvantage is that the system is quite complex and expensive, as a result of the use of cooling circuits in which a cooling liquid circulates. Another disadvantage is that the system does not allow sufficient control in case of large temperature fluctuations: the lower cooling circuit only exchanges heat with the underlying space via natural convection and radiation.

[0004] DE 20 2016 106 155 describes a system with ceiling elements that can be used both for warming up as well as for cooling the underlying space. It comprises a set of parallel, elongated ceiling elements that are provided at the top with air channels with air nozzles. The air nozzles inject air in the internal space and thus cause an air flow. Because all air nozzles are oriented in the same direction, said air flow covers the complete, underlying space. Thus, there is a very good thermal coupling between the space air and the ceiling elements. A disadvantage is however that concentrated, downstream cold traps can exist, from the ceiling into the underlying space. Such a cold trap is experienced as very unpleasant. The air nozzles are partially oriented towards the ceiling. Because they blow against the ceiling, the thermal capacity of the ceiling structure is used optimally. However, when resetting, there is a risk of overcooling the underlying pace, exactly as a result of the very good thermal coupling between the space air and the ceiling elements.

[0005] There is a need of a system for controlling the temperature in internal spaces in an energy-saving way. Preferably, that system maximally uses the thermal capacity of the ceiling structure on top of it. However, when resetting this ceiling structure, overcooling of the underlying space should stay restricted. Moreover, there is a need of such a system, which system allows a sufficiently dynamic temperature control, for application in an environment with larger temperature fluctuations. Preferably, the respective system has a very simple design and is thus also relatively cheap as to production, installation, operation and maintenance.

[0006] The present invention aims to find a solution for at least one of the above-mentioned problems.

SUMMARY OF THE INVENTION

[0007] In a first aspect, the invention relates to a ceiling element according to claim 1, for controlling the temperature in an internal space with ceiling, said ceiling element comprising an air channel with air supply, in which that air channel is provided at one side with at least one air guide plate extending in assembled state under that air channel, and in which that air channel is provided with a plurality of blow openings, for injection of air into that internal space; in particular, said blow openings are grouped along the length and at both sides of the air channel into successive clusters, in which the clusters of blow openings are arranged alternatively crosswise along both sides of the air channel.

[0008] The air guide plates ensure a better attachment of the arising air flow profile to the ceiling. An advantage thereof is that the air flow profile is therefore thermally very well coupled to the above-lying ceiling. This allows to make maximal use of the thermal capacity of the ceiling structure. Typically, the ceiling structure is cooled at night, by injecting cold outside air at ceiling level. During the day, when the heat load is higher, the space air is cooled at the ceiling structure, by continuously blowing it in at ceiling level. A part of the heat is stored at the ceiling structure, so that the underlying space stays pleasantly cool. Also, there is radiative exchange of heat between the cooled ceiling structure and the underlying space. The following night, the ceiling structure is cooled again, which cycle is continuously repeated. Because the air flow profile attaches well to the ceiling, for each ceiling element, a larger surface of the ceiling structure can be activated thermally. An advantage is that the ceiling element functions based on forced ventilation and not based on cooling fluids. Therefore, it is easier as to design and it is cheaper.

[0009] Because the successive clusters alternatively blow in a left and right direction, the air flow profile is more uniform at ceiling level. An advantage thereof is that local cold traps are avoided. Another advantage thereof is that the mixture between the air flow profile at ceiling level and the underlying space air is more gradual. The air flow profile is concentrated at ceiling level, and is largely decoupled from the underlying space air. Therefore, at night, there is no risk of overcooling of the underlying space. During the day, the flow of ceiling air is maintained, in which it gradually mixes with the space air.

[0010] In a second aspect, the invention relates to a system according to claim 8, for controlling the temperature in an internal space with ceiling. In particular, the system comprises two or more air channels. Preferably, these air channels are parallel to each other. More preferably, at least one cluster of blow openings of an air channel is oriented in line with a cluster of blow openings of an adjacent air channel.

[0011] In assembled and activated state of the system, the air channels will interact with each other. Indeed, a cluster of blow openings of the one channel generates an air flow in the direction of the suction of a cluster of blow openings of an adjacent channel. Preferably, each cluster of each air channel is oriented in line with a cluster of blow openings of an adjacent channel. This results in a uniform flow profile with continuous flow lines, that is not restricted to the environment of each air channel, but rather covers the complete ceiling surface. Because the air at ceiling level is kept moving, it keeps on hanging there for a longer period, whereby there is a good thermal coupling with the ceiling structure. It is important here that there are no concentrated downstream air flows, which could generate a local cold trap.

[0012] In a third aspect, the invention relates to a kit according to claim 15 for providing a ceiling element according to any one of the claims 1 to 7 at an internal space with ceiling. The same examples as above can be repeated in this context.

DESCRIPTION OF THE FIGURES

[0013] 

Figure 1 shows a plan view of an embodiment of an internal space with temperature control system according to the present invention, with indication of the air flow profile at ceiling level.

Figure 2 shows a transverse cross-section of an embodiment of the same internal space with temperature control system according to the present invention, with indication of the air flow profile in the plane of the cross-section.

Figure 3 shows an enlarged version of the transverse cross-section in the rectangular plane that is indicated in figure 2.

Figure 4 shows a perspective view of an embodiment of an end of an air channel with blow openings.

DETAILED DESCRIPTION OF THE INVENTION

[0014] The present invention relates to systems for controlling the temperature in internal spaces with a ceiling. More in particular, the invention relates to:

• a ceiling element,
• a system comprising one or more such ceiling elements, and
• a kit for providing such a ceiling element at an internal space with ceiling.

