Geothermal systems use the earth as a heat source and heat sink. In order to transfer heat to or from the house heat exchangers (ground loops) are installed in the ground. These consist of high density polyethylene plastic pipes. The loops are then connected to the heat pump and fluid circulated between them transferring the heat between the heat pump and the earth.
Vertical Ground Loop System
This type is used mainly where space is limited. Vertical Holes 100 to 400 feet deep are drilled in the ground, and a single loop of pipe with a u-tube at the bottom is installed. The borehole is then sealed with grout to ensure good contact with the soil. The vertical ground loops are then connected to a horizontal underground header pipe that carries fluid to the unit. The earth's temperature is more stable farther below the surface which is an advantage for the system. Vertical ground loop fields may be located under the house and garden lots. The life expectancy is in excess of 50 years.
