A modular server rack cooling structure for cooling at least one server in at least one server rack of a data center assembly includes at least a first supporting member and at least a first heat exchanger. The first heat exchanger is coupled to the first supporting member, which is configured to position the first heat exchanger in heat transfer relationship with the at least one server. The first heat exchanger is not attached to the at least one server rack. The modular server rack cooling structure is also applied to a system that includes at least a first rack and at least a second rack disposed opposite from one another to form a hot aisle or a cold aisle. A method is disclosed for installing additional heat exchangers on the support structure of a modular server rack cooling structure to meet increased cooling capacity requirements without requiring additional space.