[0015] Unless otherwise specified, all terms used in the description of the invention, including technical and scientific terms, shall have the meaning as they are generally understood by the worker in the technical field of the invention. For a better understanding of the description of the invention, the following terms are explained specifically.

[0016] "A", "an" and "the" refer in the document to both the singular and the plural form unless clearly understood differently in the context. "A segment" means for example one or more than one segment.

[0017] The terms "include", "including" and "provide with", "comprise", "comprising" are synonyms and are inclusive of open terms that indicate the presence of what follows, and that do not exclude or prevent the presence of other components, characteristics, elements, members, steps, known from or described in the state of the art.

[0018] In a first aspect, the invention relates to a ceiling element for controlling the temperature in an internal space with ceiling, said ceiling element comprising an air channel with air supply, in which that air channel is provided at one side with at least one air guide plate extending in assembled state under that air channel, and in which that air channel is provided with a plurality of blow openings, for injection of air into that internal space; in particular, said blow openings are grouped along the length and at both sides of the air channel into successive clusters, in which the clusters of blow openings are arranged alternatively crosswise along both sides of the air channel.

[0019] The air channel is preferably an elongated channel that is provided with a side wall, said channel comprising a synthetic material and/or metal. The imaginary "longitudinal direction" and the imaginary "longitudinal axis" are always oriented according to the length of the air channel. The profile of the channel, transverse to the longitudinal direction, is preferably square, rectangular, round or elliptical. However, air channels with another profile can also be used.

[0020] In the assembled state of the ceiling element in an internal space, the air channel extends along the ceiling of the internal space, under that ceiling. The air guide plate in turn extends under the air channel, preferably parallel to the ceiling. The ceiling is for example flat and horizontal. Also, the air channel and the air guide plate are then preferably mounted horizontally under the ceiling, parallel to that ceiling. When using the invention on slanted ceiling surfaces, the air channel and the air guide plate preferably follow the slope, again parallel to the ceiling. Also in case of undulating ceiling surface, the air guide plate preferably follows the undulation of the ceiling. By contrast, one can also opt for a rigid, straight or curved air channel. On the other hand, a flexible air channel can also be used, with the advantage that such an air channel can easily be led along the undulation of the ceiling.

[0021] Preferably, the air channel encloses an inner volume, which inner volume is in connection to the surrounding space air by means of said blow openings. When using the assembled ceiling element, air is brought into that inner volume, via the air supply. As a result, an overpressure is created in that inner volume with respect to the surrounding space. As a result, the air channel blows out air along said blow openings, which air is thereby injected into the internal space at ceiling level. The flow rate and the air velocity of the injected air are amongst other things dependent on the overpressure in the inner volume. In order to build up a sufficiently high overpressure, it is preferred that the air channel is closed off at both ends in the longitudinal direction; as an alternative, possibly open ends can be closed off with open ends of other air channels via connecting pieces.

[0022] The blow openings are provided at both sides of the air channel. In this document, the term "both sides" refers to two sides of the air channel, which sides are opposite with respect to the longitudinal axis of that air channel. In the assembled state of the ceiling element, under a horizontal, flat ceiling, a left side and right side can always be defined, irrespective of the profile of the air channel. This left and right side are separated in an imaginary way by means of a vertical plane comprising the longitudinal axis of the air channel. Similarly, a lower side and an upper side can be defined, that are separated in an imaginary way by means of a horizontal plane, through the longitudinal axis. In case of slanted and/or undulating ceiling surface, these definitions are adjusted correspondingly.

[0023] Preferably, the blow openings are provided at the left side and/or at the right side of the air channel in assembled state. More preferably, the blow openings provided at the left side are moreover oriented in a left sideward direction with respect to the assembled air channel. Mutatis mutandis for the right side and right sideward direction. "Left sideward direction" and "right sideward direction" are hereby defined as directions that are oriented in the imaginary left respectively right half space with respect to the air channel. The term "half space" is taken from the domain of mathematics. Said left and right half space are separated by that same, imaginary vertical plane. For example, a blow opening provided at the left side is preferably oriented in a left sideward direction. More preferably, the blow opening blows out transverse to the longitudinal direction. The blow direction can moreover be strictly horizontal, but slanted upwards or downwards, left sideward blow openings are possible. Mutatis mutandis for right blow openings with horizontal, slanted upwards or slanted downwards, right blow openings. An advantage of the latter is that air injected at the left and right side can be directed to the ceiling or the air guide plate, in which the thermal capacity of that ceiling structure or of that air guide plate is used in a more optimal way.

[0024] Preferably, the air guide plate is elongated and rectangular, and extends in the longitudinal direction along the lower side of the air channel, parallel to the ceiling. It is however also possible to provide several, successive, shorter air guide plates, along the length of the air channel. Preferably, the air guide plate is wider than the air channel, so that in the left and right direction (with respect to the assembled ceiling island), parts of the air guide plate protrude under that air channel. The left and right protruding parts are indicated as the left and right wing, respectively. The thickness of the air guide plate is preferably situated between 1 mm and 40 cm, more preferably between 3 mm and 20 cm, still more preferably between 5 mm and 10 cm. preferably, the left and right wing are symmetrical with respect to the air channel. However, according to alternative embodiments, the air guide plate has a different shape (for example, oval, circular, square, trapezoidal, or any other shape) and/or said wings are asymmetrical, if such a shape and/or positioning of the air guide plate would better fit to the shape and size of that inner space.

