Abstract:
A louver assembly for placement in an opening for regulating the inlet of air, comprising a first blade stack and second blade stack arranged in tandem, and a sill for supporting the first and second blade stack. The first and second blade stacks have a plurality of blades arranged in a horizontally-spaced and vertically-extending configuration defining a plurality of horizontally-spaced and vertical extending air passageways for the passage of air therethrough. The sill has a generally planar first portion for supporting the first blade stack and a sloped second portion for supporting the second blade stack, wherein the sloped portion and the second blade stack define therebetween a void for equalizing pressure within the assembly to facilitate the draining of water therefrom.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application Ser. No. 61/196,533, filed on Oct. 17, 2008, herein incorporated by reference in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates generally to a louver assembly that helps regulate the inlet of outside ambient air. More particularly, the invention relates to a storm louver assembly which substantially prevents air-born particulates (such as rain droplets) that are entrained in the ambient air, from passing therethrough and into the building or enclosure with which the louver assembly is associated. 
       BACKGROUND OF THE INVENTION 
       [0003]    Ventilation/HVAC systems for buildings and other enclosures are well known in the art. A core component of many ventilation systems is the need to regulate the influx of outside ambient air. One aspect of this regulation is the desired ability to prevent particulate matter from entering the ventilation system along with the outside ambient air, and louver assemblies have therefore been traditionally utilized to help control the flow of ambient air and any entrained particulate matter. 
         [0004]    Recent natural disasters and code modifications have placed larger burdens on the performance of louver assemblies that are integrated into various ventilation systems. In particular, recent code modifications have centered on reducing or eliminating the amount of rain water (i.e., water droplets) that are permitted to pass through the louver assembly and into the ventilation system as a whole. 
         [0005]    On this issue, louvers that attempt to separate water and other particles from air flowing into buildings are generally known in the art. As exemplified by U.S. Pat. No. 5,839,244, hereby incorporated by reference, such prior art louvers typically include a plurality of curved, spaced blades that define a plurality of spaced, serpentine-shaped air passageways therebetween. The air passageways direct air from the exterior of the building to the interior of the building for air conditioning of the building. 
         [0006]    When air passes into the building through the air passageways, the water particles in the air, which are heavier than the gas molecules in the air, cannot turn through the serpentine-shaped contours in the air passageways. The water molecules therefore strike the walls of the blades, agglomerate into drops and flow by gravity down the blades and out of the louvers. 
         [0007]    However, buildings in areas of the world that are especially prone to hurricanes face much tougher problems with the design of louvers. In such hurricane zones, wind-driven rain may sometimes pass through the louver and into the building. In other situations, rain may accumulate at the bottom of a louver and be pushed through the louver and into the building by a constant and steady airflow. In addition, hurricanes and tornadoes often pick up debris which may be propelled by strong winds into the louver. Depending on the size and speed of the debris, such debris may damage the louver and cause the localized yielding of welds, compromising the integrity and functionality of the louver. Moreover, increased wind speed and thus increased airflow often leads to blade flutter or “chatter,” which is undesirable. In hurricane zones, such as Miami-Dade County in the state of Florida, stringent building codes have recently been adopted which require louvers, dampers and the like to pass stringent tests for wind and wind-driven rain resistance. Additional building code provisions often require such louvers to pass missile impact, static load and cyclic load tests at varying speeds, pressures and cycles. 
         [0008]    Unfortunately, known louvers are simply not designed to withstand missile impacts of the size and speed often generated by strong storms such as hurricanes and tornadoes. Moreover, known louver assemblies have a substantial amount of blade “chatter” when subject to high winds or large airflow volumes. 
         [0009]    Therefore, in order to achieve a sufficient wind and wind-driven rain resistance, known louvers often employ a separate damper assembly behind the louver to block off water penetration. However, the closing of the damper to block off water penetration also blocks the flow of air into the building, which disqualifies such louver/damper systems from use in hurricane zones or other areas that frequently see high winds and large amounts of rain. 
