Patent Publication Number: US-2023146203-A1

Title: Vent system for protection from moisture

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims priority to each of U.S. Provisional Application No. 63/277,023, entitled “VENT SYSTEM FOR PROTECTION FROM MOISTURE” and filed on Nov. 8, 2021, and U.S. Provisional Application No. 63/306,354, entitled “VENT SYSTEM FOR PROTECTION FROM MOISTURE” and filed on Feb. 3, 2022. The entire contents of each of the above-identified applications are hereby incorporated by reference for all purposes. 
    
    
     FIELD 
     Embodiments of the subject matter disclosed herein relate to air ventilation systems operable to direct air flow between an external environment and one or more internal compartments while preventing any amount of liquid from entering the one or more internal compartments. 
     BACKGROUND 
     Persistent natural ventilation for interior spaces (e.g., of watercraft or other vehicles) may prevent biological accumulation (e.g., molds, algae, etc.) therein, as well as moisture-induced degradation. Problematically, some valves, while providing continuous air flow, may be unable to prevent at least small amounts of water from entering such interior spaces. Moreover, though purported solutions exist or have existed on the market or otherwise in the art, each of these solutions are deficient in one or more aspects. 
     For example, watertightness of certain interior spaces (such as compartments or engine rooms, sometimes referred to as “dry zones” or “dry storages”) of a facility or a vehicle (e.g., road or rail vehicle, watercraft, etc.) may be increased to control for (e.g., decrease) ambient humidity therein and/or other liquid entry. Moreover, during ventilation of such interior spaces, dryness/clearness of air entering the interior space may be increased and/or an internal temperature may be controlled to mitigate moisture accumulation. Such ventilation typically leverages one or more protruding vents, such as higher (e.g., deck level) horizontally extending windows (“hatches”), to reduce a risk of the one or more protruding vents from becoming flood points. 
     To prevent liquid entry, in certain systems, such vents may be configured to only include automated shutters. In other systems, liquid entry may be prevented by configuring the vents with manual shutters. In yet other systems, neither automatic nor manual shutters may be provided and the vents may function as typical air circulation ducts (e.g., without actively controlling air flow therethrough). In yet other systems, metal valves or valves with metal components may be implemented which may corrode or otherwise degrade in extreme environments, such as environments with relatively high salinity and/or relatively high humidity. In yet other systems, various other deficiencies may be present, such as being provided with only one conduit for entering/exiting air, having a non-smoothed external surface which may interfere with other systems (e.g., a rope or hook may inadvertently attach to the external surface), and/or having an external surface with a relatively large surface area (which may increase a chance of being compressed under force from a foot or another relatively heavy object). 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various embodiments and techniques will be described with reference to the drawings, in which: 
         FIG.  1 A  shows a simplified cross-sectional view of an air ventilation system in a first state, the first state including a manual shutter in an open position and floatable elements in a resting position, in accordance with at least one embodiment; 
         FIG.  1 B  shows a simplified cross-sectional view of the air ventilation system of  FIG.  1 A  in a second state, the second state including the manual shutter in the open position and the floatable elements blocking respective interior valve windows under the influence of water, in accordance with at least one embodiment; 
         FIG.  1 C  shows a simplified cross-sectional view of the air ventilation system of  FIG.  1 A  in a third state, the third state including the manual shutter in a closed position and the floatable elements in the resting position, in accordance with at least one embodiment; 
         FIG.  1 D  shows a simplified cross-sectional view of the air ventilation system of  FIG.  1 A  in a fourth state, the fourth state including the manual shutter in the closed position and the floatable elements blocking respective interior valve windows under the influence of water, in accordance with at least one embodiment; 
         FIG.  2 A  shows a perspective view of a frame of an air ventilation system, in accordance with at least one embodiment; 
         FIG.  2 B  shows a perspective view of a baffle of an air ventilation system, the baffle including an annular protective screen, in accordance with at least one embodiment; 
         FIG.  3    shows a cross-sectional view of an air ventilation system, in accordance with at least one embodiment; 
         FIG.  4    shows an exploded cross-sectional view of an air ventilation system, in accordance with at least one embodiment; 
         FIG.  5    shows an exploded side view of an air ventilation system, in accordance with at least one embodiment; 
         FIG.  6    shows a side view of an air ventilation system, in accordance with at least one embodiment; 
         FIG.  7    shows a top view of an air ventilation system, in accordance with at least one embodiment; 
         FIG.  8    shows an exploded perspective view of an air ventilation system, in accordance with at least one embodiment; 
         FIGS.  9 A- 9 G  show various objects and covers thereon or thereof, each including an air ventilation system operable to permit restricted fluidic communication between an external environment and at least one interior space of a respective one of the various objects and covers, in accordance with at least one embodiment; 
         FIG.  10    shows a block diagram of a method for installing an air ventilation system, in accordance with at least one embodiment; and 
         FIG.  11    shows a block diagram of a method for controlling air and liquid flows between an external environment and an interior space of an object, in accordance with at least one embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Techniques described and suggested herein include air ventilation system, including an interior duct, a frame circumscribing the interior duct, an upper cover coupled to the frame, a plurality of exterior air windows formed between the frame and the upper cover, and a valve subsystem at least partially housed within the upper cover and the frame, the valve subsystem in fluidic communication with the plurality of exterior air windows and the interior duct during at least one mode of operation of the air ventilation system, wherein the valve subsystem is configured to permit continuous air flow from the plurality of exterior air windows through to the interior duct and prevent liquid flow from reaching the interior duct during at least one mode of operation of the air ventilation system. 
     A method for controlling air and liquid flows between an external environment and an interior space of an object, in accordance with various embodiments, includes installing an air ventilation system on a surface of the object, the air ventilation system configured to permit fluidic communication between the external environment and the interior space, responsive to at least a threshold amount of liquid flowing into the air ventilation system, automatically sealing a valve subsystem of the air ventilation system such that none of the liquid reaches the interior space, and responsive to less than the threshold amount of liquid flowing into the air ventilation system, permitting air to flow into the interior space while preventing the liquid from reaching the interior space. 
     A vehicle, in accordance with various embodiments, includes a cover which is periodically exposed to precipitation, seawater, and/or freshwater, the cover including one or more apertures therethrough and enclosing an interior space, the interior space sealed from an external environment excepting for the one or more apertures, and an air ventilation system removably fastened to a first aperture of the one or more apertures, the air ventilation system sealing the first aperture such that, at the first aperture, the interior space is only able to be in fluidic communication with the external environment via the air ventilation system, wherein a valve subsystem of the air ventilation system permits persistent natural air ventilation of the interior space excepting during a first mode of operation of the air ventilation system when a liquid flow is present within the air ventilation system and a manual shutter of the valve subsystem is in an open position and during a second mode of operation of the air ventilation system when the manual shutter is in a closed position, where the first and second modes of operation do not occur contemporaneously. 
     These, as well as other aspects, advantages, and alternatives will become apparent to those of ordinary skill in the art by reading the following detailed description, with reference where appropriate to the accompanying drawings. Further, it should be understood that this summary and other descriptions and figures provided herein are intended to illustrate the invention by way of example only and, as such, that numerous variations are possible. 
     For example, the following description relates to various embodiments of an air ventilation system which permits persistent, natural (e.g., ambient) air circulation along multiple flow paths. In an example embodiment, the air ventilation system may be relatively compact, lightweight, durable, and structurally sound, with relatively smooth and high-strength external surfaces. Additionally or alternatively, the air ventilation system may be relatively easy to manufacture and assemble [e.g., via additive manufacturing or three-dimensional (3D) printing] and may be configured so as to facilitate installation in a range of vehicles (e.g., road or rail vehicles, watercraft, etc.), waterproof or water-resistant covers, etc. In one embodiment, the air ventilation system includes an air duct which is both automatically and manually restrictable/closable so as to provide at least some redundancy to prevent any amount of water from flowing therethrough. 
     In an example embodiment, the air ventilation system may maintain persistent, natural air circulation between an external environment and an interior space via floatable valves. The floatable valves may be arranged to be in a fully open position (e.g., with floatable elements of the floatable valves in a resting position) in the absence of liquid flowing into a vent circuit entrance, and in a closed position (e.g., with floatable elements blocking respective valve windows) in the presence of the liquid flowing into the vent circuit entrance from any direction so as to block a ventilation passage (e.g., from the external environment to the interior space). 
