Geothermal



=Definition= Geothermal is an option that utilizes the Earth's own thermal storage to heat heat and cool (in conjunction with heat pumps). The advantage is the central loop is always at a stable temperature that will require less heating or cooling to get to room temperature. A central circulation loop becomes the heat source and sink (much like the outside air in an all-air system). For a ground source geothermal, the heat sink is the earth. For a water source geothermal, the heat sink is a large body of water. There are several varieties of geothermal wells depending on the location: open well, standing column well, horizontal closed loop, and vertical closed loop. It is worthy to note that geothermal heat can also be used for domestic hot water and electricity production.

=Issues Addressed= A number of issues are addressed with geothermal:

Protection from calamitous events
The central loop is buried horizontally or vertically beneath the frost line, or drilled straight down. This protects most of the equipment from flood waters, falling debris, and other hazards accompanying a disaster. The heat pump units are housed indoors and the newer units generally have their controls mounted up high to offer some protection from flood waters. These built-in safeguards can help keep a geothermal system running during the aftermath of a disaster.

Effiency
Because geothermal systems are utilizing the Earth's stored energy to bring its refrigerant closer to room temperature, they are inherently more efficient. They can actually run at well above 100% efficiency due to fact that they are not "create" thermal energy, they are merely "moving" thermal energy.

=Considerations= Geothermal installations are not advised in all locations. Soil types, presence of salt water, and cost analysis based on the type recommended are all important considerations. The DDC has published a book that goes into great detail the areas of NYC that could benefit from their installation.

=Applications= Buildings that fall under the DDCs guidelines may be good candidates for this kind of technology. Sanitation facilities (being generally near the shoreline) might greatly benefit from their installation.

=Related Reports= DoE website DEC website DDC Geothermal Heat Pump Manual

= References =