Capabilities and limitations of direct free cooling in data centers

Abstract

The IT industry has undertaken strong efforts to reduce the energy consumption of IT services. Data center operators have two goals, why to reduce the energy usage: Reduce the carbon dioxide footprint and reduce the operational costs of the data center. First an overview on different approaches to optimize the energy efficiency of cooling a data center is presented. We then focus on direct free cooling, DFC. We list implications of DFC on the infrastructure of the data center due to regulation and standards. Two variants for cooling a distinct data center of Swisscom in Zurich are compared: Optimized conventional cooling and DFC. The two variants are simulated for temperatures in Zurich. We give figures for potential savings for both variants. Finally, the potential savings by optimizing the efficiency of cooling are compared to savings by reducing the energy consumed by servers e.g. with virtualization.