HP Superdome SX2000 Generic Site Preparation Guide, Fourth Edition - Page 20

HP strongly recommends to test your site for metallic particulate contamination before installing electronic equipment. Cooling Requirements Air-conditioning equipment requirements and recommendations are described in the following sections. Basic Air-Conditioning Equipment Requirements The cooling capacity of the installed air-conditioning equipment for the computer room must be sufficient to offset the computer equipment dissipation loads, as well as any space envelope heat gain. This equipment must include: • Air filtration • Cooling or dehumidification • Humidification • Reheating • Air distribution • System controls When calculating cooling requirements, include the heat generated by lighting and personnel. For example, a person dissipates about 450 Btus per hour while performing a typical computer room task. At altitudes above 10,000 feet (3,048 m), the lower air density reduces the cooling capability of air-conditioning systems. If your facility is located above this altitude, you might need to modify the recommended temperature ranges. For each 1,000 foot (305 m) increase in altitude above 10,000 feet (up to a maximum of 15,000 feet (4,572 m)), subtract 0.83 °C (34 °F) from the upper limit of the temperature range. Air-Conditioning System Guidelines Use the following guidelines when designing an air-conditioning system and selecting the necessary equipment: • The computer room air-conditioning system 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 server availability, redundant air-conditioning equipment, or capacity. • The system should be capable of handling any future 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 descending order of preference: 1. Complete self-contained package units with remote condensers. These systems are available with up or down discharge and are usually located in the computer room. 2. 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. 3. Central station air-handling units with remote refrigeration equipment. These systems are usually located outside the computer room. 20 General Site Preparation Guidelines