—In state of the art systems, workload scheduling and server fan speed operate independently leading to cooling inefficiencies. In this work we propose GentleCool, a proactive multi-tier approach for significantly lowering the fan cooling costs without compromising the performance. Our technique manages the fan speed through intelligently allocating the workload across different machines. The experimental results show our approach delivers average cooling energy savings of 72% and improves the mean time between failures (MTBF) of the fans by 2.3X compared to the state of the art.