Patent Publication Number: US-2005130581-A1

Title: Roof vent having labyrinth features

Description:
CROSS REFERENCE TO RELATED APPLICATION  
      This application claims the full benefit and priority of pending provisional application No. 60/491,405, filed, Jul. 31, 2003, entitled “Roof Vent Having Labyrinth Features”. The entire contents of this provisional application are likewise incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION  
      In the construction of roofing, it is known to provide roofs made of individual roofing elements. The elements can be flexible, such as asphalt shingles, or rigid, such as clay or concrete tiles.  
      It is also known to provide vents in the roofing structure to provide roof ventilation. However, providing such venting can introduce problems relating to the prevention of water being drawn in along with the ventilating air flow. Therefore there is a need in the art to provide an improvement of such vents.  
     BRIEF SUMMARY OF THE INVENTION  
      The present invention provides in improvement of over the art by providing an improved roof vent that includes improved ventilation features as well as improved aesthetic features.  
      Generally described, the present invention is directed towards a roof vent assembly for use in connection with an inclined roof structure including a plurality of tile members supported by a roofing support structure, the vent assembly configured to provide ventilation to the roof structure and comprising a base member configured to be attached to and supported by the roofing support structure, the base member including a ventilation hole and at least one rib below the ventilation hole, and a cowl member including a leading edge, the cowl member configured to be mounted above the ventilation hole of the base member, the cowl member also configured to cover the rib, such that a portion of air blowing up the incline of the roof structure has to pass along a labyrinth air flow path, the air flow path passing first underneath the leading edge of the cowl member and then over the rib, and finally through the ventilation hole.  
      The present invention is also directed towards a roof vent assembly for use in connection with an inclined roof structure including a plurality of tile members supported by a roofing support structure, the vent assembly configured to provide ventilation to the roof structure and comprising a base member configured to be attached to and supported by the roofing support structure, the base member including a ventilation hole and also including a front external baffle positioned proximate its front edge, and a cowl member including a leading edge, the cowl member configured to be mounted above the ventilation hole of the base member while leaving the front external baffle of the base member exposed, the leading edge being positioned behind the external baffle, such that a portion of air blowing up the incline of the roof structure has to pass along a labyrinth air flow path, the air flow path passing first over the front external baffle of the base member, underneath the leading edge of the cowl member, and finally through the ventilation hole.  
      The present invention is also directed towards roof vent assembly for positioning within a first generally horizontal course of roof tiles, the first course of tiles being adjacent to and below a second generally horizontal course of roof tiles, the vent assembly comprising A) a base defining at least one upwardly-directed surface portion and a vent portion, the surface portion of the base tending to blend in with at least some of the upper surfaces of the first course of tiles, and B) a cowl attached to and suspended above the vent portion of the base, the cowl defining at least one surface portion tending to blend in with the second course of tiles.  
      The present invention is also directed towards a roof vent assembly for positioning within a first generally horizontal course of roof tiles, the first course of tiles being adjacent to and below a second generally horizontal course of roof tiles, the vent assembly comprising A) a base defining at least one upwardly-directed surface portion and a vent portion, the surface portion of the base configured to substantially match at least some of the upper surfaces of the first course of tiles, and B) a cowl attached to and suspended above the vent portion of the base, the cowl defining at least one surface portion configured to substantially match at least some of the upper surfaces of the second course of tiles.  
      The present invention is also directed towards a method for providing a roof vent assembly positioned within a first generally horizontal course of roof tiles, the first course of tiles being adjacent to and below a second generally horizontal course of roof tiles, the method comprising the steps of A) providing a base defining at least one upwardly-directed surface portion and a vent portion, the surface portion of the base configured to blend in with at least some of the upper surfaces of the first course of tiles, and B) providing a cowl attached to and suspended above the vent portion of the base, the cowl defining at least one surface portion configured to blend in with at least some of the upper surfaces of the second course of tiles.  
      The present invention is also directed towards a method for providing a roof vent assembly positioned within a first generally horizontal course of roof tiles, the first course of tiles being adjacent to and below a second generally horizontal course of roof tiles, the method comprising the steps of A) providing a base defining at least one upwardly-directed surface portion and a vent portion, the surface portion of the base configured to substantially match at least some of the upper surfaces of the first course of tiles, and B) providing a cowl attached to and suspended above the vent portion of the base, the cowl defining at least one surface portion configured to substantially match at least some of the upper surfaces of the second course of tiles.  
