Server and storage considerations

Data centers designed and built in the last 10 years are typically capable of cooling up to 10KW of heat load per cabinet. These designs often involve either raised floor air distribution plenums 18 to 24 inches in height or non-raised floor installation and either hot or cold aisle containment structures, room ceiling heights of 8 to 9 feet, and Computer Room Air Conditioning (CRAC) units distributed around the perimeter of the room. IT equipment occupies roughly 30-35% of the total data center space. The remaining space is white space (for example, access aisles, service clearances), power distribution units (PDUs), and CRAC units. Until recently, little attention has been given to heat load assessments, equipment layout and air delivery paths, heat load distribution, and floor tile placement and openings, but this trend has changed given the heightened focus on improving energy efficiency and overall operational sustainability.

Manufacturers, including IBM, are reporting heat loads in a format suggested by the ASHRAE publication, "Thermal Guidelines for Data Processing Environments", dated January, 2004. Although this data is meant to be used to for heat load balancing, care is required when using the data to balance cooling supply and demand as many applications are transient and do not dissipate constant rates of heat. A thorough understanding of how the equipment and application behave with regard to heat load, including considerations for future growth, is required.