Sun Microsystems Sun Fire 12K, Site Planning Manual

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2-2 Sun Fire 15K/12K Systems Site Planning Guide • June 2003
2.1.1 Suggested Ambient Temperatures
The ambient temperature range of 70 degrees F to 74 degrees F (21 degrees C to 23
degrees C) is optimal for system reliability and operator comfort levels. Most
computer equipment can operate within a wide temperature range, but a level near
72 degrees F (22 degrees C) is desirable because it is easier to maintain safe
associated relative humidity levels at this temperature. Operating in this
temperature range provides a safety buffer just in case the environmental support
systems go down for a period of time. Though individual standards vary slightly, 70
degrees F to 74 degrees F (21 degrees C to 23 degrees C) should be used as an
optimal temperature choice.
2.1.2 Suggested Ambient Relative Humidity
The ambient relative humidity levels between 45% and 50% are the most suitable for
safe data processing operations. Under certain circumstances, most processing
equipment can operate within a fairly wide environmental range (20% to 80%), but
the optimal goal should be between 45% to 50% because this range:
■
Helps protect computer systems from corrosive problems associated with high
humidity levels.
■
Provides the greatest operating time buffer in the event of environmental control
system failure.
■
Helps avoid failures or temporary malfunctions caused by intermittent
interference from static discharges that occur when relative humidity is too low.
Electrostatic discharge (ESD) is easily generated and less easily dissipated in areas
where the relative humidity is below 35%, and becomes critical when levels drop
below 30%. The 5% relative humidity range might seem unreasonably tight when
compared to the guidelines used in typical office environments or other loosely
controlled areas, but it is not so difficult to maintain in a data center because of the
high efficiency vapor barrier and low rate of air changes normally present.
2.2 Basic Cooling Requirements
TABLE 2-2
and
TABLE 2-3
provide air conditioning information for the various
components in the Sun Fire 15K/12K systems based upon the maximum system
configuration. Use the worksheet in
TABLE 2-3
(see Appendix A for an expanded
form to use and retain for your records) to determine your system power and
cooling requirements. This worksheet will assist you in calculating your total system