Patent Publication Number: US-2023160603-A1

Title: Multi-modes air handling system and method

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present patent application claims the benefits of priority of U.S. Provisional Patent Application No. 62/972,818, entitled “MULTI-MODES AIR HANDLING SYSTEM AND METHOD” and filed at the United States Patent and Trademark Office on Feb. 11, 2020, the content of which is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The invention relates to the field of air handling units (AHU). More particularly, the invention relates to the field of AHU having multi-modes fans and to methods of simultaneously controlling airflows in multiple zones. 
     BACKGROUND OF THE INVENTION 
     Nowadays, most current air handling units used in commercial or agricultural buildings rely on conventional components mostly unchanged for many years. Generally, systems comprise dampers, filters and coils connected to a centrifugal fan adapted to heat the outside air before such air enters a controlled zone. Typically, such components are bulky, not only due to their individual volume but also due to the required space for ductworks and other complemental secondary components insuring the good function of the unit. 
     When necessary, the airflow may be redirected inside the unit using components such as valves, traps, etc. In some smaller or more technologically advanced units, the fan itself, such as an Electronically Commutated (EC) fan, may change the direction of its airflow by changing the rotation of its fins. The inversion of rotational movement, especially if executed in a short period of time, may require a lot of energy from the motor. Nowadays, the aerodynamic properties of fan blades are generally designed to be optimized to produce an efficient airflow in one rotational direction. Thus, reversing a fan is typically inherently inefficient and would thus amount to a high energy consumption. Due to the sheer amount of such units being used in various commercial or agricultural buildings all over the world, finding and applying a more energy and space efficient system and/or method to control and change the airflow direction would amount to tremendous costs savings. Accordingly, there is a need for a method and device that regulates one or multiple zones&#39; air characteristics with an energy efficient mode change. 
     SUMMARY OF THE INVENTION 
     The shortcomings of the prior art are generally mitigated by multi-modes heat exchanger and air ventilation system. 
     In one aspect of the invention, a multi-modes air handling unit (AHU) is provided. The AHU comprises a heat-exchanging unit in seamless fluid communication with a warm airflow and a cold airflow and comprises one or more plurimodal pivoting fans. The AHU may further comprise a controller in communication with a network, the controller being configured to receive requests from remote computerized devices, such as computers, smart phones, tablets, or the likes. The controller may further be configured to regulate characteristics of a zone upon receiving such requests. 
     In one aspect of the invention, the AHU may comprise heating, cooling, ventilation, and air control functions. Understandably, while the embodiments described herein control air, other embodiments controlling any type of fluid are within the scope of the present invention. 
     In another aspect of the invention, the heat-exchanging unit may be a heat-exchanging block. A heat-exchanging block is typically made of a plurality of parallel plates positioned to receive a first airflow in a first direction and to receive a second airflow in a second direction without being in contact with each another. The first airflow comprises mostly cold air and the second airflow comprises mostly warm air. Each airflow enters through a first surface and leaves on respective opposite surfaces, the first airflow entering through a surface adjacent to the surface entered by the second airflow. 
     In yet another aspect of the invention, at least one fan may be located at a junction of multiple airflow passages. The fan may be a directional fan adapted to be axially rotated, such as any type of fan displacing air in a unilateral direction. The fan is mounted inside a conduit on a pivoting bracket allowing at least a rotation of 90 degrees. The rotation may be powered by at least a motor. The motor may be positioned over and/or under the center point of gravity of the fan. The fan brackets may be egg-shaped and may comprise an opening at each of two extremities, each opening being fluidly connected by a passage allowing air to flow from a first extremity to the second extremity. The fan and/or associated mount are/is adapted to allow airflow from a first conduit while blocking airflow from a second conduit, thus acting as a fan and a airflow control. Each opening may be adapted to be hermetically sealed from the second conduit when allowing airflow from the first conduit, and vice-versa. The sealing generally aims at providing contact between the housing of the AHU and the fan mount at all times, even when pivoting in-between modes. By sealing the passage from other conduits, only one airflow goes through the fan. 
     In some embodiments, the AHU comprises a housing. In such embodiments, the egg-shaped fan may freely pivot or rotate within the housing. The brackets may allow removing the pivoting fan from the housing or from the AHU, such as for maintenance or replacement purposes. In other embodiments, the fan brackets may have cylindrical, spherical or any other shape allowing fitting and rotation of the fan. 
     In another other aspect of the invention, an AHU comprises two pivoting fans and may provide up to four different modes of operation. Indeed, a first mode of operation provides one fan blowing air out of a zone into the heat-exchanging unit while the other fan is blowing air from the heat-exchanging unit to the said zone. A second mode of operation provides a fan blowing air out of a zone or an area without directing air toward the heat-exchanger unit. A third mode of operation provides a fan directly blowing air into a zone, without directing air toward the heat-exchanger unit. Finally, a fourth mode of operation provides a fan blowing air directly into a zone while the other fan blows air directly out of the zone, without directing air toward the heat-exchanging unit. It is to be understood that, independently of the chosen mode, each fan may direct air into each airflow passage of its junction; into the heat-exchanging unit, out of the heat-exchanging unit, into the controlled zone and out of the controlled zone. 
     In another aspect of the invention, a defrosting/de-icing and/or cleaning apparatus on a heat-exchanging block is provided. The apparatus is attached to a housing adapted to be displaced from one side of the block to the other. The apparatus may be moved using a worm screw driven by a motor assembly. The apparatus is maintained on adjacent surfaces of the block. Typically, the defrosting and de-icing unit is mounted near a cold air inlet of the heat exchanger and the cleaning unit is located adjacent to a hot air inlet. The cleaning unit may be supplemented with a phage dispenser. 
     In yet another aspect of the invention, a method for regulating a zone by controlling one or more AHUs with the help of a network is provided. In some embodiments, the method comprises a computerized device receiving data from sensors, meteorological data, and pollution alerts. The data may be associated to one or more zones. The received data is analysed by a computerized device. In some embodiments, the calculated actions are sent as requests to each AHU unit. 
