Apparatus and method are provided for facilitating cooling of air passing through an electronics rack. The apparatus includes a heat exchange assembly hingedly mounted above and external to the rack, such that air passing above the rack from an air outlet side to an air inlet side thereof passes through the heat exchange assembly, and is cooled. The heat exchange assembly includes a support structure to support hinged mounting of the assembly above the rack, and an air-to-liquid heat exchanger coupled to the support structure. The heat exchanger has an inlet plenum and an outlet plenum in fluid communication with respective connect couplings which facilitate connection of the plenums to coolant supply and return lines, respectively. The heat exchanger also includes heat exchange tube sections, each of which has a coolant channel with an inlet and an outlet coupled to the inlet and outlet plenums, respectively.