Brazed aluminum heat exchanger

A method of manufacturing an aluminum heat exchanger, comprising:

• providing a fin having a first aperture therethrough with a flange formed around said first aperture, said fin made from a first alloy having a first melting point;
• passing a refrigerant tube through said first aperture, said refrigerant tube made from a second alloy having a second melting point;
• placing a tubular coupling on an end of said refrigerant tube, said tubular coupling made from a third alloy having a third melting point, said tubular coupling configured to couple to said tube end;
• interposing a fourth alloy between said refrigerant tube and said fin, and further interposing said fourth alloy between said refrigerant tube and said tubular coupling, said fourth alloy having a fourth melting point less than said first, second, and third melting points;
• subjecting said heat exchanger to a temperature greater than said fourth melting point but less than said first, second, or third melting points;
• and
• cooling said heat exchanger to an ambient temperature less than said fourth melting point.

A refrigeration unit, comprising:

• a heat exchanger forming a part of a refrigeration unit, said heat exchanger having:
• a fin having a first aperture therethrough with a flange formed around said first aperture, said fin made from a first aluminum alloy having a first melting point;
• a refrigerant tube made from a second aluminum alloy having a second melting point, said refrigerant tube extending through said first aperture;
• a tubular coupling made from a third aluminum alloy having a third melting point and coupled to an end of said refrigerant tube;
• and
• a fourth aluminum alloy having a fourth melting point less than said first, second, and third melting points, said fourth aluminum alloy interposed said refrigerant tube and said flange, and further interposed said refrigerant tube and said tubular coupling, and
• a compressor;
• an expansion valve;
• and
• refrigerant tubing coupling said heat exchanger, said compressor, and said expansion valve together in a closed system.