     In another aspect of the invention, a fan assembly is provided. The fan assembly comprises a first conduit, a housing pivotally attached in the conduit, the housing comprising an intake passage and an outtake passage, and a fan unit mounted to the housing. In a first mode, the housing is pivotally oriented to create a first air flow in the first conduit and in a second mode, the housing is pivotally oriented to substantially limit the air flow in the first conduit. In the second mode, the housing may also block the air flow in the first conduit. In the second mode, the housing may sealingly block the air flow in the first conduit. The fan assembly may further comprise an enclosure housing the first conduit, the enclosure possibly comprising a plurality of detachable sections. In a third mode, the housing is pivotally oriented to create a third air flow in the first conduit in an opposite direction to the first air flow. 
     The fan assembly may comprise a second conduit, wherein in the first mode, the housing further substantially limits air flow in the second conduit and in the second mode, the housing creates a second air flow in the second conduit. In the first mode, the housing may block air flow in the second conduit and in the second mode, the housing may block the air flow in the first conduit. In the first mode, the housing may sealingly block the air flow in the second conduit and in the second mode, the housing may sealingly block the air flow in the first conduit. 
     The fan assembly may comprise an enclosure housing the first and second conduits. The enclosure may further comprise a plurality of detachable sections. In a third mode, the housing is pivotally oriented to create a third air flow in the first conduit, the third airflow being opposite to the first air flow. In a fourth mode, the housing is pivotally oriented to create a fourth air flow in the second conduit, the fourth airflow being opposite to the second air flow. The fan unit may be located at an intersection between the first and the second conduit. 
     The fan assembly may comprise at least one gas sensor, the sensor being attached to the fan unit, the gas sensor detecting one or more gases characteristics. The gas sensor may be an electronic nose. The housing may have a curved shape. 
     The fan unit may further comprise a pivoting mechanism to pivot the housing in relation to the first conduit. The fan unit may further comprise a controller for activating and deactivating the pivoting mechanism. The controller may be programmed to control the rotation position of the pivoting mechanism. The fan assembly may further comprise an engagement mechanism for engaging yet disengaging the pivoting mechanism. The engagement mechanism may be a manual clutch. 
     The pivoting mechanism may comprise one or more limit switch configured to detect the current radial position of the housing. The fan unit may be a centrifugal fan or an axial fan. The housing may be rotomolded. 
     In another aspect of the invention, a multi-mode air handling unit (AHU) between a first zone and a second zone is provided. The AHU comprises a structure, a heat exchanger, a first fan assembly and a second fan assembly attached to the structure, each of the fan assemblies comprising a first and a second intersecting conduits, the first conduit being in fluid communication with a first zone and the heat exchanger and the second conduit being in fluid communication with the first zone and the second zone, a housing pivotally attached at the intersection of the first and second conduits, the housing comprising an intake passage and an outtake passage, and a fan unit mounted to the housing, the housing being pivotally orientable to alternatively create a first air flow in the first conduit, and a second air flow in the second conduit. 
     The first and second fan assemblies may be adjacent to one another. The structure may have a first surface in contact with the first zone and a second surface in contact with the second zone. The structure may comprise recesses adapted to be coupled to forks of a vehicle. The first zone may be an enclosed area and the second zone is outside. 
     The pivoting of the housing of the first fan assembly may be independent of the pivoting of the housing of the second fan assembly. The relative position of each of the housing of the first fan assembly and of the second fan assembly may allow distinct operating modes of the AHU. Each of the first fan assembly and of the second fan assembly may pivot to create a direct airflow between the first and the second zones. 
     Each of the fan assemblies may be removable from the AHU. The AHU may be configured to be installed in a flush configuration with the wall of the first zone supporting the AHU. 
     In another aspect of the invention, a method for alternating between a first air flow mode and a second air flow mode is provided. The method may comprise pivotally orienting a housing in relation to a first conduit to create a first air flow in the first conduit, the housing comprising a fan unit and pivotally orienting the housing to limit or block the first air flow in the first conduit. 
     The method may comprise pivotally orienting the housing in the first conduit to create a third air flow, the third air flow being opposite to the first air flow. The method may comprise pivotally orienting the housing to create a second air flow in a second conduit while limiting the first air flow in the first conduit. The method may further comprise pivotally orienting the housing in the second conduit to create a fourth air flow, the fourth air flow being opposite to the second air flow. 
     In another aspect of the invention, a method for controlling distinct modes of operation of an air handling unit (AHU) based on control parameters between two zones is provided, the method comprising a controller receiving control parameters from one or more capturing devices of the AHU, the controller determining a mode of operation of the AHU based on the received control parameters, and automatically pivoting at least one fan unit in relation to a conduit of the AHU to create or block an air flow in the conduit based on the determined mode of operation. 
     The method may further comprise automatically pivoting a second fan unit in relation to a second conduit of the AHU to create or block an air flow in the conduit based on the determined mode of operation. 
     The first zone further may comprise the controller receiving data from an external data source. The data from the external data source may comprise any one of the followings: meteorological data, radioactive data, air quality data and contamination data. 
     The method further may comprise training an artificial intelligence algorithm using the captured control parameters and using the trained artificial intelligence algorithm to determine the mode of operation of the AHU. The training of the artificial intelligence algorithm may comprise providing feedback from one or more user of the AHU. 
     The capture of the control parameters may comprise any one of the followings: measuring temperature, detecting virus or bacteria present in the air, measuring humidity level, sensing odors, detecting type of gas or presence of particles in air, such as carbon level. 
     In another aspect of the invention, a system for ventilating a building comprising multiple zones, each zone comprising a least one air handling unit (AHU), each AHU being configured to execute a method for controlling distinct modes of operation of an air handling unit (AHU) based on control parameters between two zones. The system may be used in an agricultural building. In another aspect, each zone may be a predetermined zone in an open area. 
     Each of the AHUs may be in data communication with one another. Each of the AHU may be controlled by a server. 
     The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. Other and further aspects and advantages of the present invention will be obvious upon an understanding of the illustrative embodiments about to be described or will be indicated in appended claims, and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice. 
     Other and further aspects and advantages of the present invention will be obvious upon an understanding of the illustrative embodiments about to be described or will be indicated in the appended claims, and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other aspects, features and advantages of the invention will become more readily apparent from the following description, reference being made to the accompanying drawings in which: 
         FIG.  1    is a perspective view of an embodiment of an AHU in accordance with the principles of the present invention. 
         FIG.  2    is an exploded view of the AHU of  FIG.  1   . 
