IT equipment mounted in racks cools itself by drawing ambient air from the data center or network room. If the heated exhaust air is allowed to return to the air inlet of the equipment, an undesirable overheating condition may occur. Data centers and network rooms should be designed to prevent equipment from drawing heated air, and this can be accomplished by widely used installation practices, or by using systems that are pre-engineered.

This paper explains how this problem occurs, provides actual examples of the effect, and shows that this problem significantly compromises the cooling of equipment when it occurs. The benefit of using airflow management blanking panels to reduce the problem is explained and quantified.