50 / 80
50
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CRAC (Computer Room Air Conditioner):
In
addition to proper maintenance, follow these tips:
•
Turn off re-heat in CRACs
(if possible).
•
Check glycol levels (freeze points):
water glycol
mix – often over time water is added diluting the
mixture in your glycol loop, which increases the risk
of freezing.
•
Cool servers per ASHRAE standards:
The latest
ASHRAE standards recommend higher setpoints,
allowing instant energy savings.
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Generators:
Standby Power systems need routine
maintenance to ensure reliable operation when a
utility failure occurs. In addition to proper
maintenance, consider these additional steps.
• Frequently check the starting batteries and block
heaters.
• Frequently check and maintain the belts and hoses.
• Frequently check and maintain all fluids.
• After every PM activity, be sure the technician has
returned the operating switch to “Auto”.
• Implement a program to annually sample and test
coolant, fuel and oil for breakdown or
contaminants.
• Automatic Transfer Test – Using Building Load
• Implement a program for annual load bank testing
(more often if possible).
• Implement a program for fuel polishing if the fuel
will be idle for long periods of time.
ROOM LAYOUT AND AIRFLOW
MANAGEMENT:
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Block the holes:
This will eliminate air loss,
promoting proper air flow and improving static
pressure:
• Install blanking panels.
• Seal cable cutouts with brush sealed floor
grommets.
• Block off the voids/holes in drywall below raised
floor and above drop ceiling.
• Seal all voids under doors leading into DC rooms and
support areas.
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Perform a Computational Fluid Dynamics (CFD)
analysis:
This will simulate the airflow through your
data center and identify problems that can lead to
overheated servers. This is generally the first step in
understanding issues and identifying opportunities for
improvement.
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Hot aisle/cold aisle layout:
This layout enables cool
air to flow to air intakes on the front of the rack and
hot air to exhaust out the back, then return to the
(CRAC) return ducts. You will reduce hot spots and
you could lower your power consumption significantly.
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Use existing drop ceilings as a return plenum and
install return air plenums on CRAC units:
This will
direct the hot air exhaust from the back of the server
racks to the return on the CRAC, reducing
recirculation of hot air.
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Use the proper floor tiles:
• Replace missing floor tiles.
• Put floor grates or perforated tiles in cold rows,
especially in front of the hottest racks. If necessary,
rearrange or change to different floor grates to
match the airflow to the heat load.
• Avoid placing floor grates too close to the CRACs,
this will “short circuit” the airflow, sending it right
back into the CRACs and rob the rest of the
room/row of sufficient cool air.
• Install solid floor tiles in hot rows to prevent cold
air from coming through the floor.
• If you still have data center hot spots, consider
installing directional or fan assisted floor tiles to
move the underfloor cooling air exactly where it is
needed.
n
Remove under floor obstructions in raised floors:
Unused cables beneath the raised floor tend to build
up over time, thereby reducing or blocking airflow. Be
sure to remove them to ensure high quality airflow to
your servers.
n
Install variable speed fans or variable speed
drives:
These devices are designed to automatically
speed up or slow down as needed to manage air flow
and reduce energy usage.
7X24 MAGAZINE SPRING 2015