Heat exchanger for a sealed cabinet

Claim 1

A sealed cabinet for housing heat generating electronic equipment, said cabinet comprising: a door on a face of the cabinet for access to the equipment, the door sealingly engaging the cabinet in a closed position; a head space within the cabinet and above the door; a heat exchanger mounted in the head space; a plurality of louvered openings in opposite faces of the cabinet for the passage of outside air through the heat exchanger; wherein the heat exchanger includes: a plurality of longitudinal air channels communicating with the louvered openings; a plurality of transverse air channels, the longitudinal and transverse air channels being formed by a plurality of layers of convoluted fins, wherein each of the layers is oriented approximately orthogonally with respect to an adjacent layer; a first plurality of fans for forcing outside air through the longitudinal air channels and the louvered openings; a second plurality of fans for forcing air within the sealed cabinet through the transverse air channels; a separating sheet disposed between adjacent layers; a layer of insulation lining inner faces of the head space adjacent the faces having the plurality of louvered openings; and an air filter disposed between the louvered openings and the first plurality of fans; wherein the first plurality of fans are adjacent each longitudinally opposed face of the heat exchanger and the second plurality of fans are adjacent each transversely opposed face of the heat exchanger.