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| Typical basement geothermal layout with ground loop |
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Cost Effective
Geothermal heat pumps save money in operating and maintenance costs. While the initial purchase price of a residential GHP system is often higher than that of a comparable gas-fired furnace and central air conditioning system, it is more efficient, thereby saving money every month. For further savings, GHP's equipped with a device called a "desuperheater" can heat the household water. In the summer cooling period, the heat taken from the house is used to heat domestic water for free. In the winter, water costs are reduced by about half.
On average, a geothermal heat pump system costs about $4500.00 per ton of capacity, or roughly $13,500 for a 3-ton unit (typical residential size). In comparison, other systems would cost about $6500+ with air conditioning. When included in the mortgage the homeowner has a positive cash flow from the beginning. For example, say that the extra $4,500 will add $35 per month to each mortgage payment. Depending on local rates, costs can even get lower, however, the energy cost savings will easily exceed this added mortgage amount over the course of each year. On a retrofit (existing house furnace and air-conditioning) the GHP's high efficiency typically means much lower utility bills allowing the investment to be recouped in an average of two to five years. In addition, some electric utilities have financing packages that make the purchase of a geothermal system even less expensive. Other utilities are providing special electric rates for homes with GHP systems installed.
Durability
Because GHP's use fewer mechanical components, the components are sheltered from the elements, leaves, dirt, and possible vandalism, geothermal heat pumps are durable and highly reliable. The underground piping used in the system often has 25 to 50 year warranties, and the GHP's themselves typically last 20 years or more.
Low Maintenance
Geothermal heat pump systems have fewer maintenance requirements than most other systems. When properly installed, the underground components are virtually worry-free. The components in the living space are easily accessible, which increases the service convenience factor and helps ensure that the upkeep is done on a timely basis.
Year-Round Comfort
Like the typical forced air furnace or central air conditioning system, a GHP system uses ductwork. A two-speed GHP system is so quiet inside a house that the users do not know it is operating because there are no blasts of cold or hot air, depending on whether it is heating or cooling season.
GHP's also improve humidity control by maintaining about 50% relative indoor humidity, making GHP's very effective in humid areas.
Quiet Operation
With GHP's there are no outside condensing units like air conditioners, so there's no concern about A/C noise near patio areas or decks, or bothering the neighbors with the constant hum of a conventional air conditioner.
Geothermal Heat Pumps Are Highly Efficient
A study by the Environmental Protection Agency (source: "Space Conditioning:The Next Frontier", EPA 430-R-93-004,April 1993) analyzed six locations representing major climate zones in the U.S. These cities (Burlington, VT; Chicago, IL; upper New York City; Portland, OR; Atlanta, GA; and Phoenix, AZ) were chosen to compare the performance and costs of emerging high efficiency space-conditioning equipment with equipment already on the market. For all locations, the findings named geothermal heat pumps as the most efficient heating and cooling systems over other types of space conditioning equipment including high-efficency gas furnaces and air conditioners. Geothermal heat pump installations in both new and existing homes can reduce energy consumption 25% to 75% compared to older conventional replacement systems. Annual operating costs were also lowest with the geothermal heat pumps. Add in the benefits of the desuperheater for hot water savings, and it's easy to see how a Geothermal Heat Pump is the most efficient system available.
GHP's Have Low Environmental Impact
Because a GHP system is so efficient, it uses a lot less energy to maintain comfortable indoor temperatures. This means that less energy often created by burning fossil fuels is needed to operate a GHP. According to the EPA, geothermal heat pumps can reduce energy consumption and corresponding emissions up to 44% compared to air-source heat pumps and up to 72% compared to electric resistance heating with standard air conditioning equipment.
Department of Energy Spreads The Word About GHP's
In 1994 the U.S. Department of Energy, working closely with the EPA, Edision Electric Institute, Electric Power Research Institute, International Ground Source Heat Pump Association (IGSHPA), National Rural Electric Cooperative Association, and industry helped to create the Geothermal Heat Pump Consortium (GHPC). The GHPC launched a national Earth Comfort program, designed to foster the development of a fast-growing, self-sustaining, national GHP industry infrastructure. DOE has also supported research and development activities. The work has targeted several areas of GHP technology lowering the cost of ground heat exchangers, and developing advanced software design.
In partnership with the GHPC, DOE's Office of Geothermal Technologies seeks to increase annual installations of GHP systems to about 400,000 by 2005 and reaching about 2 million installed (cumulative) that same year. Achieving the goal of 400,000 annual installations by 2005 will save consumers over $400 million per year in energy bills, and reduce greenhouse gas emissions by over 1 million metric tons of carbon each year.
The System Of The Future
With their high efficiency and user satisfaction, geothermal heat pumps are one option homeowners should consider. Not only will they save energy and money, they'll reduce emissions and provide indoor comfort at less cost to the environment.
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