Project Files: Closing the Loop
Company: Bosch Thermotechnology Corp.
Customer: Sandy Grove Middle School in Lumber Bridge, North Carolina
Installation: Sandy Grove utilizes a closed-loop geothermal system that comprises 160 300-foot-deep bore holes. Two-stage Bosch Thermotechnology AP models (currently sold as the LM model) and larger single-stage FHP commercial EP models comprise the 49 geothermal heat pumps in Sandy Grove’s HVAC system. A separate geothermal water-to-water heat pump provides domestic hot water, further reducing energy requirements for the school.
Completion: August 2013
Objective: Sandy Grove Middle School sought to become an energy-positive leased public school, returning more energy to the grid than it consumes. In addition to its pending Leadership in Energy and Environmental Design (LEED) Gold status, the Hoke County school system expects the project to save the county $35 million over the next 40 years, including $16 million in energy costs. The 75,391-square-foot school is the first government building whose construction was financed entirely by its own energy savings.
Work Completed: These geothermal heat pumps help to reduce overall operating costs as well as carbon dioxide emissions, making them an important factor in the school’s overall sustainability. In total, the 49 pumps provide 209 ton of cooling load across three wings of eight classrooms each, a 450-seat gymnasium, a media center, and 258-seat kitchen/dining areas. Each classroom contains its own dedicated heat pump and thermostat, therefore allowing for individual environments to be maintained. Because the temperature of the ground is relatively consistent, the system delivers a constant flow of 55°F water to the pumps, which means they require less energy to regulate Sandy Grove’s indoor temperature. The building automation system monitors and controls all HVAC systems.
Publication date: 10/10/2016