During August 2013, the country’s first predominantly African-American public high school reopened its doors as the new Laurence T. Dunbar High School. Originally founded in 1870 in Washington, D.C., the old school underwent a $122 million complete re-engineer and redesign creating a 276,536-square-foot high performance building earning a LEED for Schools Platinum certification. Dunbar’s new design features geothermal heating, photovoltaic (PV) panels, rainwater harvesting, and on-demand advanced lighting and ventilation controls. These efficiencies gained through engineering design have the potential to offer remarkable energy conservation results, considerable savings and inspiration by example.
Digging Deep
An integral piece of the design for Dunbar is the geothermal system. Geothermal systems have emerged to benefit longer lifespans for component parts; approximately 25 years for heat pumps and 50 plus years for ground loops. Compared to conventional HVAC systems, geothermal systems require minimal maintenance and have very low operating costs. Dunbar’s new geothermal system has a rated capacity between 850 to 1000 tons; the largest in Washington, D.C. The design of the vertical bore field is slated to rise less than 10 degrees over the next 30 years, and has been balanced to optimize thermal storage between the seasons.