In thermal management systems that employ EHD devices to motivate flow of air through an enclosure, spatial distribution of a ventilation boundary may facilitate reductions in flow resistance by reducing average transit distance for cooling air from an inlet portion of the ventilation boundary to an outlet portion. Some thermal management systems described herein distribute a ventilation boundary over opposing surfaces, adjacent surfaces or even a single surface of an enclosure while providing a short, “U” shaped, “L” shaped or generally straight through flow path. In some cases, spatial distributions of the ventilation boundary facilitate or enable enclosure geometries for which conventional fan or blower ventilation would be impractical. In some cases, provision of multiple portions of the ventilation boundary may allow the thermal management system to tolerate blockage or occlusion of a subset of the inlet and/or outlet portions and, when at least some of such portions are non-contiguous spatially-distributed, tolerance to a single cause of blockage or occlusion is enhanced.