Here Are the Facts on Earth Loops
Three Basic Geothermal Energy Sources
Closed-loop systems circulate a water-based solution through a "loop system " of small-diameter, high-density polyethylene underground pipes. Closed-loop systems can be installed horizontally, vertically or in a pond. Open-loop systems use an existing water well or surface water. Whether the system is open or closed, heat is transferred to or from the structure, regardless of outdoor temperature, to provide year-round comfort.