By John Niemann, Kevin Brown, and Victor Avelar
High energy costs and accelerated energy consumption rates have forced data center professionals to consider hot-air and cold-air containment strategies. According to Bruce Myatt of EYP Mission Critical, the separation of hot and cold air "is one of the most promising energy-efficiency measures available to new and legacy data centers today” (Mission Critical, Fall 2007). In addition to energy efficiency, containment allows uniform IT inlet temperatures and eliminates hot spots typically found in traditional uncontained data centers.
While hot-aisle containment is the preferred solution in all new installations and many retrofit raised floor installations, it may be difficult or expensive to implement due to low headroom or no accessible dropped ceiling plenum. Cold-aisle containment, although not optimal, may be the best feasible option in these cases.
Both hot-aisle and cold-aisle containment provide significant energy savings over traditional uncontained configurations. This paper analyzes and quantifies the energy consumption of both containment methods and concludes that hot-aisle containment can provide 43% cooling system energy savings over cold-aisle containment due mainly to increased economizer mode hours. It also concludes that new data centers designs should always use or provision for hot-aisle containment.