Air-cooled heat exchanger and thermal arrangement for stacked electronics

An air-cooled heat exchanger comprising:

• a casing, said casing having a first end and a second end and being elongated in an axial direction between said first end and said second end, said casing comprising an accommodating space with a first air inlet into said accommodating space, a second air inlet into said accommodating space, and an air outlet positioned on a first side of said casing between said first air inlet and said second air inlet;
• wherein said first air inlet is positioned at said first end of said casing, and said second air inlet is positioned at said second end of said casing;
• wherein said air outlet is centrally positioned on said first side of said casing, being substantially midway between said first air inlet and said second air inlet;
• a first plurality of high density fins, said first plurality of high density fins positioned within the accommodating space between said first air inlet and said air outlet to define a first flow path;
• a second plurality of high density fins, said second plurality of high density fins positioned within the accommodating space between said second air inlet and said air outlet to define a second flow path;
• wherein said second flow path is separated from said first flow path;
• wherein a direction of said first flow path in said first plurality of fins between said first air inlet and said air outlet is opposite to a direction of said second flow path in said second plurality of fins between said second air inlet and said air outlet, to exchange heat away from an entire length in the axial direction of a second side and from at least a majority of a length of said first side of said elongated casing;
• and
• a fan positioned to drive air into each of said first air inlet and said second air inlet.