HP Superdome SX2000 Generic Site Preparation Guide, Fourth Edition - Page 21

Basic Air-Distribution Systems A basic air-distribution system includes supply air and return air. See Table 1-5: "Product Technical Requirements Based on Customer Environments" (page 25) for more information. Configure the air-distribution system to deliver adequate supply air to the cooling air intake vents of the server equipment cabinets. Maintain supply air temperature within the following parameters: • Ceiling air supply system-From 12.8 °C (55 °F) to 15.6 °C (60 °F) • Floor air supply system-At least 15.6 °C (60 °F) If you use a ceiling plenum return air (CPRA) system or a ducted ceiling return air system, place the return air grills in the ceiling above the exhaust area or the exhaust row. The following three types of air distribution systems are listed in descending order of preference: 1. Under-floor 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. Return air from an under-floor air-distribution system can be ducted return air (DRA) above the ceiling. Locate perforated floor panels (available from the raised floor manufacturer) around the front of the system cabinets. Supply air emitted though the perforated floor panels is then available near the cooling air intake vents of the server cabinets. 2. CPRA-Supply air is ducted into the ceiling plenum from upflow air-conditioning equipment located in the computer room or from an air-handling unit (remote). The ceiling construction should resist air leakage. Place perforated ceiling panels (with down discharge airflow characteristics) around the front of the system cabinets. The supply air emitted downward from the perforated ceiling panels is then available near the cooling air intake vents of the server cabinets. Direct the return air back to the air-conditioning equipment though the return air duct above the ceiling. 3. Above-ceiling ducted air-distribution system-Supply air is ducted into a ceiling diffuser system from upflow air-conditioning equipment located in the computer room or from an air-handling unit (remote). Return air from an above ceiling ducted air-distribution system can be DRA above the ceiling or CPRA. Adjust the supply air diffuser system grilles to direct the cooling air downward around the front of the server cabinets. The supply air is then available near the cooling air intake vents of the server cabinets. Air-Conditioning System Installation All air-conditioning equipment, materials, and installation must comply with applicable construction codes. Installation of the various components of the air-conditioning system must also conform to the air-conditioning equipment manufacturer's recommendations. Air-Conditioning Ducts Ensure that the air-conditioning duct work in the computer room is separate from the duct work used for the rest of the building. If the computer room duct work is not separate from the rest of the building, it might be difficult to control cooling and air pressure levels. Duct work seals are important for maintaining a balanced air-conditioning system and high static air pressure. Adequate cooling capacity means little if the direction and rate of air flow cannot be controlled because of poor duct sealing. Also, do not expose the ducts to warm air, or humidity levels might increase. Environmental Elements 21