EP4350097A1

EP4350097A1 - Dynamic insulation wall assembly and respective control method

Info

Publication number: EP4350097A1
Application number: EP23200345.9A
Authority: EP
Inventors: Andrea Alongi; Stefano Rondo
Original assignee: Irid3 Srl
Current assignee: Irid3 Srl
Priority date: 2022-10-04
Filing date: 2023-09-28
Publication date: 2024-04-10

Abstract

A dynamic insulation wall module (1-7) is described for making air-permeable walls (110) interposed between a confined indoor environment (I) and the outdoor environment (E) of a building. The module (1-7) comprises at least one air cavity (40) in which an airflow is circulated, produced and controlled by a ventilation unit (100). Following a direction from the outdoor environment (E) to the indoor environment (I), the module (1-7) comprises at least one outer layer (10) of air-permeable material, at least one intermediate layer (30) of air-permeable material, a first air cavity (40) arranged beyond the intermediate layer (30) of air-permeable material and at least one innermost layer (60) of insulating and heat-reflecting material. The latter is arranged beyond the first air cavity (40) and before a layer (80) of rigid material including interior cladding panels.

Description

Field of the invention

The present invention relates to dynamic insulation wall modules for making air-permeable walls interposed between an indoor environment, i.e. a confined environment, and the outdoor environment of a building. The invention further relates to air-permeable walls made by the composition of these modules.

Prior art

Conventionally, buildings consist of a partially opaque and partially transparent envelope, which has the purpose to define the geometry of the same buildings and to mitigate the outdoor climatic conditions, thus ensuring the comfort conditions required by the occupants of the confined environments, thanks also to the contribution of heating and cooling systems. Additionally, these environments require adequate air changes in order to ensure adequate hygienic and sanitary conditions.
The energy required to maintain the internal thermal conditions imposed by the user depends, among other things, on the heat exchange through the envelope (conduction losses) and the heat load related to the ventilation of the environments (ventilation losses) necessary to ensure proper hygiene conditions in the presence of people. At the same boundary conditions (internal and external temperature), the heat exchange conditions through the envelope depend on the heat resistance of the envelope structures, whereas the heat load conditions related to ventilation of the environments depend on the air flow rates and the inlet temperature thereof.
In order to limit the energy requirements for winter and summer air conditioning of buildings, the common practice is to reduce conduction losses by increasing the heat resistance of the envelope, e.g. by installing layers of insulating material (by way of example, the external thermal insulation is considered). The heat resistance of the conventional envelope, and of the materials that constitute it, is an inherent and invariable characteristic thereof and affects the thermal power exchanged through the same envelope as a result of a given temperature difference between the inside and outside.
For locations characterised by cold winters, high heat resistance will always result in a better performance thereof.
Conversely, during the summer period, when it is necessary to effectively dispose of the heat present in the confined environments (as a result of people, equipment, radiation entering from windows), the high heat resistance of the envelope can result in greater loads on the air-conditioning system and, consequently, an increase in energy demand. In common practice, strategies such as shading are implemented to decrease the heat load resulting from the solar gain (screens, sunshades, vertical or horizontal overhangs, ventilated walls, etc.).
As far as ventilation losses are concerned, there are two commonly adopted practices: in many residential buildings, the air exchange is left to the manual opening of windows and doors by the users (natural ventilation), renouncing the control of air flow rates which depend on external wind conditions and many other factors, and of the inlet temperature, which will always be equal to the external air. In other habitable buildings, air changes are achieved as a result of a centralised mechanical ventilation system capable of adjusting flow rates depending on design conditions and of mitigating the inlet temperature as a result of a heat recovery unit. Italian and international regulations have aligned in setting strict limits as regards both the thermal transmittances of the envelope and the efficiency of heat recovery units in controlled mechanical ventilation systems, in order to decrease the heat demand in the winter period, and as regards the decrease of solar gains in the summer period. Thermal transmittances, which may be set by current legislation and technical regulations, are characterised by fixed and invariable limits, which describe the performance of the envelope solution.
On the other hand, as far as ventilation is concerned, it should be noted that the air entering the confined environments is not only that related to natural or mechanical ventilation, but may be due to parasitic infiltration over which the users have no control (e.g., air entering through joints between walls and windows or as a result of imperfect air-tightness of windows and doors). The common practice is that of trying to mitigate this phenomenon as much as possible, by improving the air tightness of the envelope as a whole, and quantifying its performance through measurements of the "blower door test" type typically adopted for passive houses.
However, it should be borne in mind that this approach, in the case of buildings with only natural ventilation (without installation of a controlled mechanical ventilation system), can result in healthiness problems of indoor environments: as the users are not capable of adequately controlling the entering air flow rates (e.g., by opening windows), these may not be sufficient to dispose of indoor pollutants or water vapour (especially in environments such as kitchens, bathrooms and bedrooms), thus causing the formation of interstitial condensation or condensation on inner surfaces.
It can further be observed that the ventilation as a result of the opening of windows and doors does not allow any filtering of the air fed into the rooms of the building, which, particularly in urban context, will bring therewith fine and ultra-fine particulates that are harmful to health.
WO2009112715A1 describes a wall structure comprising two air cavities delimited by continuous layers of air-impermeable materials. In more detail, air-impermeable inner and intermediate layers delimit an inner cavity, as well as an outer layer and the intermediate layer mentioned, both air impermeable, delimit an outer cavity. The airflow in these cavities may preferably be circulated by natural convection with the possible aid of solenoid valves or, if necessary, by the use of fans. The behaviour of this wall results in limited thermal performance, also in terms of filtering ability, risk mitigation of interstitial condensation, etc.
Further examples of implementations according to the known art can be found in GB2037863A and US5761864A .
Therefore, some criticalities inherently present in commonly adopted constructive practice can be summarised as follows:

the progressive increase in envelope heat resistance, also as a result of technical regulations, is a priori positive for the mitigation of winter consumption, but may result in a worsening of performance in the summer months if adequate shading strategies are not implemented;
in buildings characterised by natural ventilation (highly common in the residential sector), it is not possible to have any real control over ventilation losses, as there is no effective way, through the opening of windows and doors only, to modulate the entering air flow rates, to control their temperature and to reduce the concentration of dust therein, resulting in risks of overloading the air-conditioning systems, discomfort due to the temperatures and poor healthiness of the confined environments;
in buildings characterised by mechanical ventilation, the systems are generally of the centralised type and their operation is at the service of significant portions of the buildings and depends on daily planning, regardless of whether or not the rooms are actually occupied by persons and whether or not air change in the room is actually necessary.

A typical problem with permeable walls is the drop in internal surface temperature when air enters through the wall in winter.
A further problem with permeable walls is the need for air tightness of components which, by design, do not have to be permeable (inner layers) so as to have complete control of the air flow rates through a permeable wall of known type.

Summary of the invention

That being said, an object of the present invention is to provide a dynamic insulation wall module which allows to reduce the drawbacks highlighted so far for buildings built according to the known art.
Another object of the present invention is to provide a dynamic insulation wall module which allows to limit energy consumption for optimal air conditioning of a confined environment.
Yet another object of the present invention is to provide a dynamic insulation wall module that allows to effectively limit particulates harmful to health to enter a confined environment.
A further object of the present invention is to provide a dynamic insulation wall module that can be easily combined with other modules of the same type to make air-permeable walls.
A further object of the present invention is to provide a dynamic insulation wall module which allows to increase the efficiency of heat recovery in winter for the passage of air through the wall.
A further object of the present invention is to provide a dynamic insulation wall module which allows to mitigate the lowering of internal surface temperature in the winter period.
A further object of the present invention is to provide a dynamic insulation wall module which allows to reduce effective transmittance in winter.
A further object of the present invention is to provide a dynamic insulation wall module capable of facilitating the cooling of the masses in summer.
A further object of the present invention is to provide a dynamic insulation wall module capable of ensuring better control of the air tightness of the non-permeable wall layers.
These and other objects are achieved by the present invention which concerns dynamic insulation wall module according to claim 1. Further peculiar characteristics of the present invention are set forth in the respective dependent claims.
A dynamic insulation wall module is used to make air-permeable walls interposed between a confined indoor environment and the outdoor environment of a building. The module comprises at least one air cavity in which airflow is circulated, produced and controlled by a ventilation unit.
In an embodiment of the present invention, the module comprises, according to a direction from the external environment to the internal environment, at least the following layers:

an outer layer of air-permeable material which includes exterior cladding panels for the protection against atmospheric agents;
at least one intermediate layer of air-permeable material which is transversally crossed by airflow produced and controlled by the ventilation unit;
a first air cavity, in which airflow is circulated, which is arranged beyond the at least one intermediate layer of air-permeable material; and
a layer of insulating and heat-reflecting material, which includes at least one air-tight and thermal insulation membrane, the layer being arranged beyond the first air cavity and before a layer of rigid material that includes interior cladding panels.