         [0010]    Known louvers capable of expelling water are generally of two types. The first type is a louver that employs separate gutters or down spouts or other drainage systems for carrying the removed water away from the louver and out of the building. This type of louver is undesirable because a separate drainage system must be installed to carry the water out of the building. The second type of louver utilizes drain holes to expel water. In these louvers, there is an orifice or nozzle pressure present at these drain holes as well as in between each blade. However, until enough water builds up to overcome the orifice pressure and drain via the drain holes, the water built up inside the louver is carried though the louver and into the building with the airflow. An example of this type of louver is shown by U.S. Pat. No. 5,839,244 (Paul A. Johnson et al.). 
       SUMMARY OF THE INVENTION 
       [0011]    In view of the foregoing, it is an object of the present invention to provide a louver assembly capable of resisting the influx of wind-driven water without the use of a corresponding damper. 
         [0012]    It is another object of the present invention to provide a louver assembly having an improved blade design. 
         [0013]    It is another object of the present invention to provide a louver assembly having an improved blade design for absorbing a missile&#39;s inertial force and for allowing blade deformation without any localized yielding of welds. 
         [0014]    It is another object of the present invention to provide a louver assembly having an improved blade design to eliminate chatter under airflow. 
         [0015]    It is another object of the present invention to provide a louver assembly with an improved blade and sill design to facilitate the draining of water removed from the air away from the louver and out or away from the building. 
         [0016]    It is another object of invention to provide louver assembly that is designed to meet the stringent criteria established by the Florida Building Code and Miami-Dade County Building Code, including providing high volume flow rate, impact resistance, protection against water penetration and high wind-loads. 
         [0017]    The louver assembly of the present invention includes a plurality of stacks, positioned adjacent one another front to back. Each stack includes a plurality of elongated blades, each having opposed lower and upper edges and a support frame for supporting the blades in a horizontally-spaced and vertically extending configuration so that the blades define therebetween a plurality of horizontally-spaced and vertically extending air passageways for the passage of air into a building. The stacks are aligned so that the passageways of the first stack are aligned with the passageways of the second stack in the general direction of airflow so as to create uniform elongated air passageways. The preferred support frame includes a bottom frame member or sill for receiving and/or supporting the lower edges of the blades and a head frame member for receiving and supporting the upper edges of the blades. 
         [0018]    The preferred blades each include a screw boss at the leading edge of each blade. This screw boss acts as a “crush” point during missile impact, absorbing some of the missile&#39;s inertial force as well as allowing blade deformation without any localized yielding of welds. The preferred blades also include thicker leading and trailing edges, strengthening the blades over long spans and thus eliminating blade chatter under airflow. 
         [0019]    The preferred louver assembly also includes a sloped sill and square cut blades. This design creates a void under the back blade stack which acts to equalize the orifice pressure within the louver, allowing the water to easily drain, regardless of the pressures exerted at the face of the louver. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]    The present invention will be better understood from reading the following description of non-limiting embodiments, with reference to the attached drawings, wherein below: 
           [0021]      FIG. 1  is a simplified schematic front plan view of a louver assembly according to an embodiment of the present invention; 
           [0022]      FIG. 2  is a simplified schematic front plan view of the lover assembly of  FIG. 1  installed in an opening in a wall of a building according to an embodiment of the present invention; 
           [0023]      FIG. 3  is a sectional view of the louver assembly according to an embodiment of the present invention taken along line A-A of  FIG. 2 ; 
           [0024]      FIG. 4  is a simplified schematic side plan view of a louver assembly installed in an opening in a wall of a building according to an embodiment of the present invention; 
           [0025]      FIG. 5  is an enlarged top view of a blade of a louver assembly of  FIGS. 1-4  according to an embodiment of the present invention. 
           [0026]      FIG. 6  is a sectional view of the louver assembly according to an embodiment of the present invention taken along line B-B of  FIG. 1 ; 
           [0027]      FIG. 7  is a simplified schematic side plan view of a louver assembly according to an embodiment of the present invention; and 
           [0028]      FIG. 8  is an enlarged partial side view of the louver assembly and sill according to an embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0029]    One embodiment of a louver assembly of the present invention is indicated generally by reference numeral  10  in  FIG. 1 , and is designed to be inserted within an opening in a wall of a building to permit outside air to flow therethrough into the building while removing water particles from the air to prevent excess moisture from entering the building.  FIGS. 2 ,  3  and  4  show such a louver assembly positioned within an opening  12  in a building  14 . 
