NonStop NS2200 Series Planning Guide

Cooling and Humidity Control
Do not rely on an intuitive approach to cooling design or to simply achieve an energy balance—that
is, summing up to the total power dissipation from all the hardware and sizing a comparable air
conditioning capacity. Today’s high-performance servers use semiconductors that integrate multiple
functions on a single chip with very high power densities. These chips plus high-power-density
mass storage and power supplies are mounted in ultra-thin server and storage enclosures, which
are then deployed into computer racks in large numbers. This higher concentration of devices
results in localized heat, which increases the potential for hot spots that can damage the equipment.
Additionally, variables in the installation site layout can adversely affect air flows and create hot
spots by allowing hot and cool air streams to mix. Studies have shown that above 70°F (20°C),
every increase of 18°F (10°C) reduces long-term electronics reliability by 50%.
Because of high heat densities and hot spots, an accurate assessment of air flow around and
through the server equipment and specialized cooling design is essential for reliable server
operation.
Consult with your HP cooling consultant or your heating, ventilation, and air conditioning (HVAC)
engineer.
NOTE: Failure of site cooling with the server continuing to run can cause rapid heat buildup and
excessive temperatures within the hardware. Excessive internal temperatures can result in full or
partial system shutdown. Ensure that the site’s cooling system remains fully operational when the
server is running.
Because each cabinet houses a unique combination of enclosures, calculate the total heat dissipation
for the hardware installed in each cabinet using the worksheet for the server you are installing.
Then add together the total heat dissipation values for all the cabinets in the system. For air
temperature levels at the site, see the temperature specifications for the server you are installing.
Cooling Airflow Direction
Each enclosure includes its own forced-air cooling fans or blowers. Air flow for each enclosure
enters from the front of the cabinet and rack and exhausts at the rear.
Weight
Because each cabinet houses a unique combination of enclosures, total weight must be calculated
based on what is in the specific cabinet. For enclosure weights and weight worksheets, see
“Specifications for NonStop NS2200T Systems” (page 132) or “Specifications for NonStop
NS2200ST Systems” (page 142).
Flooring
These servers can be installed either on the site’s floor with the cables entering from above the
equipment or on raised flooring with power and I/O cables entering from underneath. Because
cooling airflow through each enclosure is front-to-back, raised flooring is not required for system
cooling.
WARNING! An unsecured cabinet is prone to tipping. Seismic rack cabinets are designed to be
bolted to the floor. Because the cabinet has no other provisions to prevent tipping, it must never
be put to use without first being bolted to the floor. Failure to do so can result in product damage
and serious personal injury or death.
Seismic rack cabinets are designed to be bolted to the floor. You can choose to install this system
in a computer room with a raised floor. If so, the typical computer room raised floor must be
reinforced to accommodate the extra weight of the servers and to provide for the desired level of
seismic protection.
Cooling and Humidity Control 129