How Chimney Containment Can Help Manage Temperatures In Data Centers
• Chimney Containment can help manage temperatures in data centers and is either provided as an integral part of the IT cabinet system or by third-party manufacturers. This form of containment consists of a solid metal chimney, which extends from the rear of the cabinet up to the ceiling return air plenum. Chimneys can be installed on individual cabinets or as a system, which spans several cabinets. Fans within the chimneys can be provided, which assist airflow and help minimize pressure buildup at the rear of any high-density cabinets.
There are several advantages to this approach. For one thing, chimney containment addresses the main disadvantage of hot-aisle containment by totally eliminating hot air from all occupied spaces so the entire room remains cool. Another advantage is increased flexibility and modularity, since the chimney cabinets can be more easily added, moved, and reconfigured. The chimney fan option can also be added later as the cabinet load grows over time. Also, the containment system can be purchased only when the cabinet itself is purchased, instead of having to install a full aisle-containment system prior to installing the cabinets in that aisle.
Disadvantages also exist. Because many chimneys have a relatively small cross-sectional area, and total cabinet airflow can be large, there is a potential for excess pressure buildup at the IT server discharge, restricting proper airflow through the servers and causing massive internal cabinet recirculation if the cabinets do not have proper separation between the front and back. The cabinet and chimney design must be carefully chosen, since gasketing, leakage, and airflow performance vary greatly between manufacturers.
Because data centers vary in their requirements, infrastructure, function, and performance, choosing the right containment strategy for a facility will require a thorough analysis, taking into account rack and air conditioning system layout, equipment density, growth, cabinet type, and more. Specific containment or chimney cabinet performance testing can also be specified to ensure intended performance.
Once a containment solution has been selected, applying it in real life can require the additional coordination of project team members. With total containment solutions, everything from selecting cabinet architecture to the containment barrier and beyond must be specified by the MEP engineer to ensure proper fire protection (including sprinkler layout and code), accessibility, performance, reliability, electrical requirements, fan requirements in the chimney systems, structural connections, and more.
While total containment solutions are making their way into today's high-density data centers and are becoming the standard for any new designs, they are currently not being employed to the extent that they should be, especially for retrofit and expansion applications. Containment strategies are often overlooked due to the increased capital costs and unfamiliarity with the scope of potential benefits. However, dismissing the benefits afforded by containment solutions can potentially result in missing out on significant operational savings and increased data center reliability. Containment may even help avoid new cooling capacity expenditures by increasing system effectiveness.
Travis Steinmetz, P.E., LEED AP, is a mechanical engineer with Environmental Systems Design, Inc. He has experience designing data centers, financial trading venues and special needs office buildings. Thomas Squillo, P.E., LEED AP, an Uptime Accredited Tier Designer, is a mechanical technical authority in the mission critical design group at Environmental System Design, with over 29 years experience designing data centers, as well as various types of commercial and institutional buildings. He can be reached at email@example.com.