         FIG.  3    is a sectional view of a cavity of the AHU of  FIG.  1   . 
         FIG.  4    is a side sectional view of the AHU of  FIG.  1   . 
         FIG.  5    is a perspective view of a fan assembly of an AHU in accordance with the principles of the present invention. 
         FIG.  6    is a sectional view of a junction of a housing of a fan assembly and of a conduit of an AHU in accordance with the principles of the present invention. 
         FIG.  7    is a top sectional view of the AHU of  FIG.  1   . 
         FIG.  8    is a front plan view of the fan assembly of  FIG.  5    shown in a first mode of operation. 
         FIG.  9    is a top sectional view of the fan assembly of  FIG.  8    about the A-A axis. 
         FIG.  10    is a front plan view for the fan assembly of  FIG.  5    shown in a second mode of operation. 
         FIG.  11    is a top sectional view of the fan assembly of  FIG.  10    about the B-B axis. 
         FIG.  12    is a top sectional view of the AHU of  FIG.  1   . 
         FIG.  13    is an illustration of an embodiment of control components of an AHU in accordance with the principles of the present invention. 
         FIG.  14    is an illustration of a system for regulating airflow in multiple zones. 
         FIG.  15    is a front perspective view of an embodiment of an AHU in accordance with the principles of the present invention. 
         FIG.  16    is a back perspective view of an embodiment of an AHU in accordance with the principles of the present invention. 
         FIG.  17    is a perspective view of an embodiment of an AHU in accordance with the principles of the present invention shown mounted in a wall and viewed from a first zone. 
         FIG.  18    is a perspective view of the AHU of  FIG.  17    viewed from the second zone. 
         FIG.  19    is a side elevation section view of the AHU of  FIG.  17    viewed from within the wall. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     A novel multi-modes air handling unit or heat exchanger and air ventilation system and method will be described hereinafter. Although the invention is described in terms of specific illustrative embodiments, it is to be understood that the embodiments described herein are by way of example only and that the scope of the invention is not intended to be limited thereby. 
     Referring now to  FIG.  1   , an embodiment of an air handling unit (AHU)  10  is illustrated. In such an embodiment, the AHU  10  comprises a structure or a frame  12 , one or more pivoting fan assemblies  20 , a heat-exchanging unit  50 . The AHU may further comprise a controller  40 . In some embodiments, the AHU  10  may further comprise a filtering system  70  and a vacuum system  80 . 
     The AHU  10  is generally positioned between two zones. In some embodiments, a first zone is in a controlled environment, such as a zone inside of a building, and a second zone is in a non-controlled environment, such as outside or exterior area, such as but not limited to the outside area of the building. In some embodiments, the AHU  10  comprises removable panels or doors  14 . The removable panels  14  are typically attached to the structure  12  of the AHU  10 . The AHU  10  may comprise a housing  11  adapted to protect the AHU  10  against the external elements, such as snow, rain, etc. The housing  11  is typically attached to the structure  12 . The housing  11  may further comprise an outer casing  13  generally aiming at protecting and isolating inner components of the AHU  10  in relation to the first and second zones. The AHU  10  may further comprise conduits or ductworks  16  fluidly connecting the first zone, each pivoting fan assembly  20  and the second zone. 
     In some embodiments, the structure  12  of the AHU  10  may further comprise notches, recesses or other shapes  18  adapted to receive forks of a vehicle, such as a tractor. When forks are inserted under and/or in the notches  18 , the AHU  10  may be moved, raised, lowered and manipulated with a vehicle. Using a vehicle may ease the installation of the AHU  10  in an opening of the building as the vehicle may align the AHU  10  with the opening and lower the said AHU  10  on an inner wall of the opening. 
     In yet other embodiments, the AHU  10  and/or structure  12  is adapted to have a flush fit with a wall or with the edges of the opening in which the AHU  10  is mounted. The flush fitting generally aims at reducing the occupied volume of the AHU  10  in one of the zones, typically the zone within the building. The flush fit generally implies having duct or conduit  16  and/or other components of the AHU  10  being positioned toward the other zone, typically outside the building. 
     In a typical embodiment, in a first mode, a fan assembly  20  is adapted to pull or drive air from the first zone through a first inlet and to blow the air towards an outlet in connection to the second zone, thus forming a first conduit  2 . In the first mode, the fan assembly  20  or fan unit  22  is oriented in the general longitudinal direction of the conduit  2 . In a second mode, the fan unit  22  or fan assembly  20  is pivoted or oriented to block air flowing in the first conduit  2 . In a preferred embodiment, the fan unit  22  or fan assembly  20  is pivoted about 90 degrees from the longitudinal direction of the first conduit. In some embodiments, the air from the first zone is blown by the fan assembly  20  toward the heat exchanger unit  50  in the second mode. 
     In a third mode, the fan assembly  20  is oriented to pull or blow air from the second zone towards the first zone, thus using the first conduit  2  in an opposite direction to the first mode. Typically, in the third mode, the fan assembly  20  is pivoted about 180 degrees from the first mode. In a fourth mode, the fan assembly  20  is adapted to block air in the first conduit  2  and to form the second conduit  4 . Preferably, in the fourth mode, the fan assembly  20  is pivoted about 270 degrees or −90 degrees from the position of the first mode. In the fourth mode, the air is preferably blown by the fan assembly  20  from the heat exchanger unit  50  towards the first zone. 
     Referring now to  FIG.  2   , an exploded view of the AHU  10  of  FIG.  1    is shown with components singled out. As shown, some components of the AHU  10  are removable or at least displaceable, aiming at easing the access to the components by a user. 
     In some embodiments having a filtering system  70 , the filtering system may be slideably attached to the structure  12  of the AHU  10 . In yet other embodiments, the filtering system  70  is mounted to at least one set of rails  72  which are attached to the structure  12 . The rails  72  allow the filtering system  70  to move at least partly in and out of the AHU  10 . As the filtering system  70  is moved out, it may be serviced or maintained. 
     In yet other embodiments, the one or more fan assembly  20  may be detachable from the AHU  10 . In such embodiments, the fan assembly  20  is part of an external housing or casing  6  which may slide in and out of the structure  12  or housing  11  of the AHU  10 . The fan assembly  20  may be fastened to the AHU  10  when inserted. In such embodiment, the housing  11  or structure  12  comprises a surface or rails to slidably receive the fan assembly  20 . 
