HP 9000 rp5400 Servers - Manual (Page 149)

Basic Air Conditioning Equipment Requirements
The cooling capacity of the installed air conditioning equipment for the computer room should
be sufficient to offset the computer equipment dissipation loads, as well as any space envelope
heat gain. This equipment should include:
•
Air filtration
• Cooling or dehumidification
• Humidification
• Reheating
• Air distribution
• System controls adequate to maintain the computer room within specified operating ranges.
Lighting and personnel must also be included. For example, a person dissipates about 450 BTUs
per hour while performing a typical computer room task.
At altitudes above 10,000 feet (3048 m), the lower air density reduces the cooling capability of
air conditioning systems. If your facility is located above this altitude, the recommended
temperature ranges may need to be modified. For each 1000 feet (305 m) increase in altitude
above 10,000 feet (up to a maximum of 15,000 feet), subtract 1.5° F (0.83° C) from the upper
limit of the temperature range.
Air Conditioning System Guidelines
The following guidelines are recommended when designing an air conditioning system and
selecting the necessary equipment:
•
The air conditioning system that serves the computer room should be capable of operating
24 hours a day, 365 days a year. It should also be independent of other systems in the building.
• Consider the long-term value of hp server availability, redundant air conditioning equipment
or capacity.
• The system should be capable of handling any future hp server expansion.
• Air conditioning equipment air filters should have a minimum rating of 45% (based on
"ASHRAE Standard 52-76, Dust Spot Efficiency Test").
• Introduce only enough outside air into the system to meet building code requirements (for
human occupancy) and to maintain a positive air pressure in the computer room.
Air Conditioning System Types
The following three air conditioning system types are listed in order of preference:
•
Complete self-contained package unit(s) with remote condenser(s). These systems are
available with up or down discharge and are usually located in the computer room.
• Chilled water package unit with remote chilled water plant. These systems are available
with up or down discharge and are usually located in the computer room.
• Central station air handling units with remote refrigeration equipment. These systems are
usually located outside the computer room.
Basic Air Distribution Systems
A basic air distribution system includes supply air and return air.
An air distribution system should be zoned to deliver an adequate amount of supply air to the
cooling air intake vents of the hp server equipment cabinets. Supply air temperature should be
maintained within the following parameters:
•
Ceiling supply system—From 55° F (12.8° C) to 60° F (15.6° C)
• Floor supply system—At least 60° F (15.6° C)
If a ceiling plenum return air system or a ducted ceiling return air system is used, the return air
grill(s) in the ceiling should be above the exhaust area or the exhaust row.
Environmental Elements 149