Chapter 2
General System and Facility Guidelines
Environmental Factors
33
Basic Air Conditioning Equipment Requirement
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:
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Air filtration
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Cooling or dehumidification
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Humidification
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Reheating
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Air distribution
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System controls adequate to maintain the computer room within the specified operating ranges of this HP
server.
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 specified for this HP server.
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 computer system availability, redundant air conditioning equipment or
capacity.
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The system should be capable of handling any future computer system 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.
