Hydrophobic heat exchangers

Abstract

A heat exchanger may be a refrigeration heat exchanger including a plurality of fins having a fin density greater than ten fins per inch, or may be a heat pump heat exchanger having a fin density of greater than eighteen fins per inch. Either heat exchanger includes a hydrophobic coating disposed on the plurality of fins for limiting the accumulation of frost.

1 . A heat pump heat exchanger comprising:
 a plurality of fins having a fin density greater than eighteen fins per inch; and   a hydrophobic coating disposed on the plurality of fins for limiting the accumulation of frost.   
     
     
         2 . The heat pump heat exchanger set forth in  claim 1 , wherein the heat pump heat exchanger is an evaporator. 
     
     
         3 . The heat pump heat exchanger set forth in  claim 2 , wherein the heat pump evaporator is a MCHX and at least one of the plurality of fins include a louver having a louver angle of about less than thirty-five degrees. 
     
     
         4 . The heat pump heat exchanger set forth in  claim 3 , wherein the plurality of fins include a variable fin density through a depth of the heat pump evaporator. 
     
     
         5 . The heat pump heat exchanger set forth in  claim 4 , wherein the plurality of fins include a wavy geometry. 
     
     
         6 . The heat pump heat exchanger set forth in  claim 4 , wherein the plurality of fins include a lanced geometry. 
     
     
         7 . The heat pump heat exchanger set forth in  claim 4 , wherein the plurality of fins include a louvered geometry. 
     
     
         8 . A refrigeration heat exchanger comprising:
 a tube for flowing a first heat transfer fluid;   a plurality of fins engaged to the tube and having a fin density greater than ten fins per inch, and wherein the plurality of fins are constructed to transfer heat from an adjacent airflow, through the tube and to the first heat transfer fluid; and   a hydrophobic coating disposed on the plurality of fins for limiting the accumulation of frost.   
     
     
         9 . The refrigeration heat exchanger set forth in  claim 8 , wherein the plurality of fins include a variable fin density through a depth of the refrigeration heat exchanger. 
     
     
         10 . The refrigeration heat exchanger set forth in  claim 9 , wherein the plurality of fins include a wavy geometry. 
     
     
         11 . The refrigeration heat exchanger set forth in  claim 9 , wherein the plurality of fins include a lanced geometry. 
     
     
         12 . The refrigeration heat exchanger set forth in  claim 9 , wherein the plurality of fins include a louvered geometry. 
     
     
         13 . The refrigeration heat exchanger set forth in  claim 9 , wherein the refrigeration heat exchanger is an evaporator and the first heat transfer fluid is a refrigerant. 
     
     
         14 . The refrigeration heat exchanger set forth in  claim 9 , wherein the first heat transfer fluid is a secondary coolant. 
     
     
         15 . The refrigeration heat exchanger set forth in  claim 13 , wherein the refrigeration evaporator is a MCHX and at least one of the plurality of fins include a louver having a louver angle of about less than thirty-five degrees.