Traditional room-cooling systems have proven very effective at maintaining a safe, controlled environment for IT equipment. However, optimizing data center energy efficiency requires moving from traditional data center densities (2 to 3 kW per rack) to an environment that can support much higher densities (in excess of 30 kW). This requires implementing an approach to cooling that shifts some of the cooling load from traditional computer room air conditioning (CRAC) units to supplemental cooling units.
High-density, supplemental cooling units are mounted above or alongside equipment racks and pull hot air directly from the hot aisle and deliver cold air to the cold aisle.
High-density supplemental cooling units can reduce cooling costs by 30 percent compared to traditional approaches to cooling. These savings are achieved because supplemental cooling brings cooling closer to the source of heat, reducing the fan power required to move air. They also use more efficient heat exchangers and deliver only sensible cooling, which is ideal for the dry heat generated by electronic equipment.
Refrigerant is delivered to the supplemental cooling modules though an overhead piping system, which, once installed, allows cooling modules to be easily added or relocated as the environment changes.
In the Energy Logic model, 20 racks at 12 kW density per rack use high-density, supplemental cooling while the remaining 40 racks (at 3.2 kW density) are supported by the traditional room cooling system. This creates an incremental 6 percent reduction in overall data center energy costs. As the facility evolves and more racks move to high density, the savings will increase.