U.S. Air Force Airman 1st Class Ryan Bray, 633rd Civil Engineering Squadron heating and ventilation journeyman, assembles a system they call “Rover” at Langley Air Force Base, Va., Nov. 20, 2014. “Rover” is a computer that reprograms the heating and ventilation systems in the dormitories. (U.S. Air Force photo by Airman 1st Class Devin Scott Michaels/Released)