Ventilation fan

Abstract

A fan wheel for a ventilation fan, the fan wheel having a wheel hub defining a rotation axis. A plurality of fan blades extend from an outer edge of the wheel hub and are spaced apart circumferentially about the rotation axis. Each of the plurality of the fan blades is arranged to lie at an angle relative to a horizontal plane perpendicular to the rotation axis resulting in a distal end of each of the fan blades being positioned circumferentially forward of a proximal end of each corresponding fan blade in a direction of travel of the fan wheel about the rotation axis.

1 . A ventilation fan comprising:
 a scroll defining an interior space, an inlet opening into the interior space, and an outlet spaced apart from the inlet,   a fan wheel arranged within the interior space and defining a rotation axis, the fan wheel comprising
 a wheel hub and 
 a plurality of fan blades each defining a proximal end coupled to the wheel hub and each fan blade extending from the wheel hub parallel to the rotation axis to a distal end, 
 wherein the distal end of at least a first of the plurality of fan blades is located circumferentially forward of a proximal end of the first of the plurality of fan blades, and 
   a motor configured to drive rotation of the fan wheel about the rotation axis in a direction of travel.   
     
     
         2 . The ventilation fan of  claim 1 , wherein the distal end of the first of the plurality of fan blades is located circumferentially forward of a proximal end of the first of the plurality of fan blades along the direction of travel of the fan wheel. 
     
     
         3 . The ventilation fan of  claim 1 , wherein the plurality of fan blades are spaced apart circumferentially about the rotation axis. 
     
     
         4 . The ventilation fan of  claim 1 , wherein the distal end of the first of the plurality of fan blades is located circumferentially forward of a proximal end of the first of the plurality of fan blades to define an angle in the range of 68 degrees to 82 degrees with respect to the rotation axis. 
     
     
         5 . The ventilation fan of  claim 4 , wherein the angle is 80 degrees. 
     
     
         6 . The ventilation fan of  claim 4 , the first of the plurality of fan blades comprises an inner edge and an outer edge located radially outward of the inner edge, and wherein the angle is defined at the outer edge of the first of the plurality of fan blades. 
     
     
         7 . The ventilation fan of  claim 6 , wherein the inner edge of the distal end of the first of the plurality of fan blades is located circumferentially forward of the inner edge of the proximal end of the first of the plurality of fan blades along the direction of travel of the fan wheel to define an inner edge angle in the range of 1 degree to 15 degrees greater than the angle of the outer edge. 
     
     
         8 . A fan wheel for a ventilation fan, the fan wheel comprising:
 a wheel hub coupled to a motor for rotation about a rotation axis, and   a plurality of fan blades coupled to an outer edge of the wheel hub and spaced apart circumferentially about the rotation axis, and   wherein each of the fan blades is arranged to lie at an angle relative to a horizontal plane perpendicular to the rotation axis such that a distal end of each of the blades is located circumferentially forward of a proximal end of each corresponding fan blade in a direction of travel of the fan wheel about the rotation axis.   
     
     
         9 . A fan wheel for a ventilation fan, the fan wheel defining a rotation axis and comprising:
 a wheel hub; and   a plurality of fan blades, a first of the plurality of fan blades comprising:
 a proximal end coupled to the wheel hub and the first of the plurality of fan blades extending from the wheel hub parallel to the rotation axis to a distal end, and 
 a fan blade inner edge located radially inward a fan blade outer edge, 
   wherein the outer edge at the distal end is located circumferentially forward of the outer edge at the proximal end to define an angle with respect to the rotation axis.   
     
     
         10 . The fan wheel of  claim 9 , wherein the angle is in the range of 68 degrees to 82 degrees. 
     
     
         11 . The fan wheel of  claim 10 , wherein the angle is 80 degrees. 
     
     
         12 . The fan wheel of  claim 10 , wherein each of the plurality of blades is configured the same as the first of the plurality of blades. 
     
     
         13 . The fan wheel of  claim 10 , wherein the inner edge of the distal end is located circumferentially forward of the inner edge of the proximal end to define an inner edge angle with respect to the rotation axis. 
     
     
         14 . The fan wheel of  claim 13 , wherein the inner edge angle is in the range of 1 degree to 15 degrees greater than the angle of the outer edge. 
     
     
         15 . The fan wheel of  claim 14 , wherein each of the plurality of blades is configured the same as the first of the plurality of blades. 
     
     
         16 . The fan wheel of  claim 15 , wherein the plurality of fan blades are spaced apart circumferentially about the rotation axis. 
     
     
         17 . The fan wheel of  claim 9 , wherein the first fan blade comprises a concave side extending between the inner and outer edges and a convex side extending between the inner and outer edges. 
     
     
         18 . The fan wheel of  claim 9  configured to be located in a scroll defining an interior space, an inlet opening into the interior space, and an outlet spaced apart from the inlet, and the fan wheel is configured to be situated in the scroll such that the distal end of the first of the plurality of fan blades is located adjacent to the inlet opening. 
     
     
         19 . The fan wheel of  claim 9 , wherein the wheel hub is configured to connect to a motor to cause rotation of the fan wheel. 
     
     
         20 . The fan wheel of  claim 9 , wherein the inner edge is curved along from the proximal end to the distal end.