[0025] When using the ceiling element in an assembled state, the injected air generates an air flow profile in the vicinity of that ceiling element. A limited air injection can already cause a significant air flow. Indeed, as a result of its speed, this air injection generates an underpressure. Environmental air is therefore suck, and taken into the air flow, with an increase of the air volume in that air current as a result. Typically, the air current widens into an air cone. The wings of the air guide plates ensure a better attachment of the created air flow profile to the ceiling. An advantage thereof is that the air flow profile is therefore thermally very well coupled to the above-lying ceiling. This allows to make maximal use of the thermal capacity of the ceiling structure. Typically, the ceiling structure is cooled at night, by injecting cold outside air at ceiling level. During the day, when the heat load is higher, the space air is cooled at the ceiling structure, by continuously blowing it in at ceiling level. As an alternative, fresh, warm external air can also be injected at ceiling level, or a mixture of space air and external air. In any of these cases, a part of the heat is stored at the ceiling structure, so that the underlying space stays pleasantly cool. Also, there is radiative exchange of heat between the cooled ceiling structure and the underlying space. The following night, the ceiling structure is cooled again, which cycle is continuously repeated. Because the air flow profile attaches well to the ceiling, for each ceiling element, a larger surface of the ceiling structure can be activated thermally.

[0026] An advantage is that such ceiling elements work based on forced air ventilation and not based on cooling fluids. Therefore, they are easier as to design and it is cheaper.

[0027] Preferably, the ceiling element also exchanges radiation heat with the underlying space. Thereto, the lower side of the air guide plate is preferably coloured in such way, that its emissivity in the infra-red spectrum is maximal. Moreover, the air guide plates are mounted at a sufficiently large distance under the ceiling. This distance is typically minimum 5 cm and maximum 1 m. In this way, the ceiling surface can also directly exchange radiation heat with the underlying space, along the air guide plates. According to a non-limiting embodiment, the air guide plate leaves a large part of the ceiling surface visible, just like a system comprising several of such air guide plates. For example, from each point of view, at least 40% of the ceiling surface is visible. A significant part of the heat exchange between the ceiling structure and the underlying space is then radiative.

[0028] As an alternative in very high internal spaces, for example with a height of 6 meter or more, one or several of such ceiling elements can be mounted freely suspended, in an horizontal plane at a particular height above the floor surface. Preferably, it is at a height of more than 2 meter and less than 4 meter above the floor surface, more preferably, at a height of minimum 250 cm and maximum 280 cm.

[0029] The blow openings are grouped along the length and at both sides of the air channel into clusters, in which the clusters of blow openings are arranged alternatively crosswise along both sides of the air channel. Preferably, the whole length of the air channel can be divided into sections in an imaginary way, in which each section is provided with precisely one cluster of blow openings, and in which the clusters of the successive sections are provided alternatively at the left side and the right side as is described above for the individual blow openings. When activating the ceiling element, each section generates an essentially horizontal air flow, perpendicular to the longitudinal axis of the air channel, which air flow for the successive sections is oriented alternatively to the left side and the right side with respect to the air channel.

[0030] Because the successive clusters alternatively blow out in a left and right direction, the air flow profile is more uniform at ceiling level. An advantage thereof is that local cold traps are avoided. Another advantage thereof is that the mixture of the air flow profile at ceiling level and the underlying space air is more gradual. The air flow profile is concentrated at ceiling level, and is largely decoupled from the air in the underlying space. Therefore, at night, there is no risk of overcooling of the underlying space. During the day, the flow of ceiling air is maintained, in which it gradually mixes with the space air. However, if a stronger cooling is desired, for example because of an increase heat load, it is sufficient to increase the flow rate and the air velocity of the injected air. This causes on the one hand an improved thermal coupling to the ceiling structure, and on the other hand a larger mixing with air in the underlying space. The ceiling elements thus allow a more dynamic temperature control.

[0031] Optionally, the blow openings are shaped into air nozzles, or air nozzles are attached to the blow openings, as a result of which a more diffuse or precisely more oriented air flow profile can be obtained. Thanks to an adequate choice of the number of blow openings, the size of the blow openings and/or the shape of the air nozzles, it is also possible to set the air velocity and the flow rate of the injected air for a particular overpressure within the air channel. Preferably, the overpressure within the air channel is between 7 and 40 Pa. Preferably, the flow rate per blow opening is between 0.5 and 65 I/min. Preferably, the maximum speed of the injected air is between 3.5 and 8.5 m.s. Preferably, the flow rate, the air velocity and the design of the ceiling element are chosen in such way that an air flow is generated at ceiling level, which air flow is characterized by imaginary flow lines extending along the ceiling and/or along these air guide plates. Such flows will better attach to the ceiling and/or to these air guide plates, with the Coanda effect as a result.

[0032] By applying one or several of these ceiling elements in an internal space with ceiling, it becomes superfluous to provide air conditioning. As an alternative, a possibly additional, active system for heating and/or cooling the internal space can be integrated into the ceiling element. Because that ceiling element makes optimal use of the thermal capacity of the above-lying ceiling structure (and possibly of the ceiling element itself), such an active system can be chosen less powerful. More in particular, such a hybrid system comprising climate ceiling islands with thermal counter-flow ventilation allows an yearly energy-saving of about 30%, when compared to a traditional system.

[0033] Preferably, the ceiling island moreover provides an acoustic damping of the space. Hereby, the noise is absorbed via the lower side of the island, but preferably, the upper side is also acoustically operative, by absorbing the indirect noise. Thereto, preferably, the lower side and/or the upper side of the ceiling element, more preferably both the lower side and the upper side thereof, are provided with noise-absorbing materials. According to a non-limiting embodiment, the air guide plate thereto comprises an "acoustic mat", or it is even built of such an acoustic mat. Furthermore, it is possible that the ceiling elements comprise fire alarms, sprinkler systems and lamps.

