Julian Kudritzki, Uptime Institute vice president, spoke at the ribbon cutting ceremony for the new Harris data center.

According to Uptime Institute Professional Services Consultant Chris Brown, the chilled water system is a typical solution for a Tier III data center. It is a looped piping system with strategically located isolation valves to allow sections of the piping system to be isolated for maintenance without impacting the computer rooms. The chiller-cooling tower combination utilized packaged units. The packaged units ease the design to make the control system concurrently maintainable. In large condenser water systems, it is difficult to operate the cooling towers without automatic control since condenser water temperature typically needs to be held in a fairly tight window. This makes running cooling towers in a local manual mode difficult. The packaged systems use on board controls that are independent of the larger building automation system.

The interesting part is the UPS system, Brown said. A typical Tier III solution is to utilize a system + system arrangement. So if the design load was 1,000 kW the design would utilize two 1,000 kW systems. The management of that type of system is easy as one only has to ensure that each dual corded computer device has a feed from each UPS. But the cost is a 50 percent stranded capacity (45 percent with a 90 percent redline). Also static UPS systems do not run at peak efficiency the lower they are loaded.

The Cyber Integration Center used a different approach, utilizing five separate UPS systems. By evenly distributing dual corded loads across all five UPS systems the UPS systems can be loaded to 67% in normal operations. With a loss of a single UPS the total load on each UPS will increase to 83%. This allows each UPS to be loaded to a higher utilization under normal operations. This results in less stranded capacity. Also by increasing the percent utilization, the static UPS will operate at a higher efficiency than at a lower utilization. This system is more complex to manage as the dual corded loads must be evenly distributed across all UPS systems, but the result is less stranded capacity and higher efficiency.