     In embodiments comprising a vacuum system  80 , the housing  11  or structure  12  of the AHU  10  may comprise an access door, panels or trap  14  covering the vacuum system  80 . The access door  14  aims at providing access for maintenance or service of the vacuum system  80  or other adjacent components. Understandably, any other known mechanism to cover yet access the vacuum system  80  may be used within the scope of the present invention. 
     In further embodiments, the AHU  10  may further comprise one or more doors  14  to access one or more components, such as cassettes or blocs, a heat-exchanger, a fluid drain, a heater, an air conditioning unit, etc. When the one or more doors  14  are opened, each of the components may be pulled out or tilted to be accessed. As an example, the heat-exchanging unit  50  may be entirely removed or may one or more the cassettes  42  may be independently removed. Furthermore, one or more of the fan assemblies  20  may be taken out of the AHU  10 , such as for maintenance or replacement purposes. The doors  14  may be embodied as sliding doors, pivoting doors or spring-loaded doors. Understandably, the components may be fastened or mounted to the structure  12  or the housing  11  and may be further adapted to be accessible during operation. The components may further be installed or uninstalled when the AHU  10  is mounted in the aperture of the building. In some embodiments, the AHU  10  may comprise doors  14  on the surface within the first zone and corresponding doors  14  on the surface facing the second zone. As such, one may service or maintain the AHU  10  while being in the first zone, typically inside the building, or while being in the second zone, typically outside. 
     Now referring to  FIG.  3   , the housing  11  or the structure  12  of the AHU  10  may comprise a cavity or enclosure  15 , typically located under the different components, such as the heat-exchanger  50 . The cavity  15  may comprise seal joints  17 , typically between the hinge of the doors  14  and the cavity  15 . The joints  17  generally provide a barrier for the liquid to exit the cavity  15  through such openings. The structure  12  or the cavity  15  of the AHU  10  may comprise a plurality of recesses, angled surfaces, or paths  19 . The recesses  19  are generally adapted to capture the liquid flowing in the cavity  15  and to direct the said liquid toward a drain or liquid discharge. In the shown embodiment, the drain is located on the bottom surface of the cavity  15 , preferably around the center of the said bottom surface which form a low point. Understandably, any other arrangement of recesses, angled surfaces and/or paths  19  allowing the flow of liquid towards a drain or an opening are within the scope of the present invention. 
     Now referring to  FIG.  4   , an embodiment of the fan assembly  20  is illustrated. The fan assembly  20  comprises a first conduit  2 , a housing  24  pivotally attached in the conduit  2 , and a fan unit  22  mounted to the housing  24 . The housing  24  typically comprise an intake passage or opening  26  and an outtake passage or opening  27 . The fan assembly  20  may further comprise a pivoting member  28 . In such embodiments, the pivoting members  28  pivots or orients the housing  24 , not shown. In other embodiments, the fan assembly  20  may comprise two fans or propellers ( 22 ,  22 ′). The two fans  22 ,  22 ′ may be installed in series and may be pivoted using the same pivoting member  28 . It may be appreciated that having two fans ( 22 ,  22 ′) in the fan assembly  20  generally aims at increasing the air pressure to provide an improve airflow per fan assembly  20  over fan assemblies  20  having a single propeller. It may further be appreciated that having two fans ( 22 ,  22 ′) in the fan assembly  20  generally allows the fan assembly  20  to remain functional in the event where one of the two fans ( 22 ,  22 ′) is defective. The fans ( 22 ,  22 ′) of the assembly  20  may be any type of fan known in the art, such as but not limited to an axial fan or a centrifugal fan. 
     The fan unit  22  typically comprises a propeller and motor. The fan unit may further comprise an integrated controllers or a switch to activate yet deactivate the fan unit. 
     The fan assembly  20  further comprises a conduit  2  in fluid communication with a zone or with a heat exchanger  50 . The conduit  2  may be integrated or moulded into an enclosure  25  of the fan assembly  20 . The conduit  2  is typically formed or moulded in the enclosure  25  of the fan assembly  20 . The conduit  2  may be an extension of the ductworks  16 . Therefore, the conduit  2  is typically the convergence of the multiple air paths if there is more than one conduit  2  for a given propeller  22 . 
     In some embodiments, the fan assembly  20  comprises two intersecting conduits ( 2 ,  4 ). The two conduits ( 2 ,  4 ) may intersect at an angle, preferably the angle being around 90 degrees. Understandably, in other embodiments, the two conduits ( 2 ,  4 ) may intersect at different angles, such as but not limited to 60 degrees and 120 degrees or 45 degrees and 135 degrees. Additionally, the conduits ( 2 ,  4 ) may converge within any plane, such as but not limited to a horizontal plane or a vertical plane. As an example, two conduits ( 2 ,  4 ) may intersect at 60 degrees from each another. 
     Now referring to  FIG.  5   , the enclosure  25  may be made of multiple sections and may have a plethora of shapes. In the present embodiment, the enclosure  25  is made of a bottom  27  and a top portion  28 . In other embodiments, the enclosure  25  may be made of more than two sections or may be unitary. The different configuration generally aim at easing production, assembly and/or disassembly. The enclosure  25  may further be made of plastic or be moulded. The enclosure  25 , and various other components of the AHU  10 , may be rotomolded. Furthermore, the shape, length and overall configuration of the conduits ( 2 ,  4 ) may vary according to the space available in the AHU  10  or the configuration of the AHU  10  or of the building. In such an embodiment, the conduits ( 2 ,  4 ) are shaped as a 90 degrees elbow. Understandably, in yet other embodiments, the said conduits ( 2 ,  4 ) may have any configuration based on the selected configuration of the AHU  10 . 
     The housing  24  of the fan assembly  20  is pivotally mounted to the enclosure  25 , preferably using a pivoting mechanism  30 . The pivoting mechanism  30  may comprise a pivoting member  32  which may activated by a motor  34 . The pivoting member  32  orients or pivots the housing  24  around a substantially vertical axis  23 . The pivoting member  32  may be embodied as a pivoting device or a bracket connected to a pivoting device adapted to rotate the pivot axis  23 . 