      Therefore, it is an object of the present invention to provide an improved roof structure.  
      It is a further object of the present invention to provide an improved roof structure, which includes at least one roof vent.  
      It is a further object of the present invention to provide an improved roof vent.  
      It is a further object of the present invention to provide an improved roof vent that includes improved rain exclusion features.  
      It is a further object of the present invention to provide an improved roof vent that includes improved wind exclusion features.  
      It is a further object of the present invention to provide an improved roof vent that includes improved aesthetic features.  
      It is a further object of the present invention to provide an improved roof vent that includes improved aesthetic features while at the same time including improved functional features.  
      It is a further object of the present invention to provide an improved roof vent that is economical to manufacture while still providing improved functional and aesthetic features.  
      It is a further object of the present invention to provide an improved roof vent that is economical to sell while still including improved functional and aesthetic features.  
      Other objects, features, and advantages of the present invention will become apparent upon reading the following detailed description of the preferred embodiment of the invention when taken in conjunction with the drawing and the appended claims.  
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
      Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:  
       FIGS. 1-7  are drawings of one embodiment of the invention, which includes the use of a “flat” vent assembly including a single external baffle  34  in front of a cowl  20 .  
       FIG. 1  is a pictorial view of a first embodiment of a flat vent assembly  10  according to one aspect of the present invention. The vent assembly  10  includes a cowl  20 , a base  30 , and a cowl retention member  40 .  
       FIG. 2  is a left side elevational view of the flat vent assembly  10  shown in  FIG. 1   
       FIG. 3  is a right side elevational view of the flat vent assembly  10  shown in  FIG. 1 .  
       FIG. 4  is a foot (or “leading”) end elevational view of the flat vent assembly  10  shown in  FIG. 1 .  
       FIG. 5  is a head (or “trailing”) end elevational view of the flat vent assembly  10  shown in  FIG. 1 .  
       FIG. 6  is a top plan view of the flat vent assembly  10  shown in  FIG. 1 .  
       FIG. 7  is a lower plan view of the vent assembly  10  according to one aspect of the present invention. As may be seen, the cowl  20  is visible through the two vent cavities  32 , which are provided in the base  30  of the vent assembly  10 .  
       FIG. 8  is a pictorial view of a second embodiment of a flat roof vent assembly  110 .  
       FIG. 9  is an exploded view of that shown in  FIG. 8 , showing some components thereof, namely the cowl  120  and the base  130 .  
       FIG. 10  is a pictorial view of a third embodiment of a flat roof vent assembly  210 . This assembly  210  includes a cowl  220  and a base  230 . The assembly  210  also includes a cowl retention member not shown in this figure but illustrated later as  240  in  FIG. 13 .  
       FIG. 11  is an isolated pictorial view of the base  230  of  FIG. 10 . It may be seen that there is an upturned peripheral wall  236  extending around the vent opening  232 , which is defined by the base. The upturned wall  232  is configured to reduce the opportunity for water to pass therethrough; instead the water is preferably diverted down the slope and out of the vent.  
       FIG. 12  is an isolated view of the cowl  220  of  FIG. 10 , except the cowl has been “flipped over” 180 degrees to show its underside. The cowl  220  includes two types of elongate members, which extend downwardly in a common orientation. The first type of elongate members are “standoff feet”  225 , and the second type are “engaging tabs”  226 . In the embodiment shown there are six (6) of the standoff feet  225 , and six (6) of the engaging tabs  226 , although other numbers could be used.  
       FIG. 13  is a bottom plan view of a cowl retention member  240 , as the member would be viewed if the vent assembly was viewed from the underneath when assembled. The cowl retention member  240  is in one embodiment a single one piece molded design although other designs are contemplated. The cowl retention member  240  includes a continuous peripheral wall  241 , which will be seen to be shaped somewhat like a pentagon, and in any case shaped corresponding to the vent opening  232  in the base  230  of the flat roof vent assembly  210 . Positioned about the wall  241  is a plurality (six are shown in this embodiment) of cowl engaging portions  242 , which are configured to engage the six corresponding tabs  226  of the cowl  220 . Referring now also to  FIG. 15 , this peripheral wall  241  could be thought of as having an “L”-shaped transverse cross section comprised of a first wall  241 -A, which fits within the vent opening, and a second, “flange” wall  241 -B, which when installed fits in planar contact with the underside of the floor plate  231  of the base, proximate the vent opening. The cowl-retaining member  240  also includes a plurality of ribs  247  which provide structural integrity to the member  240 .  
