Fan Blade

Abstract

A heating, ventilation, and/or air conditioning (HVAC) system includes an outdoor unit having an outdoor fan configured to generate an airflow. The outdoor fan includes a fan blade assembly having a plurality of fan blades. Each fan blades is formed from a constant and/or uniform thickness material and includes an upwardly curved leading edge that causes a lower surface of the fan blade to contact the air first as the fan blade assembly is rotated and causes air attachment to the lower surface such that an eddy of air is trapped, recirculated, and/or generally passed more slowly through a recirculation zone, defined generally as the angularly trailing space behind the upwardly curved leading edge and between the upwardly curved leading edge and the remainder of an upper surface.

What is claimed is: 
     
         1 . A heating, ventilation, and/or air conditioning (HVAC) system, comprising:
 a fan blade assembly, the fan blade assembly comprising:
 at least one fan blade comprising an upwardly curved leading portion. 
   
     
     
         2 . The HVAC system of  claim 1 , wherein the upwardly curved leading portion is configured to serve as a boundary for an air recirculation zone. 
     
     
         3 . The HVAC system of  claim 1 , wherein the upwardly curved leading portion is configured to cause a lower surface of the at least one fan blade to serve as a leading portion of the at least one fan blade. 
     
     
         4 . The HVAC system of  claim 1 , wherein the upwardly curved leading portion is configured to attach flow to the low pressure side of the fan blade. 
     
     
         5 . The HVAC system of  claim 4 , wherein an upper surface of the at least one fan blade is configured to serve as a trailing boundary for the air recirculation zone. 
     
     
         6 . The HVAC system of  claim 1 , wherein the upwardly curved leading portion comprises at least one of a stamped form and a substantially single thickness material. 
     
     
         7 . The HVAC system of  claim 1 , wherein the upwardly curved leading portion comprises a hook configured to serve as a leading boundary for an air recirculation zone. 
     
     
         8 . The HVAC system of  claim 1 , wherein the fan blade assembly comprises two or more fan blades. 
     
     
         9 . The HVAC system of  claim 1 , wherein the at least one fan blade comprises stamped sheet aluminum. 
     
     
         10 . The HVAC system of  claim 1 , wherein the at least one fan blade comprises stamped sheet steel. 
     
     
         11 . The HVAC system of  claim 1 , wherein the at least one fan blade comprises plastic. 
     
     
         12 . The HVAC system of  claim 1 , wherein the at least one fan blade is based on a transformation of the Gottingen 417a profile. 
     
     
         13 . A method of manufacturing a fan blade, comprising:
 providing a sheet of substantially constant thickness material; and   stamping the sheet into a form comprising at least one of an upwardly curved leading portion.   
     
     
         14 . The method of  claim 13 , wherein the sheet comprises metal. 
     
     
         15 . The method of  claim 13 , wherein the form is based on a transformation of the Gottingen 417a profile. 
     
     
         16 . The method of  claim 13 , wherein the upwardly curved leading portion is configured to serve as a leading boundary for an air recirculation zone. 
     
     
         17 . A fan blade, comprising:
 a uniform thickness material; and   a upwardly curved leading portion.   
     
     
         18 . The fan blade of  claim 17 , wherein the single thickness material comprises stamped sheet metal. 
     
     
         19 . The fan blade of  claim 17 , wherein the upwardly curved leading portion is configured to serve as a boundary for an air recirculation zone. 
     
     
         20 . The fan blade of  claim 17 , wherein the upwardly curved leading portion is configured to cause a lower surface of the fan blade to serve as a leading portion of the fan blade.