in a data center that cools servers using an airflow from a central fan , rather than individual server fans , the cooling needs for each server are met by creating a sufficient pressure differential across each server . because the pressure differential is the same for all of the servers , it is desirable to operate the data center such that each server needs the same pressure differential for proper cooling . accordingly , a load balancer assigns tasks to the servers based on the known cooling needs of each server in order to balance the pressure differential needed to cool the server . this information may also be sent to the central fan to ensure that a sufficient pressure is created by the fan . determining the cooling needs beforehand avoids spikes in server temperature , thereby enabling the servers to operate safely at a temperature closer to their maximum rated temperatures .