Thereby, this results in wall modules and, therefore, walls composed of these modules, in which the passage of the airflow through the solid matrix of the permeable layers allows to obtain a dynamically insulated system with better efficiency than the known art. Additionally, the air-permeable layers allow the circulation of air in both directions, between indoor and outdoor environments, adapting more easily to changes in climatic conditions.
The layers of air-permeable materials facilitate the exchange of airflows with the air cavities provided in the wall module and ensure the filtering of the external airflow entering the module, whereas the innermost layer of insulating and heat-reflecting material reduces the thermal transmittance of the module, i.e. it is used to mitigate the problems of lowering the internal surface temperature of the permeable walls in winter and to ensure the air-tightness toward the inside of the layers. Air-tightness control obtained with the innermost layer of insulating and heat-reflecting material is necessary to allow the invention to be operated properly.
Additionally, the layer of insulating and heat-reflecting material with the air-tight membrane allows to have complete control of the air flow rates through the permeable wall modules.
A second air cavity, in which airflow is circulated, may be arranged between the outer layer of air-permeable material, i.e. that which includes exterior cladding panels for the protection against atmospheric agents, and at least one intermediate layer of air-permeable material. The latter may consist of, for example, fibrous insulation panels or the like.
In an embodiment of the present invention, the module may further comprise a layer of rigid air-impermeable material arranged between the first air cavity and the layer of insulating and heat-reflecting material, and a third air cavity, without supply of airflows, which is arranged between the layer of insulating and heat-reflecting material and the layer of rigid material which includes interior cladding panels.
In an embodiment, the exterior cladding panels of the outer layer of air-permeable material are juxtaposed to each other in a detached way to allow the passage of airflow entering, or exiting, the second air cavity through the gaps present between each of the adjacent panels.
In another embodiment, the exterior cladding panels of the outer layer of air-permeable material are juxtaposed to each other in a compact way and the passage of airflow entering, or exiting, the second air cavity is ensured by a plurality of holes provided in the panels.
In another embodiment, the exterior cladding panels of the outer layer of air-permeable material are juxtaposed to each other in a compact way and the passage of airflow entering, or exiting, the second air cavity is ensured by one of more vents provided in the outer layer of air-permeable material.
In another embodiment, the outer layer of air-permeable material consists of at least one panel of a material of no-fines concrete type, or similar material of capacitive and high-permeability type, with solid matrix of communicating cells. In this embodiment, the outer layer of air-permeable material is placed in direct contact with the at least one intermediate layer of air-permeable material.
According to a possible embodiment of the present invention, a wall module may further be equipped with a ventilation unit for the control of the airflow in the second air cavity and/or the first air cavity.
Sensors may be provided that provide control signals to the ventilation unit, e.g. temperature sensors, humidity sensors, differential pressure sensors, etc.
Dynamic insulation wall modules, according to the various embodiments of the present invention, may be coupled to each other to form an air-permeable wall. In the wall thus made, the second air cavity of each module is in fluid communication with the second air cavity of the adjacent modules; likewise, the first air cavity of each module is in fluid communication with the first air cavity of the adjacent modules. At least one of the modules preferably comprises a ventilation unit for the control of the airflow in the second air cavities and/or the first air cavities.

Brief description of the drawings

Further characteristics and advantages of the present invention will be more evident from the following description, made for illustration purposes only and without limitation, referring to the accompanying schematic drawings, in which:

Figure 1 is a sectional view of a wall module for a new construction according to an embodiment of the present invention;
Figures 2 and 2A are sectional views of wall modules for renovating an existing construction according to some embodiments of the present invention;

