Patent Publication Number: US-6220956-B1

Title: Soffit fan

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Not Applicable 
     STATEMENT REGARDING FED SPONSORED R &amp; D 
     Not Applicable 
     REFERENCE TO MICROFICHE APPENDIX 
     Not Applicable 
     BACKGROUND OF THE INVENTION 
     This invention relates to attic/roofing ventilation systems, specifically to a forced air system. 
     Buildings have long incorporated ventilation systems in their attics or roof crawl spaces. Current systems include natural convection systems, a combination of soffit vents, roof vents, gable vents, and ridge vents; forced air systems, a combination of natural convection methods and roof/gable fans; and turbines, a combination of natural convection methods and non-powered turbines. These systems are intended to prevent and remove excessive heat and moisture buildup from attic or roof crawl spaces, or similar spaces. The removal of the excess heat and moisture would lower energy costs for cooling and heating, and would preserve and add longevity to roofing systems. 
     Current systems are unable to adequately remove the excessive heat trapped in attic spaces. Natural convection systems must wait for attic space air to become heated and expand before cooler air can begin to filter into the attic space. This waiting period, ultimately, is allowing radiant heat to get a jump-start on heating the attic space. 
     Forced air systems and turbines rely on the suction of less dense air and are, therefore, inefficient. This inefficiency is similar to the flight limitations of a helicopter. Helicopters are limited by altitude because air becomes less dense at higher altitudes. A helicopter reaches maximum altitude when the motion of the blades through the less dense air cannot generate enough lift to compensate for the weight of the aircraft. Thus, air density directly relates to the efficiency of the blades of a helicopter or a fan. 
     As a result of current systems&#39; inadequacies, there is a need for a more efficient and effective ventilation system that will help to provide more comfortable living, to lower energy costs for cooling and heating, and to preserve and add longevity to roof and shingle lives. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention provides an apparatus for use in ventilating an attic or roof crawl space, or similar space, which becomes a heat and/or moisture trap. The invention increases air flow in the attic space, and therefore improves ventilation and provides many advantages. 
     Accordingly, several objects and advantages of the invention are: 
     (a) to provide an apparatus that will help to lower energy costs for cooling and heating; 
     (b) to provide an apparatus that will add longevity to roofing systems; 
     (c) to provide an apparatus that will accelerate natural convection venting of heated, trapped air from an attic space; 
     (d) to provide an apparatus that will reduce heat loading within a building; 
     (e) to provide an apparatus that will control moisture due to humidity within an attic space; 
     (f) to provide an apparatus that will reduce moisture due to condensation within an attic space; 
     (g) to provide an apparatus that can be installed on new construction or onto existing buildings; and 
     (h) to provide an unobtrusive, inconspicuous ventilation apparatus. 
     Further objects and advantages are to provide an apparatus whose production requires minimal new tooling resulting in its relatively inexpensive manufacture. Still further objects and advantages will become apparent from a consideration of the ensuing description and drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the invention shown in an elevation view in section of the upper portion or attic space of a building such as a house. 
     FIG. 2 is a perspective view of the invention mounted in a soffit. 
     FIG. 3A is a view in section from the ground up of the major components of the invention mounted in a soffit when the invention is not in operation. 
     FIG. 3B is a view in section from the ground up of the major components of the invention mounted in a soffit when the invention is in operation. 
     FIG. 4 is an exploded detailed view of the invention. 
    
    
     REFERENCE NUMERALS IN DRAWINGS 
     
       
         
           
               
               
               
             
               
                   
                   
               
             
            
               
                   
                 10 conventional roof 
                 12 attic or roof crawl space 
               
               
                   
                 14 building 
                 16 air flow 
               
               
                   
                 18 roof ridge ventilator 
                 20 ridge opening 
               
               
                   
                 22 ceiling 
                 26 soffit 
               
               
                   
                 28 screen 
                 30 soffit fan 
               
               
                   
                 32 soffit vent 
                 34 temperature/moisture switch 
               
               
                   
                 36 louver 
                 38 fan guard 
               
               
                   
                 40 mounting bracket assembly 
                 42 mounting screw 
               
               
                   
                 44 fan 
                 46 electrical cord 
               
               
                   
                 48 louver stopper 
               
               
                   
                   
               
            
           
         
       