       FIG. 14  is an isolated view of that shown in the dotted line circle of  FIG. 13 , with the addition of a tab  266  shown in dotted line extending up into the plane of the paper. The figure shows an exemplary cowl engaging portion  242  of the cowl retention member  240 , particularly showing the manner in which a tab  226  (shown in transverse cross section in dotted line) engages the barb  245  defined by the cowl retention member  240 , and is contained on its sides by loop  246 . This engagement is done by engagement between the barb  245  and a hole  226 H in the end of the tab  226 , shown in  FIG. 12 . As may be seen, the loop  246  may include needed small (three are shown) locating stubs (not numbered), which locate the position of the tab  226  in its desired place. It may be understood that as the tab is pressed into place (it would be moved towards the viewer during the insertion process), the barb  245 , essentially being a hump of plastic, “snaps” into place in the hole  226 H in the end of the tab  266 , thus interlocking the cowl retention member  240  relative to the cowl. As discussed elsewhere, the cowl retention member  240  and the cowl  220  combine to capture the base  230  therebetween. Reference can also be made to  FIG. 20  to better understand the manner in which the cowl retention member  240  fits up within the hole in the base  230 .  
       FIG. 15  is an isolated view illustrating the manner in which the peripheral wall  241  (of the cowl retaining member  240 ) fits within the opening  232  of the base  230 . The orientation shown is with the base directed upwardly, with the view from the side. The peripheral wall  241  could be thought of as having an “L”-shaped transverse cross section comprised of a first wall  241 -A, which fits within the vent opening, and a second, “flange” wall  241 -B, which when installed fits in planar contact with the underside of the floor plate  231  of the base, proximate the vent opening. This allows the peripheral wall  241  (of the cowl retaining member  240 ) to fit within the opening  232  of the base  230  in a “nesting manner. The nesting is shown in  FIG. 20 .  
       FIG. 16  is a pictorial view of a two-humped vent assembly  510  according to the present invention. The two-humped vent assembly  510  includes a cowl  520  and a base  530 . As may be seen, the base  530  includes multiple nail hole locations  539 , and also includes two standoff nodules  538 , which extend downwardly to provide support of the base  530  atop the battens or other supporting roof structure or members that support the tiles.  
       FIG. 17  is another view of the vent assembly of  FIG. 16 , except that the view is from a lower perspective to show the manner in which the cowl  520  extends upwardly relative to the base  530 . This view also shows the use of a “segmented” front external baffle configuration, in which the front baffling function is provided by baffle segments  535  which are located in the upwardly curved or “valley” sections  536  of the base  530 .  
       FIG. 18  is an isolated view of a portion of the cowl  520 , illustrating the manner in which the downwardly-directed standoff feet  525  (a.k.a. support feet) contact the floor plate  531  of the base  530 .  
       FIG. 19  is an isolated view of a portion of the underside of the base  530 , illustrating a standoff nodule  538 , which contacts the roofing structure supporting the tiles and vents.  
       FIG. 20  is a pictorial view, viewed from the underside, illustrating the interaction between a two-humped vent assembly  510  (viewer&#39;s left) and a typical similarly shaped tile “T” (viewer&#39;s right). Particularly this shows the use of a location tab  537 , which extends from the base  530 . This location tab  537  and the base of the two-humped vent assembly  510  combine to capture the typical similarly shaped tile to assist in the relative positioning of the two and to keep the vent attached to the roof.  
       FIG. 21  is a pictorial view of a three-hump vent assembly  710 , which includes a cowl  720  and a base  730 . The base includes a front external baffle  731  which as may be seen has a substantially nominal height, and conforms to the curved and flat portions  735 ,  736 , respectively, of the upwardly-directed upper major surface of the base  730 .  
       FIG. 22  is an illustrative view illustrating the dual-level matching concept, as provided by a flat vent assembly configuration  10  mounted atop a roof supporting surface SS (which could be provided by battens, a flat surface, or otherwise as known in the art). The flat vent assembly  10  is mounted in one course of tiles, which is above a course of tiles including tile A, and below a course of tile including tile B. As may be understood, the upper surface  20 S of the cowl  20  is substantially in the same plane P as is the upper surface of the flat tile B, while the upper major surface  30 S of the base  30  of the flat vent assembly  10  is aligned with the upper surfaces of other tiles in its same course.  
