Geo-Thermal Air-conditioning/heating Systems

Why Use Geothermal?

According to the Environmental Protection Agency a geothermal heat pump system is the lowest in greenhouse emissions and is the most environmentally responsible heating and cooling alternative available today. Geothermal systems are highly energy-efficient and typically require small amounts of electricity to harness the earth’s renewable energy. High efficient geothermal technology is capable of fully utilizing the earth’s natural heat storage, that is a constant 50-55 degrees in the northeast, as the primary source to generate heating and cooling your home.
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An Investment in Savings

A typical homeowner can save in the range of $600 to $1,200 annually (actual savings vary depending on usage, weather and local utility rates) with the installation of a geothermal system. How? The use of geothermal loops allows geothermal units to use only a relatively small amount of electricity. The unit merely transfers heat to and from the earth, rather than creating it from fossil sources like conventional systems. With geothermal you will enjoy savings up to 60% over conventional systems, and a short investment payback. Plus, governments and utilities often offer tax credits and rebates for the installation of geothermal heat pumps.
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How It Works

No matter where you live, the underground temperature remains relatively constant all year, even though outdoor temperatures may vary widely. Geothermal systems utilize this stable resource as a renewable energy source for your home.

Every geothermal system has three major subsystems or parts:

  1. An earth loop for transferring heat in the earth
  2. A heat pump compressor unit to concentrate and move the heat
  3. An indoor heat distribution system.

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EarthLinked® Direct Exchange (DX) system has 3 major components:

  1. An earth loop system to exchange heat with the earth via a heat transfer refrigerant that circulates through the loops.
  2. A heat pump that moves heat or cool between the building and the earth via the earth loops.
  3. A distribution system to distribute comfort throughout the building.
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The EarthLinked® DX system has two options for water heating:

  1. A desuperheater to capture waste heat from the air conditioning cycle and move it to the water heater.
  2. A full-demand water heater, where the EarthLinked system supplies all of your hot water needs year-around.
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Earthlinked Loop System Is Engineered For Maximum Efficiency

The earth loops are like arteries in a human body. The loops are connected to the heat pump to circulate refrigerant and directly exchange thermal energy with the earth. EarthLinked ground loops have the smallest size and smallest footprint in the market. They have the highest temperature differential with the earth, which means they can use the least amount of earth contact to work effectively. The long-lasting earth loops are made of copper, one of the few metals that exist naturally as an element in the earth. A noble metal, copper resists corrosion because of the protective film that forms naturally on its surface. In rare exceptions where pH readings exceed safe levels, we install the proprietary Cathodic Protection System in-ground to preclude copper corrosion in harsh conditions. The earth loops are pre-assembled and can be installed in three different configurations—horizontal, vertical or diagonal—for maximum design flexibility and cost-effectiveness.

Depending upon underground conditions, loops using vertical or diagonal configurations are typically installed in less than two days, whereas horizontal loops can be installed in a single day.
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The Heat Pump – is the heart of the DX system

Like a pulsing heart, the heat pump circulates the refrigerant through the earth loops to exchange thermal energy with the earth. No complex digital or mechanical equipment is required. Just three mechanically simple devices (a compressor, a condenser and an evaporator) enclosed in a small indoor unit and integrated to work seamlessly, leveraging the natural laws of physics. The system is more reliable and efficient than other geothermal systems because it has no water circulating pump, intermediate heat exchanger or thermostatic expansion valve.

The heat pump is engineered for easy integration with the building’s heat distribution system. Because the unit is fully enclosed, it can be installed indoors and does not have to withstand the stress of extreme temperature changes and inclement weather.

In the Winter heating mode, heat is extracted from the earth by using that heat to evaporate the refrigerant (any temperature above -40°F is sufficient) which then passes through the compressor where its pressure and temperature are increased. The hot refrigerant then gives up its heat by heating cool air that passes through the fan coil in the air handler (or by heating the water that is flowing through a radiant hydronic system). Having given up its heat, the refrigerant condenses into a liquid and returns to the earth loop to take on more heat. (A water-based geothermal heat pump also has a water pump to move water through its water loop in the ground and a water-to-refrigerant heat exchanger.)

In the Summer cooling mode, the process is reversed. The liquid refrigerant passing through the fan coil in the air handler (like the coils in an air conditioner) is evaporated and passes through the compressor where its heat is concentrated and increased. The hot refrigerant vapor then gives up its heat as it circulates in the earth loop, condenses into a liquid, then returns to the building to take on more heat. (A water-based geothermal heat pump relies upon a water loop to extract heat from the earth and transport it to a heat exchanger adjacent to the heat pump, where the heat is transferred into the heat pump system, and the cycle is reversed in the summer.)
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The Importance of AHRI Efficiency Ratings and ENERGY STAR

Heating and cooling systems are independently rated based on their performance. In the U.S. there are two primary information resources available to the consumer, AHRI and ENERGY STAR. EarthLinked Technologies participates in both programs.

