Simultaneous use of air-side and water-side economizers with the air source heat pump in a data center for cooling and heating production

Due to the development of information technology, energy consumption of data centers is increasing continuously and quickly. Therefore, finding solutions for minimizing the energy consumption of data centers and reducing the greenhouse gas emissions is essential. In this paper, a combined free cooling and waste heat recovery system is proposed to reduce the electrical energy consumption of a data center in Mashhad and to save the natural gas fuel consumption of its adjoining office building, as a case study. Two types of economizers including air-side economizer (ASE) and water-side economizer (WSE) systems are used for free cooling as well as an air source heat pump (ASHP) used as a waste heat recovery system. In fact, in this study, the effect of simultaneous use of the air-side economizer (ASE), water-side economizer (WSE) and air source heat pump (ASHP) is investigated for improving the energy performance index of the data center. For this reason, a thermoeconomic-environmental analysis is performed to study the performance of the proposed system. The results show that the proposed system have the electricity and natural gas saving potentials of more than 250 MWh/year and 15,000 m(3)/year respectively, which leads to 267 ton/year of CO2 emission reduction. Furthermore, it is found that the Power Usage Effectiveness (PUE) index can decrease down to 2.07, indicating an improvement of 16% in the calculated energy efficiency of the data center. Finally, economic analysis shows that payback period of the proposed system will be 2.5 years.