    
    
      It may also be understood that this same type of dual level matching applies to the other vent configurations. Although having a curved upper surface, the upper surface of the cowls of the assemblies  510 ,  710 , likewise tend to blend in with the upper, curved, surfaces of the tiles in the next course above, while the curved upper major surfaces of the bases of these assemblies blend in with the tiles in their same course.  
     DETAILED DESCRIPTION OF THE INVENTION  
      The present inventions now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the invention are shown in the figures. Indeed, these inventions may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout.  
      General Construction and Operation  
      Generally described, the vent assemblies described herein include a base, which is attached relative to the supporting roof structure, and a cowl, which is attached to the base and covers a ventilation hole in the base.  
      In roof vents, the inventor has noted that in certain instances it is desirable to bring the leading edge of the vent cowl in line with the leading edge of adjacent field tiles. In so doing, a constant shadow line is created on the roof, improving aesthetic integration. However, this has been a challenge to the inventors because of the conflicting functional need to prevent wind driven rain entry through the vent.  
      One particular concept according to one aspect of the present invention is to use internal labyrinths to afford this rain protection. This provides an improvement over the prior art by allowing the cap (a.k.a. cowl) to come to the leading edge of the vent, in-line with the leading edge of adjacent roof tiles. This enables a more aesthetic, integrated appearance on the roof.  
      Another concept according to the present invention is the use of a front, external, baffle in front of the leading edge of the vent cowl.  
      Another concept according to the present invention relates to the provision of two different “levels” in the vent assembly, each of which matches the contour of a different course of tiles amongst which the vent is mounted. Said another way, the invention includes the generic concept of matching tile profiles with vent profiles.  
      Detailed Discussion  
      More detailed discussion is now made of the various embodiments of the vent assemblies of the present invention. By way of reference, it should be noted that the term “leading” edge is meant to indicate the edge of the tile or tile vent that faces “down” the roof towards the ground. This could also be termed the “lower” or “foot” edge. Conversely, a “trailing” edge is meant to indicate the edge of the tile that faces “up” the roof, away from the ground. This could also be termed the “upper” or “head” edge. “Side” edges are the remaining edges that connect the two.  
      There are three general types of vent assemblies that are used under the present invention: a flat vent assembly, a “dual hump” vent assembly, and a “triple hump” vent assembly. These assemblies are configured to be used with tiles that have the same general shape; such tiles will be recognized by one skilled in the art. However it should be understood that the present inventions described herein could be used with other shapes of tiles. Furthermore, a concept shown in association with one vent assembly (e.g., a flat vent assembly) could be used with another vent assembly (e.g., a dual hump vent assembly).  
      The Flat Vent ( FIGS. 1-15 )  
      Reference is first made to  FIG. 1 , which is a pictorial view of a flat vent assembly  10  according to one aspect of the present invention. The vent assembly  10  includes a cowl  20 , a base  30 , and also includes in one embodiment a cowl retention member (not shown in  FIG. 1 ). As discussed in later detail, the base member  30  fits within a first course of tiles, and in at least one embodiment includes an upwardly directed surface portion (in this case, flat) that tends to conform to (or “match”) upwardly directed surfaces of the other tiles in the first course of tiles. The cowl member  20  includes an upwardly directed surface portion (in this case, also being flat) that tends to follow the profile of the course of tiles above the first course, this course being now referenced as the “second” course.  
      A cowl retention member (not shown in  FIG. 1 , but discussed in further detail later) is contemplated for use with this assembly  10  under one embodiment of the present invention. Under such an embodiment, the cowl retention member would attach to tabs extending down from underneath the cowl. These tabs would fit within holes, blind or otherwise, that would accept the downwardly-extending pin tips and retain them. When such an engagement is made, the cowl retention member and the cowl combine to grip the base.  
      Referring now also to  FIG. 7 , the base  30  includes a floor plate  31  (which defines what may be referenced as a “lower major surface”), two vent cavities  32  (see  FIG. 7 —note one or more than two cavities could also be used), a generally planar raised shelf  33  having a U-shaped outline (which defines what may be referenced as an “upper major surface”), a front external baffle  34 , first and second internal baffles  35 ,  36 , (shown in other figures such as  FIG. 7 ) and defines left and right edges  38 ,  39 .  
