Jerry Riley, Headquarters Air Force Civil Engineer Support Agency heating, venting and air conditioning equipment specialist, checks the air flow of a room in Building 7450 during an inspection at Ellsworth Air Force Base, S.D., Sept. 19, 2012. Riley travels around the world to inspect Air Force facilities for proper airflow and energy efficiency. Insufficient airflow can lead to a build up of carbon monoxide, causing an unhealthy work environment. (U.S. Air Force photo by Airman 1st Class Kate Thornton-Maurer/Released)