     Accordingly, one technical effect of at least one embodiment of the air ventilation system provided herein is that persistent, natural air circulation between the external environment and the interior space may be improved while automatically blocking any amount of liquid from entering into the interior space via the ventilation passage. 
     In some embodiments, the air ventilation system may be implemented for ventilation of an interior space (e.g., a compartment or an engine room) of a facility or a vehicle (e.g., road or rail vehicle, watercraft, etc.) which may benefit from persistent, natural, dry air circulation and one or more of consistent internal temperature (e.g., within a threshold temperature range), moisture content less than a threshold upper limit, or prevention of water or other liquid flow through a ventilation passage (e.g., from the external environment to the interior space). 
     In an example embodiment, a frame may be utilized, on which may be positioned all auxiliary elements for controlling/restricting air and liquid flows, such as the floatable valve including floatable elements and a baffle. For example, the floatable valve may be configured as a ball valve. In such an example, the floatable elements may be lightweight floatable balls: sensitive and responsive to the presence of a liquid flowing into a vent circuit entrance included in the frame, yet configured to rest in respective seats in the absence of the liquid to permit air masses to circulate between the external environment and the interior space. 
     In an additional or alternative embodiment, a monolithic top cover may be positioned over a plurality of protective walls surrounding an annular protective screen to protect against particulates (e.g., dust, dirt, etc.) from entering a ventilation circuit at least partially enclosed by the frame. In certain embodiments, the annular protective screen may additionally prevent small invertebrates (e.g., mosquitoes and other insects, arachnids, mollusks, etc.) from entering the interior space. 
     In certain embodiments, the top cover may include a plurality of reinforced inner side ribs and a plurality of first fastener holes, wherein the plurality of reinforced inner side ribs may extend away from the top cover in a direction of the frame. The frame may include a plurality of second fastener holes, at least some of which may be opposite and complementary to the plurality of first fastener holes such that each complementary pair of first and second fastener holes may be aligned to receive a single respective fastener. A deflector may further be included, the deflector positioned opposite to the top cover, such that the frame may be sandwiched between the deflector and the top cover. The deflector may include a plurality of third fastener holes, with at least some of the plurality of second fastener holes being opposite and complementary to the plurality of third fastener holes such that each complementary pair of second and third fastener holes may be aligned to receive a single respective fastener. In some embodiments, a cover or other surface of the facility or the vehicle may be securely and sealingly sandwiched between the frame and the deflector upon providing the complementary pairs of second and third fastener holes with respective fasteners. 
     For example, four first fastener holes may pass through and be evenly spaced about a circumference of the top cover, and four second fastener holes may pass through and be evenly spaced about a circumference of the frame, each of the four second fastener holes respectively opposite to and aligned with the four first fastener holes. Further, four third fastener holes may pass through and be evenly spaced about a circumference of the deflector, and four additional second fastener holes may pass through and be evenly spaced about the frame along a first inner circle concentric with the circumference of the frame, each of the four additional second fastener holes respectively opposite to and aligned with the four third fastener holes. By providing each complementary fastener hole pair (e.g., complementary first and second fastener holes or complementary second and third fastener holes) with a fastener, the top cover, the frame, and the deflector may be securely fastened to one another via evenly distributed fasteners. Further, by sealingly sandwiching the cover or other surface of the facility or the vehicle between the frame and the deflector, the top cover, the frame, and the deflector may be positioned to control/restrict air and liquid flows into the interior space of the facility or the vehicle enclosed by the cover or other surface (e.g., one or more valves may be positioned along a ventilation circuit within the top cover, the frame, and the deflector to control/restrict the air and liquid flows). 
     In some embodiments, to facilitate assembly of the air ventilation system, a plurality of first frame side slots may be provided around the circumference of the frame, where the plurality of first frame side slots may respectively receive the plurality of reinforced inner side ribs of the top cover. In additional or alternative embodiments, the annular protective screen may include a plurality of inner side ribs, and a plurality of second frame side slots may be provided around a second inner circle concentric with the circumference of the frame, where the plurality of second frame side slots may respectively receive the plurality of inner side ribs of the annular protective screen. 
     In an example embodiment, a manual shutter may be provided within the air ventilation system, the manual shutter actuatable between closed and fully open positions (and partially open positions therebetween) via rotation along a thread. By rotating along the thread, an applied pressure may be maintained against a gasket when the manual shutter is in the closed position to seal a main window of a duct configured in the frame and thereby prevent air from entering the interior space of the facility or the vehicle. 
     Referring now to  FIGS.  1 A- 1 D , simplified cross-sectional views respectively depicting an air ventilation system  8  (also referred to herein as a vent system  8 ) in first, second, third, and fourth states are respectively shown. Specifically, the simplified cross-sectional views are taken along a plane inclusive of a central axis  80  of the air ventilation system  8 , about which the air ventilation system  8  exhibits rotational symmetry.  FIGS.  1 A- 1 D  depict one embodiment of the air ventilation system  8  which may be assembled and configured similarly to the embodiments depicted in  FIGS.  2 A- 8    and which may operate in a substantially similar manner in practice (when the term “substantially” is used herein, it is meant that the recited characteristic, parameter, or value need not be achieved exactly, but that deviations or variations, including, for example, tolerances, measurement error, measurement accuracy limitations, and other factors known to those of skill in the art, may occur in amounts that do not preclude the effect the characteristic was intended to provide). Accordingly, excepting minor configurational differences, the description provided below with reference to  FIGS.  1 A- 1 D  may be additionally applied to the embodiments depicted in  FIGS.  2 A- 8   . In certain embodiments, additional components and/or functionalities may also be included in the embodiments depicted in  FIGS.  2 A- 8    which are not described in detail below with reference to  FIGS.  1 A- 1 D  and which may be additionally applied to the embodiments depicted in  FIGS.  1 A- 1 D . Similarly, additional components and/or functionalities which are described in detail with reference to a subset of the embodiments depicted in  FIGS.  2 A- 8    may be additionally applied to remaining embodiments depicted in  FIGS.  2 A- 8   . 
     A set of Cartesian coordinate axes  190  is shown in  FIGS.  1 A- 1 D  for contextualizing positions of the various components of the air ventilation system  8  and for comparing between the various views of  FIGS.  1 A- 1 D . Specifically, x-, y-, and z-axes are provided which are mutually perpendicular to one another, where the x- and z-axes define a plane of the cross-sectional views shown in  FIGS.  1 A- 1 D  and the y-axis is perpendicular thereto. As shown, the central axis  80  may be parallel with the z-axis. 
     Referring now to  FIG.  1 A , the air ventilation system  8  may include a frame  26 , which may be of monolithic construction. In an example embodiment, the frame  26  may be configured as a main support of the air ventilation system  8  such that other components (e.g., upper cover  10 , deflector  9 ; see below) of the air ventilation system  8  may be coupled to, or positioned relative to, the frame  26 . A cross-section of the frame  26  perpendicular to the central axis  80  may be substantially circular in shape. The frame  26  may include a barrel  49  positioned at a center of the frame  26  with respect to the central axis  80  and concentric with a circumference of the frame  26 . 
     In an example embodiment, a guide  30  may be positioned at a center of the barrel  49  with respect to the central axis  80 . The guide  30  may be held in place by a plurality of holders  31  positioned within the barrel  49 , the guide  30  including internal threading so as to receive external threading of a manual shutter  21 . The plurality of holders  31  may extend from an inner surface of the barrel  49  to an outer surface of the guide  30  opposite an inner surface of the guide  30  including the internal threading. The plurality of holders  31  may be evenly spaced with respect to rotation about the central axis  80 , e.g., in a spoked configuration. For example, three holders  31  may be evenly spaced about the central axis with angles of 120° therebetween. 
     In an example embodiment, the manual shutter  21  may include a cap  18 , the cap  18  including a gasket slot  63  about a circumference of the cap  18  and a gasket  29  clearance fit within the gasket slot  63 . The circumference of the cap  18  may be substantially equivalent to an inner circumference of the barrel  49  such that the gasket  29  may be positioned in face-sharing contact with the inner surface of the barrel  49  when the manual shutter  21  is in the closed position, thereby sealing an interior space  81  of an object  1 ,  7  (e.g., a facility or a watercraft or other vehicle) and preventing air (and moisture) from entering therein. 