      The cowl  20  is attached to the base  30  of the vent assembly  10  by use of a vent retention member discussed below, and covers the vent holes  32  (a.k.a. vent “cavities”) in the base  30 , and also covers the first and second internal baffles  35 ,  36 , and discussed in later detail. However, the baffle  34  could be considered to be in “front” of the front edge of the cowl  20 , and the cowl  20  “behind” the baffle  34 .  
       FIGS. 2 and 3  are left and right side elevational views of the assembly shown in  FIG. 1 .  
       FIG. 4  is a foot (or “leading”) end elevational view of the assembly shown in  FIG. 1 .  FIG. 5  is a head (or “trailing”) end elevational view of the assembly shown in  FIG. 1 .  
       FIG. 6  is a top plan view of the assembly shown in  FIG. 1 . As may be seen, this view shows the top view of the single external baffle  34 , the single cowl  20  (although two numbers  20  are shown in the figure), and the U-shaped raised shelf  33 . Referring now also to  FIG. 1 , this U-shaped raised shelf  33  extends upwardly relative to the floor plate  31 , such that a depression of sorts is provided, within which the cowl  20  can fit. This fit provides for a configuration in which the top, upwardly directed, surface of the cowl  20  is substantially parallel to the top, upwardly directed, surface of the U-shaped raised shelf  33 , yet the top surface of the cowl  20  is higher than the surface of the shelf  33 . This is in order to provide an aesthetic appearance of the overall vent assembly by providing the “dual-level matching” concepts noted above that is provided by the upwardly directed surface portion of the base  30  tending to conform to, and blend in with, (or “match”) upwardly directed surfaces of the other tiles in the first course of tiles (that the vent is in) and the upwardly directed surface portion of the cowl member  20  tending to follow the profile of the “second” course, above the first course. However, the function is to provide a vent feature, which could not otherwise be provided with a conventional flat tile.  
      It may be seen that the cowl  20  of  FIG. 6  (and  FIG. 1 ) shows a simulated “split line” down through the center of the cowl. This is to simulate two tile elements. It should be understood that that line could be removed (such as is the case with the next embodiment shown in  FIG. 8 ), or other line, contour, or relief configurations could be used. It should also be noted that other texturing configurations could be used as well.  
       FIG. 7  is a lower plan view of the vent assembly  10  according to one aspect of the present invention. As may be seen, the cowl  20  is visible through the two vent holes  32  (a.k.a. cavities), which are provided in the base  30  of the vent assembly  10 .  
      Although this view shown in  FIG. 7  is from the underneath of the assembled vent assembly  10 , it is helpful in viewing and understanding certain features that affect airflow and water drainage on the other side of the base  30 . As the base  30  is molded out of relatively thin planar plastic through a molding process (including but not limited to thermoforming, vacuum forming, injection molding, etc.), it may be understood that due to the relatively consistent wall thickness, that which is seen on one side of the blow molded material can give a good idea of the appearance of the other side of the blow molded material. For example, a depression in one side would correspond to a protrusion on the other side. This is particularly helpful in explaining the shape of the external baffle  34  and its cooperating first and second internal baffles  35 ,  36 .  
      As noted elsewhere in this application, when the flat vent assembly  10  is assembled and is in its upright position as shown in  FIG. 1 , the external baffle is positioned outside of the cowl  20 . However, the first and second external baffles  35 ,  36 , respectively, are positioned underneath the cowl  20 .  
      When wind, combined with rainwater, blows “up” the roof, it will tend to blow along a serpentine path, first over the external baffle  34 , and then immediately dip down and under the leading edge of the cowl  20 . At this point, the air will then have to go up over the first internal baffle  35 , down into a trough, which is in between baffles  35 , and  36 , and then up over the second internal baffle  36 . Air crossing the crest of the second internal baffle  36  is then free to continue under the cowl  20  and out downwardly through the two vent cavities (or cavity)  32  in the floor plate  31 .  
      It may be understood that sloping ramps  37  exist on the opposing ends of the first and second internal baffles. These sloping ramps  37  provide for escaping waterflow from water that may be deposited when crossing the external baffle  34  or the first internal baffle  35 .  
