Orifice boundary layer suction method and system

Abstract

An air-conveying device for use in an HVAC system having an interior surface and an exterior surface. An air-moving device is arranged and disposed to move air through the air-conveying device adjacent to the interior surface of the air-conveying device. The air-conveying device conveys air having passed through an HVAC heat exchanger. The air-conveying device includes one or more openings disposed and arranged to provide a pressure differential sufficient to cause passage of air through the openings from an area adjacent to the interior surface to an area adjacent to the exterior surface in order to decrease aerodynamic drag.

1 . An air-conveying device for use in an HVAC system comprising: 
 a passageway having an interior surface and an exterior surface opposite the interior surface;    the passageway being arranged and disposed to permit flow of air through the passageway adjacent to the interior surface upon activation of an air-moving device;    a plurality of openings in the passageway extending from the interior surface to the exterior surface, the plurality of openings being disposed and arranged to permit flow of air through the plurality of openings from an area adjacent to the interior surface to an area adjacent to the exterior surface in order to decrease aerodynamic drag in the passageway; and    wherein the flow of air through the plurality of openings occurs in response to a pressure difference between the interior surface and the exterior surface.    
   
   
       2 . The air-conveying device of  claim 1 , wherein the flow of air through the openings reduces an amount of power required by an air-moving device to move air through the passageway.  
   
   
       3 . The air-conveying device of  claim 1 , wherein the plurality of openings each have a substantially rectangular geometry.  
   
   
       4 . The air-conveying device of  claim 1 , wherein the plurality of openings each have a substantially circular geometry.  
   
   
       5 . The air-conveying device of  claim 1 , wherein the passageway is a diffuser for a heat exchanger unit in an HVAC system.  
   
   
       6 . The air-conveying device of  claim 5 , wherein the passageway has a substantially frustoconical geometry.  
   
   
       7 . The air-conveying device of  claim 1 , wherein the passageway is an orifice for a heat exchanger unit in an HVAC system.  
   
   
       8 . The air-conveying device of  claim 7 , wherein the orifice has a substantially cylindrical geometry.  
   
   
       9 . A method for reducing aerodynamic drag in an air-conveying device comprising: 
 providing an air-conveying device having an interior surface, and an exterior surface and openings extending between the interior surface and the exterior surface;    flowing air with an air-moving device through the air-conveying device; and    diverting a portion of airflow through the air-conveying device from an area of higher-pressure air adjacent to the interior surface to an area of lower pressure air adjacent to the exterior surface through the openings in the air-conveying device to increase the laminar flow of the air in the air-conveying device.    
   
   
       10 . The method of  claim 9 , wherein the diverting of air through the openings reduces the amount of power required by the air-moving device to move air through the air-conveying device.  
   
   
       11 . The method of  claim 9 , wherein the step of providing an air-conveying device includes locating the openings around the perimeter of the air-conveying device.  
   
   
       12 . The method of  claim 9 , wherein the step of providing an air-conveying device includes locating the openings adjacent to an exit of the air-conveying device.  
   
   
       13 . The method of  claim 9 , wherein the air-conveying device is a diffuser for a heat exchanger unit in an HVAC system.  
   
   
       14 . The method of  claim 13 , wherein the diffuser has a substantially frustoconical geometry.  
   
   
       15 . The method of  claim 9 , wherein the air-conveying device is an orifice for a heat exchanger unit in an HVAC system.  
   
   
       16 . The method of  claim 15 , wherein the orifice has a substantially cylindrical geometry.  
   
   
       17 . A heat exchanger unit for an HVAC system comprising: 
 a housing having an interior space;    a heat exchanger coil disposed in the housing;    an air-moving device disposed in the housing to move air through the heat exchanger coil and the housing; and    an air-conveying device being arranged and disposed to permit flow of air from the interior space of the housing upon operation of the air-moving device, the air-conveying device comprising: 
 an interior surface and an exterior surface opposite the interior surface;  
 a plurality of openings extending from the interior surface to the exterior surface, the plurality of openings being disposed and arranged to permit flow of air through the plurality of openings from an area adjacent to the interior surface to an area adjacent to the exterior surface in order to decrease aerodynamic drag in the air-conveying device; and  
 wherein the flow of air through the plurality of openings occurs in response to a pressure difference between the interior surface and the exterior surface.  
   
   
   
       18 . The heat exchanger unit of  claim 17 , wherein the flow of air through the openings reduces an amount of power required by the air-moving device.  
   
   
       19 . The heat exchanger unit of  claim 17 , wherein the plurality of openings each have a substantially rectangular geometry.  
   
   
       20 . The heat exchanger unit of  claim 17 , wherein the plurality of openings each have a substantially circular geometry.  
   
   
       21 . The heat exchanger unit of  claim 17 , wherein the air-conveying device is a diffuser.  
   
   
       22 . The heat exchanger unit of  claim 21 , wherein the air-conveying device has a substantially frustoconical geometry.  
   
   
       23 . The heat exchanger unit of  claim 17 , wherein the air-conveying device is an orifice.  
   
   
       24 . The air-conveying device of  claim 23 , wherein the orifice has a substantially cylindrical geometry.