Hot aisle containment consists of a physical barrier that guides hot exhaust airflow back to the AC return.
Hot aisle containment (HAC) takes advantage of the natural properties of warm air rising. The HAC system directs the upward airflow to an AC return system such as a drop-ceiling void. The HAC can increase cooling efficiency by 30% or more. Several cascading adjustments include: temperature and RH set points, lower AC fan speeds, and an increased chilled water set point.
Hot Aisle Containment focuses on isolating hot exhaust air on its return to the CRAC units or on its way out of the building. And this method of containment is clearly the trend for most new enterprise data center builds. Why do so many architects and engineers prefer and specify this method of air segregation? Three reasons. One, with the often-accompanying energy efficiency measure of airside economization designs that flood the whole room with cold air are easy to build. Two, it is much easier to achieve airflow balance with a common cold zone. Three, a common cool area in the space is more comfortable for users. For these reasons, containment on the hot side sees wide adoption in new data center builds.