Ventilation fan

Abstract

A ventilation fan includes a scroll formed to define an interior space, an inlet opening into the interior space, and an outlet opening into the interior space and spaced apart from the inlet. A fan wheel is coupled to the scroll within the interior space and includes a plurality of fan blades configured to rotate about a vertical rotation axis to draw air into the interior space to ventilate a room positioned adjacent to the ventilation fan. An inlet collar is coupled to an exterior surface of a bottom wall of the scroll and extends through the inlet. The inlet collar has a upper, distal end located above a lower end of each of the plurality of fan blades when the ventilation fan is installed above or adjacent to a ceiling of the building.

1 . A ventilation fan comprising
 a scroll formed to define an interior space, an inlet opening into the interior space, and an outlet spaced apart from the inlet,   a fan wheel coupled to the scroll and arranged to lie within the interior space, the fan wheel including a plurality of fan blades configured to rotate about a vertical rotation axis to withdraw air into the interior space to ventilate a room positioned adjacent to the ventilation fan,   an inlet collar coupled to an exterior surface of a bottom wall of the scroll and extending through the inlet, the inlet collar having a upper, distal end located above a lower end of each of the plurality of fan blades, and   a fan grille arranged to overlie the inlet of the scroll, the fan grille including a perimeter rim adapted to engage a wall of the room when the fan grille is fully installed, a grille plate arranged to extend substantially parallel to and in spaced apart relation to the inlet, a plurality of louvers interconnecting the perimeter rim and an outer edge of the grille plate and spaced apart from one another to define a plurality of grille intake openings, and a flow director coupled to an interior surface of the grille plate facing toward the scroll and arranged to extend toward the inlet collar and the inlet to the scroll and to cooperate with the inlet collar to guide air being withdrawn through the plurality of grille intake openings into the inlet of the scroll.   
     
     
         2 . The ventilation fan of  claim 1 , wherein the flow director includes a proximal end fixed to the grille plate, a distal end arranged to lie at the inlet or within the interior space of the scroll, and a flow-director body extending between the proximal end and the distal end and having a diameter that decreases from the proximal end to the distal end. 
     
     
         3 . The ventilation fan of  claim 2 , wherein the flow-director body decreases exponentially from the proximal end to the distal end such that an outer surface of the flow-director body has a first slope at a first distance from the proximal end and a second slope at a second distance from the proximal end, the first slope being less than the second slope and the first distance being less than the second distance. 
     
     
         4 . The ventilation fan of  claim 3 , wherein the outer surface of the flow-director body cooperates with the inlet collar to provide a curved flow path between the flow-director body and the inlet collar. 
     
     
         5 . The ventilation fan of  claim 2 , wherein a diameter of the proximal end of the flow director is greater than a maximum diameter of the inlet collar. 
     
     
         6 . The ventilation fan of  claim 2 , wherein the flow-director body is hollow and the flow director further includes a noise-reducing filler within the flow-director body. 
     
     
         7 . The ventilation fan of  claim 1 , wherein the inlet collar includes a collar mount fixed to a bottom wall of the scroll, a collar elbow coupled to the collar mount, and a collar extension extending into the interior space and having the upper, distal end located above the lower end of each of the plurality of fan blades. 
     
     
         8 . The ventilation fan of  claim 7 , wherein the collar mount extends radially outward away from the collar elbow and the vertical rotation axis and the collar elbow has a convexly-shaped curvature relative to the fan grill. 
     
     
         9 . A ventilation fan comprising
 a scroll formed to define an interior space, an inlet opening into the interior space, and an outlet spaced apart from the inlet,   a fan wheel coupled to the scroll and arranged to lie within the interior space, the fan wheel including a plurality of fan blades configured to withdraw air into the interior space to ventilate a room positioned adjacent to the ventilation fan, and   a fan grille arranged to overlie the inlet of the scroll, the fan grille including a perimeter rim adapted to engage a wall of the room when the fan grille is fully installed, a grille plate arranged to extend substantially parallel to and in spaced apart relation to the inlet, a plurality of louvers interconnecting the perimeter rim and an outer edge of the grille plate and spaced apart from one another to define a plurality of grille intake openings, and a flow director coupled to an interior surface of the grille plate facing toward the scroll and arranged to extend through the inlet to the scroll to guide air being withdrawn through the plurality of grille intake openings and into the inlet of the scroll.   
     
     
         10 . A ventilation fan comprising
 a scroll formed to define an interior space, an inlet opening into the interior space, and an outlet spaced apart from the inlet,   a fan wheel coupled to the scroll and arranged to lie within the interior space, the fan wheel including a plurality of fan blades configured to withdraw air into the interior space to ventilate a room positioned adjacent to the ventilation fan, and   an inlet collar coupled to an exterior surface of a bottom wall of the scroll and extending through the inlet, the inlet collar having a upper, distal end located above a lower end of each of the plurality of fan blades.