HP Integrity Superdome SX1000 User Guide, Sixth Edition - HP Integrity Superdo - Page 151

Site Preparation Electrical and Environmental Guidelines Table 5-1 Controlled Computer Room Environment Specifications Temperature (dry bulb οC)a Relative Humidity %; Non condensing Dew Pointb Rate of Change (°C/hr., max) Allowablec,d Recommendede Allowabled Recommendede 15 to 32 20 to 25 20 to 80 40 to 55 17 5 (59ο to 90ο F) (68ο to 77ο F) a. Dry bulb temperature is the regular ambient temperature. Derate maximum dry bulb temperature 1°C/300 m above 900 m. b. Must be non-condensing environment. c. With installed media, the minimum temperature is 15°C and maximum relative humidity is limited to 80%. Specific media requirements may vary. d. Allowable: equipment design extremes as measured at the equipment inlet. e. Recommended: target facility design and operational range. 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. Air Conditioning System Guidelines The following guidelines are recommended when designing an air conditioning system and selecting the necessary equipment: • The air conditioning system serveing 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. • 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 "AShRA 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 u, 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. Chapter 5 139