Creative Commons

By taking into consideration the fact that modern societies require more and more information to be digitally processed, stored and transferred, it is conspicuous that the data centers constructed in order to support the aforementioned IT activities require a continuously increased amount of energy for the maintenance of its regular operation. The total amount of energy supplied to the data center can be divided into two different streams, the energy required by the IT equipment and the energy needed to run the physical infrastructure. The main purpose of this dissertation is to explore to which extent the integration of the energy-efficient method of deploying cooling systems that support the operation in economizer mode is able to mitigate the economic and environmental impacts deriving from the continuous growth of the IT industry. The first part of the thesis will discuss the various traditional cooling architectures that are usually deployed within the data center industry. The qualitative and quantitative comparison of the aforementioned cooling systems will illustrate which configuration is considered to have the greater contribution to the energy improvement of a data center. For the realization of the quantitative comparison a hypothetical medium-to-large data center is introduced. However, the observations made by the aforementioned comparison indicate that even the most energy efficient cooling system requires a significant amount of energy. Therefore, the operation of a data center in economizer mode is considered to be a smart idea to be adopted by the data center operators. In the second part of the thesis, the various types of economizer modes will be discussed, while their qualitative and quantitative comparison conducted by using the hypothetical medium-to-large data center introduced in the previous part, will illustrate that the air conditioner with indirect air evaporative cooler is the cooling architecture that maximizes the benefits that can be extracted by the operation of a data center in economizer mode. The suitability of this cooling architecture is proved to be irrevocable by the influence of the weather conditions prevailing on a geographical location or by the supply inlet temperature that is required by the data center operator. Last but not least, it is concluded that the national and international energy legislation does not seem to favor the utilization of economizer mode, while hampering the integration of further energy efficiency measures. -ii- This dissertation was written as a part of the MSc in Energy Systems at the International Hellenic University. I would like to sincerely thank my supervisor, Dr. Agis Papadopoulos, for supporting my thesis proposal and providing me the required guidance. Amongst my friends, I would like to thank Nikolas Papanotas for coming up with and proposing me this brilliant subject and for having several interesting discussions over this issue. Last but not least, I would like to express my deepest love and gratitude for my family for supporting and encouraging me during the attendance of the master in Energy Systems.