AHRI (Air Conditioning, Heating and Refrigeration Institute) is the trade association representing manufacturers of more than 90% of the central air-conditioning and commercial refrigeration equipment installed in North America. EarthLinked Technologies was one of the founding members of the Direct Geo-exchange Section of AHRI that established Standard 870 for performance certification.

Two of AHRI’s most important functions are the development of performance rating standards and the administration of performance certification programs for eligible products. Participation in the program is voluntary and is open to members and nonmembers of AHRI on an equal basis. AHRI regularly selects random samples of equipment for testing. The equipment is tested using procedures set forth in the AHRI standard to verify performance ratings.

To complete the performance test, a heat exchanger is used in lieu of an actual earth loop. EarthLinked efficiencies at AHRI test conditions are 77°F entering fluid in the cooling mode and 32°F entering fluid in the heating mode.

ENERGY STAR is a joint program of the U.S. Environmental Protection Agency and the U.S. Department of Energy that was created to help consumers save money and protect the environment through energy efficient products and practices.

The EarthLinked® system is in the Direct Expansion (DX) category and is defined by Energy Star as a geothermal heat pump system in which the refrigerant is circulated in pipes buried in the ground (rather than using a heat transfer fluid, such as water or antifreeze solution in a separate closed loop, and a fluid-to-refrigerant heat exchanger).

When tested under AHRI 870 conditions, a DX system must achieve a minimum EER of 15. The Energy Efficiency Ratio (EER) is a measure of cooling efficiency that represents the ratio of total cooling capacity to electrical energy input. The Coefficient of Performance (COP) is a measure of heating efficiency that represents the ratio of total heating capacity to electrical energy input. The minimum requirement for COP is 3.5. The EarthLinked system meets or exceeds that requirement.
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Space heating and cooling

Thousands of families around the world use EarthLinked to heat or cool homes of all sizes and styles. The system enables you to maintain comfortable and stable temperatures that you select year-round.
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Air handling and radiant floor heat

EarthLinked is designed for easy integration with various air distribution systems installed in your home to circulate hot or cool air depending on the season. Alternatively, you can connect to a radiant floor heating option to distribute heat evenly and efficiently throughout your home. With this configuration, heat is distributed through hot water circulated in a piping system in your floor. The radiant floor option provides up to 40% additional energy savings added to those already delivered by the EarthLinked system.
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Hot water

You can use the EarthLinked system to heat water up to 120°F (49°C), optimizing your energy consumption and saving money. The system uses waste heat given off in the air-conditioning mode in summer or natural heat stored in the ground and harvested by the heating mode in winter. Either way, you can reduce your water-heating costs by as much as 75% compared to electric resistance heating.
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Swimming pool heating

No matter the size of your pool, you can use the EarthLinked system to quietly heat the water to a comfortable temperature without harmful combustion byproducts—all with the highest efficiency.
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Depending on site conditions, an EarthLinked system can be installed in one to two days. Once the appropriate system capacity is identified, the following steps are taken:

  1. Choosing the appropriate loop configuration. Earth loops can be installed in vertical, diagonal or horizontal configurations to provide the lowest cost method, depending upon space availability. The design options are flexible to adapt to site conditions and available space.
  2. Drilling for space efficiency. Depending on the loop configurations chosen, holes are drilled in the ground or installed horizontally in the excavated space.
  3. The copper loops. After the holes are drilled or excavated, the earth-loops are inserted. These loops circulate the refrigerant continuously from the earth loop field to the heat pump and distribution equipment in the building. Once the loops are installed, the holes are grouted to assure good earth contact and no voids.
  4. Connecting the earth loops to the manifold. All of the loops are joined either to the supply or return manifold where the earth loops converge, channeling refrigerant through the lines that are connected to the compressor.
  5. The role of the compressor. The refrigerant lines are connected to the compressor, which increases the pressure and temperature of the refrigerant. Heat energy released by the pressurized refrigerant may be channeled either to the building if heat is needed or to the earth if cooling is needed. The process is controlled by a thermostat and a reversing-valve.
  6. Connecting an air handler. The refrigerant line may then be run from the compressor to an air handler. The air handler is used to transfer heat from the refrigerant to the air and circulate the heated air in the building, or to remove it from the building in summer by exchanging it from the circulating air into the refrigerant line for transport to the earth.
  7. Connecting a radiant hydronic system. In the alternative, the refrigerant line may be run from the compressor to a refrigerant-to-water heat exchanger that is used to transfer heat into a hot water circulating system to heat the building.
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