Tax credits are available at 30% of the cost for Geothermal Heat Pumps.                                       E-mail John

Geothermal Heating & Cooling Information

  Geothermal heating and cooling takes advantage of the natural stable warmth stored in the earth. Normally the earth temperature is around 55 degrees F (13 degrees C) at depths of 10 ft. In climates warmer than 55 degrees F (13 degrees C), this can be used to air condition a building, and in colder climates (those under 55 degrees F or (13 degrees C) it can be used for heating. This is accomplished by one of a number of methods. A geothermal heat pump uses the extracted water or transfer fluid (such as water mixed with antifreeze) as a heat source in winter and a heat sink in summer. Some geothermal heat pumps provide heating and cooling via forced air distribution, and others through the heating and/or chilling of water for radiant type systems. Some systems are used for heating domestic hot water.
   Geothermal heating and cooling systems use the natural constant ambient temperature of the earth to heat in the winter and cool in the summer. This is accomplished with a compressor or heat pump unit, the liquid heat exchanger medium, and the air delivery system.
   Quite simply, geothermal systems in heating take heat from the earth, transfer that heat to a refrigerant, then distribute the heat into the structure with a forced-air or hydronic system.
   In air conditioning, geothermal systems take heat from the structure, transfer the heat to the refrigerant, then transfer the heat back to the water or loop fluid. This works the same as a standard air conditioner, except a geothermal system uses water or loop fluid at a constant temperature (average 50 degrees) instead of varying outdoor temperature.
   In other words, it's like heating and cooling your home when it's 50 degrees outside all year!

How Does Geothermal Heating Work

   Since water from the Earth is a constant temperature (approximately 55 degrees F in the Northeast), the geothermal heat pump has a constant source of 55 degrees F energy with a open loop system.
   With a closed loop system the fluid circulates continuously inside the buried pipe, absorbing heat from the earth during the winter for use inside your home or business. In warmer months, the fluid takes heat from indoors and transfers it back into the earth.
   An increasingly popular approach, especially in residential geothermal systems, is a "slinky" coil. A slinky is a coil of plastic tubing spread out and overlapped in a trench and buried. Slinky coils are installed horizontally at the bottom of a three-foot-wide trench. (Depth my vary by location, but at least 5 ft.) This method concentrates the heat transfer surface into small volume, requiring less land area and shorter trenching - a big plus for homeowners.
   The geothermal heat pump is not subject to freezing like an AAHP unit, and operates without any problem regardless of outside temperatures.
   The geothermal heat pump is extremely efficient; up to 400% more efficient than conventional heating systems according to the US Department of Energy.

      Types of geothermal heating and cooling systems:

Closed Loop.
  Loops of pipe are buried at a depth of 6 ft (2 m) and greater in the ground. Pipes are placed horizontally (buried in trenches) or buried in deep, vertically-drilled holes, often 200 ft (60 m) and greater below ground level. Water and antifreeze (or other transfer fluid) are circulated through the heat exchanger (heat pump) and back out through the loops continuously. Some closed loop systems bypass a portion of their working fluid with a thermostat to keep the source temperature stable.

Open Loop.
  Pipes draw water from a nearby water well or a shallow body of water. Once this water passes through the heat pump, it is released back to its source, generally as far from the intake as possible.                   Loop Parts loop pit field done

      Geothermal heating is one of the most efficient ways to heat a building.

  If you have sufficient area, the initial cost can be minimized by using a horizontal loop system. If you have limited space, then the cost rises as you need to drill wells deep enough into the earth to take advantage of the earth's temperature. It also has ongoing costs for the electricity to power the fluid circulation pump and the heat pump compressor. Otherwise, geothermal heating is much more efficient than air heat pumps and other supplemental electric heat used in warmer climates.
  Geothermal heating and cooling has the added benefit that it requires no burning of fossil fuels at the heating site, as opposed to systems that use natural gas or heating oil fired furnaces. But in order to achieve the most comfort, geothermal heat pumps can be paired with a natural gas heater to dramatically reduce, but not eliminate, the amount of fuel needed to heat a building.

      With geothermal air conditioning the process essentially works in reverse.