Figure 3 is a sectional view of a possible embodiment of an outer layer of air-permeable material and Figure 3A is a perspective detail depicting the airflows through the outer layer of Figure 3;
Figure 4 is a sectional view of a possible embodiment of an outer layer of air-permeable material and Figure 4A is a perspective detail depicting the airflows through the outer layer of Figure 4;
Figure 5 is a sectional view of a possible embodiment of an outer layer of air-permeable material and Figure 5A is a perspective detail depicting the airflows through the outer layer of Figure 5;
Figure 6 is a sectional view of a possible embodiment of an outer layer of air-permeable material;
Figure 7 is a sectional view of a wall module according to a possible embodiment of the present invention;
Figure 8 is a sectional view of a wall module according to a possible embodiment of the present invention;
Figure 9 is a sectional view of a wall module according to a possible embodiment of the present invention;
Figure 10 is a sectional view of a wall module according to a possible embodiment of the present invention;
Figure 11 is a perspective view of a wall module according to a possible embodiment of the present invention;
Figure 12 is a perspective view of a wall module according to a possible embodiment of the present invention;
Figure 13 is a perspective view of a wall module according to a possible embodiment of the present invention;
Figure 14 is a perspective view of a wall module according to a possible embodiment of the present invention; and
Figure 15 is a perspective view of a wall formed by some of the wall modules of Figures 11 to 14.