     In an example embodiment, the manual shutter  21  may include a handle  20  and a knob  19  coupled to (e.g., monolithically formed with) the handle  20 , the knob  19  operable to rotate the handle  20  via application of manual torque. Specifically, to manually adjust the manual shutter  21  between the fully open position depicted in  FIG.  1 A  (see also  FIG.  1 B ) and the closed position (see  FIGS.  1 C- 1 D ), the handle  20  may be rotated via actuation of a seat (not shown at  FIG.  1 A ; see seat  75  of  FIG.  4   ) with the knob  19 . For example, the knob  19  may be rotated counterclockwise to adjust the manual shutter  21  from the fully open position to the closed position and the knob  19  may be rotated clockwise to adjust the manual shutter  21  from the closed position to the fully open position. 
     In an example embodiment, the frame  26  may include a plurality of protective baffles  32  positioned about an outer circle concentric with a circumference of the frame  26 . Specifically, the plurality of protective baffles  32  may be evenly spaced along the outer circle with respect to rotation about the central axis  80  so as to mitigate solid particulates (e.g., dirt, dust, etc.) and other waste from entering the air ventilation system  8 . 
     The air ventilation system  8  may include an upper cover  10  configured as a substantially smooth dome (optionally with a plurality of raised strips, such as reinforced top strips  38  of  FIG.  5   , e.g., to provide additional protection to the upper cover  10  when stepped on or impacted by a falling object) at least partially enclosing an upper chamber  22  between the upper cover  10  and a lid  11 . In an example embodiment, a plurality of exterior air windows  13  may be formed between the upper cover  10  and an annular ledge  56  of the frame  26 , such that the plurality of exterior air windows  13  may be positioned about the circumference of the frame  26 . Specifically, the plurality of exterior air windows  13  may be evenly spaced along the circumference of the frame  26  with respect to rotation about the central axis  80 . In embodiments including the upper cover  10  configured as the substantially smooth dome, the substantially smooth dome configured as an elliptical surface, air may be naturally convected through the plurality of exterior air windows  13  following an external air current in the external environment  82  induced by wind or motion of the object  1 ,  7 . 
     The air ventilation system  8  may include a deflector  9  positioned so as to form a lower portion of the air ventilation system  8  (e.g., extending into the interior space  81 ). Specifically, the deflector  9  may be positioned on an underside of, and at least partially within, a cover (or other surface)  2 ,  4 ,  6 ,  34  of the object  1 ,  7  on which the air ventilation system  8  may be installed, the cover  2 ,  4 ,  6 ,  34  extending substantially perpendicularly from the central axis  80 . In some embodiments wherein a thickness of the cover  2 ,  4 ,  6 ,  34  is less than a threshold thickness, the deflector  9  may be directly coupled to the frame  26 . In other embodiments wherein the thickness of the cover  2 ,  4 ,  6 ,  34  is greater than the threshold thickness, the deflector  9  may be coupled to the frame  26  via an interposed ancillary air pipe  28 . Specifically, a length of the ancillary air pipe  28  may be substantially equal to the thickness of the cover  2 ,  4 ,  6 ,  34 . 
     The air ventilation system  8  may include a valve subsystem  52  to control or restrict water and air flow into the interior space  81 . In an example embodiment, interior components within the air ventilation system  8 , e.g., positioned in a central portion of the air ventilation system  8  so as to be interposed between the cover  2 ,  4 ,  6 ,  34  and the lid  11 , may be operable to control or restrict water and air flow into the interior space  81  may be included in the valve subsystem  52 . In an additional or alternative embodiment, the valve subsystem  52  may be positioned within a central portion of the frame  26  delimited by the plurality of protective baffles  32 . 
     As shown,  FIG.  1 A  illustrates the air ventilation system  8  in the first state, including the manual shutter  21  in an open position (e.g., in a partially open position or the fully open position) and a plurality of floatable elements  15  in a resting position. Specifically, the resting position may include the plurality of floatable elements  15  at rest in a plurality of seats  16 , respectively, the plurality of seats  16  positioned opposite to a plurality of interior valve windows  27 , respectively. 
     In an example embodiment, the plurality of interior valve windows  27  may be formed in a baffle  12  positioned at a top end of the barrel  49 . In some embodiments, the baffle  12  may include an annular protective screen  14  (e.g., the annular protective screen  14  may be monolithically formed with the baffle  12 ), which may permit air to substantially freely circulate from an external environment  82  (e.g., through the plurality of exterior air windows  13  and the annular protective screen  14 ) into a valve chamber  17  at least partially surrounded by the baffle  12 . In other embodiments, the annular protective screen  14  may be a separate component from the baffle  12 . In such embodiments, the annular protective screen  14  may be directly couplable to the baffle  12  (e.g., the annular protective screen  14  may be removably secured to the baffle  12  without any intervening components therebetween). Moreover, in such embodiments, the annular protective screen  14  being separate from the baffle  12  may facilitate manufacturing of the air ventilation system  8  in that various configurations of the annular protective screen  14  may be interchangeably coupled to the baffle  12 . 
     When the air ventilation system  8  is in the first state (e.g., the plurality of floatable elements  15  is in the resting position), the air within the valve chamber  17  may further flow through the plurality of interior valve windows  27  and into an underlid (or lower) chamber  23 . The underlid chamber  23  may be fluidly coupled to an interior duct  25  passing through the cover  2 ,  4 ,  6 ,  34  (e.g., at least partially surrounded by the deflector  9  and/or the ancillary air pipe  28 ) via a main window  53  circumscribed by a top annular ring  60 , thereby permitting the air to pass from the underlid chamber  23  through the interior duct  25  and into the interior space  81 . As shown, the lid  11  and the baffle  12  may partition the underlid chamber  23  from the upper chamber  22 . 
     Referring now to  FIG.  1 B , the air ventilation system  8  is illustrated in the second state, including the manual shutter  21  in the open position (e.g., the partially open position or the fully open position) and the plurality of floatable elements  15  respectively blocking the plurality of interior valve windows  27  under the influence of water (e.g., each of the plurality of floatable elements  15  may have a density less than a density of water). Specifically, the water may induce the plurality of floatable elements  15  to float upwards from the plurality of seats  16  to the plurality interior valve windows  27 . When the plurality of floatable elements  15  respectively block the plurality of interior valve windows  27 , water and air may be prevented from circulating between the external environment  82  and the interior space  81  (even though the manual shutter  21  is in the open position in the second state). 
     Referring now to  FIG.  1 C , the air ventilation system  8  is illustrated in the third state, including the manual shutter  21  in the closed position and the plurality of floatable elements  15  in the resting position. When the manual shutter  21  is in the closed position, water and air may be prevented from circulating between the external environment  82  and the interior space  81 . 
     Referring now to  FIG.  1 D , the air ventilation system  8  is illustrated in the fourth state, including the manual shutter  21  in the closed position and the plurality of floatable elements  15  respectively blocking the plurality of interior valve windows  27  under the influence of the water. When the manual shutter  21  is in the closed position and the plurality of floatable elements  15  respectively block the plurality of interior valve windows  27 , water and air may be prevented from circulating between the external environment  82  and the interior space  81 . 
     Referring now to  FIGS.  2 A- 8   , various views of the air ventilation system  8  and individual components thereof are depicted. Perspective views depicting the frame  26  and the baffle  12  of the air ventilation system  8  are shown in  FIGS.  2 A and  2 B , respectively. Assembled and exploded cross-sectional views depicting the air ventilation system  8  are shown in  FIGS.  3  and  4   , respectively. Specifically, the cross-sectional views of  FIGS.  3  and  4    are taken along a plane A (see  FIGS.  5  and  6   ) inclusive of the central axis  80 . Exploded and assembled side views depicting the air ventilation system  8  are shown in  FIGS.  5  and  6   , respectively. A top view depicting the air ventilation system  8  is shown in  FIG.  7   , at least illustrating features of the upper cover  10 . An exploded perspective view depicting the air ventilation system  8  is shown in  FIG.  8   . Hereinbelow, description of  FIGS.  2 A- 8    is concatenated and each of  FIGS.  2 A- 8    may be referred to interchangeably where relevant. For example, reference may be made to one or more specific figures when one or more of  FIGS.  2 A- 8    illustrate a given component or aspect of the air ventilation system  8  with at least some particularity. 
