All geothermal heating and cooling systems require the use of loops to function. In simple terms, loops are circuits of pipe that are used to circulate water and/or ethanol through the heat pump. They can be installed in the ground, or in a body of water. There are three primary types of loops used in standard geothermal systems; horizontal, vertical and pond loops.
Horizontal loops are the most common geothermal loops used today, where adequate land is available. To install a horizontal geothermal loop, a series of trenches are dug in the ground to accommodate the polyethylene piping. A typical horizontal loop installation requires approximately an acre of land.
Vertical loops are used when there are certain restrictions at the installation site. In most cases, this refers to the physical space available for the installation, but it can also refer to challenges related to excavation. During a vertical loop installation, a drilling rig is used to bore holes in the ground, which accommodate the necessary piping for the geothermal heating system.
Pond loops are used when an adequate body of water is available for use on the property. In an installation such as this, a series of loops is fixed to a steel frame. Once the loops have been secured to frame, and the air has been purged from them, they are ready to be sunk to the bottom of the pond. Lake loops are very similar to pond loops, except they do not have a fixed frame.