Geothermal Loops

The ground/earth loop provides the infrastructure for accessing and continually exchanging thermal energy between the earth and the building. GeoExchange loop systems can be classified as either closed or open. Closed Loop systems consist of a continuous, sealed, underground or submerged loop field of high-density polyethylene pipe through which a heat-transfer fluid is circulated between the ground and the heat pump. Closed Loop systems are installed in various configurations (horizontal, vertical or in a pond) dependent upon site characteristics. Open Loop/Groundwater systems are designed to use groundwater for the purpose of extracting or rejecting heat.

Vertical Loop

Vertical systems are used when land area is limited. For a vertical system, holes are drilled 10-20 feet apart and 100-400 feet deep in a grid matrix. A pair of pipes that are connected at the bottom with a U-bend are inserted into each bore hole. The pipes are then manifolded together and brought into the home.

Horizontal Loop

This type of installation is generally the most cost-effective for residential installations where sufficient land is available. It requires trenches to be dug by a backhoe or trencher to approximately 6 feet. GeoExchange pipe is then layered in the trenches, and the trenches are backfilled with soil.

Pond/Lake Loop

If the site has an adequate body of water close to the residence, approx. 1/2 acre by 8 feet deep, this may be the lowest cost option. Supply and return pipes are run underground from the home to the pond/lake and connected to a series of closed coils. These coils are submerged to the bottom of the pond/lake.

Open-Loop System

This type of system is used when an abundant supply of quality well water is available. Ground water is withdrawn from the aquifer/well and pumped into the heat pump. The discharge water is directed to a secondary well. The supply aquifer/well must have adequate capacity to provide flow for the heat pump and domestic water.