     A set of Cartesian coordinate axes  290  is shown in  FIGS.  2 A- 8    for contextualizing positions of the various components of the air ventilation system  8  and for comparing between the various views of  FIGS.  2 A- 8   . Specifically, x-, y-, and z-axes are provided which are mutually perpendicular to one another. In  FIGS.  3  and  4   , the x- and z-axes define the plane A and the y-axis is perpendicular thereto. In  FIGS.  5 - 7   , the y- and z-axes define the plane A and the x-axis is perpendicular thereto. As shown, the central axis  80  may be parallel with the z-axis. 
     In an example embodiment, and as shown in  FIG.  2 A , the frame  26  may be configured with an inner round plate  44  circumscribing the barrel  49  in a plane perpendicular with the central axis  80 . The inner round plate  44  may include an outer annular shelf or terrace  47  on which a plurality of half-round slots  54  set in the inner round plate  44  may be superimposed. The plurality of half-round slots  54  may be clearance fit to a plurality of inner half-round ribs  46  included in the annular protective screen  14  (see  FIG.  2 B ). 
     In an example embodiment, the frame  26  may include a plurality of upper barrel ribs  50  extending from the inner round plate  44  and directly coupled to an inner wall  24  of the valve chamber  17 . Specifically, the plurality of upper barrel ribs  50  may be evenly spaced around a circumference of the barrel  49  with respect to rotation about the central axis  80 . Each adjacent pair of the plurality of floatable elements  15  may be interposed by one of the plurality of upper barrel ribs  50  so as to maintain each of the plurality of floatable elements  15  separate from one another (e.g., such that a space may be provided between each adjacent pair of the plurality of floatable elements  15 ). 
     In an example embodiment, the frame  26  may include a plurality of outer stakes  48  and a plurality of inner stakes  64 , each of the plurality of outer stakes  48  and the plurality of inner stakes  64  extending from the inner round plate  44 . Specifically, the plurality of outer stakes  48  may be evenly spaced around a first circle circumscribing and concentric with the circumference of the barrel  49  with respect to rotation about the central axis  80 , and the plurality of inner stakes  64  may be evenly spaced around a second circle circumscribing and concentric with the circumference of the barrel  49  with respect to rotation about the central axis  80 . In some embodiments, and as shown in  FIG.  2 A , each of the plurality of outer stakes  48  and each of the plurality of inner stakes  64  may be circular in shape. 
     In an example embodiment, when the plurality of floatable elements  15  is in the resting position, each of the plurality of floatable elements  15  may rest on a respective one of the plurality of seats  16  formed as two adjacent outer stakes  48  and an inner stake  64  positioned between the two adjacent outer stakes  48  with respect to rotation about the central axis  80 . Accordingly, each of the plurality of seats  16  may be formed as three stakes  48 ,  64  which may prevent a respective one of the plurality of floatable elements  15  from moving away from a corresponding one of the plurality of interior valve windows  27 . 
     In an example embodiment, a gasket  67  may be positioned at least partially within a gasket slot  62  of the frame  26 . The gasket  67  may be sandwiched between the baffle  12  and the frame  26  so as to provide a seal therebetween, e.g., to prevent water from entering the interior duct  25  from the valve chamber  17  (see  FIGS.  3  and  4   ). 
     In an example embodiment, a gasket  66  may be positioned at least partially within a gasket slot  61  of the baffle  12 . The gasket  66  may be sandwiched between the lid  11  and the baffle  12  so as to provide a seal therebetween, e.g., to prevent water from entering the underlid chamber  23  from the upper chamber  22  (see  FIGS.  3  and  4   ). 
     In an example embodiment, one or more of the gaskets  29 ,  66 , and  67  may be welded into one or more of the gasket slots  63 ,  61 , and  62 , respectively. In such an embodiment, the one or more of the gaskets  29 ,  66 , and  67  may be prevented from freely rotating or otherwise shifting within the one or more of the gasket slots  63 ,  61 , and  62  (e.g., thereby facilitating manufacturing of the air ventilation system  8 ). 
     In an example embodiment, the lid  11  may include an inner annular slot  58  to prevent movement of the lid  11  perpendicular to the central axis  80 . Specifically, the inner annular slot  58  may receive a top annular outer ring  57  of the baffle  12 , the top annular outer ring  57  sized so as to be clearance fit within the inner annular slot  58 . 
     In an example embodiment, each of the upper cover  10 , the lid  11 , and the deflector  9  may include a plurality of fastening grooves  69 . Specifically, the plurality of fastening grooves  69  of the upper cover  10  may be respectively aligned with a plurality of inner fastening stubs  70  of the upper cover  10  evenly spaced about a circumference of the upper cover  10  with respect to rotation about the central axis  80 , the plurality of fastening grooves  69  of the lid  11  may be respectively aligned with a plurality of inner fastening stubs  71  of the lid  11  evenly spaced about a circumference of the lid  11  with respect to rotation about the central axis  80 , and the plurality of fastening grooves  69  of the deflector  9  may be respectively aligned with a plurality of inner fastening stubs  72  of the deflector  9  evenly spaced about a circumference of the deflector  9  with respect to rotation about the central axis  80 . 
     In an example embodiment, the frame  26  may include a plurality of side fastening stubs  42  respectively aligned with the plurality of inner fastening stubs  70 . Accordingly, the plurality of side fastening stubs  42  may be evenly spaced about, or substantially about, the circumference of the frame  26  with respect to rotation about the central axis  80 . Each of the plurality of side fastening stubs  42  and each of the plurality of inner fastening stubs  70  may include one of a plurality of fastener holes  33  such that each aligned side fastening stub  42  and inner fastening stub  70  may receive a single fastener  83  (see, e.g.,  FIG.  3    for aligned fastening stubs  42 ,  70 ;  FIG.  8    for fasteners  83 ) to removably fasten the upper cover  10  to the frame  26 . 
     In an example embodiment, the baffle  12  may include a plurality of top fastening stubs  73  respectively aligned with the plurality of inner fastening stubs  71 . Accordingly, the plurality of top fastening stubs  73  may be evenly spaced about, or substantially about, a circumference of the baffle  12  with respect to rotation about the central axis  80 . Each of the plurality of top fastening stubs  73  and each of the plurality of inner fastening stubs  71  may include one of the plurality of fastener holes  33  such that each aligned top fastening stub  73  and inner fastening stub  71  may receive a single fastener  83  (see, e.g.,  FIG.  3    for aligned fastening stubs  71 ,  73 ;  FIG.  8    for fasteners  83 ) to removably fasten the baffle  12  to the lid  11 . 
     In an example embodiment, the frame  26  may include a plurality of inner fastening stubs  43  respectively aligned with the plurality of inner fastening stubs  72 . Accordingly, the plurality of inner fastening stubs  43  may be evenly spaced about, or substantially about, the circumference of the frame  26  with respect to rotation about the central axis  80 . Each of the plurality of inner fastening stubs  43  and each of the plurality of inner fastening stubs  72  may include one of the plurality of fastener holes  33  such that each aligned inner fastening stub  43  and inner fastening stub  72  may receive a single fastener  83  (see, e.g.,  FIG.  3    for aligned fastening stubs  43 ,  72 ;  FIG.  8    for fasteners  83 ) to removably fasten the frame  26  to the deflector  9 . The plurality of inner fastening stubs  43  may be positioned closer to the central axis  80  than the plurality of side fastening stubs  42 . Orthographic projections of one of the plurality of inner fastening stubs  43  and one of the side fastening stubs  42  may be at least partially obscured by an orthographic projection of one of the reinforced top strips  38  onto the plane perpendicular with the central axis  80 . 
     In an example embodiment, the plurality of floatable elements  15  may be positioned within the valve chamber  17  (e.g., adjacent to the inner wall  24 ) and at least partially enclosed by the baffle  12 . In certain embodiments, the plurality of floatable elements  15  may not be affixed, adhered, or otherwise physically coupled to one another or any other component of the air ventilation system  8  so as to freely move between the plurality of seats  16  and the plurality of interior valve windows  27  (however, and as described in detail above, movement of each given floatable element  15  may be restricted so that the given floatable element  15  may only rest on a corresponding one of the plurality of seats  16  in the resting position and may only block a corresponding one of the interior valve windows  27  under the influence of water). 
