Outdoor heat exchanger coil

Abstract

A coil system for an outdoor heat exchanger in a HVAC system. The coil system comprises an integrated subcooler coil section positioned between the primary coil section and the expansion valve. A distributor combines the individual refrigerant streams from the coils of the primary coil section into a single refrigerant stream before separating the stream among the different coils of the subcooler section. The subcooler coil section is positioned such that the incoming air stream is directed directly at the subcooler coil section to maximize the difference in temperature between the air stream and the refrigerant within the subcooler section.

What is claimed is: 
     
         1 . A heat exchanger for transferring heat between a refrigerant stream and an outdoor air stream in an HVAC system, comprising:
 a plurality of primary coils defining a first primary coil section and a second primary coil section, each primary coil receiving a portion of a primary refrigerant stream, the primary coils arranged in an outdoor airstream path such that the portions of the primary refrigerant stream exchange a first quantity of heat with the outdoor airstream path;   a plurality of subcooler coils defining a subcooler coil section having a front face mount orientation with respect to the plurality of primary coils, each subcooler coil receiving a portion of a subcooler refrigerant stream, the subcooler coils arranged such that the portions of subcooler refrigerant stream exchange a second quantity of heat with the outdoor airstream path; and   a subcooler distributor assembly fluidly coupled between the primary coil section and the subcooler coil section, wherein the subcooler distributor assembly receives the portions of primary refrigerant stream from each of the plurality of primary coils and combines the plurality of primary refrigerant streams into a subcooler refrigerant stream, wherein the subcooler refrigerant stream is separated into the portions of subcooler refrigerant stream, each subcooler refrigerant stream being directed into one of the subcooler coils.   
     
     
         2 . The heat exchanger of  claim 1 , wherein the first primary coil section defines a bottom primary coil section and the second primary coil section defines a top primary coil section. 
     
     
         3 . The heat exchanger of  claim 1 , wherein the front face mount orientation of the subcooler coil section positions the subcooler coil section in front of the bottom primary coil section, such that an outdoor air stream passes over the subcooler coils before contacting the primary coils of the bottom primary coil section. 
     
     
         4 . The heat exchanger of  claim 1 , wherein the subcooler distributor assembly comprises at least one venturi distributor in a vertical orientation, said vertical orientation promoting even distribution of the portions of subcooler refrigerant steam into each subcooler coil. 
     
     
         5 . The heat exchanger of  claim 1 , wherein the first primary coil section includes at least as many primary coils as the second primary coil section, and wherein the subcooler coil section has a front face mount orientation with respect to the first primary coil section. 
     
     
         6 . The heat exchanger of  claim 1 , wherein the second primary coil section includes at least as many primary coils as the first primary coil section, and wherein the subcooler coil section has a front face mount orientation with respect to the first primary coil section. 
     
     
         7 . The heat exchanger of  claim 1 , further comprising a first distributor assembly positioned between a refrigerant inlet and the plurality of primary coils, the first distributor assembly receiving a refrigerant inlet stream, the first distributor separating the refrigerant stream into the portions of primary refrigerant stream and directing each portion of primary refrigerant stream into the corresponding primary coil. 
     
     
         8 . The heat exchanger of  claim 7 , further comprising a second distributor assembly positioned between the subcooler coil section and a refrigerant outlet, the second distributor assembly receiving the portions of subcooler refrigerant stream and combining the portions of subcooler refrigerant stream into a refrigerant outlet stream. 
     
     
         9 . The heat exchanger of  claim 8 , wherein the first distributor assembly, the second distributor assembly and the subcooler distributor assembly each comprise at least one venturi distributor in a vertical orientation. 
     
     
         10 . A method for transferring heat between a refrigerant stream and an outdoor air stream in an HVAC system, comprising:
 separating a refrigerant stream into a plurality of primary coil streams, each primary coil stream being directed through a corresponding one of a plurality of primary coils positioned so as expose each primary coil to an outdoor air stream, wherein a first quantity of heat is transferred between each primary coil stream stream and the outdoor air stream;   collecting a portion of the plurality of primary coil streams exiting from the primary coils;   combining the portion of the plurality of primary coils stream into a subcooler coil stream;   separating the subcooler coil stream into a plurality of portions of subcooler coil stream; and   feeding each portion of subcooler coil stream through a corresponding one of a plurality of subcooler coils, each subcooler coil positioned to expose each subcooler coil to the outdoor air stream, wherein a second quantity of heat is transferred between each portion of subcooler coil stream and the outdoor air stream.   
     
     
         11 . The method of  claim 10 , further comprising:
 arranging the plurality of primary coils into a first primary coil section and a second primary coil section, wherein the portion of the plurality of primary coils streams is collected from the first primary coil section.   
     
     
         12 . The method of  claim 11 , further comprising:
 arranging the plurality of subcooler coil sections into a subcooler coil section; and   mounting the subcooler coil section to the first primary coil section such that the subcooler coil section has a front face mount orientation with respect to the outdoor air stream.   
     
     
         13 . The method of  claim 12 , wherein arranging the plurality of primary coils into the first primary coil section and the second primary coil section, further comprises:
 including at least as many primary coils in the first primary coil section as are included in the second primary coil section.   
     
     
         14 . The method of  claim 12 , wherein arranging the plurality of primary coils into the first primary coil section and the second primary coil section, further comprises:
 including at least as many primary coils in the second primary coil section as are included in the first primary coil section.   
     
     
         15 . The method of  claim 10 , wherein collecting a portion of the plurality of primary coil streams exiting from the primary coils, further comprises:
 collecting a condensed portion of the plurality of primary coil streams exiting from the primary coils.   
     
     
         16 . The method of  claim 10 , wherein combining the portion of the plurality of primary coils stream into a subcooler coil stream, further comprises:
 using a vertically oriented venturi distributor to combine the portions of the plurality of primary coils stream into the subcooler coil stream.