Detailed description

Figure 1 shows a dynamic insulation wall module to make air-permeable walls interposed between an indoor environment I and the outdoor environment E of a building.
Following the direction from the outside E to the inside I, the module 1 in Figure 1 comprises an outer layer 10 of air-permeable material that includes exterior cladding panels for weather protection; at least one intermediate layer 30 of air-permeable material which may comprise fibrous insulation panels, such as mineral fibres, glass wool, wood fibres or the like; a layer 50 of rigid air-impermeable material, such as e.g. wood, plasterboard, fibreboard or the like; a layer 60 of insulating and heat-reflecting material that includes at least one air-tightness and thermal insulation membrane; and a layer 80 of rigid material that includes interior cladding panels.
A first air cavity 40 is arranged between the intermediate layer 30 of air-permeable material and the layer 50 of rigid air-impermeable material, the latter being placed in contact with the layer 60. An air flow produced by a ventilation unit 100 is circulated in the first air cavity 40 (Figs. 7-10).
A second air cavity 20 is arranged between the outer layer 10 of air-permeable material and the intermediate layer 30 of air-permeable material. Also in the second air cavity 20, if present, airflow produced by the ventilation unit 100 may possibly be circulated.
A plurality of sensors, such as e.g. temperature sensors, humidity sensors, etc., may be provided in the air cavities 20 and 40 and/or in the outdoor and indoor environments, to provide control signals to the ventilation unit 100.
A third air cavity 70, without supply of airflows, may be arranged between the layer 60 of insulating and heat-reflecting material and the layer 80 of rigid material which includes interior cladding panels.
Figure 2 shows a wall module 6 for renovating an existing construction. Also in this case, following the direction from the outside E to the inside I, the module in Figure 2 comprises an outer layer 10 of air-permeable material that includes exterior cladding panels for weather protection; at least one intermediate layer 30 of air-permeable material which may include fibrous insulation panels, such as e.g. mineral fibres, glass wool, wood fibres or the like; and a layer 60 of insulating and heat-reflecting material which includes at least one air-tightness and thermal insulation membrane. The layer 60 of insulating and heat-reflecting material may be placed directly in contact with the pre-existing masonry 90.
Similarly to the embodiment in Figure 1, a first air cavity 40 is arranged between the intermediate layer 30 of air-permeable material and the layer 60 of insulating and heat-reflecting material that may be placed in contact with the pre-existing masonry 90. In the first air cavity 40, airflow produced by a ventilation unit 100 is circulated. A second air cavity 20 is arranged between the outer layer 10 of air-permeable material and the intermediate layer 30 of air-permeable material. Also in the second air cavity 20, airflow produced by the ventilation unit 100 may possibly be circulated.
Figure 2A also shows a wall module 7 for renovating an existing construction. The module in Figure 2A also comprises an outer layer 10 of air-permeable material that includes exterior cladding panels for weather protection; at least one intermediate layer 30 of air-permeable material which may include fibrous insulation panels, such as mineral fibres, glass wool, wood fibres or the like; and a layer 60 of insulating and heat-reflecting material which includes at least one air-tightness and thermal insulation membrane.
The first air cavity 40 that is beyond the intermediate layer 30 of air-permeable material is delimited by a layer 50 of rigid air-impermeable material, such as e.g. wood, plasterboard, fibreboard or the like. The layer 50 is followed by a non-ventilated air cavity 70 further delimited by a layer 60 of insulating and heat-reflecting material that includes at least one air-tightness and thermal insulation membrane. Also in the embodiment of Figure 2A, the layer 60 is placed in contact with the pre-existing masonry 90.
This way, the layer 60 of insulating and heat-reflecting material is protected against dust which would degrade its surface performance. Alternatively, the same advantage could also be obtained by placing the layer 60 of insulating and heat-reflecting material in contact with the layer 50 of rigid air-impermeable material, thus leaving the air cavity 70 between the layer 60 and the pre-existing masonry 90 unventilated.
Returning to the embodiment of Figure 1, the outer layer 10 of air-permeable material that includes the exterior cladding panels can be made in various forms. For example, as depicted in Figures 3 and 3A, the exterior cladding may consist of single panels 11 arranged in one or more layers. The passage of airflow entering, or exiting, the second air cavity 20 can be ensured by the spaces 12, i.e. the gaps, between adjacent panels 11. This way, it is possible to make systems of hanging facades. The sequence of the remaining layers 30, 50, 60, 80 and air cavities 40 and 70 is the same as that shown in Figure 1.
Figures 4 and 4A depict an embodiment still based on that of Figure 1, in which the exterior cladding of the outer layer 10 consists of compact panels 13, i.e. mutually juxtaposed, arranged in one or more layers. The passage of airflow entering, or exiting, the second air cavity 20, i.e. the air permeability of the exterior cladding of the outer layer 10, is ensured by a plurality of holes, in particular micro-holes 14 with adequate surface distribution. The sequence of the remaining layers 30, 50, 60, 80 and air cavities 40 and 70 is the same as that shown in Figure 1. This embodiment is also suitable for making systems of hanging facades.
Figures 5 and 5A depict an embodiment still based on that of Figure 1, in which the exterior cladding of the outer layer 10 consists of panels 15 in one or more impermeable layers. The passage of airflow entering, or exiting, the second air cavity 20 is ensured by vents 16 having dimensions which are determined depending on the design parameters. The sequence of the remaining layers 30, 50, 60, 80 and air cavities 40 and 70 is the same as that shown in Figure 1.
Figure 6 depicts a particular embodiment still based on that of Figure 1, in which the exterior cladding layer consists of at least one panel 18 of high permeability capacitive material, with solid matrix of communicating cells, such as e.g. a material of the "no-fines concrete" type. The panel 18 may be placed directly in contact with the intermediate layer 30 of air-permeable material. The diffuse permeability of the panel 18 may make the use of the second air cavity 20 outside the intermediate layer 30 of air-permeable insulating material unnecessary. The sequence of the remaining layers 30, 50, 60, 80 and air cavities 40 and 70 is the same as that shown in Figure 1.
Figures 7 to 10 depict various embodiments of a wall module which is shown in schematic form, with at least two air cavities 20 and 40 in which airflow can be circulated under the control of a ventilation unit 100.
The sectional view of Figure 7 shows a wall module 2 in which the ventilation unit 100 is embedded into the module. The sectional view of Figure 8 depicts a wall module 3 in which the ventilation unit 100 embedded into the module is equipped with a thermo-hygrometric air treatment system 101, e.g. a system of the fan coil type installed in series to ventilation unit 100.
In the sectional view of Figure 9, the wall module 4 comprises a fixture 102, e.g. a window or the like, and the ventilation unit 100 embedded into the same module.
In the sectional view of Figure 10, the wall module 5 comprises a fixture 102, e.g. a window or the like, and an external shading system 103 integrated with the ventilation unit 100.
The directions of the supply and extraction airflows, which are parallel and/or perpendicular, are depicted in Figures 7 to 10 by way of example only and may vary depending on whether or not there is a fan-coil or the like.
Figures 11 to 14 depict in perspective some embodiments of the wall modules described so far, with reference to Figures 1 to 10. The wall module 1 in Figure 11 is a simple module, i.e. without a ventilation unit embedded therein, as that denoted by 1 in Figure 1; the wall module 3 in Figure 12 corresponds to that of the view in Figure 8 and a vent 105 for ejecting air toward the outside, which may be possibly masked inside the facade system, is also highlighted; the wall module 4 in Figure 13, with the vent 105 highlighted, corresponds to that of the view in Figure 9; the wall module 5 in Figure 14, with the vent 105 highlighted, corresponds to that of the view in Figure 10.
The view of Figure 15 highlights a wall 110 formed by a plurality of dynamically insulation modules, e.g. three wall modules 1 (Figs. 1 and 11) and a wall module 5 (Figs. 10 and 14).
In the wall 110, the second air cavity 20 of each module is in fluid communication with the second air cavity 20 of the adjacent modules. Similarly, the first air cavity 40 of each module is in fluid communication with the first air cavity 40 of the adjacent modules. In other words, the air cavities in which the airflows circulate (ventilated air cavities) are continuous along the adjacent modules. If necessary, the second air cavities 20 may be interrupted at vertical and/or horizontal partitions toward adjacent rooms by installing an air-impermeable layer, e.g. a layer of non-permeable insulating material.
Various modifications may be made to the embodiments shown so far without departing from the protection scope of the present invention. For example, it is also possible to provide embodiments in which the ventilation unit 100 is a component separated from the wall modules.

