Site Preparation Guide, Third Edition - Server Expansion Unit

Appendix A
General Site Preparation Guidelines
Environmental Elements
19
Environmental Elements
The following environmental elements can affect a server installation:
• Computer room preparation
• Cooling requirements
• Humidity level
• Air-conditioning ducts
• Dust and pollution control
• ESD prevention
• Acoustics (noise reduction)
Computer Room Preparation
The following guidelines are recommended when preparing a computer room for a 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 (under
floor distribution).
• Ensure a minimum clearance of 12 in. 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 in. (or local code minimum clearance) from the top of the server cabinet to the fire sprinkler
heads.
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 should be sufficient to
offset the computer equipment dissipation loads, as well as any space envelope heat gain. This equipment
should include:
• Air filtration
• Cooling or dehumidification
• Humidification
• Reheating