     In some embodiments, the pivoting mechanism  30  comprises a servomotor  33 , not shown, and a pivoting member  32 . The servomotor  33  is configured to control the rotation of the pivoting member  32 , thus controlling the orientation of the fan assembly  20 . The pivoting member  32  is operatively connected to the housing  24 . As the fan unit  22  is mounted in the housing  24 , the air flow is rotated accordingly. The housing  24  is typically pivotally mounted to the enclosure  25  through a central axis  23  of the housing  24 , allowing the housing  24  to rotate around itself or around the vertical axis  23 . Understandably, in other embodiments, the pivoting member  32  may be adapted to allow pivoting around a generally horizontal axis if conduits ( 2 ,  4 ) are adapted accordingly. Having another axis of rotation may allow the implementation of vertical conduits  16  which may thus be greatly beneficial in applications having limited space. 
     In yet other embodiments, the pivoting mechanism  30  may be operatively connected to or in communication with a controller  40 . The controller  40  may be configured to activate and/or deactivate the pivoting mechanism  30 . The controller  40  may be further configured or programmed to control the radial/rotational position, the speed of rotation and/or the direction of rotation of the pivoting mechanism  30 . Understandably, the controller  40  may be a component of the AHU  10  or be embodied as an external module. 
     The fan assembly  20  may further comprise an engagement mechanism  35  for engaging yet disengaging the pivoting mechanism  30  of the fan assembly  20  or fan unit  22 . In some embodiments, the embodied engagement mechanism  35  is a clutch system allowing the engagement and disengagement of the pivoting mechanism  30 . In such embodiments, the fan assembly  20  comprises a drive mechanism  36  engaged by the engagement mechanism  35  and driving the pivoting mechanism  30 . The drive mechanism  36  may comprise a drive belt or chain engaging the pivoting member  32  and a spline  37  of the clutch system  35 . The spline  37  may move vertically to engage yet disengage a rotation mechanism  34 . The rotation mechanism  34 , generally a motor, may rotate a drive shaft in either direction. A pivoting handle  38  may further be connected to the spline  37  to raise or lower said spline  37 . The pivoting handle  38  may allow a user to manually disengage the motor  34  to the spline  37  when required. 
     The fan assembly may further comprise a tensioning system  39 . The tensioning system  39  may be slidably connected to the clutch system  35 . The tensioning system  39 , by translating the clutch system  35  away or towards the pivoting mechanism  30 , increases or lowers the tension in the drive belt  36 . Understandably, the rotation mechanism  34  and the tensioning system  39  may be controlled by the controller  40 . 
     The fan assembly  20  may further comprise at least one limit switch  42  configured to detect the current radial position of the housing  24  and to communicate the said position to the controller  40 . In the embodiment shown, two limit switches  42  are configured to be in contact with disks  31  of the pivoting mechanism  30 . Accordingly, the disks  31 , typically embodied as a pulley, of the pivoting mechanism  30  may comprise disturbances, such as embosses or recesses, not shown, on the surface or at the periphery of the disk  31 . When the disk  31  is turning, the disturbances contact the limit switches  42 , thus activating one of the said limit switches  42 . The activation or deactivation of a limit switch  42  indicates that the housing  24  is pivoted to a predetermined position, such as pivoted 90 degrees or 270 degrees, etc. Understandably, other systems may be used to determine the position of the disk  31 , such as a position encoder. 
     The housing  24  comprises side walls  21  alternatively positioned between apertures or inlet/outlet. The side walls  21  are generally sized to at least partially block air from one of the conduits ( 2 ,  4 ). In other embodiments, the side walls  21  may completely block the airflow of one of the conduits ( 2 ,  4 ) while the apertures allow the airflow from the fan unit  22  to circulate in the other conduit ( 2 ,  4 ). The housing  24  is generally shaped to allow pivoting movements of the fan unit  22  within the conduits ( 2 ,  4 ), preferably at the intersection of the conduits  23 . 
     In the present embodiment, the side walls  21  are curved. The curved side walls  21  generally provide a rounded, oval or egg shape to the housing  24 . In some embodiments, the housing  24  has a rounded shape or has rounded edges to ease the pivoting. Understandably, any other shape allowing pivoting and sealing functions may be used, such as cylindrical, oval, round or even square. 
     The side wall  21  may further comprise a ledge or lip at the periphery. Such ledge or lip typically aims at increasing the rigidity of the side wall  21  and/or to seal the inlet/outlet aperture when contacting a seal  44  of the said aperture or of the conduit  2 . 
     In an embodiment, the housing  24  may be taken out of the enclosure  25  or conduits ( 2 ,  4 ) without disassembling the entire conduits ( 2 ,  4 ) or enclosure  25 . Similarly to the enclosure  25 , the housing  24  may further comprise more than a pair of side walls  21 . As an example, the housing  24  may comprise a top section and a bottom section. 
     The housing  24  may further comprise sealing means  44 , such as a rubber band or other sealing material allowing efficient blocking of air between the walls  21  and the conduits ( 2 ,  4 ). The sealing means  44  generally surrounds the openings of the housing  24 , such as the inlet and/or outlet. The sealing band  44  may also be attached to the edges of the side walls  21  to block air at the junction of the side walls  21  and the conduits ( 2 ,  4 ) or enclosure  25 . h. Understandably, any type of sealing means blocking the air from one conduit in conjunction with the side walls  21  may be used within the scope of the present invention. 
     Referring now to  FIG.  6   , a sectional view of the junction between the housing  24  of a fan assembly  20  and the conduit ( 2 ,  4 ) or enclosure  25  is illustrated. When the housing  24  is positioned to create an airflow in one conduit ( 2 ,  4 ), the side walls  21  of the housing  24  may be sealingly connected to a sealing joint  44  located on the periphery of the junction between the conduit ( 2 ,  4 ) or the enclosure  25  and the housing  24 . Accordingly, the airflow present in the conduit ( 2 ,  4 ) does not leak or is substantially maintained within the fan unit  22  with the said conduit. The sealing joint  44  may be made of any sealing material known in the art. 
     In yet other embodiments, the system  10  may further comprise sensors, not shown, upstream and/or downstream from each fan  22 . Such sensors may be configured to analyse the airflow. In an example, the sensor detects and communicate data about the airflow or pressure of the airflow. When the airflow or pressure lowers or increases, an alert or any action may be triggered. As another example, if the airflow is lowered, the resulting data may be associated in a leak or perforation resulting in an air loss. In such an example, the fan assembly  20  or housing  24  may be disassembled to further investigate the air loss. The sensors may be gas sensors adapted to detect a variety of gases characteristics. For example, the sensors may be adapted to detect presence of bacteria and/or viruses in the airflow. The sensors may further include sensor configured to detect odors. In an embodiment, the gas sensors may be an electronic nose adapted to detect a variety of gases and odors. 
