HP rp5400 Site Preparation Guide - rp5400 - Page 17

General Site Preparation Guidelines Environmental Elements • 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. The following three types of air distribution system are listed in order of recommendation: • Underfloor air distribution system-Downflow air conditioning equipment located on the raised floor of the computer room uses the cavity beneath the raised floor as plenum for the supply air. Chapter 1 9