In 2006, a large Internet Service Provider (ISP) located in Dulles, VA selected DN Tanks to build a mission critical Thermal Energy Storage (TES) tank to service their data center. The data center which operates 24 hours each day could not afford the consequences that would result if their chilled water cooling system were to experience downtime. This TES tank, now our third built TES tank for this same ISP, was designed to provide back-up cooling for the central plant in the event that the chillers experience unexpected downtime.

The engineer for the project, Dunlap & Partners, designed the revisions to the chilled water system which included the addition of a new TES tank. The tank was specified to be capable of storing enough chilled water equal to the peak cooling load for the facility for a period of two hours. In addition, the chilled water pressure drop through the tank was specified to stay below 3 psi even in the event that the pumps were to require a delivery flow rater of 5,184 gpm which is the maximum flow rate to the building.

Poole & Kent, the mechanical contractor, provided the new chilled water piping, pumps, and valves in addition to overseeing the installation of this TES tank. DN Tanks together with Poole & Kent worked closely with the owner and engineers in ensuring that the TES system was constructed within the agreed upon schedule, and commissioned expeditiously so that the data center would be protected with this reservoir of chilled water.

In August of 2007, representatives of the owner, the mechanical contractor, the engineer, and DN Tanks commissioned the TES system. The commissioning process included shutting down all chillers during the middle of a weekday of the data center operation. Immediately upon shutting down the chillers, the new TES system was energized and chilled water from the TES tank became the sole source of cooling for the facility. The system remained in this mode for 1 hour and 40 minutes, while the TES tank operated flawlessly.

Chilled Water Thermal Storage