Geothermal systems transfer heat from your home to the earth in the cooling mode, or from the earth to your home in the heating mode. Water is used as the heat transfer medium through a closed loop piping system buried in the ground. By using this stable thermal source, geothermal heat pumps provide energy efficient comfort year around with a factory-tested and sealed packaged unit, without the need for a noisy outdoor fan, or a flue.
The environmental advantages of geothermal systems have caught the eye of governmental agencies such as the Environmental Protection Agency (EPA) and the Department of Energy (DOE). Because geothermal technology is lowest in CO2 emissions, it provides a solution to global warming by primarily using the natural energy of the earth. EarthPure® (R-410A) zero ozone depletion refrigerant is available for ClimateMaster geothermal heat pumps for an even friendlier system.
There are two types of geothermal systems commonly installed in North America, closed loop geothermal, and open loop (well water systems). Both types of systems work well and achieve very similar operating costs. An open loop system is less expensive to install, but over time could require more maintenance. A closed loop system is more expensive up front, but requires almost no maintenance.
GEODONICS – Geothermal Heat Pumps & Hydronic Radiant Panels
Download slides for webcast here before listening.
Vertical (Drilled) Closed Loop
Vertical Loops are used extensively where land area is limited or soil conditions prohibit digging horizontal loops. A pair of pipes with a special U-Bend assembly at the bottom are inserted into a bore hole that averages between 150 to 300 feet deep per ton [13 to 27 meters per kW] of equipment. These holes are then backfi lled with a special grout solution to ensure good contact with the earth
Horizontal (Trenched or Bored) Loop
Horizontal Loops are installed in areas where the soil conditions allow for economical excavation. Taking up more land area than any other loop type, they are used where space permits. Trenches are normally about 4 to 6 feet [1.2 to 1.8 meters] deep with multiple pipes placed in the trench at different depths. Normally, several hundred feet [over 100 meters] of trench is required, but where space permits these loops are considered desirable.
Pond/Lake Loop
Pond Loops are usually very economical to install. If a pond or lake at least eight feet [2.5 meters] deep is available, pond loops can utilize the water (rather than soil) to transfer heat to and from the pond. A coiled pipe is placed in the water, which should cover about 1/2 acre [0.2 hectare]. An average home would require about 900 feet [27 meters] of pipe. Reduced installation costs and high performance are characteristic of this type of loop.
Open Loop
Open Loop installations actually pump water from an underground aquifer through the geothermal unit and then discharge that water to a drainage ditch or pond. The geothermal unit processes the heat energy from the water just like a closed loop installation. Discharging water to a “return” well is Sometimes effective, but sending water to a pond or lake is considered more reliable.