Data center containment has gone mainstream over the past decade, which has led to widespread implementation and adoption by many sites. In fact, according to a recent survey by the Uptime Institute, 80% of sites have implemented either hot or cold aisle containment. However, although containment is experiencing a high rate of adoption, there are still many misconceptions and therefore many considerations to look at when evaluating the different options and strategies that are available. The most common consideration is determining whether to contain hot aisles or cold aisles. Other considerations include hard vs soft containment, partial vs full containment, and many others. This session will evaluate the different scenarios in which each of these considerations is more applicable, including retrofit vs new construction, and discuss strategies after containment has been implemented to maximize the cooling efficiency and cost savings benefits.