For laboratories, the greatest energy challenge is meeting ventilation airflow requirements while maintaining a comfortable and functional interior environment. When exhaust-driven ventilation requirements exceed the airflow required for sensible cooling, and supply temperature reset for the air supply is limited by humidity control or the presence of load-driven labs on the same air system, reheat is often seen as the only alternative. This column discusses how reheat energy and the wasted energy of the offset sensible cooling are major opportunities for energy savings in these buildings.