Energy and Exergy Analysis of Modular Data Centers

The data center industry focuses on initiatives to reduce its enormous energy consumption and to minimize its adverse environmental impact. Modular data centers provide considerable operational flexibility in that they are mobile and are manufactured using standard containers. This paper develops steady-state energy and exergy destruction models for modular data centers with the open-source EnergyPlus software package. Three different cooling approaches are examined: direct expansion (DX) cooling, evaporative cooling (direct evaporative cooling, DEC, in this study), and free air cooling (air-side economization in this study). This paper shows that for hot and arid climates like those in the southwestern U.S., augmenting DX cooling with evaporative and free air cooling can result in energy savings of up to 38% and 36%, respectively. This paper also applies exergy analysis to suggest that the Energy Reuse Effectiveness of the data center increases with decreasing ambient (outdoor) temperature and increasing server inlet-outlet temperature difference. Furthermore, simulations indicate that the use of passive cooling techniques (e.g., DEC and free air cooling) decrease data center heating, ventilation, and air-conditioning energy consumption, except in extremely hot and humid climates.