Data Center Handbook, 2nd Edition

10WIRELESS SENSOR NETWORKS TO IMPROVE ENERGY EFFICIENCY IN DATA CENTERS

Levente Klein, Sergio Bermudez, Fernando Marianno, and Hendrik Hamann

IBM TJ Watson Research Center, Yorktown Heights, New York, United States of America

10.1 INTRODUCTION

Data center (DC) environments play a critical role in maintaining the reliability of computer systems. Typically, manually controlled air‐cooling strategies are implemented to mitigate temperature increase through usage of computer room air conditioning (CRAC) units and to eliminate overheating of information technology (IT) equipment. Most DCs are provisioned to have at least the minimum required N CRAC units to maintain safe operating conditions, with an additional unit, total N+1 provisioned to ensure redundancy. Depending on the criticality of DC operations, the CRAC units can be doubled to 2N to increase DC uptime and avoid accidental shutdown [1].

The main goal of control systems for CRAC units is to avoid overheating and/or condensation of moisture on IT equipment. The CRAC units are driven to provide the necessary cooling and maintain server's manufacturer‐recommended environmental operating parameters. Many DCs recirculate indoor air to avoid accidental introduction of moisture or contamination, even when the outdoor air temperature is lower than the operating point of the DC. Most DCs operate based on the strategy of maintaining low temperature in the whole DC, and their local (in‐unit) control loops are based on recirculating ...