[0034] According to a further preferred embodiment, the distance between the air channel and the air guide plate is minimum 3 mm and maximum 250 mm. In the assembled state of the ceiling element, a vertical separation is thereto provided between the air channel and the air guide plate. Such a separation allows for a passage between the air channel and the air guide plate, for a free passage of air. Optionally, this passage is interrupted at several places by mounting elements, for attachment of the air guide plate to the ceiling/air channel. More preferably, the distance is more than 5 mm, still more preferably more than 10 mm, still more preferably less than 100 mm, still more preferably less than 80 mm. Preferably, the distance is such that it enhances a flow, which flow is characterised by imaginary flow lines extending along the ceiling and/or along the air guide plate.

[0035] When activating the assembled ceiling island, each cluster will inject a flow of air, from that air channel into that internal space. This injected air generates an air flow profile in the vicinity of that ceiling element. A limited air injection can already cause a significant air flow. Indeed, as a result of its velocity, this air injection generates an underpressure. Environmental air is therefore suck, and taken into the air current, with an increase of the air volume in that air current as a result. Typically, the air current widens into an air cone. In particular, the cluster causes an indirect suction of ceiling air from the opposite lateral direction, via said passage. As a result, at ceiling level, an air flow with continuous flow lines is caused, which flow lines cross the longitudinal axis in a perpendicular way at the level of each cluster of blow openings. Preferably, these flow lines essentially extend along that ceiling and/or along that air guide plate. An advantage is that the air flow profile at ceiling level is more continuous. The flow that is blown away by one cluster of blow openings, is split and is partially suck by adjacent clusters of blow openings of the same ceiling element. As a result, the injected air stays longer at ceiling level. At night, when resetting the ceiling structure, cold external air that is blown in at ceiling level, thus gets more time to heat at the ceiling structure, before it is mixed with the underlying space air. On the other hand, fresh, warm external air that is injected during the day, also gets more time to cool at the ceiling structure, before it goes down into the underlying space.

[0036] In a further or alternative, preferred embodiment, a passage is left between the ceiling and the air channel, which channel is minimum 3 mm and maximum 250 mm, with the same result and the same advantages as described above. An additional advantage is that the air flow profile still adheres better to the ceiling surface.

[0037] According to a further preferred embodiment, each cluster comprises minimum 5 and maximum 200 blow openings. Preferably, the number of blow openings comprised in each cluster, is superior to 10, more preferably inferior to 100, still more preferably inferior to 50, still more preferably inferior to 20. Optionally, the air channel is moreover provided with additional, individual blow openings that do not necessarily belong to a cluster. According to a non-limiting example, the ceiling element comprises additional blow openings for slightly interrupting the circulation at ceiling level, so that locally a better mixture with the underlying space air is obtained. This causes a controlled local cold trap, and a better, local cooling in the underlying area in the internal space.

[0038] According to a further preferred embodiment, the successive clusters in the longitudinal direction of the air channel are alternated with separations without blow openings; said separations are minimum 2 cm and maximum 100 cm long. Successive sections are thus each provided with precisely one cluster of blow openings, and moreover comprise distances without blow openings, together forming the separations without blow openings, between these clusters. An advantage thereof is that it ensures an improved continuity of the flow profile at ceiling level, with less large speed gradients and in which frontally colliding and/or closely passing air flows are avoided. Indeed, the blow openings of adjacent clusters are oriented oppositely and therefore cause opposite air flows. The frontal colliding and/or closely passing of such, opposite air flows would result in stationary air at ceiling level. Stationary, cold/cooled air goes down and thereby generates an (often) undesired, local cold trap. By including the above-mentioned separations, opposite air flows pass at a mutual distance. As a result, the passing air flows are not brought to a standstill. Moreover, the ceiling air between both flows forms a vortex. This air is thus kept moving at ceiling level, and will therefore mix less quickly and in a less localized way with the underlying space air.

[0039] According to a further preferred embodiment, the blow openings of a cluster are arranged in two or more rows along each other, which rows extend in the length of the air channel. In the assembled state of the ceiling element, the blow openings of a cluster are thus arranged in two or more rows above each other, which rows extend horizontally, in the length of the air channel. Preferably, the blow openings within each row are thereby provided at regular separations of each other.

[0040] More preferably, the blow openings within a cluster are moreover arranged according to a triangular grid, in which these blow openings are positioned on imaginary vertices of that grid. According to a non-limiting example, the blow openings of each cluster are arranged in two or more, parallel rows above each other, with regular separations between adjacent blow openings of the same row. Moreover, the positions of blow-openings of adjacent rows are offset a half separation with respect to each other. In this way, an isosceles triangular grid is formed with vertex a. The inventors have surprisingly found that, under the correct conditions of air velocity and flow rate, such a configuration of blow openings generates an air flow, which air flow is characterized by imaginary flow lines extending along that ceiling and/or along that air guide plates. As a result of the Coanda effect, such flows adhere much better to the ceiling surface. Preferably, the vertex α varies between 10° and 160°, more preferably between 20° and 140°, still more preferably between 30° and 120°C, and still more preferably between 40° and 100°. More preferably, the vertex α is about 60°, so that the blow openings within the cluster are arranged according to a triangular equilateral grid.

[0041] Preferably, the generated air flows comprise turbulences. An advantage of air flows with turbulences is that there is a better transfer of heat within such air flows, transverse to its flow lines. Moreover, the generated air flows are preferably characterised by thin boundary layers, where they flow along a surface, and in particular where they flow along a ceiling and/or along an air guide plate. Preferably, the thickness of these boundary layers is maximum 10 mm, preferably maximum 5 mm, and more preferably maximum 1 mm. An advantage or air flows with thin boundary layers is that the heat transfer between such flow lines and the fixed surfaces along which they flow, through that boundary layer, are strongly enhanced. In particular, such an air flow will show a much better heat exchange with the ceiling and/or with the air guide plates.

