A lattice wick system has a plurality of granular wicking walls configured to transport liquid through capillary action in a first direction, each set of the plurality of granular wicking walls forming respective vapor vents between them to transport vapor. Granular interconnect wicks are embedded between respective pairs of the granular wicking walls to transport liquid through capillary action in a second direction substantially perpendicular to the first direction. The granular interconnect wicks have substantially the same height as said granular wicking wall so that the plurality of granular wicking walls and granular interconnect wicks enable transport of liquid through capillary action in two directions and the plurality of vapor vents transport vapor in a direction orthogonal to the first and second directions.