     In an example embodiment, the plurality of floatable elements  15  may be configured as a plurality of lightweight floatable balls  15  and each of the plurality of interior valve windows  27  may be circular in shape, with a diameter of each of the plurality of interior valve windows  27  being less than a diameter of each of the plurality of lightweight floatable balls  15 . Accordingly, the plurality of lightweight floatable balls  15  may respectively seal the plurality of (circular) interior valve windows  27  under the influence of water. 
     In an example embodiment, at least some of the plurality of upper barrel ribs  50  may include respective fastener holes  33 . The at least some of the plurality of upper barrel ribs  50  including the fastener holes  33  may be respectively aligned with fastener holes  33  disposed in the baffle  12 , such that each aligned upper barrel rib  50  and fastener hole  33  in the baffle  12  may receive a single fastener  83  (see, e.g.,  FIG.  3    for aligned rib  50  and hole  33 ;  FIG.  8    for fasteners  83 ) to removably fasten the frame  26  to the baffle  12 . 
     In an example embodiment, the valve subsystem  52  may include the manual shutter  21 , the plurality of floatable elements  15 , the baffle  12 , and the lid  11 . The upper cover  10  may be provided to protect the valve subsystem  52  and may take on various configurations. Accordingly, in some embodiments, various configurations of the upper cover  10  may be interchangeably coupled to the valve subsystem  52  based on a particular use case, the object  1 ,  7  (e.g., whether the object  1 ,  7  is a particular type of facility or vehicle), etc. In certain embodiments, the upper cover  10  may function as a separate guarding system (such as a dorade box and the like) to prevent liquid entry from the external environment  82  into the air ventilation system  8  (and thereby prevent liquid entry into the interior space  81 ). In additional or alternative embodiments, the upper cover  10  may be selected to minimize a profile thereof, e.g., extending from the cover  2 ,  4 ,  6 ,  34 . 
     In an example embodiment, each of the frame  26  and the deflector  9  may be couplable to the ancillary air pipe  28 . Specifically, the frame  26  may include an inner annular ancillary air pipe lip  36  extending into a bottom face of the frame  26  (e.g., opposite to the deflector  9 ) and the deflector  9  may include an inner annular ancillary air pipe lip  35  extending into a top face of the deflector  9  (e.g., opposite to the frame  26 ). Each of the inner annular ancillary air pipe lips  35  and  36  may be sized so as to be clearance fit to the ancillary air pipe  28 . Accordingly, an inner diameter of each of the inner annular ancillary air pipe lips  35  and  36  may be substantially equal to an outer diameter of the ancillary air pipe  28 . In embodiments wherein the ancillary air pipe  28  is present, a length of the ancillary air pipe  28  may be substantially equal to the thickness of the cover  2 ,  4 ,  6 ,  34 . 
     In an example embodiment, the manual shutter  21  may be inserted into an orifice  37  (see  FIG.  3   ) extending through the deflector  9  along the central axis  80 . Specifically, components of the manual shutter  21 , such as the cap  18 , the knob  19 , and the handle  20 , may intersect with, and be rotationally symmetric with respect to, the central axis  80 . Additionally, orthographic projections of such components of the manual shutter  21  may at least partially overlap with an orthographic projection of the orifice  37  in the plane perpendicular to the central axis  80 . 
     In an example embodiment, the air ventilation system  8  may extend along the central axis  80  from an uppermost extent (e.g., above the cover  2 ,  4 ,  6 ,  34  when the air ventilation system  8  is installed on the object  1 ,  7 ) at a top surface of the upper cover  10  to a lowermost extent (e.g., below the cover  2 ,  4 ,  6 ,  34  when the air ventilation system  8  is installed on the object  1 ,  7 ) at a bottom surface of the knob  19 . Accordingly, when the air ventilation system  8  is installed on the object  1 ,  7 , at least a portion of the air ventilation system  8 , such as at least a portion of the manual shutter  21  (e.g., the knob  19  and at least a portion of the handle  20 ) and at least a portion of the deflector  9 , may enter the interior space  81 , while a remaining portion of the air ventilation system  8 , excepting component(s) of the air ventilation system  8  extending through the cover  2 ,  4 ,  6 ,  34 , may extend into the external environment  82 . 
     In an example embodiment, the frame  26  may include an annular bottom slot  51 . The annular bottom slot  51  may permit additional sealing as desired. For example, an adhesive sealant (e.g., selected to maintain sealing upon exposure to salt water) may be supplied within and throughout the annular bottom slot  51 , and the air ventilation system  8  may be installed on the cover  2 ,  4 ,  6 ,  34  such that a bottom surface of the frame  26  is in face-sharing contact with a top surface of the cover  2 ,  4 ,  6 ,  34 , the adhesive sealant thereby being placed in direct contact with the top surface of the cover  2 ,  4 ,  6 ,  34 . In alternative embodiments wherein the cover  2 ,  4 ,  6 ,  34  is a clean and flat surface or a substantially clean and substantially flat surface, a gasket (not shown at  FIGS.  2 A- 8   ) may be welded into the annular bottom slot  51  and no adhesive sealant may be supplied within the annular bottom slot  51 ; such configurations may facilitate manufacturing of the air ventilation system  8 , e.g., by reducing costs and complexity. As an example, the gasket may be formed from a silicone or a silicone composite material, e.g., the same material from which the gaskets  29 ,  66 , and  67  are formed. 
     In an example embodiment, the annular bottom slot  51  may be formed by installing the valve subsystem  52  on the frame  26 . In such embodiments, the valve subsystem  52  may be removed from the air ventilation system  8 , e.g., along the annular bottom slot  51 , and installed in another ventilation or guarding system (e.g., in a dorade box with a cowl). 
     In an example embodiment, the upper cover  10  may include a plurality of reinforced top strips  38  respectively aligned with a plurality of skirts  65  extending to the frame  26  parallel to the central axis  80 , where adjacent pairs of the plurality of exterior air windows  13  may be respectively interposed by the plurality of skirts  65 . Accordingly, the plurality of skirts  65  may be evenly spaced about, or substantially about, the circumference of the upper cover  10  with respect to rotation about the central axis  80 . 
     In an example embodiment, the upper cover  10  may include a plurality of inner side ribs  39  (see  FIG.  4   ). Specifically, the plurality of inner side ribs  39  may be evenly spaced about, or substantially about, the circumference of the upper cover  10  with respect to rotation about the central axis  80 . As an example, each of the plurality of inner side ribs  39  may be semicircular in shape. 
     In an example embodiment, the frame  26  may include an annular outer shelf or terrace  59 . A plurality of half-round slots  45  may be set in the annular outer shelf or terrace  59  so as to be superimposed on the annular ledge  56 , the plurality of half-round slots  45  respectively aligned with the plurality of inner side ribs  39 . Accordingly, the plurality of half-round slots  45  may be evenly spaced about, or substantially about, the circumference of the frame  26  with respect to rotation about the central axis  80 . The plurality of half-round slots  45  may be sized so as to receive the plurality of inner side ribs  39 , respectively (e.g., the plurality of inner side ribs  39  may be respectively clearance fit to the plurality of half-round slots  45 ). 
     In an example embodiment, each component of the air ventilation system  8  (e.g., all components or all components not formed from a metal, such as the fasteners  83 ) may be formed from a synthetic or semi-synthetic plastic and/or a synthetic or semi-synthetic plastic composite. Specifically, the plastic and/or the plastic composite may be selected to withstand prolonged exposure (e.g., over a lifetime use of the air ventilation system  8 ) to aggressive, corrosive, or otherwise extreme conditions, such as natural salt water, extreme ambient temperatures (e.g., between −50° C. and 50° C.), relatively high ambient humidity (e.g., greater than 70% relative humidity), relatively high wind speeds (e.g., greater than 40 mph), and storm conditions. Accordingly, in some embodiments, no electrical components (e.g., reliant upon metal components) may be included in the air ventilation system  8 . In additional or alternative embodiments, more complex subassemblies (e.g., utilizing a greater amount of time and skill to manufacture than the valve subsystem  52 ) may not be included in the air ventilation system  8 . As such, the air ventilation system  8  may be assembled from relatively simple plastic materials selected to operate with less resistance and/or greater reliability. In other embodiments, one or more electrical (e.g., solar-powered) ventilators (not shown at  FIGS.  2 A- 8   ) may be included in the air ventilation system  8  to promote further air circulation. 