[0042] Preferably, the air flow has a sufficiently high velocity, so that it shows the so-called "parallel behaviour, far in the turbulent area". It is then characterized by imaginary flow lines extending along that ceiling and/or along that air guide plates, with thin boundary layers in between. Moreover, it then comprises turbulences.

[0043] According to a further preferred embodiment, the width of the air guide plates is minimum 8 cm and maximum 700 cm. An advantage thereof is that, dependent on the size of the ceiling surface, the flow profile at ceiling level covers the majority of the ceiling surface.

[0044] In a second aspect, the invention relates to a system for controlling the temperature in an internal space with ceiling, said system comprising at least one air channel extending along that ceiling, which air channel is provided with a plurality of blow openings, for injection of air into that internal space; in particular, said blow openings are grouped along the length and at both sides of that air channel into successive clusters, in which these clusters of blow openings are arranged alternatively crosswise along both sides of that air channel. Preferably, the blow openings are as described above. The corresponding above-mentioned advantages can thus be repeated in this context. Such a system will amongst other things generate a flow profile that adheres well to the ceiling surface, and that will as a result be concentrated close to that ceiling surface.

[0045] Preferably, the system comprises two or more of such air channels. Preferably, these air channels are parallel to each other. More preferably, at least one cluster of blow openings of an air channel is oriented in line with a cluster of blow openings of an adjacent air channel.

[0046] According to a further preferred embodiment, at least two adjacent air channels are parallel to each other, in which the blow openings of at least one cluster of the one air channel are in line with a cluster of blow openings of the other air channel.

[0047] In assembled and activated state, the air channels will therefore interact with each other. Indeed, a cluster of blow openings of the one channel generates an air flow in the direction of the suction of a cluster of blow openings of an adjacent channel. Preferably, each cluster of each air channel is in line with a cluster of blow openings of an adjacent channel. This results in a uniform flow profile with continuous flow lines, that is not restricted to the environment of each air channel, but rather covers the complete ceiling. Because the air is kept moving at ceiling level, it keeps on hanging there for a longer period, whereby there is a good thermal coupling with the ceiling structure. It is important here that no concentrated downstream air flows arise hereby, which could generate a local cold trap. In the meantime, there is a limited mixture between ceiling air and underlying space air, at the level of the boundary layer between both. At the side walls, the air flow is bent away. As a result, it slows down and can go down partially, in which mixing with the underlying space air also takes place there.

[0048] Moreover, it is not necessary that each cluster of the above-described air channels comprises as much blow openings. The number of blow openings can vary per cluster. According to a non-limiting embodiment, the clusters that are directed to an adjacent side wall of the internal space, comprise less blow openings than those oriented towards adjacent air channels, for example only about half of it. However, preferably, each cluster has the same number of blow openings.

[0049] According to a further preferred embodiment, the system comprises two or more ceiling elements, as described above. Thereby, one or more of the air channels are provided with one or more air guide plates. These air guide plates have as a function that this flow is mainly concentrated at ceiling level. In an alternative embodiment, the system with air channels is however used freely suspended, without air guide plates. According to another, alternative embodiment, the system is applied in the plenum of a climate ceiling. Thereby, that plenum is separated from the underlying space, by means of a structure that is partially open in surface, preferably between 30% and 90% open, still more preferably about 50% open. According to a number of non-limiting examples, said structure is made of expanded metal, or it relates to a perforated structure, or a structure with parallel beams or sheaths, that are provided at regular intervals. According to another, alternative embodiment, the system is applied in the plenum of a climate ceiling, in which that plenum is largely separated from the underlying space. According to another, non-limiting embodiment, holes are thereby provided with a diameter of 300 mm to 400 mm, for exchanging radiation heat between the ceiling structure and the underlying space. According to a non-limiting embodiment, the above-mentioned, noise-absorbing materials are treated in that plenum. Therefore, "acoustic mats" can for example be used.

[0050] Optionally, use is made of additional suction installations and/or installations for air injection. However, preferably, they do not disturb said air flow profile, or only slightly.

[0051] According to a further preferred embodiment, the distance between adjacent air channels is minimum 10 cm and maximum 800 cm. An advantage thereof is that adjacent ceiling elements interact optimally, as described above. Preferably, there is a good distribution of ceiling elements over the complete ceiling surface, so that the resulting flow profile covers that complete ceiling surface.

[0052] According to a further preferred embodiment, the system is a hybrid system. Such a hybrid system offers the possibility to actively heat and/or cool, by means of water transporting or air transporting circuits, electrical heating elements, or by means of Peltier elements. Preferably, these means for heating and/or cooling are provided at the upper side of the air guide plates. In a preferred embodiment of the hybrid system, the injected air itself is previously heated and/or cooled.

[0053] An advantage of electrical heating elements and Peltier elements is that they allow to control the temperature of very locally determined spaces or parts of spaces. In cold areas, an electrical, hybrid system has the advantage that at night, heat can be generated and stored in the ceiling structure, making use of lower rates for electricity. This heat is released during the day.

