High efficiency ceiling fan

Abstract

Ceiling fan energy consumption efficiency is enhanced with fan blades that have an angle attack that decreases from root end to tip end at higher rates of decrease nearer their tip ends than at their root ends.

1 . A high efficiency ceiling fan having a plurality of fan blades mounted for rotation about a fan axis of blade rotation and with the blades having a greater angle of attack at a location adjacent said fan axis than distally said fan axis with the rate of change in angle of attack therebetween being non-uniform, the blade angle of attack decreasing continuously from adjacent said fan axis to distally said fan axis, and therein the blade angle of attack decreases at a plurality of incrementally different rates from adjacent said fan axis to distal said fan axis.  
   
   
       2 . The high efficiency ceiling fan of  claim 1  wherein the blade angle of attack decreases in two different incrementally fixed rates.  
   
   
       3 . The high efficiency ceiling fan of  claim 2  wherein the blade angle of attack decreases approximately 0.5 degrees per inch adjacent said fan axis to approximately 0.7 degrees per inch distally said fan axis.  
   
   
       4 . A high efficiency ceiling fan having a plurality of fan blades mounted for rotation about a fan axis of blade rotation and with the blades being twisted at a plurality of fixed rates of decrease as they extend from a position adjacent the fan axis at a twist rate that decreases non-uniformly from a position adjacent the motor to the blade tip end.  
   
   
       5 . The high efficiency ceiling fan of  claim 4  wherein the blade angle of attack decreases in two different incrementally fixed rates.  
   
   
       6 . The high efficiency ceiling fan of  claim 5  wherein the blade angle of attack decreases approximately 0.5 degrees per inch adjacent said fan axis to approximately 0.7 degrees per inch distally said fan axis.