     In an example embodiment, each of the gaskets  29 ,  66 , and  67  may be formed from a silicone or a silicone composite. In an alternative embodiment, at least some components of the air ventilation system  8 , such as the baffle  12  and the cap  18 , may be at least partially formed from a silicone or a silicone composite. In such an alternative embodiment, one or more of the gaskets  29 ,  66 , and  67  may not be included in the air ventilation system  8 , as at least some sealing functionality may be provided by other silicone/silicone composite-based components of the air ventilation system  8 . 
     Referring now to  FIG.  10   , a block diagram of a method  1000  for installing an air ventilation system, such as the air ventilation system  8  described in detail above with reference to  FIGS.  1 A- 8   , is shown. As such, components described hereinbelow with reference to the method  1000  are numbered in accordance with the embodiments of  FIGS.  1 A- 8   . Embodiments of methods for installing air ventilation systems are not limited to the below description of the method  1000 . For instance, in certain embodiments, individual steps discussed with reference to the method  1000  may be added, removed, substituted, modified, or interchanged. 
     At block  1002 , the method  1000  of installing the air ventilation system  8 , e.g., in the cover  2 ,  4 ,  6 ,  34 , may include cutting or otherwise forming an aperture, e.g., a circular aperture, in the cover  2 ,  4 ,  6 ,  34 . Specifically, a diameter of the circular aperture may be substantially equal or slightly greater than an inner diameter of the deflector  9  or the outer diameter of the ancillary air pipe  28  such that the deflector  9  or the ancillary air pipe  28  may be clearance fit to the circular aperture. When included, the ancillary air pipe  28  may be cut to a length substantially equal to the thickness of the cover  2 ,  4 ,  6 ,  34 . 
     At block  1004 , the method  1000  may further include assembling the valve subsystem  52  by positioning on the frame  26 , in sequence, the plurality of floatable elements  15 , the gasket  67 , the annular protective screen  14 , the baffle  12 , the gasket  29 , the manual shutter  21 , the gasket  66 , and the lid  11 . 
     At block  1006 , the method  1000  may further include applying an adhesive sealant along and throughout the annular bottom slot  51 , and positioning the frame  26  on the cover  2 ,  4 ,  6 ,  34 . 
     At block  1008 , the method  1000  may further include inserting the deflector  9  or the ancillary air pipe  28  through the circular aperture, and removably fastening the deflector  9  in position. When the ancillary air pipe  28  is included, for example, the cover  2 ,  4 ,  6 ,  34  may extend between the inner annular ancillary air pipe lips  35  and  36 . In such examples, the ancillary air pipe  28  may be secured in position by removably fastening the frame  26  to the deflector  9  (e.g., via fasteners  83 , with each fastener  83  received by a respective aligned pair of inner fastening stubs  43  and  72 ). In examples where the thickness of the cover  2 ,  4 ,  6 ,  34  precludes direct fastening of the frame  26  to the deflector  9  (e.g., the cover  2 ,  4 ,  6 ,  34  may be a wood deck), fasteners  83  provided to inner fastening stubs  43  and  72  may removably fasten the frame  26  and the deflector  9 , respectively, to the cover  2 ,  4 ,  6 ,  34  itself. Alternatively, if the ancillary air pipe  28  is not included (e.g., when the cover  2 ,  4 ,  6 ,  34  is sufficiently thin and/or soft to removably fasten the deflector  9  to the frame  26  without substantial leakage), portions of the deflector  9  and the frame  26  in direct contact with the circular aperture (e.g., at the inner annular ancillary air pipe lips  35  and  36 ) may be reinforced with greater (e.g., double) thickness. As such, greater sealing may be provided at the air ventilation system, which may extend a lifetime use of the cover  2 ,  4 ,  6 ,  34  (e.g., by preventing moisture from directly entering the circular aperture from the external environment  82 ). Whether or not the ancillary air pipe  28  is included, in certain examples, fasteners  83  provided to aligned pairs of inner fastening stubs  43  and  72  may be inserted so as to enter through either the frame  26  or the deflector  9 , or through both (e.g., half of the fasteners  83  may be inserted so as to enter through the frame  26  and a remaining half of the fasteners  83  may be inserted so as to enter through the deflector  9 ). 
     At block  1010 , the method  1000  may further include positioning the upper cover  10  above the frame  26  and the valve subsystem  52  (e.g., opposite to the deflector  9 ), and removably fastening the upper cover  10  as positioned. Specifically, the upper cover  10  may be positioned in direct contact with the frame  26  (e.g., such that the plurality of skirts  65  are in direct contact with the annular outer shelf or terrace  59  and the plurality of inner side ribs  39  are respectively clearance fit to the plurality of half-round slots  45 ) and removably fastened to the frame  26  (e.g., via fasteners  83 , with each fastener  83  received by a respective aligned pair of side fastening stub  42  and inner fastening stub  70 ). 
     When the air ventilation system  8  is fully installed, such as via the process described hereinabove, liquid (e.g., from periodic exposure to seawater and/or freshwater and/or precipitation such as rain, sleet, and/or snow, where periodic exposure may occur at least once per year on average or more frequently depending on weather and/or a current location of the cover  2 ,  4 ,  6 ,  34 ) may be prevented or substantially prevented from passing into the cover  2 ,  4 ,  6 ,  34  via the circular aperture while still allowing air circulation therethrough. 
     Referring now to  FIG.  11   , a block diagram of a method  1100  for controlling air and liquid flows between an external environment and an interior space of an object, e.g., via an air ventilation system such as the air ventilation system  8  described in detail above with reference to  FIGS.  1 A- 8   , is shown. As such, components described hereinbelow with reference to the method  1100  are numbered in accordance with the embodiments of  FIGS.  1 A- 8   . Embodiments of methods for controlling air and liquid flows between external environments and interior spaces of objects are not limited to the below description of the method  1100 . For instance, in certain embodiments, individual steps discussed with reference to the method  1100  may be added, removed, substituted, modified, or interchanged. 
     At block  1102 , the method  1100  may include installing the air ventilation system  8  in the cover (or other surface)  2 ,  4 ,  6 ,  34  of the object  1 ,  7  (e.g., a facility or a watercraft or other vehicle). An exemplary method of installing the air ventilation system  8  is described in detail above with reference to  FIG.  10   . As described herein, the air ventilation system  8  may be configured to permit fluidic communication between the external environment  82  and the interior space  81  of the object  1 ,  7 . 
     At block  1104 , the method  1100  may include determining if a liquid flowing into the air ventilation system  8  is less than a threshold amount. In an example embodiment, the threshold amount may be a sufficient amount of liquid to spill up and into the underlid chamber  23  via the plurality of interior valve windows  27 , e.g., were the plurality of floatable elements  15  not present. 
     If the liquid flowing into the air ventilation system  8  is greater than or equal to the threshold amount, the method  1100  may proceed to block  1106 , where the method  1100  may include automatically sealing the valve subsystem  52  such that none of the liquid may reach the interior space  81 . For example, the valve subsystem  52  may include at least two chambers (e.g., the chambers  17 ,  23 ), wherein one of the at least two chambers (e.g., the valve chamber  17 ) may be in fluidic communication with the external environment  82 , and wherein one of the at least two chambers (e.g., the underlid chamber  23 ) may be in fluidic communication with the interior space  81 . As such, automatically sealing the valve subsystem  52  may include severing fluidic communication between the one of the at least two chambers in fluidic communication with the external environment  82  and the one of the at least two chambers in fluidic communication with the interior space  81 . 
     If the liquid flowing into the air ventilation system  8  is less than the threshold amount, the method  1100  may proceed to block  1108 , where the method  1100  may include permitting the air to flow into the interior space  81  while preventing the liquid from reaching the interior space  81 . For example, when less than the threshold amount of the liquid is present, a level of the liquid may not be high enough to overcome the inner wall  24  and enter into the interior duct  25  and thereby the interior space  81  (e.g., even without the plurality of floatable elements  15  automatically sealing the plurality of interior valve windows  27 ). 
