Extending Air-Cooled Data Center Emergency Cooling Duration with Phase Change Material: An Experimental Study

Data center failure due to power outage can lead to huge economic losses and goodwill impairment. In this research an attempt has been made to extend emergency cooling duration under different power outage scenarios: a complete power outage, an outage affecting the chiller-side while the air handling unit remained operational, and an outage targeting the chiller. The study experimentally focused on temperature variations at the inlet and outlet of a specific 42U cabinet. The results showed that during a complete power outage, there was a significant temperature rise, with the highest recorded inlet temperature in the cabinet reaching 34 °C. In the scenario where only the air handling unit is operated without the chilled water pump, inadequate heat exchange led to a rise in the returning hot air, with a maximum inlet temperature of 30.5 °C. However, in a chiller-targeted outage, the pump circulated chilled water in a cold-water storage, resulting in improved heat exchange and an inlet temperature of only 19.4 °C. Furthermore, the study explored using a fin-and-tube heat exchanger containing PureTemp27 as a phase change material (PCM) to extend emergency cooling time. When the fan supply voltage is 7V, the findings showed an approximate 8-minute extension with a heat load of 5 kW and a 5-minute extension with a heat load of 7.5 kW. Increasing the fan supply voltage to 12 V showed no significant difference. This research provides valuable insights into applying PCM during emergencies in data centers.