Staff Sgt. Aaron Washington (right) and Senior Airman Kevin Gillaspie, 633rd Civil Engineer Squadron heating, ventilation and air conditioning technicians, make the appropriate adjustments to an HVAC system after running tests on the system, Sept. 18, 2012, at Langley Air Force Base, Va. With tasks like these, civil engineers take the data collected and conduct a “repair versus replace” analysis to determine the best way to handle the system. (U.S. Air Force photo by Airman 1st Class Austin C. Harvill/Released)