A data center cooling system includes an outer container that defines a first volume; an inner container that defines a second volume and is positioned within the first volume, the inner container including an air outlet that includes an airflow path between the first and second volumes; a liquid seal to fluidly isolate a liquid phase of a non-conductive coolant that fills at least a portion of the first and second volumes from an ambient environment; and a plurality of electronic heat-generating devices at least partially immersed in the liquid phase of the non-conductive coolant to transfer a heat load to the non-conductive coolant.