Horizontal loops are installed using a backhoe or excavator. Trenches are dug approximately 5 feet deep by 36" wide. Coils of pipe are rolled in the trench from the beginning of the trench to the end and back. One continuous pipe is used for each circuit. Once all of the pipe is rolled out, the trenches are backfilled with the same soil as excavated. These trenches are typically left in a mounded condition to allow for natural settling. The length and number of these trenches is determined by the total required heating and cooling for the home. Generally speaking, an area of ½ acre or more is needed to install this style of loop system.
Vertical loops are usually installed on smaller subdivision properties or where future land use requires the loop field to be kept to a smaller area. With vertical installations, a well driller will drill one hole for each ton of geothermal equipment. The depth of these holes is determined by the required heating and cooling of the home and by the drilling conditions. Occasionally, more than one hole per ton is needed if the drilling conditions are poor. The holes are placed 10 feet apart from one another.
Pond loops are used when a pond is either already present or when one needs to be constructed for water retention or backfill of a new home. In order for the pond to be considered, it must have a surface area of 3000 sq. ft. per ton of equipment and have a consistent depth of 8 feet or better at the driest time of the year. Coils of pipe are floated into the pond and filled with the loop solution. The coils then sink to the bottom and come to rest on top of concrete blocks that have been strapped to the coils of pipe.
Open loop systems use water from your existing domestic water well. Water is drawn from your well, run through your furnace, and then dumped into a suitable discharge site. These sites may include ponds, streams, wetlands, or any other method that will not negatively impact adjoining properties. Great care must be taken in well pump and pressure tank sizing if an open loop is considered. Water quality should also be tested prior to deciding to use an open loop application. Poor water quality can lead to more frequent maintenance and shortened equipment life.