       FIG. 8  is a pictorial view of a flat roof vent assembly  110 . As may be seen, this second embodiment does not include an external baffle such as  34  in the previous embodiment. Instead, the cowl  120  extends all the way towards its foot end so that it is substantially flush with the foot end of the base  130 . This provides an aesthetically pleasing image. The cowl  120  can be attached to the base in the same manner as in the previous embodiment.  
       FIG. 9  is an exploded view of that shown in  FIG. 8 , showing some components thereof, namely the cowl  120  and the base  130 .  134  is a large internal baffle,  135  is a first small internal baffle, and  136  is a second small internal baffle. As may be seen in this case, all three of the baffles are covered by the cowl. However, the relative shapes of the three baffles  134 ,  135 , and  136  are similar to those of the previously discussed baffles  34 ,  35 , and  36 .  
       FIG. 10  is a pictorial view of a third embodiment of a flat roof vent assembly  210 . This assembly  210  includes a cowl  220  and a base  230 . The assembly  210  also includes a cowl retention member not shown in this figure but illustrated later as  240  in  FIG. 13 .  
      The base  230  includes a floor plate  231  (which defines a lower major planar portion), a raised shelf  233  (which defines an upper major planar portion), and a front external baffle  234 . The base also includes nailing locations  239  to receive nails for fastening the base to a supporting roof structure.  
      The cowl  220  includes downwardly oriented standoff feet  225  which bias on the top surface of the floor plate  231 .  
       FIG. 11  is an isolated pictorial view of the base  230  of  FIG. 10 . It may be seen that there is an upturned peripheral wall  236  extending around the “quasi-pentagon” vent opening  232 , which is defined by the base. The upturned wall  232  is configured to reduce the opportunity for water to pass therethrough; instead the water is preferably diverted down the slope and out of the vent.  
      Also shown in  FIG. 11  is the location where a location tab is mounted on the underside of the base at location  238 . The location tab itself cannot be seen in this view, but due to the thin wall of the base the mounting depression for the location tab shows through when the base is viewed from the tap. The portion of the tab that extends sidewardly is shown in dotted line. The function of this tab is similar to that discussed later in connection with location tab  537  in  FIG. 20 . However, the generally planar tab has its primary planar surfaces positioned in planes relatively parallel to the generally planar floor plate  231 .  
       FIG. 12  is an isolated view of the cowl  220  of  FIG. 10 , except the cowl has been “flipped over” 180 degrees to show its underside. The cowl  220  includes two types of elongate members, which extend downwardly in a common orientation. The first type of elongate members are “standoff feet”  225 , and the second type are “engaging tabs”  226 , which have holes  226 H proximate their free tips. In the embodiment shown there are six (6) of the standoff feet  225 , and six (6) of the engaging tabs  226 , although other numbers could be used.  
       FIG. 13  is a bottom plan view of a cowl retention member  240 , as the member  240  would be viewed if the vent assembly were viewed from the underneath when assembled. The cowl retention member  240  is in one embodiment a single one piece molded design although other designs are contemplated. The cowl retention member  240  includes a continuous peripheral wall  241 , as seen to be shaped somewhat like a pentagon (described herein as a “quasi-pentagon”), and in any case shaped corresponding to the vent opening  232  in the base  230  of the flat roof vent assembly  210 . Positioned about the wall  241  is a plurality (six are shown in this embodiment) of cowl engaging portions  242 , which are configured to engage the six corresponding tabs  226  of the cowl  220 . Referring now also to  FIG. 15 , this peripheral wall  241  could be thought of as having an “L”-shaped transverse cross section comprised of a first wall  241 -A, which fits within the vent opening, and a second, “flange” wall  241 -B, which when installed fits in planar contact with the underside of the floor plate  231  of the base, proximate the vent opening. The cowl-retaining member  240  also includes a plurality of ribs  247  which provide structural integrity to the member  240 .  