     At block  1110 , the method  1100  may include determining whether the manual shutter  21  is in the open position or the closed position. If the manual shutter is in the open position, the method  1100  may return to block  1108  to continue permitting the air to flow into the interior space  81  while preventing the liquid from reaching the interior space  81 . If the manual shutter is in the closed position, the method  1100  may proceed to block  1112 , where the method  1100  may include sealing the valve subsystem  52  (e.g., by closing the manual shutter  21 ) such that neither the liquid nor the air reaches the interior space  81 . 
     Referring now to  FIGS.  9 A- 9 G , various objects  1 ,  7  [e.g., watercraft or other floating facility, such as a boat, a kayak, or a yacht; a road vehicle, such as a recreational vehicle (RV) or passenger car; a dry storage box; etc.] and covers  2 ,  4 ,  6 ,  34  (e.g., a deck, a deck head, a hatch, a storage cover, etc.) thereon or thereof are depicted, each including the air ventilation system  8 . Specifically, and as described in detail above with reference to  FIGS.  1 A- 8   , the air ventilation system  8  may be operable to permit restricted fluidic communication between the external environment  82  and at least one interior space (e.g., the interior space  81 ; not shown at  FIGS.  9 A- 9 G ) of a respective one of the various objects  1 ,  7  and covers  2 ,  4 ,  6 ,  34 . For example, the air ventilation system  8  may include at least two chambers (e.g., the chambers  17 ,  23 ; not shown at  FIGS.  9 A- 9 G ), wherein one of the at least two chambers (e.g., the valve chamber  17 ) may be in continuous (e.g., uninterrupted) fluidic communication with the external environment  82 , and wherein one of the at least two chambers (e.g., the underlid chamber  23 ) may be in fluidic communication with the at least one interior space. However, during certain modes of operation of the air ventilation system  8 , fluidic communication between the at least two chambers, and thereby between the external environment  82  and the at least one interior space, and/or between the at least two chambers and the at least one interior space may be restricted or altogether prevented. 
     As an example, and as shown at  FIGS.  9 A and  9 C , the object  1  may be a boat  1 , such as a motorboat  1  (see  FIG.  9 A ) or a sailing or motorized yacht  1  (see  FIG.  9 C ), including a deck  2 , the deck  2  including one or more hatches  6 , one or more dry storage boxes  7 , and a saloon compartment  3  with a deck head  4  provided with one or more windows  5 . In the depicted embodiment, one or more air ventilation systems  8  may be positioned at each of the deck  2 , the one or more dry storage boxes  7 , the one or more hatches  6 , a forward end of the deck head  4 , and above other interior compartments (e.g., where sufficient natural ventilation may not persist). 
     As another example, and as shown at  FIG.  9 B , the object  1  may be a small watercraft  1 , such as a kayak  1 , including the deck  2  provided with the one or more dry storage boxes  7 . In the depicted embodiment, one or more air ventilation systems  8  may be positioned at each of the one or more dry storage boxes  7 . 
     As another example, and as shown at  FIG.  9 D , the object  1  may be a road vehicle  1 , such as an RV  1 , including the deck  2  (also referred to as a “roof” or “top,” at least in the context of the RV  1 ). In the depicted embodiment, one or more air ventilation systems  8  may be positioned at the deck  2 , e.g., above restroom, shower, and/or bath compartments, and/or other rooms. The one or more air ventilation systems  8  may support persistent natural air circulation/ventilation and a drier ambient climate inside of the RV  1  irrespective of weather conditions (e.g., when the RV  1  is not in use for a relatively lengthy duration). 
     As another example, and as variously shown at  FIGS.  9 E- 9 G , the object  1  [e.g., the motorboat  1  (see  FIG.  9 E ), a passenger car  1  (see  FIG.  9 F ), the RV  1  (see  FIG.  9 G ), etc.] may be covered by the cover  34 , such as a storage cover  34  (e.g., for seasonal storage). In the depicted embodiments, one or more air ventilation systems  8  may be positioned at the storage cover  34 . 
     In one embodiment, a vent system adapted for persistent air circulation between a delimited interior space of a facility or vehicle and an external environment, the vent system including: a frame; an upper cover; a plurality of exterior air windows formed between the frame and the upper cover; a valve subsystem positioned between the frame and the upper cover, the valve subsystem including: a baffle including a plurality of interior valve windows, the baffle partitioning the vent system into at least two chambers, the at least two chambers including an underlid chamber and a valve chamber; and a plurality of floatable elements positioned within the valve chamber, the plurality of floatable elements freely resting on a plurality of seats, respectively, when no liquid is present within the vent system; and a ventilation circuit configured to protect the delimited interior space from moisture accumulation via reversible opening and closing of the ventilation circuit to control liquid penetration from one or more of precipitation including rain, sleet, and/or snow, seawater and waves therefrom, or freshwater and waves therefrom, the ventilation circuit passing through the plurality of exterior air windows and the valve subsystem, wherein each of the plurality of floatable elements is actuated by liquid flow entering the vent system via the plurality of exterior air windows so as to automatically close and seal the plurality of interior valve windows and thereby prevent the liquid flow from entering the delimited interior space. In one example of the vent system, the vent system further includes wherein the ventilation circuit extends continuously from the external environment, through the plurality of exterior air windows, through the plurality of interior valve windows of the valve subsystem, and to the delimited interior space to permit air circulation between the external environment and the delimited interior space while controlling liquid penetration. In one example of the vent system, optionally including the preceding example of the vent system, the vent system further includes wherein the ventilation circuit prevents liquid penetration via actuation of the valve subsystem. In one example of the vent system, optionally including one or more of the preceding examples of the vent system, the vent system further includes wherein the valve subsystem automatically closes and seals the ventilation circuit. In one example of the vent system, optionally including one or more of the preceding examples of the vent system, the vent system further includes wherein the valve subsystem automatically closes and seals the ventilation circuit via actuation of the plurality of floatable elements. In one example of the vent system, optionally including one or more of the preceding examples of the vent system, the vent system further includes wherein the underlid chamber is in fluidic communication with the delimited interior space, and wherein the valve chamber is in fluidic communication with the external environment. In one example of the vent system, optionally including one or more of the preceding examples of the vent system, the vent system further includes wherein the baffle further includes an annular protective screen. In one example of the vent system, optionally including one or more of the preceding examples of the vent system, the vent system further includes wherein the upper cover includes a domed upper surface, and wherein the plurality of exterior air windows is positioned opposite to and underneath the domed upper surface. In one example of the vent system, optionally including one or more of the preceding examples of the vent system, the vent system further includes a plurality of protective baffles positioned at or adjacent to a portion of the ventilation circuit intaking air from the external environment. In one example of the vent system, optionally including one or more of the preceding examples of the vent system, the vent system further includes wherein the valve subsystem further includes a shutter manually operable to control air flow from the external environment. In one example of the vent system, optionally including one or more of the preceding examples of the vent system, the vent system further includes wherein the shutter includes external threading. In one example of the vent system, optionally including one or more of the preceding examples of the vent system, the vent system further includes a guide, wherein internal threading of the guide receives the external threading of the shutter. In one example of the vent system, optionally including one or more of the preceding examples of the vent system, the vent system further includes wherein the shutter includes a knob. In one example of the vent system, optionally including one or more of the preceding examples of the vent system, the vent system further includes wherein the shutter further includes a handle, the handle coupled to the knob via a seat of the knob. In one example of the vent system, optionally including one or more of the preceding examples of the vent system, the vent system further includes wherein the liquid flow is prevented from entering the delimited interior space when the shutter is in an open position. In one example of the vent system, optionally including one or more of the preceding examples of the vent system, the vent system further includes wherein the shutter is moved from an open position to a closed position via manual rotation of the knob, optionally responsive to air in the external environment being less than a threshold air temperature. In one example of the vent system, optionally including one or more of the preceding examples of the vent system, the vent system further includes wherein the valve subsystem is couplable to multiple configurations of the upper cover. In one example of the vent system, optionally including one or more of the preceding examples of the vent system, the vent system further includes wherein no metal or electrical components are included. In one example of the vent system, optionally including one or more of the preceding examples of the vent system, the vent system further includes a deflector, each of the deflector and the frame including an inner annular ancillary air pipe lip to fit an ancillary air pipe having a length equal to a thickness of a cover of the facility or vehicle on which the vent system is installed, the inner annular ancillary air pipe lips having an equal diameter to one another. In one example of the vent system, optionally including one or more of the preceding examples of the vent system, the vent system further includes