         [0030]    While the louver assembly  10  is discussed as being disposed within an opening in a wall of a building or the like, it will be readily appreciated, however, that the louver assembly  10  may be integrated into any known ventilation system, including those systems having stand-alone components, without departing from the broader aspects of the present invention. 
         [0031]    As best shown in  FIGS. 3 and 4 , the louver assembly comprises two vertical blade stacks, a first blade stack  16  and a second blade stack  18 , arranged in tandem such that the first blade stack  16  faces outside the building in which it is installed and the second blade stack  18  is positioned directly behind the first blade stack. 
         [0032]    With reference to  FIGS. 1-3 , each blade stack is bounded on the left side by a female jamb frame member  20  and on the right side by a male jamb frame member  22 . The support frame for the louver assembly further includes a head frame member  24  which is wide enough to receive the upper edges of the blades in each blade stack, and a sill  26  which supports the bottom of each blade stack and facilitates the draining of water from the louver assembly, as described below. The head frame member  24  may extend the entire horizontal length of the opening, thus receiving the upper edge of each blade. 
         [0033]    The male and female jamb members allow multiple louver assemblies to be joined together to span an opening of almost any dimension. In particular, when louvers are joined together or with additional louvers to span a wider opening, the end frame member on the right side of the left-most louver is replaced with a male-type jamb, and the end frame member on the left side of the right-most louver is replaced with a female-type end frame member. 
         [0034]    As alluded to above, each blade stack  16 ,  18  of the louver assembly  10  includes a plurality of vertically extending blades  28  which, in the preferred embodiment, are uniformly spaced apart. The support frame, comprising the male and female jamb frame members  20 ,  22 , the head frame member  24  and the sill  26 , supports the blades  28  in a horizontally-spaced and vertically extending configuration such that the blades define therebetween a plurality of horizontally-spaced and vertically extending air passageways  30  for directing air from an exterior of the building to an interior of the building. The blade stacks  16 ,  18  are aligned so that the passageways of the first stack are aligned with the passageways of the second stack in the general direction of airflow so as to create uniform, elongated and serpentine shaped air passageways. (See  FIG. 3 ). 
         [0035]    Referring now to  FIG. 5 , an exemplary blade  28  of the louver assembly  10  is shown. Each blade is preferably formed from extruded aluminum and presents a generally sine wave shaped profile having opposed lower and upper edges  32 ,  34 , opposed leading and trailing edges  36 ,  38  and opposed right and left vertically extending faces  40 ,  42 , respectively. 
         [0036]    The blades  28  are positioned in the intermediate locations of the stacks  16 ,  18  between jamb members  20 ,  22 . Each blade includes an arcuate hook  44  extending from its left face  40  in a direction generally towards the leading edge  36 , and a plurality of horizontally-spaced projections  46  and an L-shaped tab  48  extending outwardly from its right face  42 . Each blade  28  also includes a pair of enlarged tabs, a front tab  50  and a rear tab  52 , at its leading and trailing edges  36 ,  38 , respectively. The blades  28  also each include an angled tab  54  extending approximately from a point where the left face  40  meets the rear tab  54 . These features cooperate to impede the flow of air-driven water particles through the louver assembly, as discussed below. 
         [0037]    As further shown in  FIG. 5 , each blade  28  has a screw boss  56  formed in the front tab  50  adjacent the leading edge  36 . The screw boss  56  is generally defined by a semi-circular cutout, void or channel in the front tab  50  which extends for the vertical height of the blade  28 . The screw boss  56  acts as a “crush” point during missile impact, such as when debris may be throw at, or otherwise driven into, the louver assembly during high wind conditions. The screw boss  56  absorbs some of the missile&#39;s inertial force and allows for blade deformation without any localized yielding of welds. That is, the screw boss  56  allows for the leading and trailing edges  36 ,  38  to be manufactured thick enough to allow for the welding of the blades to the sill  26  while still allowing for blade deformation to absorb forces associated with missile impact. Moreover, as noted above, the blades  28  are configured with thicker front and rear tabs  50 ,  52 , which act to strengthen the blade spans, thus eliminating blade “chatter” under airflow. In the preferred embodiment, the front and rear tabs  50 ,  52  are at least wider than the distance between the left face  40  and right face  42  (i.e., the width of the blade span) of the blades  26 , and can even be twice or more times greater that the width of the blade span. 
