Technological advances are dramatically increasing the server power in data centers. Such data centers use a combination of liquid immersion cooling for high-load servers and conventional air cooling systems for low-load hard disk drive (HDD) storage. This paper proposes a server room where each zone is managed according to the heat density. A cooling system was built using general-purpose element equipment, and the power consumption and power usage effectiveness (PUE) were measured for the cooling system operating under energy-saving methods. The experimental and simulation results confirmed that stable driving of the cooling system could be realized. Using general-purpose element equipment and general energy-saving methods with the proposed system realized an annual average PUE of less than 1.04.