Loop Configuration

The ground loop system utilizes polyethylene pipes circulating a water/antifreeze solution to extract heat from soil beneath the frost line. In cooling mode, the pipes return heat to the earth.
There are four basic ground loop configurations and two basic types of geothermal systems.

Vertical Loop:
These loop systems are used mainly when land area is limited. A drilling rig is used to bore holes to depths of approximately 125 to 250 feet deep. A u-shaped loop of high density polyethylene pipe is inserted. The holes are then filled with a sealing solution prior to backfilling. The system is closed loop meaning that the same solution placed in the system is continuously re-circulated through the system.

Horizontal Loop:
These loop systems are used when adequate land is available. Loop installers use a chain trencher or back hoe to dig trenches. Each trench is approximately 6 feet deep. Trench lengths range from 100 to 300 feet, depending on loop design and application. This process is also a closed loop system.

Pond Loop:
Popular in cottage country this option is available if a large body of water is present. A half-acre, 8 feet deep body of water is usually sufficient for the average home. This closed loop system places coiled pipe on the bottom of the body of water.

Open Loop:
This system does not continuously run the same solution through the geothermal system. Ground water is pulled from one location, run through the geothermal unit, and discharged into another location. Two requirements are needed for an open loop system. The first is an abundant supply of well water must be available to satisfy the demands of the unit as well as domestic. The second is that the discharge water is sent directly to a separate recharge well. In a few instances, a ditch, field tile, stream or pond may be acceptable.