DCN May 2016 - Page 22

design & facilities management the savings resulting from running the chillers in economiser mode have to be greater than the energy expended in running the dry coolers, server fans and CRAHs. Study Data centre operators need a better understanding of how IT equipment operates and how its reliability is impacted at high temperatures. Although allowing chillers to operate in economiser mode for a greater part of the year produces immediate energy savings these are offset by the greater burden placed on other parts of the cooling infrastructure. Dry coolers must operate when the chillers are in economiser mode. Furthermore, there is an increase in the energy expended by fans both in the server racks themselves and in the computer room air handlers (CRAH) as the airflow cubic feet/m (CFM) requirements increase as temperature rises. For raised temperatures to be successful in reducing overall energy requirements, therefo &R