[0054] Preferably, the above-mentioned water transporting or air transporting circuits are meandering and/or helical; more preferably, they are meandering. According to a non-limiting embodiment, the air guide plates are coated completely or partially along the upper side with expanded metal. On top of this expanded metal, a meandering, water transporting heating and/or cooling circuit is then provided. The expanded metal is then actively heated and/or cooled. The air, that flows along that expanded metal, is in turn heated and/or cooled actively, via that expanded metal. According to another, non-limiting embodiment, the invention is applied in a plenum, which plenum is separated from the underlying space by means of a separation in expanded metal. On top of said separation, a meandering, water transporting circuit is again provided, in which the same effect is obtained. It should be underlined that, in each of these embodiments, the expanded metal can be replaced by a perforated metal plate material, or by any other expanded material with sufficiently high coefficient for thermal conduction and convection, as is known in the state of the art.

[0055] Preferably, the ceiling structure is a concrete deck comprising reinforced concrete. Concrete has indeed a high thermal capacity, as a result of which a concrete deck is extremely appropriate for storing heat in a passive or hybrid system for the control of temperature. Instead or additionally, it is possible to provide phase change materials (PCMs) at the ceiling structure and/or at the ceiling elements, for increasing its global thermal capacity. PCMs have a very large heat storage capacity thanks to their phase change path between solid and liquid, with a phase transition temperature in the vicinity of room temperature.

[0056] According to a further preferred embodiment, said internal space is adjacent to a façade side, and said air channels extend perpendicular to that façade side.

[0057] A significant part of the blown air, coming from the blow openings that are nearest to the façade, bends away in the direction of the façade where it is mixed with the space air. On the other hand, space air that is located at the façade, will, however moderately, be sucked by the nearest blow openings. This effect is further enhanced if, as a result of external factors, for example sun radiation on the outer side of that façade, lots of heat is generated in the vicinity of that façade. Thereby, the space air that has been heated at the façade, will be flow, bent away upwards, in the direction of the air nozzle and the cool blown air will be bent away downwards in the direction of the façade. An advantage is that the zone of the internal space in the vicinity of the façade will therefore be cooled more, so that the sun radiation is compensated.

[0058] The mixture of ceiling air with underlying space air is typically the largest near the ends of the air channels. Indeed, a part of the air flows there along the façade side and slows down, as a result of viscous friction effects along that façade side. The decelerated, cold air has the tendency to go down and mixes then with the underlying space air. Preferably, said internal space is adjacent to a façade side, and the air channels extend perpendicular to that façade side. Walls are typically very subject to temperature fluctuations. This is in particular the case for southwardly oriented façades that are shined upon by the sun. It is then advantageous that one end of the air channels is situated along that façade, so that the cooling effect is reinforced locally. Preferably, the distance between the end of the air channels and the façade is minimum 0.1 m, more preferably 1.0 m, and more preferably minimum 1.5 m. Preferably, this distance is maximum 5 m, still more preferably maximum 3 m. According to an alternative embodiment, the air channels extend inclined with respect to the wall, in which again an end of each air channel is situated close to that façade. This will still further enhance the cooling effect.

[0059] In a third aspect, the invention relates to a kit for providing a ceiling element as described above at an internal space with ceiling, the kit comprising at least one air channel with air supply, in which that air channel is provided with a plurality of blow openings, the kit further comprising at least one air guide plate and a plurality of mounting elements. In particular:

• said blow openings are grouped along the length and at both sides of the air channel into clusters, which clusters of blow openings are arranged alternatively crosswise along both sides of the air channel, and
• the mounting elements are configured for mounting that air channel in a suspended way under that ceiling and for mounting that air guide plate in a suspended way under that air channel, in which the distance between that air channel and that air guide plate is minimum 3 mm and maximum 250 mm.

[0060] The air guide plate can be either suspended to the air channel or suspended to the ceiling. According to a non-limiting embodiment, the air channel is supported by the air guide plate, via the suspension structure of that air guide plate. The above-mentioned advantages can be repeated here.

DETAILED DESCRIPTION OF THE FIGURES

[0061] The invention will now be further described by means of the following examples and attached figures, without being limited thereto.

[0062] Figure 1 is a plan view of an embodiment of an internal space that is provided with a system according to the present invention, for controlling the temperature of that internal space. Moreover, the figure shows the air flow profile that is generated at ceiling level by that system. The system comprises two ceiling elements 1. Each of both ceiling elements 1 comprises an air channel 2, which air channels 2 extend horizontally under the ceiling of the internal space along that ceiling and parallel to each other. Moreover, each ceiling element 1 comprises two air guide plates 3, that are attached in turn under the air channels 2, parallel to the ceiling. The air guide plates 3 are in line and are connected to each other. The use of shorter air guide plates 3 can be advantageous at transport. Still, the same effect is obtained as if only one air guide plate 3 with double length per ceiling element 1 had been provided. Between an air channel 2 and the underlying air guide plate(s) 3, a vertical interspace of about 5 cm is provided each time, for free passage of air. The air channels 2 are provided with laterally oriented blow openings 4, which blow openings 4 are arranged according to length of the air channel 2 in successive clusters 5 of blow openings. These successive clusters 5 are arranged alternatively crosswise at opposite sides of the air channels 2. Between the successive clusters 5 of blow openings, along the length of the air channel 2, separations are left free without blow openings 4. Each air channel 2 is provided with an air supply 7, through which air is blown into that air channel 2. As a result of the overpressure, thereby building up in the inner volume of the air channel, that air channel 2 blows out air laterally via said blow openings 4. This generates an air flow profile at ceiling level, which air flow profile is not limited to the environment of each ceiling element 1. As a result of the interaction between adjacent ceiling elements 1, said air flow profile covers almost the complete ceiling surface.