       FIG. 14  is an isolated view of that shown in the dotted line circle of  FIG. 13 , with the addition of a tab  266  shown in dotted line extending up into the plane of the paper. The figure shows an exemplary cowl engaging portion  242  of the cowl retention member  240 , particularly showing the manner in which a tab  226  (shown in transverse cross section in dotted line) engages the barb  245  defined by the cowl retention member  240 , and is contained on its sides by loop  246 . This engagement is done by engagement between the barb  245  and a hole  226 H in the end of the tab  226 , shown in  FIG. 12 . As may be seen, the loop  246  may include needed small (three are shown) locating stubs (not numbered), which locate the position of the tab  226  in its desired place. It may be understood that as the tab is pressed into place (it would be moved towards the viewer during the insertion process), the barb  245 , essentially being a hump of plastic, “snaps” into place in the hole  226 H in the end of the tab  266 , thus interlocking the cowl retention member  240  relative to the cowl. As discussed elsewhere, the cowl retention member  240  and the cowl  220  combine to capture the base  230  therebetween.  
      This engagement is done by engagement between the barb  245  and a hole  226 H in the end of the tab  226 , shown in  FIG. 12 . As may be seen, the loop  246  may include, if needed, small (three are shown) locating stubs (not numbered) which locate the position of the tab  226  in its desired place. It may be understood that the tab is pressed into place and the barb  245  “snaps” into place in the hole  226 H in the end of the tab  266 , thus interlocking the cowl retention member  240  relative to the cowl. As discussed elsewhere, the cowl retention member  240  and the cowl  220  combine to capture the base  230  therebetween.  
       FIG. 15  is an isolated view illustrating the manner in which the peripheral wall  241  (of the cowl retaining member  240 ) fits within the opening  232  of the base  230 . The orientation shown is with the base directed upwardly, with the view from the side. The peripheral wall  241  could be thought of as having an “L”-shaped transverse cross section comprised of a first wall  241 -A, which fits within the vent opening, and a second, “flange” wall  241 -B, which when installed fits in planar contact with the underside of the floor plate  231  of the base, proximate the vent opening. This allows the peripheral wall  241  (of the cowl retaining member  240 ) to fit within the opening  232  of the base  230  in a “nesting manner. The nesting is shown in  FIG. 20 .  
      The Two Humped Vent ( FIGS. 16-20 )  
       FIG. 16  is a pictorial view of a two-humped vent assembly  510  according to the present invention. The two-humped vent assembly  510  includes a cowl  520  and a base  530 . As may be seen, the base  530  includes multiple nail hole locations  539 , and also includes two standoff nodules  538 , which extend downwardly to provide support of the base  530  atop the battens or other supporting roof structure or members that support the tiles.  
       FIG. 17  is another view of the vent assembly of  FIG. 16 , except that the view is from a lower perspective to show the manner in which the cowl  520  extends upwardly relative to the base  530 . This view also shows the use of a “segmented” front external baffle configuration, in which the front baffling function is provided by baffle segments  535  which are located in the upwardly curved or “valley” sections  536  of the base  530 .  
       FIG. 18  is an isolated view of a portion of the cowl  520 , illustrating the manner in which the downwardly-directed standoff feet  525  (a.k.a. support feet) contact the floor plate  531  of the base  530 .  
       FIG. 19  is an isolated view of a portion of the underside of the base  530 , illustrating a standoff nodule  538 , which contacts the roofing structure supporting the tiles and vents.  
       FIG. 20  is a pictorial view, viewed from the underside, illustrating the interaction between a two-humped vent assembly  510  (to the viewer&#39;s left) and a typical similarly shaped tile “T” (to the viewer&#39;s right). Particularly this shows the use of a location tab  537 , which extends from the base  530 . This location tab  537  is in one embodiment plastic and riveted to the base  530 . This location tab  537  and the base of the two-humped vent assembly  510  combine to capture the typical similarly shaped tile to assist in the relative positioning of the two and to keep the vent attached to the roof.  
      The Three Humped Vent (Villa) ( FIG. 21 )  
       FIG. 21  is a pictorial view of a three-hump vent assembly  710 , which includes a cowl  720  and a base  730 . The base includes a front external baffle  731  which as may be seen has a substantially nominal height, and conforms to the curved and flat portions  735 ,  736 , respectively, of the lower major upwardly-directed surface of the base  730 .  
      It should be understood that the front external baffle could also be configured so as to have a substantially straight upper edge, such that the thickness of the baffle would vary depending on from where the wall was extending. For example, the wall would be at its thickest when extending upwardly from the flat segments  736 .  
      The Cowl Fastening System  
      As noted above, under one embodiment of the invention, the cowl fastening system described below that includes a cowl retention member  240 , as shown in  FIG. 13 .  
