Data center cooling management and analysis - a model based approach

As the hub of information aggregation, processing, and dissemination, today´s data centers consume significant amount of energy. The data center electricity consumption mainly comes from the IT equipment and the supporting cooling facility that manages the thermal status of the IT equipment. The traditional data center cooling facility usually consists of chilled water cooled computer room air conditioning (CRAC) units and chillers that provide chilled water to the CRAC units. Electricity used to power the cooling facility could take up to a half of the total data center electricity consumption, and is a major contributor to the data center total cost of ownership. While the data center industry has established the best practice to improve the cooling efficiency, the majority of it is rule of thumbs providing only qualitative guidance. In order to provide on demand cooling and achieve improved cooling efficiency, a model based description of the data center thermal environment is indispensable. In this paper, a computationally efficient multivariable model capturing the effects of CRAC units blower speed and supply air temperature (SAT) on rack inlet temperatures is introduced, and model identification and reduction procedures are discussed. Using the model developed, data center cooling system design and analysis such as thermal zone mapping, CRAC units load balancing, and hot spot detection are investigated.