A significant component of the Zero Net Energy strategy for the Health Professions & Student Services Building is the use of ground source heat pumps to heat and cool the building. Ground Source Heat Pumps use the relatively constant earth temperature, which is around 52° Fahrenheit, to provide heating and cooling for the building. The advantage of the ground source heat pump system is that for every unit of energy the heat pumps use, more units of heating or cooling are produced. This provides tremendous energy savings over traditional fossil fuel heating and cooling.
The geothermal system begins in the parking lot, below which there are 50 geothermal wells. Six-inch diameter holes were drilled to 500 feet and then 50,000 linear feet of high-density polyethylene pipe was installed in the boreholes and grouted with a thermally enhanced betonites grout. A series of header piping connects the wells to the building and circulates a biodegradable mix of ethanol and water antifreeze solution to the heat pumps in the building. Inside the building the heat pumps circulate the warm or cool fluid through HVAC distribution systems including forced air and chilled beams to keep the building at a steady 70°.
In the summer, heat extracted from the building is circulated to the wells and that 52° fluid returns to the heat pumps to cool the building. In the winter, the cool fluid is circulated from the building to the wells and the returning 52° fluid is boosted by the heat pumps to heat the building to a comfortable 70°. The energy efficiency results of this pilot project will be monitored to inform the design and operation of future state owned facilities in order to save energy, reduce greenhouse gas emissions, provide cost savings and stimulate clean energy technology.