Here Are the Facts on Residential Loops

Four Basic Geothermal Energy Sources
Closed-loop systems circulate a water-based solution through a "loop" of small-diameter, underground pipes. Closed-loop systems can be installed horizontally, vertically or in a pond. Open-loop systems use an existing water well. Regardless of whether the system is open or closed, heat is transferred to or from the home to provide year-round comfort, no matter what the outdoor temperature is.

	Horizontal Loops Often used when adequate land surface is available. Depending on system needs and space available, pipes are placed in trenches that range in length from 100 to 400 feet.
	Vertical Loops The ideal choice when available land surface is limited. Drilling equipment is used to bore small-diameter holes from 75 to 300 feet deep.
	Pond (Lake) Loops Very economical to install when a large body of water is available. Coils of pipe are simply placed on the bottom of the pond or lake.
	Open loops (Well-Water Systems) In ideal conditions, an open-loop application can be the most economical type of geothermal system. These use groundwater from a well as a direct energy source.
	(Click on the loop diagrams for larger images)