Recessed fan inlet cover

Abstract

A recessed fan inlet cover, for covering an enclosure inlet opening of an exhaust fan enclosure to provide an air flow channel into the fan enclosure while impeding sound emission from the fan enclosure, the fan inlet cover comprising: a cover frame having an outer peripheral edge extending outward of the enclosure inlet opening and having an inner edge defining a substantially planar frame surface, the frame having an upwardly recessed mounting surface joined to the inner edge with an arcuate wall, the mounting surface having an intake opening; and a cover plug mounted to the recessed mounting surface downwardly spaced from the mounting surface, the plug having a substantially planar plug surface co-planar with said frame surface, the plug having an outer peripheral edge with an inwardly projecting lip, the plug having a sound absorbing layer on an upper surface opposite said planar plug surface; wherein an air flow channel is defined between said arcuate wall and said lip.

1 . A recessed fan inlet cover, for covering an enclosure inlet opening of an exhaust fan enclosure to provide an air flow channel into the fan enclosure while impeding sound emission from the fan enclosure, the fan inlet cover comprising:
 a cover frame having an outer peripheral edge extending outward of the enclosure inlet opening and having an inner edge defining a substantially planar frame surface, the frame having an upwardly recessed mounting surface joined to the inner edge with an arcuate wall, the mounting surface having an intake opening; and   a cover plug mounted to the recessed mounting surface downwardly spaced from the mounting surface, the plug having a substantially planar plug surface co-planar with said frame surface, the plug having an outer peripheral edge with an inwardly projecting lip, the plug having a sound absorbing layer on an upper surface opposite said planar plug surface; wherein an air flow channel is defined between said arcuate wall and said lip.   
     
     
         2 . The recessed fan inlet cover of  claim 1  wherein the air flow channel has an intake area relative to an enclosure inlet opening area is in the range of 40-60 percent. 
     
     
         3 . The recessed fan inlet cover of  claim 2  wherein the air flow channel has an intake area relative to an enclosure inlet opening area is in the range of 45-55 percent. 
     
     
         4 . The recessed fan inlet cover of  claim 1  including a sloping planar wall extending upwardly and inwardly from the the inner edge to the arcuate wall.