Performance Comparison of Data Center with Different Airflow Management Technologies

Compared with new technologies such as liquid cooling system, two-phase cooling system and integrated system, air cooling system is still widely used in data center. Nowadays, with the increase of power density of rack, the airflow in data center needs to be upgraded to keep the rack temperature in a suitable range. However, the performance of data center with different airflow managements is still unclear, especially at high power density of rack, which is important to select the suitable airflow management technology. Therefore, this paper discusses the performance of four airflow management technologies regarding the free cooling strategy: Case 1 (raised floor and cold aisle containment (CAC) supply / CRAC direct return); Case 2 (CRAC direct supply / hot aisle containment (HAC) return); Case 3 (Overhead duct supply / CRAC direct return); and Case 4 (Overhead duct supply / HAC return). By using the validated model, it was found that Case 4 had the best thermal performance, followed by Case 3, Case 2 and Case 1. The arrangement of air duct supply and HAC return can reduce the hot air recirculation, cold air bypass, and uneven cooling capacity distribution as much as possible. Case 2 was not suggested when the rack power density was higher than 10kW; while only Case 4 can be used when the rack power density reached 15kW. With the increase of power density, annual PUE showed an increasing tendency, in which Case 4 also had the lowest annual PUE. However, Case 3 was the most suitable one in practical application due to highest economic performance when rack power density was lower than 12.5kW