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

✓ Plugged openings (cables, power) not in cold aisle. Block at the server or
other IT equipment cable tailgates and cable openings in the raised floor
to prevent cold air losses and improve efficiencies.
✓ Two tiles on both hot and cold aisles. Enables both tiles to be pulled up
to ease access to underneath floor. Having tiles with many perforations
(holes) in the cold aisle is a must.
✓ Tile and CRAC placement can be optimized (temperature and air flow)
with fluid dynamic analysis. Moving air with fewer direction changes is
best. Watch out for too many perforations, and do not place any perfo-
rated tiles within four tiles from CRAC.
✓ Cables overhead—even power. Leave under floor for pumping and air
flow. When laying out cables, make sure they do not impede airflow if
under raised floor (or above). A tray or trough can be made.
✓ If cables are already under the floor, manage them. Remove cables when
no longer needed. Keep “rats nesting” of cables to a minimum.
✓ Auto lights out. Lights need to be on only when someone is inside the
data center.
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✓ Shock and vibration support for racks. This is a must-do for earthquake
regions and can be planned when refreshing equipment or greening the
data center.
✓ Lighting on back of racks for ease of servicing.
✓ New generation battery, flywheel, and diesel generator backup. Flywheel
can provide a very green way to keep up the power system until genera-
tors start. Equipment has substantially improved in energy efficiency in
the last year. Use the latest generation of UPS, flywheel, and generators.
Newer generations of UPS are much more efficient than older genera-
tions.
✓ Negotiate with the electric utility for going off grid (use generators) in
rare peak-demand situations. Utilities will pay for the capability to shed
load that might potentially cause a brownout or a blackout. The data
center can contribute to the electric grids resilience by working with the
utility.
✓ Redundancy design for power and cooling. Eliminate common cause fail-
ures whereever possible, including UPS, by having flywheel and batteries
rather than redundant battery UPS.