Datacenter power savings through high ambient datacenter operation: CFD modeling study

In a typical datacenter, almost 40% of the total power consumption is spent on datacenter cooling. In addition, the capital expenditure costs for the cooling infrastructure are also significant. Large Internet Portal Datacenters are looking at every possible way to reduce the cooling cost. One of the emerging trends in the industry is to move to higher ambient datacenter operation. Some datacenter operators are even wanting to operate the datacenters at ambient as high as 40C. It is shown that both server power increase and facility level cooling power savings must be considered to determine net power savings at the datacenter level. CFD modeling is used to demonstrate that following best practices in airflow management: using blanking panels, floor layout, eliminating cable obstructions, hot/cold aisle containment and bypass and re-circulation reduction are first important steps to get ready for high ambient datacenter operation. It is shown that without these practices, there is large variation in inlet air temperature from one server to other creating hotspots forcing thermostats on CRAC units to be set low. It is shown that CFD modeling can be used to quantify how cooling path management improves with hot/cold aisle containment. The study shows that significant datacenter level power savings can be achieved by operating the datacenter up to 35C with the use of Economizers.