Avoidable mistakes that are routinely made when installing cooling systems and racks in data centers or network rooms compromise availability and increase costs. These unintentional flaws create hot-spots, decrease fault tolerance, decrease efficiency, and reduce cooling capacity. Although facilities operators are often held accountable for cooling problems, many problems are actually caused by improper deployment of IT equipment outside of their control. This paper examines these typical mistakes, explains their principles, quantifies their impacts, and describes simple remedies.
The air distribution system is a part of the data center that is not well understood, and facility operators and IT personnel often take actions involving airflow that have unintentional and adverse consequences to both availability and cost. Flawed airflow implementation has not been a serious problem in the past, due to low power density in the data center. However, recent increases in power density are beginning to test the capacity of cooling systems and give rise to hot-spots and unexpected limitations of cooling capacity. Decisions such as facing all racks in the same direction are often made for cosmetic reasons to project image; but as users and customers become more educated they will conclude that people who do not implement airflow correctly are inexperienced, which is the opposite of the original intent. Adopting a number of simple policies and providing a simple justification for them can achieve alignment between IT and Facilities staff resulting in maximum availability and optimized TCO.