Simulation Helps Keep One of the World’s Top Data Centers Cool

CCG Facilities Integration used FloVENT to optimize the design of a powerful data center in Virginia and help it maintain Tier 4 functionality – the highest possible.

“FloVENT provided the ideal tool for optimizing the performance of ACC4 because of its ability to accurately model the room, the IT equipment and complete cooling system.”

A very large and powerful data center

CCG, a leading consulting engineering firm in Baltimore, Maryland, was tasked to design a system to cool Dupont Fabros Technology’s (DFT’s) extremely powerful ACC4 data center in Ashburn, Virginia. Not only does the data center’s computing and communications equipment need to be kept cool, but it was required to maintain a Tier 4 level of functionality – the highest possible.

DFT considers ACC4 to be its prototype for future ground-up development projects and says that its flexible design and enhanced power and cooling capacity make it one of the leading data center facilities in the world.

FloVENT models are verified

CCG began modeling the facility in the early stages of the design process so that they could provide feedback to DFT on the cooling efficiency of various cooling system configurations.

“We selected FloVENT as our modeling tool because FloVENT accurately models airflow through the fans and the raised floor so you can be sure that the simulation is accurate,” said Margaret Sam Sheehan, Director of Mechanical Engineering at CCG.

CCG mechanical engineers have validated FloVENT models with multiple types of air handlers and obstructions above and below the raised floor and obtained measurements that matched CFD predictions within 1°F.

Tier 4 functionality is established

CCG used FloVENT to evaluate different aspect ratios for the room to optimize the cooling efficiency while meeting the needs of the building’s occupants.

Another challenge was to have a low raised floor to minimize the cost of building materials but be high enough to move the volume of air required to cool the facility. A 48-inch raised floor was used in the ACC4 data center, but CCG was able to reduce the floor height to 42 inches in its next project, the ACC5 data center.

CCG evaluated many computer room air handlers in ACC4 and ACC5 with different building configurations. The most difficult challenge was to maintain the IT equipment air inlets at safe temperatures when some air handlers failed. CCG engineers used FloVENT to validate that the facility can operate safely (per ASHRAE guidelines) with multiple air handlers shut down. This, in addition to other measures, helped the building establish its Tier 4 functionality.

“ACC4 is now fully operational and all of the feedback has been very positive,” Sheehan concluded. “The cooling system has performed without any hiccups.”

“We selected FloVENT as our modeling tool because FloVENT accurately models airflow through the fans and the raised floor so you can be sure that the simulation is accurate.”