A data center system includes a container to contain electronic racks of IT components operating therein, a cooling unit disposed underneath the electronic racks to receive cool liquid from a chiller unit, to exchange heat generated from the IT components, and to transmit the hot liquid carrying the exchanged heat back to the chiller unit. Each electronic rack includes a housing to house IT components arranged in a stack, a first rack aisle formed on a first side of the IT components to direct cool air received from the cooling unit upwardly, and a second rack aisle formed on a second side of the IT components to direct hot air to the cooling unit downwardly, where the host air is transformed from the cool air from the first rack aisle by flowing through an air space between the IT components.