First Things First…..
There is often a mis-conception that you need to have a Geo-Thermal “hot spot” to install Geothermal in your home or business. While the Geothermal Heating District in Boise’s north end provides ‘hot water’ for heating, it can’t provide a means for cooling. Geothermal energy is available virtually everywhere and can provide heating and cooling using a water source heat pump(WSHP) by WaterFurnace.
What is Geothermal Heating and Cooling?
Also known as GeoExchange, Geothermal heating and cooling uses the earth’s renewable energy source to heat and cool your home. By tapping into the earth, a few feet below the earth’s surface, we are able to capture the earth’s constant temperature and move it into your home.
70% of your home’s total energy bills comes from heating, cooling, and hot water. The best way to save on energy is to improve your home’s energy efficiency. Installing a WSHP dramatically improves the efficiency of heating and cooling systems and provides “free” hot water in the summer month. Your yard has a large amount of free energy and by adding loops buried into the ground we can transfer that energy to your home for all of your heating and cooling needs.
Three Basic Geothermal Energy Sources Options
| Open Loop Options | |
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Well- Water Systems In ideal conditions, an open-loop application can be the most economical type of geothermal system. These use groundwater from a well as a direct energy source. |
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Closed Loop Options |
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If enough land is available (acre +) horizontal loops can be installed. One or more trenches are dug using a backhoe or chain trencher. HDPE pipes are inserted and trenches are backfilled. The more pipe per foot of the trench, the shorter the trench can be. Trenches range from 100 to 300 feet. |
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Vertical loops are installed if land space is limited and/or soil content is not conductive enough for horizontal loops. Installing vertical loops requires the use of a drilling rig. Multiple holes are drilled (depending on the size of home) about 10 feet apart. A double pipe connected by a U bend at the end of the pipe is inserted in the hole. The hole is then filled with grout to provide good contact around the pipe and to seal the hole. The pipes are connected by a header system a few feet below the ground, which are then brought in through the foundation of your home and connected to the unit. Typical drilling depth is 200′. |
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Pond Loop Option |
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If you have access to an adequate size body of water close to your home a pond loop can be installed. A series of earth loops are coiled and then sunk to bottom of the pond. Typically a 1/2 acre with 8′ depth is usually adequate. Ideally the body of water needs to be within 200′ feet of your home. If the pond is further than the recommended 200′ the benefit of using a pond loop is greatly reduced because of trenching, materials, and pumping costs. |
Getting Technical
We are using the same basic technology found in your home’s refrigerator. The core concept to refrigeration is moving heat energy. Your refrigerator removes heat from food; we remove heat from the ground to heat your home and we remove heat from your home to cool it. Heat flows from hot matter to cold matter. The ground acts as a giant solar collector by storing heat energy a few feet below the earth’s surface. The temperature a few feet down remains constant and unaffected by the outdoor temperatures. By placing pipes (earth loops) in the ground we are able to exchange energy. The warm earth releases heat energy into the cooler loops and then is transferred to the geothermal unit. Cold liquid refrigerant passes through the water-to-refrigerant heat exchanger. The heat exchanger is made of copper, and consists of a tube within a tube, water from the loop travels through one tube (inside tube) refrigerant passes through the other (outside tube). As the fluid flows through the heat exchanger, heat energy is transferred from the loop fluid to the refrigerant through the copper wall separating the two. This heat transfer causes the cold liquid refrigerant to turn into a gas. This gas is sucked into the compressor where it is compressed. Once compression is complete, the refrigerant will be very hot (160 degrees) and discharged through a reversing valve into the coil. This coil is similar to a radiator device, with thin aluminum fins attached to the copper refrigerant tubing. The refrigerant is passed through the coil from which return air from the house passes over the coil, heat is released from the refrigerant and absorbed by the cooler air passing by. This is a result of warm air that is then passed through your ductwork (forced air system). The cooling process is the same concept but in reverse.
Geothermal Heating and Cooling Benefits
* Lower Operating Cost
* Lower Life Cycle Cost
* Enhanced Comfort
* Safe
* Clean
* Quiet
* Reliable
* Environmentally Friendly
* Flexible