     
     DETAILED DESCRIPTION OF THE INVENTION 
     As shown in FIG. 1, a building  14  is comprised of a conventional roof  10  that surmounts and partially encloses a space typically referred to as an attic or roof crawl space  12 . Attic  12  is further bound and defined by upper surface portions of a ceiling  22 . A ridge opening  20  is located at the top of roof  10  in a roof ridge ventilator  18 . A temperature/moisture switch  34  is mounted in the upper portion of attic  12 . A soffit fan  30  is located in a soffit  26  under the eaves of roof  10 . 
     FIG. 2 shows a closer look at the placement of soffit fan  30  in building  14 . Typical placement of soffit fan  30  is under the eave of roof  10 , between the end of the eave and the wall, in the center of soffit  26  and along the same line as a soffit vent  32 . The top of soffit fan  30  is in attic  12 . 
     FIGS. 3A and 3B show the appearance of the major components of soffit fan  30  installed in soffit  26  along the same line as soffit vent  32 . Both Figs show a mounting bracket assembly  40  that is used to attach soffit fan  30  to soffit  26  using mounting screws  42 . Both Figs also show a fan guard  38 , a fan  44 , a set of louvers  36 , and a screen  28 . The difference between FIGS. 3A and 3B is that FIG. 3A depicts soffit fan  30  while not operating and FIG. 3B depicts soffit fan  30  while operating. Note in FIG. 3A that fan  44  is motionless and louvers  36  are closed whereas in FIG. 3B, the blades of fan  44  are not seen as a result of their motion, thus giving the illusion of translucence and louvers  36  are open. 
     FIG. 4 shows a breakdown of soffit fan  30 . From top to bottom, soffit fan  30  is described as follows. Fan guard  38  is attached to fan  44 . An electrical cord  46  is attached to fan  44  to provide power. Fan  44  is connected to mounting assembly  40 . Louvers  36  are attached to mounting assembly  40 . Louvers  36  are fully open once they come in contact with and are stopped by a louver stopper  48 . Finally, screen  28  covers mounting assembly  40 . 
     Operation of soffit fan  30  will now be explained. 
     Referring to FIG. 1, when temperatures rise and solar heat is incident on roof  10 , typically the result is a substantial increase in thermal loading in attic  12  and a radiant heat trap. The trapped attic air expands as it is heated. In order to vent this undesirable trapped heat in attic  12 , switch  34  signals soffit fan  30  to begin operating. Alternatively, a sensed moisture difference between ambient air and the air located in attic  12  could trigger switch  34  to signal soffit fan  30  to begin operating. 
     When fan  44  begins operating, the suction of an air flow  16  causes louvers  36  to open until they come in contact with a louver stopper  48 , as shown in FIG.  4 . Air flow  16  enters into attic  12 . 
     Referring to FIG. 4, fan guard  38  protects fan  44  from debris and insulation in attic  12 . Screen  28  covers soffit fan  30  on the outside to aid in preventing insect infestation, bird nesting, and other foreign object damage or intrusion. Louvers  36  are used to aid in preventing foreign object intrusion and to provide an unobtrusive, inconspicuous appearance. A view from the ground up at the major components of soffit fan  30  while it is operating is shown in FIG.  3 B. Note that louvers  36  are open and that the blades of fan  44  are not seen as a result of their motion giving the illusion of translucence. 
     Referring to FIG. 1, air flow  16  is being pulled by soffit fan  30  into attic  12 . Air is also entering attic  12  through soffit vents  32 . As this cooler air flow  16  enters attic  12 , it displaces the heated and/or moisture-laden air. The displaced air rises and is expelled through ridge opening  20  in roof ridge ventilator  18 . Because soffit fan  30  significantly increases cooler air flow  16  into attic  12 , this process accelerates natural convection. 
     Accelerated natural convection continues until attic  12  temperature and/or moisture decreases and switch  34  signals soffit fan  30  to cease operating. Once fan  44  stops, soffit fan  30  returns to its dormant state with louvers  36  closed due to gravity, as shown in FIG.  3 A. 
     Conclusion, Ramifications, and Scope 
     Accordingly, the reader will see that the soffit fan of this invention provides efficient accelerated natural convection ventilation in attic or roof crawl spaces. In addition, the soffit fan has additional advantages in that: 
     it helps lower energy costs related to cooling and heating 
     it helps prolong and preserve roof and shingle lives 
     it helps reduce heat loading in buildings 
     it helps reduce moisture in attic or roof crawl spaces 
     it is an unobtrusive, inconspicuous ventilation apparatus 
     Although the description above contains many specificities, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of the invention. Many other variations are possible. For example, the soffit fan is not limited by shape, it can have other shapes such as square, circular, oval, etc.; the screen cover is optional; the louvered system may be substituted, altered, or omitted; fasteners may be substituted or altered; power may come from an alternate source; the fan type, classification, specifications, and parameters are not limited; etc. 
     Thus the scope of the invention should be determined not by the examples given, but by the appended claims and their legal equivalents.