The University of North Carolina at Chapel Hill’s Botanical Garden, a leader in native plant conservation and education in the southeastern United States for more than 30 years, is a "conservation garden." The mission of the garden is to inspire understanding, appreciation and conservation of plants in gardens and natural areas and to advance a sustainable relationship between people and nature.[1] True to this mission, the UNC Botanical Garden’s Totten Centre is one of the most sustainable and energy efficient buildings amongst all the UNC buildings. This is due in large part to its geothermal heating and cooling system that enables the building to saves on nearly 50 percent of its energy expenditures.
Geothermal Energy
Geothermal energy is a form of renewable energy that is derived from the heat contained in the Earth’s core. Geothermal energy is extracted from the relatively stable earth core temperature of 54º to 56ºF. Even in colder areas, the ground contains heat; at a depth of 10 feet, the ground is a constant 55ºF. Geothermal heating is a practical and energy saving alternative for heating and cooling a building. A nearby water source is used as a heat sink in the warm months and heat source in the winter month.
Environmentally Friendly
Geothermal is an environmentally friendly means of heating and cooling because it does not require as much non-renewable energy and fossil fuel to reach the same temperature as other systems. A geothermal system is also less expensive to operate than traditional heating and cooling systems.
Geothermal coils
At the Botanical Garden’s, a closed loop geothermal coil system heats and cools water. In a closed loop system, the most popular type of geothermal installation, water is circulated throughout small diameter loops. A closed loop system can be set up vertically or horizontally in the ground, or submerged in water.
At UNC, water from deep wells (3500 feet) within the botanical garden is circulated through the underground geothermal coils. These coils, nearly three and a half miles of closed pipes, use the earth’s constant temperatures to cool or heat water according to a thermostat setting. The geothermal pipes run to and fro the wells to the building. In essence, the water, which is simply used to carry warmth or freshness, is cooled and heated again and again.
The Botanical Garden's Education Center has been given the U.S. Green Building Council's Leadership in Energy and Environmental Design’s platinum certification, the highest award for green buildings.
PVC Plus Drilling Inc. supplies a complete range of drilling products and geothermal accessories that are used in geothermal heating and cooling installations. PVC Plus Drilling can supply you with geothermal fittings, slotted pipe, geothermal grouts and HDPE geothermal pipes.
1. http://www.ncbg.unc.edu
2. http://www.leed.net
3. http://reesenews.org/2011/03/29/n-c-botanical-garden-goes-geothermal/13089/
4. http://ncbg.unc.edu/pages/4/
5. http://www.energync.net/wdocs/EPC_Wind_Hyrdo_Geothermal.pdf