wherein the plurality of floatable elements has a density less than a density of water so as to float upon water and automatically close the plurality of interior valve windows upon entry of the water into the valve chamber via the ventilation circuit. In one example of the vent system, optionally including one or more of the preceding examples of the vent system, the vent system further includes an annular protective screen, wherein the annular protective screen is: monolithically formed with the baffle; or formed as a separate component from the baffle such that the baffle is couplable to multiple configurations of the annular protective screen. In one example of the vent system, optionally including one or more of the preceding examples of the vent system, the vent system further includes wherein the annular protective screen is formed as the separate component from the baffle, each of the annular protective screen and the baffle being formed from a silicone or a silicone composite, or wherein the vent system further includes a plurality of gaskets welded to the baffle. In one example of the vent system, optionally including one or more of the preceding examples of the vent system, the vent system further includes wherein the upper domed surface is an elliptical domed surface, and wherein air is naturally convected through the plurality of exterior air windows following an external air current induced by wind or motion of the facility or vehicle. In one example of the vent system, optionally including one or more of the preceding examples of the vent system, the vent system further includes wherein the upper cover and the plurality of exterior air windows are configured to mitigate solid particulates from entering the ventilation circuit. In one example of the vent system, optionally including one or more of the preceding examples of the vent system, the vent system further includes wherein the upper cover includes a plurality of reinforced top strips to provide additional protection to the upper cover when stepped on or impacted by a falling object. In one example of the vent system, optionally including one or more of the preceding examples of the vent system, the vent system further includes wherein the upper cover includes a plurality of inner side ribs, and wherein the frame includes a plurality of half-round slots, the plurality of half-round slots sized so as to receive the plurality of inner side ribs, respectively. In one example of the vent system, optionally including one or more of the preceding examples of the vent system, the vent system further includes wherein the frame is configured a main support for the vent system such that other components of the vent system are coupled to, or positioned relative to, the frame. In one example of the vent system, optionally including one or more of the preceding examples of the vent system, the vent system further includes a deflector, wherein each of the upper cover, the frame, and the deflector includes a plurality of fastening stubs, each fastener stub of the plurality of fastener stubs of the frame aligned with a fastener stub of the plurality of fastening stubs of the upper cover or a fastener stub of the plurality of fastener stubs of the deflector such that the frame is fastened to each of the upper cover and the deflector via the aligned fastener stubs, and wherein a thickness of a cover of the facility or vehicle on which the vent system is installed is small enough such that no additional ancillary air pipe is provided at the cover. In one example of the vent system, optionally including one or more of the preceding examples of the vent system, the vent system further includes wherein the frame includes an inner annular ancillary air pipe lip to receive an ancillary air pipe of a length equal to a thickness of a cover of the facility or vehicle on which the vent system is installed. In one example of the vent system, optionally including one or more of the preceding examples of the vent system, the vent system further includes wherein the baffle further includes an annular protective screen, and wherein the frame includes an inner round plate with an outer annular shelf or terrace, the outer annular shelf or terrace clearance fit to the annular protective screen. In one example of the vent system, optionally including one or more of the preceding examples of the vent system, the vent system further includes wherein the annular protective screen includes a plurality of inner half-round ribs, and wherein a plurality of half-round slots is superimposed on the inner round plate, the plurality of half-round slots clearance fit to the plurality of inner half-round ribs. In one example of the vent system, optionally including one or more of the preceding examples of the vent system, the vent system further includes wherein the frame includes an inner round plate and a plurality of outer stakes extending from the inner round plate, and wherein adjacent pairs of the plurality of outer stakes at least partially form respective seats of the plurality of seats. In one example of the vent system, optionally including one or more of the preceding examples of the vent system, the vent system further includes wherein the frame includes a barrel positioned at a center of the frame. In one example of the vent system, optionally including one or more of the preceding examples of the vent system, the vent system further includes wherein the upper cover includes a plurality of reinforced top strips, and wherein the frame includes a plurality of side fastening stubs for fastening the upper cover to the frame, an orthographic projection of each side fastening stub of the plurality of side fastening stubs at least partially obscured by an orthographic projection of a respective reinforced top strip of the plurality of reinforced top strips. In one example of the vent system, optionally including one or more of the preceding examples of the vent system, the vent system further includes wherein the frame includes an annular bottom slot, and wherein an adhesive sealant is supplied within and throughout the annular bottom slot to seal the vent system to a cover of the facility or vehicle on which the vent system is installed, or wherein a silicone gasket is welded into the annular bottom slot, the cover is a clean and flat surface, and no adhesive sealant is supplied within the annular bottom slot. 
     The specification and drawings are to be regarded in an illustrative rather than a restrictive sense. It will, however, be evident that various modifications and changes may be made thereunto without departing from the broader spirit and scope of the invention as set forth in the claims. 
     Other variations are within the spirit of the present disclosure. Thus, while the disclosed techniques are susceptible to various modifications and alternative constructions, certain illustrated embodiments thereof are shown in the drawings and have been described above in detail. It should be understood, however, that there is no intention to limit the invention to the specific form or forms disclosed but, on the contrary, the intention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention, as defined in the appended claims. 
     The use of the terms “a” and “an” and “the” and similar referents in the context of describing the disclosed embodiments (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Similarly, use of the term “or” is to be construed to mean “and/or” unless contradicted explicitly or by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. The term “connected,” when unmodified and referring to physical connections, is to be construed as partly or wholly contained within, attached to, or joined together, even if there is something intervening. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. The use of the term “set” (e.g., “a set of items”) or “subset” unless otherwise noted or contradicted by context, is to be construed as a nonempty collection comprising one or more members. Further, unless otherwise noted or contradicted by context, the term “subset” of a corresponding set does not necessarily denote a proper subset of the corresponding set, but the subset and the corresponding set may be equal. The use of the phrase “based on,” unless otherwise explicitly stated or clear from context, means “based at least in part on” and is not limited to “based solely on.” 
     Conjunctive language, such as phrases of the form “at least one of A, B, and C,” or “at least one of A, B and C,” (i.e., the same phrase with or without the Oxford comma) unless specifically stated otherwise or otherwise clearly contradicted by context, is otherwise understood within the context as used in general to present that an item, term, etc., may be either A or B or C, any nonempty subset of the set of A and B and C, or any set not contradicted by context or otherwise excluded that contains at least one A, at least one B, or at least one C. For instance, in the illustrative example of a set having three members, the conjunctive phrases “at least one of A, B, and C” and “at least one of A, B and C” refer to any of the following sets: {A}, {B}, {C}, {A, B}, {A, C}, {B, C}, {A, B, C}, and, if not contradicted explicitly or by context, any set having {A}, {B}, and/or {C} as a subset (e.g., sets with multiple “A”). Thus, such conjunctive language is not generally intended to imply that certain embodiments require at least one of A, at least one of B and at least one of C each to be present. Similarly, phrases such as “at least one of A, B, or C” and “at least one of A, B or C” refer to the same as “at least one of A, B, and C” and “at least one of A, B and C” refer to any of the following sets: {A}, {B}, {C}, {A, B}, {A, C}, {B, C}, {A, B, C}, unless differing meaning is explicitly stated or clear from context. In addition, unless otherwise noted or contradicted by context, the term “plurality” indicates a state of being plural (e.g., “a plurality of items” indicates multiple items). The number of items in a plurality is at least two but can be more when so indicated either explicitly or by context. 
     Operations of processes described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. 
     The use of any and all examples or exemplary language (e.g., “such as”) provided herein is intended merely to better illuminate embodiments of the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention. 
     Embodiments of this disclosure are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for embodiments of the present disclosure to be practiced otherwise than as specifically described herein. Accordingly, the scope of the present disclosure includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the scope of the present disclosure unless otherwise indicated herein or otherwise clearly contradicted by context. 
     All references including publications, patent applications, and patents cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.