Everything (and more) you ever wanted to know about Earth Loops

There are four basic types of ground loop systems, that can be divided into two basic categories, closed loops and open loops. All of these approaches can be used for residential and commercial building applications. If this guide isn't enough to answer ALL of your questions, please don't be afraid to contact us and we'll be glad to answer any of your questions.

For closed loop systems, an antifreeze solution is circulated through plastic pipes buried beneath the earth's surface. During the winter, the fluid collects heat from the earth and carries it through the system and into the building. During the summer, the system reverses itself to cool the building by removing heat from the building, carrying it through the system and releasing it in the ground. Most systems are also equipped with a device to divert some of the energy towards the creation of free hot water in the summer and provides very inexpensive hot water in the winter.

Open loop systems operate on the same principle as closed loop systems and can be installed where an adequate supply of suitable water is available and open discharge is feasible. Benefits similar to the closed loop system are obtained.

Horizontal Loops

This type of installation is generally most cost-effective for residential installations, particularly for new construction where sufficient land is available. It requires a large pit to be excavated about 8 feet deep and about 400 foot long. A slinky loop method of looping pipe allows for a much shorter trench, which may cut down on installation costs and makes horizontal installation possible in areas it would not be with conventional horizontal applications.

Another variation on the horizontal loop is the horizontal bore system. This uses a boring machine that bores horizontally 12-20 feet below the surface, providing for excellent loop performance while leaving the existing landscaping undisturbed. This system is often used in retrofit applications and is typically a little more expensive than a trench system, but less expensive than a vertical loop system.

Vertical Loops

Where the land area required for horizontal loops is not available or otherwise prohibitive, vertical loops are an excellent choice. Vertical loops also minimize the disturbance to existing landscaping. For a vertical system, holes (approximately four inches in diameter) are drilled about 12-20 feet apart and 100-400 feet deep. Into these holes go two pipes that are connected at the bottom with a U-bend to form a loop. The vertical loops are connected with horizontal pipe (i.e., manifold), placed in trenches, and connected to the heat pump in the building.

Pond Loops

If the site has an adequate water body, this may be the lowest cost option. A supply line pipe is run underground from the building to the water and coiled into circles at least eight feet under the surface to prevent freezing. The coils should only be placed in a water source that meets minimum volume, depth, and quality criteria.

Open Loops

This type of system, also called "pump and dump," uses well water that circulates directly through the heat pump system. Once it has circulated through the system, the water is discharged into a local stream or pond. This option is obviously practical only where there is an adequate supply of relatively clean water, and all local codes and regulations regarding groundwater discharge are met.