Ground Water Systems (Open Loop) have been utilizing the earth's natural heat source/heat sink ability for over 40 years. Ground Water Systems draw water from an aquifer via a supply well, pass through the Geothermal heat pump's heat exchanger where heat is exchanged with the refrigerant inside your FHP unit. The water is then returned to the aquifer by being disposed back out to a pond, lake or low area to filter back naturally to the aquafers. Ground water temperatures remain very constant (usually within a degree) throughout the year despite wide variations in outside air temperature; therefore your FHP unit will maintain it's super high efficiency no matter how hot or cold it is outside. Ground Water Systems are ideally suited for homes that have existing water wells available or a good potential source for well water. When ground water is available this system usually has the lowest installed cost.
* This system is recommended only if the quality of your water exhibits low iron content.

Closed-loop systems are becoming more common. They utilize the natural thermal properties of the earth in a similar manner to the ground water systems. There are 4 types of closed loop systems. All types use a continuous loop where the heat transfer fluid is circulated.

HORIZONTAL - A horizontal loop is usually the most cost effective when adequate yard space is available and trenches are easy to dig. Using trenchers or backhoes digging trenches six to eight feet below the ground, you then lay a series of parallel plastic pipes or slinkies. The trench is then back filled, taking care not to allow sharp rocks or debris to damage the pipe. A typical horizontal loop will have an average of 800' feet of pipe buried in a 400' long trench, which will generally supply one ton of heat.
*Benes Well Drilling does not recommend this type of system due to year-round efficiency and the depth and land area required to install this system.

VERTICAL - Vertical loops are preferred in many installations where yard space is insufficient and where preservation of existing landscaping is desirable. Contractors bore vertical holes in the ground 180-200 feet deep. Each hole contains a single loop of pipe with a U-bend at the bottom. The hole is then grouted to improve the thermal conductivity. Each vertical pipe is then connected to a horizontal pipe underground, then connected to a manifold underground with one line running in and one line running out from the heat pump inside the structure. The manifold can be installed inside the home if space is available for an additional cost. Vertical loops are generally more expensive to install, but maintain a more constant year-round efficiency.
*Due to it's efficiency, Benes Well Drilling recommends the vertical system and has them on their own homes.

SLINKY - Slinky loops are used to reduce the heat exchanger per foot trench requirements but require more pipe per ton of capacity. This pipe is coiled like a slinky, overlapped and laid in a trench. Two-pipe systems may require 600-800 feet of more pipe buried in a 125' trench, that will basically give you one ton of heat. The trench length decreases as the number of pipes in the trench increases or as slinky overlap increases.
*Note that with this system and the lines crossing over each other, one line can tend to rob heat from the others and efficiency levels drop. Therefore, this system is not highly recommended by Benes Well Drilling.

POND - Pond (or lake) loops are a special kind of closed loop system and may be the most economical closed loop system to install. Where there is a pond or stream that is deep enough and with enough flow, closed loop coils can be placed on the bottom where it can utilize the consistent temperature and outstanding heat transfer characteristics of the water. Geothermal transfer fluid is pumped in as in the other closed loop ground systems. No wells and very little trenching are required - cutting installation costs. The FHP Manufacturing Pond or Lake System is not subject to the cruel outside air temperatures that all air-to-air heat pumps are subject to year after year.
* This system is the least recommended system by us as it's efficiency can vary due to water temperature - dependent upon the size of your pond or water source. Also, this system is more difficult to get approval for compliancy through the DNR on public lakes due to opportunities there are for boats, etc to hit these lines, potentially creating problems.

Geothermal heating and cooling systems can be connected to the earth in a variety of ways. High system performance is dependent upon good installation practices and knowledge of equipment.

Benes Well Drilling is licensed and certified for installation of geothermal closed loop systems.

For more information on geothermal heating systems, visit Mid-American Energy or IGSHPA (International Ground Source Heat Pump Association) at IGSHPA - Down to Earth Energy. You will have to click your "back" button to return to this page.