     In a preferred embodiment, the sensor is attached or mounted to the housing  24  of the fan assembly  22 , typically on a bracket positioned in the air flow created by the fan assembly  22 . As the housing  24  is pivoted, the sensor is maintained in the airflow, thus limiting the number of sensors required as the sensor always follows the airflow. 
     Referring now to  FIG.  7   , a top down sectional view of the AHU  10  is shown. In such an embodiment, the fan assembly  20  is pivoted to form the first conduit  2 . In this embodiment, the air from the second zone is blown from an outlet conduit by the propeller  22  to an inlet conduit towards the first zone. 
     In some embodiments, the outside air passes through the heat-exchanging unit  50  before being blown by the propeller  22 . While passing through the heat-exchanging unit  50 , the warm air flow exchanges energy with the cold air flow, resulting in a supply airflow warmer than initially collected. A second mode requires the propeller  22  to be pivoted by 180 degrees or in opposite direction from the first mode. In such mode, the air flow moves in an opposite direction still in the first conduit  2 , thus the air flows from the first zone to the heat-exchanging unit  50 . 
     In a third and fourth mode of use, air flow may be direct from one zone directly to the other, such as without going through the heat-exchanger  50 . In such modes, all the fans  22  may direct air in the same direction, both in or out of the first zone toward the second zone, or in opposite directions. In the third and fourth modes, the airflow is directed in the second conduit  4  and at least partially blocked in the first conduit  2 . In order to change the mode of use, the housing  24  may rotate clockwise or counter clockwise around a central pivot point  23  until the desired position is reached. 
     In another embodiment of the invention, sensors may be installed at different positions in and out of the AHU  10  to detect if ice has been formed and blocks or reduces the airflow or the pivoting movement of the propeller assemblies. Fans  22  direction may be temporarily reversed in order to send warm air in an otherwise cold area until the situation is resolved. 
     In another mode, the housing  24  of the fan assembly  20  is pivoted or oriented within the fan assembly  20  to form the first conduit, also referred as the blower mode. The air from either the first or second zones enters an inlet portion of the first conduit, goes through the propeller assembly and is blown toward an outlet portion of the first conduit toward the second or first zones respectively. 
     In yet other embodiments, the AHU  10  may comprise blinds  46 . The blinds  46  may be positioned between the first and/or second zone and the fan assembly  20 . In yet other embodiments, the blinds  46  are installed in between shutters  48  and the fan assembly  20 . The blinds  46  are typically passive and block outside light may get into the inside zone when the fan assembly  20  is oriented as such. It may especially be useful in applications wherein animals are comprised, as light may scare off some animals, such as in farming or agricultural use. 
     In other embodiments, the AHU  10  comprises shutters  48  at each fluid inlet and fluid outlet. The shutter  48  may be gravity driven shutters or mechanically operated shutters adapted to be open and closed by an activation mechanism, not shown. The activation of the shutters  48  may be controlled by the controller  40 . 
     In some embodiments, the AHU  10  comprises one or more additional fan assemblies  20  either stacked horizontally or vertically with regard to the first fan assembly  20 . Generally, two fan assemblies  20  may be necessary to make the heat-exchanging unit  50  function properly as two airflows of different temperatures are necessary to allow heat exchange. In such an embodiment, the two fans assemblies  20  may be pivoted to each form a second conduit  4 , also referred as a blower mode. Understandably, the blower mode may be adapted to blow air from a first zone to a second zone or vice versa by pivoting the propeller assemblies  20  by 180 degrees. 
     As illustrated, it may be appreciated that the fan assemblies  20  may be offset from the center width-wise of the AHU  10 . Offsetting the positioning of the fan assemblies  20  from the center of the AHU  10  may allow for the installation of other components inside the structure  12  rather than outside of the structure  12 . For example, the offset configuration may allow the installation of the vacuum system  80  inside the structure  12  of the AHU  10  rather than outside. 
     In yet another embodiment, the AHU  10  may further comprise make up air unit (not shown), also known as recycled exhaust air unit. In such embodiments, the make up air unit is adapted to mix the airflow entering the AHU  10 , such as the outside air, to an airflow coming from the building, typically a heated airflow. By mixing a warm airflow to the entering airflow, having a generally lower temperature, the temperature of the resulting airflow is higher than the temperature of the entering airflow. 
     The make up air unit generally aims at reducing the energy required to produce a warm resulting airflow. In one embodiment, the make up air unit comprises a conduit having a damper. Preferably, the conduit is fluidly connected to the docking providing the entering airflow, upstream from the heat-exchange unit  50 . In yet another embodiment, the make up air unit may comprise a conduit  16  having a damper, the conduit  16  being fluidly connected to the exhausted airflow leaving the heat-exchange unit  50  and to the entering airflow upstream from the heat-exchanger unit  50 . In both embodiments, the exhaust airflow has a higher temperature than the entering airflow. Understandably, the said conduits  16  and dampers may have any shape and configurations known in the art. In a further embodiment, the opening and closing of the dampers may be controlled by communicating directly with the AHU  10  through the network. 
     Referring back to  FIG.  5   , an embodiment of a fan assembly  20  is shown forming the first conduit  2 . In such an embodiment, the conduit  2  comprises a first outer portion in fluid communication with the first zone and a second outer portion in fluid communication with the heat exchanger unit  50 . In such embodiments, the conduit  2  is curved to allow air to be directed to the cassette section which may comprise the heat exchanger unit  50  with limited space. Understandably, in other embodiments, to optimize the flow of air and to fit within the AHU  10 , the conduit  2  encompassing the housing  24  may have any other compatible shape. 
     The second conduit  4  generally comprises a third outer portion in fluid communication with the first zone and a fourth outer portion in fluid communication with the second zone. Such third and fourth outer portions are generally forming the second conduit  4 . Other additional outer portions may be added as to form supplementary conduits. As example, a third conduit, not shown, may be connected to the bottom of a top fan assembly  20  and to the top of a bottom fan assembly  20 . 