[0063] A particular cluster 5' of blow openings injects a flow of air, from that air channel 2 into the internal space. This injected air generates an air flow profile in the vicinity of that ceiling element 1. A limited air injection can already cause a significant air flow. Indeed, as a result of its velocity, this air injection generates an underpressure. Environmental air is therefore suck in, and taken into the air current, with an increase of the air volume in that air current as a result. Typically, the air current widens into an air cone. In particular, air is suck from the other side of the air channel 2, via the above-mentioned interspace for free passage of air, as a result of that same underpressure. The cluster 5' of blow openings on the one ceiling element 1 thus has a sucking effect on the forward air flow generated by the cluster 5" of the adjacent ceiling element 1. This applies to each of the clusters of blow openings: each cluster 5 on the one ceiling element is in line with a corresponding cluster on the adjacent ceiling element 2 and generates as a result either a sucking air flow or an airflow that is suck itself. In this way, the ceiling air is kept moving continuously. And this over the whole length of the air channels 2, via successive left 8 and right 9 forward air flows. These air flow split up against the left respectively right side walls, after which they bend away; the split air flows are largely suck again by the adjacent clusters 5 of blow openings. At the separations 6 without blow openings, vortices 10 arise, so that the air flow is also maintained there at ceiling level. In each case, the air flow profile is such that no frontal collision between air flows arise, and that opposite air flows never pass closely. The air channels preferably extend perpendicular to the façade 11, if the internal space would be adjacent to a façade 11. An enhanced mixing between that ceiling air and the underlying space air then takes place, at that façade side 11.

[0064] According to another example, the internal space is long and small, and is provided with a system that comprises only one ceiling element, oriented according to the length of the internal space. That ceiling element then interacts especially with the left and right side wall of the internal space, via successive left and right oriented air flows that split and bend away as described above.

[0065] According to another example, the internal space is provided with ten parallel ceiling elements, similar to the situation shown in figure 1. The internal eight ceiling elements interact in the same way with their adjacent ceiling elements. The left and right, external ceiling elements moreover interact with the left and right side wall of the internal space, via successive left and right left oriented flows that split and bend away.

[0066] It will be clear that the number of parallel ceiling element that is comprised in the system can be freely chosen.

[0067] A "transverse cross-section" should be understood here as a cross-section in a vertical plane, which plane is perpendicular to the longitudinal axis of the air channels.

[0068] Figure 2 shows a transverse cross-section of the internal space along line AA in figure 1, with indication of the air flow profile in the plane of that cross-section. The system comprises two air channels 2 that have a rectangular profile. Along the lower side of each air channel 2, an air guide plate 3 is provided, with interspace 12 of about 5 cm between both, for free passage of air. The blow openings 4 of the one ceiling element 1 are oriented in line with the blow openings 4 of the adjacent ceiling element 1; in the plane of the present cross-section, both are oriented to the right. As a result thereof, a forward air flow from the left to the right arises in this plane, at ceiling level. At the level of the right side wall, this air flow bends away horizontally. Moreover, an increased mixing between the ceiling air 13 and the underlying space air 14 takes place there. Also in the area between the ceiling elements, there is a gradual mixture of ceiling air 13 with space air 14. The ceiling air 13 is continuously kept moving, and is therefore coupled thermally well to the ceiling structure 15 on top of it.

[0069] Figure 3 shows an enlarged version of the rectangular plane that is indicated in figure 2. The blow openings 4 are provided with air nozzles.

[0070] Figures 4A-F schematically show a number of transverse cross-sections of ceiling elements 1 according to the present invention, which ceiling elements 1 are mounted each time under a ceiling 16. The ceiling elements 1 are thereby provided suspended under the ceiling structure 15 (each time shown only partially, as a shaded area). Each ceiling element 1 comprises an air channel 2 and an air guide plate 3. Each time, the air channel 2 is provided sideward with blow openings 4, which blow openings 4 are in turn provided with air nozzles. For simplifying the figures, no mounting elements are shown for suspended mounting of the air channel 2 and of the air guide plate 3 under the ceiling 16. Also, no distinction is made between blow openings 4 in the transverse plane of the cross-section on the one hand and blow openings 4 that are located deeper in the figure, along the longitudinal axis on the other hand. Figure 4A shows an embodiment of a ceiling element 1 with an air channel 2, which air channel 2 has a rectangular profile. Between the air channel 2 and the air guide plate 3, an interspace 12 is left for free passage of air. The blow openings 4 are arranged in two rows on top of each other, which rows extend in the length (transverse to the figure). Figure 4B shows an alternative embodiment that builds on the embodiment of figure 4A, and in which moreover an interspace 12 is left for free passage of air, between the ceiling 16 and the air channel 2. Figure 4C shows an alternative embodiment, in which the air guide plate 3 is attached this time under the air channel 2. At the top, an interspace 12 is however left for free passage of air, between the ceiling 16 and the air channel 2. Figure 4D shows an alternative embodiment that is similar to the embodiment of figure 4B. The blow openings 4 are still arranged alternatively crosswise at opposite sides of the air channels 2. However, they are no longer provided in the left wall and right wall of that air channel 2, but rather in the lower wall and upper wall of that air channel. The blow openings 4 are further provided with air nozzles, which air nozzles bend way the flow 90° in left and right, sideward directions. Figure 4E shows an alternative embodiment that is similar to the embodiment of figure 4B. Here, the air channel 2 has a circular profile. Moreover, the air channel 2 is provided at opposite sides with only one row of blow openings 4, which rows extend in the longitudinal direction of that air channel 2. Figure 4F shows an alternative embodiment that is similar to the embodiment of figure 4E. Here, the air channel is provided with two rows of blow openings 4 on top of each other, extending according to the longitudinal direction. The upper row of blow openings 4 are oriented upwards 45° with respect to the horizontal plane; these blow openings 4 blow against the ceiling 16. The lower row of blow openings 4 are oriented downwards 45° with respect to the horizontal plane; these blow openings 4 blow against the air guide plate 3.

