mixing of the air or there might be ar-
eas where it’s leaking.”
In one case, Synapsense in-
stalled 3,674 sensors throughout a
Those vanity plates are only one
problem with standard hardware. “If
you take a standard off-the-shelf server
there are probably quite a few things
that need to be improved to have it
work more efficiently,” says Bianca
Schroeder, a computer scientist at
the University of Toronto and the co-
author of a recent paper on data cen-
ter efficiency (see the Further Reading
list). For example, Schroeder notes
Ambient air flows through Facebook’s data center in Prineville, oR, and cools the servers
inside the 334,000-square-foot facilty.
chanical chillers at all. “We don’t need
them,” says Weihl, who was previously
Google’s energy efficiency czar.
At Facebook’s Prineville facility,
ambient air flows into the building,
passing first through a series of filters
to remove bugs, dust, and other contaminants, then into a long corridor.
On hot days, when the outside temperature rises above 80 degrees Fahrenheit, the air moves through a fine mist
of micron-sized droplets of water suspended in the corridor. Some of the
mist evaporates on contact with the
warmer outside air. This reduces the
temperature, and the mildly chilled
air then passes through another filter,
which captures the droplets of water
that did not evaporate. The end result
is a rush of cool air flowing into the
PhotograPh by ChuCk goolsbee
When it is too cold outside, the
control system automatically mixes in
some of the 85 to 90 degree Fahrenheit
air coming out of the back of the servers
to bring it up to the right temperature.
“We don’t want 20 degree Fahrenheit
air going into our servers,” Weihl says.
Drastic changes in temperature could
cause components to expand and contract, creating mechanical stresses that
might lead to permanent damage.
problem. Companies have also begun demonstrating the importance of
managing circulation within the space.
When Synapsense audits a facility, its
technicians install wireless sensors
throughout the building to measure
temperature, pressure, humidity, and
more. Pandey says Synapsense often
identifies intense hot spots—warmer
areas that force the fans and mechanical chillers to work harder to manipulate the temperature, thus increasing
energy usage. “You might have enough
cool air, but it’s not going to the right
places,” he explains. “There might be
the most efficient
now hover at
closer to 80 degrees
instead of sweaters,
the technicians walk
around in shorts.
The source of the cool air in traditional data centers is only part of the