How Geothermal Works
Imagine a heating and cooling system that delivers up to four units of energy for every unit you purchase. A system so efficient that it saves you energy and money on winter heating, summer air conditioning and year round water heating. An environmentally friendly system that uses a clean, safe, natural and renewable source of heat -- the sun.
Ultimately the sun is always the energy source. The 'burning' question though is: How do we tap into this energy source? The answer may be buried right in your back yard. Deep below the earth's surface, the temperature is close to the average annual temperature for the area. There, thanks to the earth's insulating quality, seasonal variations in temperature have little effect. The technology to take advantage of this energy source is surprisingly simple. Dig a trench or drill a well, use everyday commodity materials and you have it: An Earth Heat Exchanger. Couple it to a TETCO geothermal heat pump and the result is year around comfort.
Types of Geothermal Heat Pump Systems
There are four basic types of ground loop systems. Three of these—horizontal, vertical, and pond/lake—are closed-loop systems. The fourth type of system is the open-loop option. Which one of these is best depends on the climate, soil conditions, available land, and local installation costs at the site. All of these approaches can be used for residential and commercial building applications
This type of installation is generally most cost-effective for residential installations, particularly for new construction where sufficient land is available. It requires trenches at least four feet deep. The most common layouts either use two pipes, one buried at six feet, and the other at four feet, or two pipes placed side-by-side at five feet in the ground in a two-foot wide trench. The Slinky method of looping pipe allows more pipe in a shorter trench, which cuts down on installation costs and makes horizontal installation possible in areas it would not be with conventional horizontal applications. 
Large commercial buildings and schools often use vertical systems because the land area required for horizontal loops would be prohibitive. Vertical loops are also used where the soil is too shallow for trenching, and they minimize the disturbance to existing landscaping. For a vertical system, holes (approximately four inches in diameter) are drilled about 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. 
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. 