In the past, most data-center cooling systems were designed
based on rules of thumb or trial and error, and large margins of
safety were used to compensate for the inaccuracies in those
approaches. But the rapid increase in the power density of
modern computing, networking, and storage equipment means that
energy costs for power and cooling frequently are higher than
the cost of the information-technology equipment they support,
when amortized over a typical three-year period. It has become
critical to analyze data-center design to optimize the local
airflow and heat-transfer conditions that play such an important
role in cooling-system performance. Computational-fluid-dynamics
(CFD) software tools provide the ability to simulate the
performance of data centers and predict the effects of air
handlers, power-dissipation sources, raised floors, and other
features on temperatures throughout a data center. Following is
a case of CFD being used to simulate a typical data center and
evaluate the effect of design ch