A geothermal system is an electrically-powered device that uses the natural heat storage ability of the earth and/or the earth's ground water to heat and cool your home.

2. How does it work?

A few feet beneath the surface, the earth's temperature remains fairly constant-ranging from 45^oF or so in northern latitudes to about 70^oF in the deep south-year round. A geothermal system takes advantage of this constant temperature to provide extremely efficient heating and cooling.

In winter, a water solution circulating through pipes buried in the ground absorbs heat from the earth and carries it into the home. The geothermal system inside the home uses a heat pump to concentrate the earth's thermal energy and then to transfer it to air circulated through standard ductwork to fill the interior space with warmth.

In the summer, the process is reversed: heat is extracted from the air in the house and transferred through the heat pump to the ground loop piping. The water solution in the ground loop then carries the excess heat back to the earth. The only external energy needed for the geothermal system is the small amount of electricity needed to operate the ground loop pump, fan, and compressor.

3. Is Geothermal new?

Not really. The basic technology has been around for more than 50 years, and many homeowners and businesses have been enjoying the benefits of geothermal for over 20 years.

In recent years many improvements have been made in the materials used, the installation methods, and the efficiencies of the compressors, pumps and other equipment.

4. What types of loops are available?

There are 2 main types of loops: open and closed. An open loop system uses well water as the energy source when it is available in sufficient quantity and quality. Often, the existing domestic water well can be used to provide required energy exchange for a geothermal system.

The closed loop alternative uses plastic pipes through which fluid is circulated to exchange temperatures with the earth. Vertical, horizontal or pond loops are used.

5. Does the underground pipe system really work?

The buried pipe, or "ground loop", is the most recent technical advancement in geothermal technology. The idea to bury pipe in the ground to gather heat energy began in the 1940s. But it's only been in the last few years that new designs and improved pipe material have been combined to make a geothermal unit the most efficient heating and cooling systems available.

6. How much groundwater does an open-loop system need?

A geothermal system using an open-loop system needs a different amount of water depending on the size of the unit and the manufacturer's specifications. The water requirement of a specific model is usually expressed in gallons per minute and is listed in the specifications for that unit. Generally, the average system will use 4 to 8 gpm while operating.

7. Does an open-loop system cause environmental damage?

NO! They are pollution free. The geothermal unit merely removes heat from or adds heat to the water. No pollutants are added whatsoever. The only change in the water returned to the environment is a slight increase or decrease in the temperature. However, before an open loop system is considered, both the quantity and quality of the groundwater should be determined. An acceptable point of water discharge must be determined.

8. What are the major benefits to the homeowner?

Homeowners enjoy lower utility bills (40% to 80% lower than with conventional systems), lower maintenance, and higher levels of comfort, year-round. Even more than that, though, they have the peace of mind of knowing they're being environmentally responsible.

Since a geothermal system burns no fossil fuel to produce heat, it generates far fewer greenhouse gas emissions than a conventional furnace, and completely eliminates a potential source of poisonous carbon monoxide within the home. Even factoring in its share of the emissions from the power plant that produces electricity to operate the geothermal system, total emissions are far lower than for conventional systems.

9. Can you be more specific about the environmental advantages?

According to data supplied by the U.S. Department of Energy and USEPA, a typical 3-ton residential geothermal system produces an average of about one pound less CO2 per hour of use than a conventional system. To put that in perspective, if just 100,000 homes were converted to geothermal, the country could reduce its CO2 emissions by 880,000,000 lb.

That would be the equivalent of converting about 58,700 cars to zero-emission vehicles, or planting more than 120,000 acres of trees.

And the waste heat removed from the home's interior during the cooling season can be used to provide virtually free hot water-resulting in a total savings in hot water costs of about 30% to 50% annually, and lowering emissions even further.

10. Is geothermal energy used primarily in homes?

Not really. While many homes have been fitted with geothermal systems, commercial enterprises, including factories, retail stores, office building and schools also use geothermal to save energy and protect the environment. In fact, there are more than half a million installations in the United States today.

According to the U.S. EPA, schools are a particularly attractive place for the use of this technology. Across the country, schools using geothermal right now are saving an estimated $25,000,000. in energy costs-which can be used instead for better educational equipment and more teachers. These schools also save a half-billion pounds of CO2 emission per year.

Should all of the nation's schools convert to geothermal, the EPA has estimated that we could reduce oil imports by 61 million barrels annually, and provide the same environmental benefits of planting 8 million acres of trees or converting nearly 4 million cars to zero-emission vehicles.

If the same comparison were made across all commercial and residential segments, the potential for environmental benefit would be staggering.

11. Does geothermal cost more?

That depends on how you measure cost. While they do cost more to install in homes than conventional systems, because of the ground loop piping, geothermal systems typically have the lowest life-cycle cost of any heating and cooling system. Heating and cooling for a typical 2,000-sq.-ft. home can run as low as $1. a day.

Altogether, geothermal systems are a sound investment. The amount they save the homeowner every month in energy costs is more than enough to offset their higher installation cost resulting in a positive monthly cash flow.

Remember, too, that geothermal means extra savings on repair, maintenance, and hot water bills. And the energy efficiency of geothermal adds value to the home.