         [0038]    Each blade stack, and the blades positioned therein, is supported by the sill  26 . As best shown in  FIG. 8 , the sill comprises a generally planar first portion  58  for supporting the first blade stack  16 , a sloped second portion  60  for accommodating and supporting the second blade stack  18 , and a generally vertically extending backsplash portion  62  adjacent the sloped second portion  60  for further preventing water particles from passing through the louver assembly into the interior of the building. Preferably, the sloped portion  60  is at an angle of approximately  14  degrees from horizontal. Importantly, lower edges  32  of the blades  28  of the second blade stack  18  are square-cut, i.e. not mitered, such that the lower edges  32  of the blades  28  of the second stack  18  and the sloped portion  60  of the sill  26  define therebetween a void  64 . 
         [0039]    Returning now to  FIGS. 3 and 5 , in operation, air is directed into a building through the louver assembly  10  in the direction of arrows A. As the air traverses the passageways  30 , the water particles in the air, which are heavier than the gas molecules in the air, cannot turn through the sine wave shaped contours. The water molecules therefore strike the walls of the blades  28  and are otherwise caught by the arcuate hook  44 , projections  46 , L-shaped tab  48  and angled tab  54  and removed from the air, thereby preventing the water molecules from passing through the assembly  10  and into the building. The water molecules that have been trapped by the blades  28  eventually agglomerate into drops and flow by gravity down the faces  40 ,  42  of the blades  28  to the sill  26  and out of the assembly, as hereinafter described. 
         [0040]    Prior art louvers, such as that disclosed in U.S. Pat. No. 5,839,244, utilize drain holes to expel water that collects at the bottom of the louvers. With such louvers, there is an orifice or nozzle pressure at these drain holes as well as between each blade, so that until enough water builds up to overcome the orifice pressure and drain via the drain holes, water accumulates inside the louver and is carried through the louver with airflow and into the building. 
         [0041]    With the present invention, however, the void  64  equalizes the pressure within the louver, allowing water to easily drain, regardless of pressures exerted at the face of the louver. Because the pressure within the louver assembly is equalized by the void  64 , water particles that have been caught by the blades are permitted to flow onto the sill  26  and drain off the front of the sill  26  and out of the assembly  10 . The sloped portion  60  of the sill  26  also aids in this draining by initiating a downhill stream of water, thereby pushing any water collected on the first planar portion  58  out of the assembly. 
         [0042]    As will be readily appreciated, this blade/sill configuration does not allow rain, even wind-driven rain to penetrate the louver assembly and enter the building. Accordingly, no damper is needed to ensure that water does not pass through the louver, even in high wind or hurricane conditions. As such, the louver assembly of the present invention may be used to regulate the influx of outside ambient air even in storm conditions. 
         [0043]    The components of each support frame described above are preferably formed from aluminum, but may also be formed of other suitable materials. When assembled, each blade stack  16 ,  18  is preferably 48″ wide by 48″ high, and 4″ deep. As assembled, the entire louver assembly  10  and its support frame is approximately 48″ wide by 48″ high, and 8″ deep, although multiple assemblies may be joined together as described above to span openings of greater dimension. In the preferred embodiment, the blades of each stack are uniformly spaced apart at a distance of approximately 1¼″, measured from the center of one blade tab to the center of the next adjacent blade tab. In addition, each blade  28  takes up approximately 1.705″ in width, measured from edge to edge, i.e., a point of tangential contact on the arcuate hook (left most edge) to a line drawn through the opposing edges of the tabs  50 ,  52  (right most edge). 
         [0044]    In the preferred embodiment, the sill  26  is approximately 8.3″ deep and 7.5″ tall, and may include an angle (not shown) or other supporting structure beneath the backsplash portion  62  for supporting the rear-most portion of the sill  26 . 
         [0045]    Mounting of the louver assembly inside an opening in a building can be done by various techniques known in the art. As shown in  FIGS. 3 ,  4  and  8 , such mounting can be accomplished via the use of complimentary brackets and screws secured to the louver frame and to the building. 
         [0046]    Although this invention has been shown and described with respect to the detailed embodiments thereof, it will be understood by those of skill in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed in the above detailed description, but that the invention will include all embodiments falling within the scope of this disclosure.