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The Greening of IT
130 How Companies Can Make a Difference for the Environment

cooling system capacity, but also has exposed inefficiencies in existing
approaches to data center cooling. As a result, cooling now represents the sec-
ond highest opportunity for IT energy cost-savings in many facilities (just
after reducing the IT equipment load).
These savings can be significant. For example, a 3 MW IT facility would
require 6 MW of power, assuming that support systems consume about the
same amount of power as the IT systems. If electricity costs were $.10 per
KWH, the total annual energy costs for this facility would be $5.25 million
($600/hour × 8,760 hours). A 10 percent reduction in the IT load would cre-
ate savings of $260,000, whereas a 30 percent improvement in cooling sys-
tem efficiency would generate savings of approximately $580,000. This
simple example emphasizes the importance of cooling efficiency in our over-
all goal of reducing energy use at data centers.
One basic concern is that chillers and other data center cooling equipment
are not concerns we IT people have had to deal with. My own graduate
degrees are in mechanical engineering, so I do have the background.
Nevertheless, we IT people usually think of data center cooling as something
the Heating, Ventilation, and Air Conditioning (HVAC) engineers will han-
ptg
dle. However, for green IT and green data centers in particular, we need to
concentrate on all the key areas, and cooling for IT systems is very much a
key area. In June 2008, The New York Times ran a front-page story in the busi-
ness section with a headline, “Demand for Data Puts Engineers in the
Spotlight.” The article went on to state that “In Silicon Valley, the stars have
long been charismatic marketing visionaries and cool-nerd software wizards.
By contrast, mechanical engineers who design and run computer data centers
were traditionally regarded as little more than blue-collar workers in the
high-tech world.” However, The New York Times article went on to state that
today data center experts are no longer taken for granted. The torrid growth
in data centers to keep pace with the demands of Internet-era computing,
their immense need for electricity, and their inefficient use of that energy
pose environmental, energy, and economic challenges. So, people with the
skills to design, build, and run a data center that does not endanger the
power grid are suddenly in demand. Their status is growing, as are their
salaries. Expertise in data center cooling is not only critical for energy conser-
vation; it also appears that the status of the engineers working on the data
center plumbing will continue to grow.
In considering the topic, the first step is to evaluate and analyze the
energy used at your data centers by the cooling equipment. If you have an
electric meter that shows your energy use just for the cooling equipment,