[0071] Figure 5 shows a perspective view of an embodiment of a piece of air channel 2 with blow openings 4. The respective air channel 2 has a closed end 17. The air channel 2 is provided sideward with successive clusters 5 of blow openings, that are arranged alternatively at opposite sides of the air channel 2, with separations 6 without blow openings in between. The blow openings 4 are provided with sideward air nozzles. Within each cluster 5, the blow openings are arranged in two rows on top of each other, and this in such way that they form a triangular equilateral grid. The generated air flow is therefore laminar, and will better adhere to the above-lying ceiling, in the assembled state of the ceiling element 1. The lower row has six blow openings 4, while the upper row has seven blow openings 4.

[0072] Figures 6A-C each show a side view of an embodiment of a piece of air channel 2 with blow openings 4, which blow openings are arranged in clusters 5. Each time, the blow openings 4 are arranged in two rows 18 on top of each other, which rows 18 extend horizontally, in the length of the air channel 2. Within each row, the blow openings 4 are provided at regular intervals from each other. In the embodiment of figure 6A, the blow openings 4 are arranged according to a square grid, in which these blow openings 4 are positioned on imaginary angular points of that grid. In the embodiment of figure 6B, the blow openings 4 are arranged according to a triangular equilateral grid, with vertex α of about 60°C. In the embodiment of figure 6C, the blow openings 5 are arranged according to a triangular isosceles grid, with vertex α of about 90°C.

[0073] The enumerated elements on the figures are:

1. Ceiling element

2. Air channel

3. Air guide plate

4. Blow openings

5. Clusters without blow openings

6. Separations without blow openings

7. Air supply

8. Left forward air flow

9. Right forward air flow

10. Vortex

11. Façade

12. Interspace for free passage of air

13. Ceiling air

14. Underlying space air

15. Ceiling structure

16. Ceiling

17. Closed end

18. Row of blow openings

Claims

1. A ceiling element 1 for controlling the temperature in an internal space with ceiling 16, said ceiling element 1 comprising an air channel 2 with air supply 7, in which said air channel 2 is provided at one side with at least one air guide plate 3 extending in assembled state under said air channel 2, and in which said air channel 2 is provided with a plurality of blow openings 4, for injection of air into said internal space, characterized in that said blow openings 4 are grouped along the length and at both sides of the air channel 2 into successive clusters 5, in which the clusters 5 of blow openings 4 are arranged alternatively crosswise along both sides of the air channel 2.

2. The ceiling element 1 according to previous claim 1, characterized in that the distance between the air channel 2 and the air guide plate 3 is minimum 3 mm and maximum 250 mm.

3. The ceiling element 1 according to any one of the previous claims 1 and 2, characterized in that each cluster 5 comprises minimum 5 and maximum 200 blow openings 4.

4. The ceiling element 1 according to any one of the previous claims 1 to 3, characterized in that the successive clusters 5 are alternated in the longitudinal direction of the air channel 2 with separations 6 without blow openings; said separations 6 being minimum 2 cm and maximum 100 cm.

5. The ceiling element 1 according to any one of the previous claims 1 to 4, characterized in that the blow openings 4 of a cluster 5 are arranged in two or more rows 18 along each other, which rows 18 extend in the length of the air channel 2.

6. The ceiling element 1 according to any one of the previous claims 1 to 5, characterized in that the blow openings 4 within a cluster 5 are arranged according to a triangular grid.

7. The ceiling element 1 according to any one of the previous claims 1 to 6, characterized in that the width of the air guide plate 3 is minimum 8 cm and maximum 700 cm.

8. A system for controlling the temperature in an internal space with ceiling 16, said system comprising at least one air channel 2 extending along that ceiling 16, which air channel 2 is provided with a plurality of blow openings 4, for injection of air into that internal space, characterized in that said blow openings 4 are grouped along the length and at both sides of that air channel into successive clusters 5, in which these clusters of blow openings 4 are arranged alternatively crosswise along both sides of that air channel 2.

9. The system according to the previous claim 8, characterized in that the system comprises two or more of these air channels 2.

10. The system according to the previous claim 9, characterized in that at least two adjacent air channels 2 are parallel to each other, in which the blow openings 4 of at least one cluster 5 of the one air channel 2 are in line with a cluster 5 of blow openings 4 of the other air channel 2.

11. The system according to any one of the previous claims 9 to 10, characterized in that the distance between adjacent air channels 2 is minimum 10 cm and maximum 800 cm.

12. The system according to any one of the previous claims 8 to 11, characterized in that the system comprises two or more ceiling elements 1 according to any one of the claims 1 to 7.

13. The system according to any one of the previous claims 8 to 12 characterized in that the system is a hybrid system.

14. The system of any one of the previous claims 8 to 13, characterized in that said internal space is adjacent to a facade side 11, and that said air channels 2 extend perpendicular to that facade side 11.

15. Kit for providing a ceiling element 1 according to any one of the claims 1 to 7 to an internal space with ceiling 16, the kit comprising at least one air channel 2, in which the air channel 2 is provided with a plurality of blow openings 4, the kit further comprising at least one air guide plate 3 and a plurality of mounting elements, characterized in that

- said blow openings 4 are grouped along the length and at both sides of the air channel 2 into successive clusters 5, which clusters 5 of blow openings 4 are arranged alternatively crosswise along both sides of the air channel 2, and

- the mounting elements are configured for mounting that air channel 2 in a suspended way under that ceiling 16 and for mounting that air guide plate 3 in a suspended way under that air channel 2, in which the distance between that air channel 2 and that air guide plate 3 is minimum 3 mm and maximum 250 mm.

Drawing