     In such embodiment, the fan assembly  20  comprises a housing  24 . In a typical embodiment, the fan unit  22  is positioned about the junction of the first and second conduits ( 2 ,  4 ). In some embodiment, the housing  24  comprises a pivoting member  32  pivotally mounted to the housing  24  at a pivot point  23 . In an embodiment, the pivoting member  32  may be a servomotor while in another embodiment, the pivoting member  32  may be connected to a controller  40  or to a motor (not shown) to control and/or automate the rotation of the housing  24 . The pivoting member may further comprise a limit switch  42  to measure the rotation of the fan assembly  20 . Understandably, any other mean to allow the fan unit  22  to pivot about the conduits ( 2 ,  4 ) may be used within the scope of the present invention. As examples, the motor  34  may be installed over or under the housing  24  depending on required performances and/or on available space. The housing  24  may be curved, generally aiming at allowing free rotation of the fan  22  within the conduits ( 2 ,  4 ) while alternatively sealing outer portions of the first conduit  2  or outer portions of the second conduit  4 . Understandably, any other shape having similar functions as the above-described curved mount  24  may be used within the scope of the present invention. 
     Referring now to  FIGS.  8  and  9   , an embodiment of a fan assembly  20  shown in a first mode of operation is shown. In such an embodiment, the fan assembly  20  is positioned in such a way as to let air flow from the interior of a first zone to the heat-exchanging unit  50 , thus forming the first conduit  2 . While the fan assembly  20  is positioned in the first mode of operation, the second conduit  4  is blocked and/or sealed by the side walls  21  of the fan assembly  20 , thus acting as a valve. 
     Referring now to  FIGS.  10  and  11   , an embodiment of a fan assembly  20  shown in a second mode of operation is shown. In such an embodiment, the fan assembly  20  is positioned to let air flows directly between the first zone and second zone (or vice-versa), thus forming the second conduit  4 . While the fan assembly  20  is positioned in the second mode of operation, the first conduit  2  is blocked and/or sealed by the side walls  21  of the fan assembly  20 , thus acting as a valve. 
     Understandably, in some embodiments, the opening may not be hermetically sealed from the second conduit  4  or first conduit  2 . In some embodiments, the conduits ( 2 ,  4 ) or enclosure  25  may not be in contact with the housing  24 , but may still block a substantial portion of the airflow. 
     Referring now back to  FIGS.  1  and  2   , an embodiment of a heat-exchanging unit  50  is illustrated. The heat-exchanging unit  50  may be any heat-exchanging unit allowing two or more airflows to exchange heat within said heat-exchanging unit  50 . In the illustrated embodiment, the heat-exchanging unit  50  comprises a plurality of replaceable counter flow heat-exchanging cassettes or plate blocs  52 . In such embodiment, each bloc  52  may be adjacent to another bloc  52  and/or in contact with the adjacent bloc  52 , preferably through at least a dampening portion  54 . The dampening portion  54  may be embodied as a frame around a side surface of a bloc  52  and is generally made of flexible or semi-flexible material, such as but not limited to rubber. The dampening surface  54  may further have heat isolating and liquid repellent properties to prevent heat or humidity to circulate between two adjacent blocs  52 . The dampening surface  54  may further be configured to dampen the force applied to the adjacent surfaces of each of the blocs  52  to prevent possible breaks. It may be noted that singular blocs  52  of the heat-exchanging unit  50  may be removed from the unit independently from other blocs  52  of the same unit  50 , such as for maintenance or replacement. 
     Understandably, over time, adjacent blocs  52  may drift apart from one another and result in leaks of heat or humidity around the heat-exchanging unit  50 . The AHU  10  may further comprise a compression system  56 . The compression system  56  is configured to be accessible by a user when doors  14  of the AHU are opened. In some embodiments, the compression system  56  comprises a handle  57 . The handle  57  may be in pivoting connection with push bars  58  located on the heat-exchanging bloc  52 . A user may thus pivot the handle  57  to press the pushing bars  58  against a side of the heat-exchanging unit  50 , consequently compressing each adjacent bloc  52  against one another. 
     Now referring to  FIG.  12   , the AHU  10  may comprise filtering system  70 . The filtering system  70  is configured to filter the airflow between a conduit  16  of a fan assembly  20  and a zone. Accordingly, an airflow entering or leaving the structure  12  from the external zone may pass through the filtering system  70  and get filtered. The filtering system  70  illustrated is a centrifugal filter activated by an actuator  74  located in the center of the cylindrical shape of said filter  70 . It may be appreciated that the filtering system  70  may cover the entire area around the output or input of an associated conduit  16  so that no air flow may avoid being filtered. The filtering system  70  may further comprise a limit switch  75  configured to count the number of rotations of the system  70  for better tracking and/or control of the same. In some embodiments, the filtering system  70  may comprise a motor instead of an actuator to rotate the filter media. The motor  74  may be located at the center of the rotating filter media. 
     Back to  FIGS.  1  and  2   , the AHU  10  may further comprise a vacuum system  80 . The vacuum system  80  may comprise a vacuum device  82 , one or more pipes  84  and an outlet. The vacuum system  80  is generally configured to clean the filter system  70 . In such embodiments, an inlet pipe  85  is positioned adjacent to the filter media, thus removing debris or particles from the filter while it is rotating. The vacuum system  70  may further comprise a liquid discharge pipe system  86  in fluid communication with a liquid discharge opening of the AHU. The liquid discharge pipe system  86  is configured to remove humidity or liquids from the vacuum system  70  out of the AHU  10 . The vacuum system  80  or the drain may comprise one way flap or valve  87  to block the entry of air flows from outside the said liquid discharge pipe system  86 . Understandably, the vacuum system  80  may be in fluid communication with other systems of the AHU  10  if required and is thus not limited to fluidly communicate with the filtering system  70  and the liquid discharge opening of the AHU  10 . 
     Referring now to  FIG.  13   , an embodiment of the control system  90  of an AHU  10  is schematically illustrated. The arrows of  FIG.  13    generally represent the direction of the transfer of data between elements. The system  90  comprises sensors  92  attached to components  94  of the AHU  10 , a controller  91  adapted to receive data from the sensors  92  and from external sources  96  through a network  98 . 