      As noted above, referring generally to  FIGS. 10-15 , the cowl  220  includes two types of elongate members, which extend downwardly in a common orientation. The first type of elongate members are “standoff feet”  225 , and the second type are “engaging tabs”  226 . In the embodiment shown there are six (6) of the standoff feet  225 , and six (6) of the engaging tabs  226 , although other numbers could be used.  
      When the cowl retention member  240  is installed, the standoff feet  225  have their bottom tips contacting and biasing atop (but not engaging) the floor surface  231  (a.k.a. the lower major surface) of the base  230 , at locations spaced around the opening in the base. The engaging tabs  226  extend down and through the vent opening  232  of the base, and engage corresponding engagement portions  242  of the cowl retention member  240 .  
      The cowl retention member  240  has an outer perimeter, which has a quasi-pentagon shape that allows the cowl retention member  240  to fit into, and “nest” within the pentagon-shaped opening of the base. The engaging tabs  226  of the cowl snap-fit into engagement portions  242  of the cowl retention member  240 , such that the cowl retention member  240  and the feet  225  of the base  230  capture the base therebetween. The engaging tabs do not touch the base, only the cowl retention member  240 . The cowl retention member also includes ribs  247  which span the opening; these ribs are for are these for structural integrity.  
      Alternatives and Accessories  
      Although the above configurations contemplate the use of a cowl retention member, other configurations may be used to fasten the cowl to the base without departing from the spirit and scope of the present invention. For example, L-shaped bracket-type hardware elements (not shown) may be attached to the base and the cowl, and flexible members may be used to connect the hardware together and to provide a flexible but spaced-apart connection between the cowl and the base. In such a configuration no cowl retention member would be used.  
      The vent assemblies described above can also be used in conjunction with a flat screen provided underneath the vent hole in the base of the vent assembly. A “cloaking device” (not shown) could also be used which acts like a flashing and screen. Essentially, the cloaking device includes a base defining an opening, flashing extending about the periphery of the opening, and a screen at the top of the flashing. The flashing component, which operates similar to that currently in the art, sheds water away from the hole and the screen prevents bugs and rodents from crawling into the attic space.  
      The cloaking device is nailed to the roof deck over the hole to allow the air into the attic space. The underlayment will overlap the top of the base of the cloaking device so water runs off the underlayment onto the cloaking device, is stopped by the raised wall and runs off the sides back onto the underlayment.  
      It may be noted that the “labyrinth” feature noted elsewhere in this application may be used in combination with the “dual-level matching” feature, or either feature may be used alone.  
      It should be understood that although certain combinations of internal and external baffles have been shown for purposes of indication, it should be understood that there are other alternative configurations that still manage to be covered by the present invention. For example, instead of using two small internal baffles, three or one internal baffles could be used; in fact, any reasonable number of internal baffles could be used within engineering limitations. At the same time, a large external baffle could be used as shown in the first embodiment, with the large external baffle having various height possibilities, depending on the severity of the weather of the application. Furthermore, the embodiments shown above discuss baffles with a vertical orientation. It should be noted that this is just one embodiment and in fact a horizontal labyrinth is also envisioned for the same purpose. Furthermore it could also be said that air passes “through” the labyrinth as opposed to “over” the labyrinth in such situations.  
      The Dual-Level Matching Concept  
       FIG. 22  is an illustrative view illustrating the dual-level matching concept, as provided by a flat vent assembly configuration  10  (having a cowl  20  and base  30 ) mounted atop a roof supporting surface SS (which could be provided by battens, a flat surface, or otherwise as known in the art). The flat vent assembly  10  is mounted in one course of tiles, which is above a course of tiles including tile A, and below a course of tile including tile B. As may be understood, the upper surface  20 S of the cowl  20  is substantially in the same plane P as is the upper surface of the flat tile B, while the upper major surface  30 S of the base  30  of the flat vent assembly  10  is aligned with the upper surfaces of other tiles in its same course.  
      It may also be understood that this same type of dual level matching applies to the other vent configurations. Although having a curved upper surface, the upper surface of the cowls of the assemblies  510 ,  710 , likewise tend to blend in with, match, and simulate the upper, curved, surfaces of the tiles in the next course above, while the curved upper major surfaces of the bases of these assemblies blend in with, match, and simulate the tiles in their same course.  
      Conclusion  
      Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.