  Heat is transferred from the building into the ground. Traditional air conditioning transfers heat from the indoors to the outside air which is usually hotter than the temperature the system is trying to achieve indoors. Since the ground temperature at a depth of 10 ft (3 m) is about 55 degrees F (13 degrees C) and since ground transfer is more efficient than air transfer, geothermal air conditioning is much more efficient. Additionally, as a byproduct of the heat exchange process, a large amount of excess heat is generated. This heat can be used to heat domestic hot water before it is dissipated into the ground.

This is a geothermal heatpump in heating


Geothermal Troubleshooting Help

1. In a WSHP, the Evaporator Coil is a tube filled with water (called the Water Source Coil) and sealed inside of another larger tube filled with Freon Gas. This is known as a Tube-In-A-Tube Heat Exchanger.
2. As the very cold Freon Gas flows through the outside tube of the Evaporator Coil the water flowing through the inside tube of the Evaporator Coil warms the Freon Gas. (Purple) The heat pump cycle begins as cold liquid refrigerant passes through a heat exchanger and absorbs heat from the water solution circulating through the ground loop.
3. The Compressor then compresses the Freon Gas (The Freon Gas that absorbed heat from the water solution circulating through the ground loop), causing it to become very hot and under high-pressure, raising its temperature to more than 160 degrees and pushes it into the Reversing Valve. (Red)
4. If the system thermostat is set to heating, then the Reversing Valve moves the hot high-pressure Freon Gas into the coil. (Red)
5. As the hot high-pressure Freon Gas moves through the Condenser Coil, the Fan blows air over the coil, heating the Conditioned Air Space and cooling the Freon Gas. The heat is removed from the gas and transferred to air, which is then circulated into your house. (The temperature of the heated air or water is about 100 degrees.) The gas cools and condenses into its liquid form as it moves through the Condenser Coil. (Pink)
6. When the cooled Freon Liquid moves through the Expansion Valve, the liquid evaporates back into its gaseous form in the Evaporator Coil and gets very cold in the evaporation process. (Blue)
Then the process starts over again.

This is a geothermal heatpump in cooling.


Geothermal Troubleshooting Help

1. In a WSHP, the Fan blows air over the Evaporator Coil, cooling the Conditioned Air Space and warming the Freon Gas. (Purple) Moving warm air out of your house and through the Evaporator Coil absorbing the heat into the Freon Gas.
2. The Compressor compresses the Freon Gas (The Freon Gas that absorbed heat from the warm air circulating through house), causing it to become very hot and under high-pressure, and moves it into the Reversing Valve. (Red)
3. If the system thermostat is set to cooling, then the Reversing Valve moves the hot high-pressure Freon Gas into the Condenser Coil (This is known as a Tube-In-A-Tube Heat Exchanger). (Red)
4. As the very hot Freon Gas flows through the outside tube of the Condenser Coil the water flowing through the inside tube of the Condenser Coil, heating the water and cooling the Freon Gas., and the gas condenses into its liquid form as it cools. (Pink)
5. When the cooled Freon Liquid goes through the Expansion Valve, the liquid evaporates back into its gaseous form in the Evaporator Coil and gets very cold in the evaporation process. (Blue)
Then the process starts over again.

Hot Water Generator


   Another feature on most geothermal systems is a Hot Water Generator. Hot Water Generators, or HWG's, take refrigerant from the compressor, where it is very hot, and directs it to another small coaxial heat exchanger. In this HWG heat exchanger, water from a standard domestic hot water tank flows through, picking up heat from the hot refrigerant. This heat exchanger is double-walled, and vented so that there would be no contamination from the refrigerant if a leak occurred.

The HWG accomplishes three functions.

First, it typically heats 60% to 80% of a home's hot water for FREE utilizing waste heat from the refrigeration process.
Second, it increases the efficiency of the compressor by removing some of the heat from the compressor.
Third, it increases the life expectancy of the compressor by allowing it to operate at a cooler temperature.

      H W G unit hookup    H W G hot tank 1    H W G hot tank 2    H W G top of hot water tank    H W G bottom of water tank

Geothermal Installations






Geothermal Heating & Cooling Information with annotated diagrams. Current geothermal installations save more than 14 million barrels of crude oil per year.