     The sensors  92  is typically installed or coupled to some or all of the components  94  of the AHU  10  and are configured to collect data from operations and status of the components  94 . As an example, a carbon dioxide sensor may be installed in the supply shaft of the exterior air to determine the level of carbon dioxide entering the building. Another example may be an airflow sensor installed at the intake or inlet of the AHU  10  or within exhaust ducts. The airflow sensor determines the speed of the airflow and may possible to determine if ice or debris is blocking the airflow. The sensors  92  may be configured to communicate the data to the controller  91 . 
     The controller  91  may be embodied as any computerized device, such a controller board, a computer, or a small size computerized device. The controller  91  may be located within or outside the AHU  10 . The controller is generally configured to receive data collected from the sensors  92 , to process the received data and/or to calculate if the data is over some predetermined thresholds, to send or receive the received data or processed data from and to the network  98 , and to communicate with the components  54 . The presented order may not represent the actual sequence of operation of the controller  91  which may vary and is to be determined by the network&#39;s  98  parameters. The controller  91  is further configured to control components such as to start or stop fan assemblies  20 , to actuate pivoting of the fan assemblies  20  and to adjust the speed of one or more propellers  22 . 
     The information from external sources  96  may comprise public alerts issued by authorities or related organisms, weather information or any connection to remote systems providing data. 
     In some other embodiments, the controller  91  may further be configured to execute a program providing deep learning capabilities in order to identify the best behavior for simultaneous multi-zone optimal control. The identification of the best behavior may use historical data as a parameter. 
     Referring now to  FIG.  14   , an embodiment of a system for regulating airflow in multiple zones  100  is illustrated. The system  100  comprises a plurality of AHU  10  in communication with a first zone  102  and a second zone  104 , each forming separate areas (areas  1  to  3  in this embodiment). Understandably, an area could comprise a plurality of AHUs  10 . Each AHU comprises a control system  90  adapted to communicate with the network  98 . In an embodiment, the first zone is the interior of a building wherein the second zone is the exterior of the same. In other embodiments, the first and the second zones are interiors of either the same or different buildings. 
     The control system  90  of each AHU  10  uses sensors  9292  to collect data from the components  94  which may represent properties or parameters of the first zone  102 , the second zone  104  or the AHU  10  itself. Each controller  90  may send the collected data through the network  98  to a central controller  106 , such as, but not limited to, a server, a computer, a tablet, a smartphone or any computerized or computational device. The central controller  106  may also be in communication with each AHU  10 . 
     The central controller  106  may be configured to display or communicate data to a user about one or more zones  102 , the performance of the AHUs  10 , the quality of exterior  102  air or any other relevant information through a computerized device connected to the network  98 . 
     The central controller  106  may further be configured to receive a request from a user to change possible control parameters and to process and communicate the request or computed action to the AHUs  10 . As an example, a request to change the inside temperature of a building may be adjusted or the times of an AHU&#39;s  10  sleep timer may be changed to save energy. 
     In some embodiments, if a first AHU  10  may not connect to the central controller  106 , the first AHU  10  may establish a connection with a second reachable AHU  10  in communication with the central controller  106 . The second AHU  10  may thus act as an intermediary between the first AHU  10  and the central controller  106  until the connection between the first AHU  10  and the central controller  106  is restored. In another embodiment, the second AHU  10  may also communicate both its data and preceding AHU&#39;s  10  data to other AHUs  10  until it reaches one that can reach the central controller  106 . 
     The central controller  106  may further be configured to receive data from external providers  108  such as meteorological stations or toxic airborne agents&#39; alert providers. The central controller  106  may be further configured to control the AHUs  10  when one or more parameters is out of an acceptable range or if an alert is received from such external providers  108 . The central controller  106  may be configured to send a request to a plurality or all the AHUs  10  to reduce as much as possible the dangerous impact of external factors. As an example, the central controller  106  may be configured to create a positive pressure in a building by allowing air through a filter adapted to absorb the pollutant or dangerous substance. As an example, the central controller  106  may request all AHUs  10  to operate as inbound blowers and to request application of the filter to all air entering the building. As another example, a central controller  106  may request that the AHUs  10  be configured to block air intake from a building side facing the wind by closing the supply air operation of specific AHUs  10  once an alert of a nearby chemical fire is received. The system  100  may be particularly useful in ventilating a building comprising multiple zones, each zone comprising at least one air AHU  10  as described above. For example, the system may be adapted to be used in agricultural buildings. 
     Now referring to  FIG.  15   , an embodiment of an AHU  10  is shown in a front view. The embodied AHU  10  comprises a filtering system  70 , two fan assemblies  20 , a vacuum system  80 , a controller  40  and closed doors  14  over the cassette region. The viewed face of the AHU  10  may generally be installed towards a zone that is inside a building and may be installed flush with the supporting walls of said building. It may be understood that the shown AHU  10  may comprise any of the features described above. 
     Now referring to  FIG.  16   , an embodiment of an AHU  10  is shown in a back view. The embodied AHU  10  comprises two fan assemblies. The viewed face of the AHU  10  may generally be installed towards a zone that is outside of a building and may be installed flush with the supporting walls of said building. It may be understood that the shown AHU  10  may comprise any of the features described above. 
     Referring now to  FIGS.  17  to  19   , an embodiment of an AHU  10  is shown mounted in a wall  60 . In such embodiment, the AHU  10  is mounted in an opening  61  of a wall  60  of a building. The AHU  10  is positioned between a first zone  62  and a second zone  64 . In a typical use, the first zone  62  is inside the building and the second zone  64  is outside of the building. In the present embodiment, the AHU  10  is flush mounted to the inside wall  60 . Access may be provided for maintenance or other purposes through one or more doors  14  positioned on the outside and the inside of the unit  10 . In flush mount embodiments, the AHU  10  may protrude from the surface of the wall  60  in contact with the second zone  64 . In the shown embodiment, the protuberance of the AHU  10  in the second zone  64  allows having a first inlet/outlet on a side wall and another inlet/outlet on the back wall. Understandably, any other positions of the AHU  10  in the wall  60  are comprised in the scope of the present invention. 
     While illustrative and presently preferred embodiments of the invention have been described in detail hereinabove, it is to be understood that the inventive concepts may be otherwise variously embodied and employed and that the appended claims are intended to be construed to include such variations except insofar as limited by the prior art.