Properly maintained fan systems in commercial buildings provide energy savings and a healthy, comfortable environment for building occupants. But knowing when to make improvements and necessary updates can be challenging for facility managers and maintenance staff. This resource, Tune-Up Your Fan Systems for Improved Performance, from National Renewable Energy Laboratory provides guidance for implementing routine operations and maintenance, and opportunities for replacements and improvements that can help with energy savings. The guidance also features an easy-to-understand rating system of A-C to indicate the level of effort needed to maintain or improve the fan systems, and the expected impact in savings and timing for payback for these efforts. This guidance pulls together resources from AMCA, ASHRAE, U.S. Department of Energy, Environmental Protection Agency, and other industry organizations.