Claims

A dynamic insulation wall module (1-7) for making air-permeable walls interposed between an indoor environment of a building and the outdoor environment, comprising at least one air cavity in which an airflow is circulated, produced and controlled by a ventilation unit (100), characterised by comprising, according to a direction that goes from the outdoor environment to the indoor environment, at least the following layers:
- an outer layer (10) of air-permeable material, which includes exterior cladding panels for the protection against atmospheric agents;

- at least one intermediate layer (30) of air-permeable material which is transversally crossed by an air flow produced and controlled by said ventilation unit (100);

- a first air cavity (40), in which an airflow is circulated, arranged beyond said at least one intermediate layer (30) of air-permeable material; and

- a layer (60) of insulating and heat-reflecting material, which includes at least one airtight and thermal insulation membrane, said layer (60) being arranged beyond said first air cavity (40) and before a layer (80) of rigid material that includes interior cladding panels.
The wall module (1-7) according to claim 1, wherein a second air cavity (20), in which an airflow is circulated, is arranged between said outer layer (10) of air-permeable material, which includes exterior cladding panels for the protection against atmospheric agents, and said at least one intermediate layer (30) of air-permeable material.
The wall module (1-7) according to one of the preceding claims, wherein a layer (50) of rigid air-impermeable material is arranged between said first air cavity (40) and said layer (60) of insulating and heat-reflecting material, and wherein a third air cavity (70) without supply of airflows is arranged between said layer (60) of insulating and heat-reflecting material and said layer (80) of rigid material which includes interior cladding panels.
The wall module (1-7) according to claim 2, wherein said exterior cladding panels of the outer layer (10) of air-permeable material are juxtaposed to each other in a detached way to allow the passage of an airflow entering, or exiting, said second air cavity (20) through the gaps between each of the adjacent panels.
The wall module (1-7) according to claim 2, wherein said exterior cladding panels of the outer layer (10) of air-permeable material are juxtaposed to each other in a compact way, and wherein a plurality of holes is provided in said panels to allow the passage of an airflow entering, or exiting, said second air cavity (20).
The wall module (1-7) according to claim 2, wherein said exterior cladding panels of the outer layer (10) of air-permeable material are juxtaposed to each other in a compact way, and wherein one or more vents are provided in said outer layer (10) of air-permeable material to allow the passage of an airflow entering, or exiting, said second air cavity (20).
The wall module (1-7) according to claim 1, wherein said outer layer (10) of air-permeable material consists of at least one panel (18) of no-fines concrete type material, or a similar material of capacitive and high-permeability type, with solid matrix having interconnected cells, and wherein said outer layer (10) is placed in direct contact with said at least one intermediate layer (30) of air-permeable material.
The wall module (1-7) according to claim 2, further comprising a ventilation unit (100) for controlling the airflow in said second air cavity (20) and/or in said first air cavity (40).
A dynamic insulation wall (110) comprising a plurality of dynamic insulation modules according to claims 2 to 8, wherein the second air cavity (20) of each module is in fluid communication with the second air cavity (20) of the adjacent modules, wherein the first air cavity (40) of each module is in fluid communication with the first air cavity (40) of the adjacent modules, and comprising at least one ventilation unit (100) for controlling the airflow in said second air cavities (20) and/or in said first air cavities (40).