Roof mounted ventilation assembly

Abstract

A roof mounted ventilation assembly having an integrated supply and relief fan assembly. The assembly is drum shaped with a central portion circumferentially defined by centrifugal blades that extend between top and bottom plates. Both top and bottom plates have a central opening, respectively, and axial supply fan blades are disposed within the central opening of the top plate. A supply duct extends through the central portion, fluidly coupling the central openings. The supply duct fluidly communicates a roof-mounted air intake to a supply discharge plenum operatively associated with an interior space. An inlet collar is fluidly couples the remainder of the central portion not closed off by the supply duct to the interior space, wherein relief air in this remainder of the central portion is urged by the centrifugal blades out exhaust ducts to the external environment in a direction transverse relative to axial supply air.

What is claimed is: 
     
         1 . A roof mounted ventilation system for a structure, the system comprising:
 an integrated supply and relief fan assembly mounted to an upper portion of the structure;   an air inlet disposed above and relative to the integrated supply and relief fan assembly;   a supply discharge plenum fluidly coupled to the air inlet by way of a supply conduit, wherein the supply discharge plenum is disposed in an interior space of the structure; and   the integrated supply and relief fan assembly comprising a supply axial fan portion and a relief centrifugal fan portion, wherein the supply axial fan portion is fluidly coupled to the supply conduit, wherein the supply fan comprising a plurality of axial fan blades, and wherein the relief centrifugal fan portion fluidly couples the interior space with an external environment,   whereby the supply axial fan portion draws in a supply air flow from the air inlet.   
     
     
         2 . The system of  claim 1 , wherein a direction of a relief air flow urged by the relief centrifugal fan portion to the external environment is transverse relative a direction of the supply air flow. 
     
     
         3 . The system of  claim 1 , wherein the relief centrifugal fan portion comprises backward inclined centrifugal blades. 
     
     
         4 . The system of  claim 1 , wherein the relief centrifugal fan portion comprises forward curved centrifugal blades. 
     
     
         5 . The system of  claim 1 , further comprising a drive shaft operatively associated with the integrated supply fan and the relief fan assembly to drive both the supply axial fan portion and the relief centrifugal fan portion. 
     
     
         6 . The system of  claim 2 , wherein the drive shaft selectively pressurizes the interior space through a ratio of the supply air flow to a relief air flow. 
     
     
         7 . An integrated supply and relief fan assembly for a roof mounted ventilation system for a structure, the assembly comprising:
 a central portion circumferentially defined by a plurality of centrifugal blades that extend between top and bottom plates;   each said plate having a central opening;   an axial supply fan disposed within the central opening of the top plate;   a supply duct extending through the central portion, fluidly coupling the central openings; and   the plurality of centrifugal blades fluidly communicates with a remainder portion of the central portion outside the supply duct.