Rack based CDU's, with 80-120kW heat transfer capacity at average 10°C - 15°C approach temperature and 160kW at approach temp claimed by competitive systems. Over 2 x more efficient than comparable in rack 4U CDU's. This rack based CDU's are equipped with 2 redundant multistage immersion pumps and can effectively cool multiple racks or high-powered HPC systems with 2 x higher pressure and flow rate than any other solution.