A system for cooling electronic equipment is provided. The system includes enclosures with front and rear doors for holding assemblages of electronics, front and rear heat exchangers housed within each of the front and rear doors, respectively, a series of separate supply lines configured with control valves and flow control sensors that provide liquid coolant to each of the heat exchangers, a series of separate return lines configured with temperature sensors for exiting coolant from each of the heat exchangers, separate air purging valves for each of the supply and return lines and a series of spray shields. The spray shields prevent coolant leaks from entering an inlet airflow and protect the electronics from coolant leaks. The control valves are actuated by a controller in response to readings from the temperature and flow control sensors to separately control coolant flow to each of the front and rear heat exchangers.