Site Preparation Guide, Second Edition - HP Integrity cx2620 Server

3,000 volts. HP recommends building this consideration into your designs for floor coverings,
humidity control, airflow, dust control, and personnel traffic. Consider the following precautions
against ESD:
• Use antistatic flooring.
• Maintain humidity at 40–55 percent relative humidity.
• Follow airflow recommendations.
• If raised flooring is present, use a 2-foot x 2-foot (61-cm x 61-cm) grounding grid.
• Always use appropriately sized AC power ground wires.
• Limit personnel traffic to two floor tiles away from equipment.
Cellular Telephone and Wireless Usage
HP recommends not using cell phones within a data center, especially within 9.8 feet (3 m) of
any high-availability equipment.
Comprehensive Discussion
The following environmental elements can affect a server installation:
• Computer room preparation
• Airflow
• Cooling requirements
• Humidity level
• Electrostatic discharge (ESD) prevention
• Acoustics (noise reduction)
Computer Room Preparation
The following guidelines are recommended when preparing a computer room for the server:
• Locate the computer room away from the exterior walls of the building to avoid the heat
gain from windows and exterior wall surfaces.
• When exterior windows are unavoidable, use windows that are double- or triple-glazed
and shaded to prevent direct sunlight from entering the computer room.
• Maintain the computer room at a positive pressure relative to surrounding spaces.
• Use a vapor barrier installed around the entire computer room envelope to restrain moisture
migration.
• Caulk and vapor seal all pipes and cables that penetrate the envelope.
• Use at least a 12-inch raised floor system for minimum favorable room air distribution system
(underfloor distribution).
• Ensure a minimum clearance of 12 inches between the top of the server cabinet and the
ceiling to allow for return air flow and ensure that all ceiling tiles are in place.
• Allow 18 inches (or local code minimum clearance) from the top of the server cabinet to the
fire sprinkler heads.
Airflow
• Ensure that hot and cold aisles are parallel to airflow patterns. This recommendation causes
cooling air to be released into cold aisles, where opposing rows have intake grills oriented.
• Additionally, ensure that opposing row exhaust grills face each other, without cooling air.
• A parallel orientation encourages low impedance airflow back to the HVAC.
• If raised flooring is used, route cables underneath the floor to be parallel to the airflow to
prevent airdams
• Keep air throws from HVAC equipment to the heat loads they serve within 75 feet of each
other.
Environmental Elements 31