A multi-rack assembly is provided which includes adjacent first and second electronics racks, each being at least partially air-cooled, and an air-to-liquid heat exchanger associated with the first rack for cooling at least a portion of air passing through the first rack. The heat exchanger, which is disposed at the air inlet or air outlet side of the first rack and is coupled in fluid communication with a coolant loop to receive coolant from the loop and exhaust coolant to the loop, transfers heat from air passing thereacross to coolant passing therethrough. The assembly also includes a cooling unit, associated with the first rack and cooling coolant in the coolant loop, and an airflow director associated with the second rack and facilitating ducting at least a portion of air passing through the second rack to also pass across the heat exchanger associated with the first rack.