February 16, 2009
As part of Wilson Community College’s construction of its new Student Services Building, a series of geothermal heat pumps were installed to provide the heating, cooling and hot water supply for the building. A geothermal heat pump, also known as a “ground source’ heat pump, takes the heat reserves stored from within the earth and provides the heating, cooling, and hot water for a building or a residence.
Traditional systems for heating and cooling are referred to as “air cooled” systems. A traditional air conditioning system in the summer months will take the hot outside air and push it across refrigerated coils in order to cool it. This causes the compressor in the system to have to work extremely hard to cool the refrigerant coils in order for the air inside a home, office or building to stay comfortable. In the heating season, a traditional heat pump system uses the outside air, which a great deal of the time is below freezing, in order to transfer heat. Traditional cooling and heating systems require sizeable amounts of energy in order to provide comfortable airflow to a home, office, or building.
A geothermal heat pump functions like a traditional heat pump in that it uses refrigerant to capture and move heat between indoors and out. The main difference between geothermal heat pump systems versus traditional air-cooled heat pump systems is that the traditional system collects and purges heat by using outside air. Geothermal systems use the earth below the home or building site as the heat source or heat sink and transfers the heat through extended loops of refrigerant filled pipe buried in the ground. For example, during the heating season, a geothermal heat pump will remove heat from the earth and put it into a home or building. The cooler air from the home or building is then returned to the earth. In the cooling season, the heat pump takes the heat from inside the home or building and transfers it back to the earth. Because geothermal heat pumps use the renewable and constant source of heat from the earth, they are:
The earth maintains a constant temperature of 40-75 degrees year round, even in the summer months. Because of the relatively stable temperature range from within the earth, a geothermal system is able to operate all year round under a lower temperature gradient between the indoor and outdoor temperatures in both the heating and cooling seasons. This lower temperature gradient can result in a significant energy savings of as much as 40% in the cooling season and 75% in the heating season.
Wilson Community College selected geothermal heat pumps manufactured by Earthlinked Technologies. The
expertise that an Earthlinked geothermal system utilizes is known as “Direct Exchange Geothermal”. As part of
this technology, a system of several direct access earth loops (constructed of copper) and refrigerant flow control
technology, allow refrigerant to exchange heat directly with the earth. The system of direct access loops are buried <
deep underground.
“The new Student Services Building uses nine Earthlinked heat pumps working in conjunction with nine York air- handling units to provide heating, cooling, and ventilation throughout the building. The entire site has nine diagonal loop well fields to support these systems. In addition, one of the nine heat pumps has an additional heat exchanger that heats the water for the restrooms as a by-product of the building conditioning process. Home Energy Incorporated installed the heat pumps, refrigerant piping, and wells. Biggs HVAC installed the air-handling units, controls, and ductwork. All of the work was done as a part of Macallen Construction Company’s general contract of the new Student Services Building.” (Charles Ladd, P.E., AIA Williard Ferm Architects, PA). The overall design of the geothermal heat pump system project was completed by Williard Ferm Architects, PA.
For additional information on the companies that were involved in the geothermal heat pump installation
at Wilson Community College, you can visit their Websites:
http://www.earthlinked.com
http://thehomeenergycompany.com
http://www.biggshvac.com
http://www.williardferm.com
Claudine LaBrake is the Sustainability/Business & Industry Coordinator in the Department of Continuing Education at Wilson Community College. LaBrake is a UNC-Wilmington graduate with a B.A. in Environmental Studies and a Minor in Chemistry. She is also a former Environmental, Health and Safety Manager with 10 years of experience in Industry and Manufacturing.
Claudine LaBrake
Sustainability Coordinator
Continuing Education
Wilson Community College | P.O. Box 4305 • 902 Herring Avenue | Wilson, NC 27893 | Phone: (252) 291-1195 | Fax: (252) 243-7148