Nicknamed “The Big Green” years ago for the color of their uniforms, Ottoville Local School District, Ohio, can boast of another big, green achievement.  The new K-12 building, which opened in September 2003, features an energy-efficient geoexchange system for heating, ventilating and air conditioning (HVAC).  This system, which relies on the earth’s stable temperature for its energy-efficiency, not only saves the school district significant energy costs.  It also influenced the standards of the Ohio School Facilities Commission and has convinced other schools to use similar HVAC systems that are efficient and cost-effective.