Cross-flow heat exchanger

A heat exchanger extending laterally in a first direction and a second direction, the heat exchanger comprising:

• a plurality of tubes extending in the first direction through which a first fluid is configured to flow, each of the plurality of tubes having waves that repeat at regular intervals along the first flow direction and being spaced from one another vertically and laterally in the second direction;
• a header extending in the first direction and attached to each of the plurality of tubes, the header being configured to convey the first fluid to each of the plurality of tubes;
• and
• a plurality of flow voids formed between the plurality of tubes, the plurality of flow voids extending in the second direction through which a second fluid is configured to flow such that the second fluid is in thermal contact with the plurality of tubes,
• wherein the plurality of tubes are arranged laterally in rows with tubes being vertically offset from adjacent tubes to form a zig-zag pattern such that the second fluid is able to contact an entire surface of each tube to provide increased thermal energy transfer.