The magic that allows you to heat and cool your home with solar energy stored in water or in the earth !

How Geothermal Systems Work

   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 cooling, 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!

This is a geothermal heatpump in heating.

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.

   Since water from the Earth is a constant temperature (approximately 55°F in the Northeast), the WSHP has a constant source of 55°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 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 WSHP is not subject to freezing like an AAHP unit, and operates without any problem regardless of outside temperatures.
   The WSHP is extremely efficient; up to 400% more efficient than conventional heating systems according to the US Department of Energy.

This is a geothermal heatpump in cooling.

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 Evaporator Coil the water flowing through the inside tube of the Evaporator 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.

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