Geothermal / Exchange Heating & Cooling
Cost Comparisons

Mother Earth fortunately has many splendid characteristics. One of them happens to be the fact that the temperature of the subsoil about 5 to 10 feet below the surface remains fairly constant year-round. The temperature, once you get to this level, happens to be in the mid-fifties F. If you start to tunnel deep into the earth, the temperature actually starts to rise.

Traditional Heat Pumps

If you own a traditional heat pump, you know that they produce a cool heat. This is just how they operate. The limitation is due in part to the fact that an air transfer heat pump can only grab so much heat in a given amount of time from air that is 28 degrees! Traditional air transfer heat pumps are most efficient when the outdoor air temperature is around 55 degrees or so. Now isn't that convenient! Imagine if you could surround the heat pump refrigerant with 55 degree temperatures all of the time? That is exactly what you can do with a properly designed and installed geothermal / exchange heat pump system.

Great For Every Building

Geothermal systems are used in commercial applications, schools, and all sorts of different places other than homes. Those places that are blessed with lakes or large ponds really have it made. As long as the pond doesn't freeze solid during the winter months, you are golden! Think. When you jump into a pond or a lake and go fairly deep, the water is very cool - say in the 50 or 60 degree range. Well, there you go...... All you have to do is lay the geothermal loop on the bottom of the pond. It gets buried by water instead of dirt. What's more, the transfer of heat to and from the loop is nearly 100 percent efficient when surrounded by water.

Soil Types are Important

The heat transfer from the soil to the buried ground loop is a function of the soil's density, air and moisture content, and its composition. Dense, moist clay soils work best. Dry sand is the worst. Heat transfer works best when you have the least amount of air and the greatest amount of compaction of soil molecules around the ground loop.

If you have bad soil, don't give up. You may be able to bring enough soil in from a different location. There are also other ways to surround the loop with a dense fill material. The amount of dense fill is a design consideration. You must work with a company that has experience in these areas. Don't be a lab rat for a beginning or new company! Ask for references of other places where a loop has been installed in bad soil.

Extra Cost

What does it cost to go with one of these fancy geothermal systems? It depends on many factors. The outside loop is the most expensive extra element. The duct work and air handling equipment are a wash since you would have installed these with a standard system.

Residential geothermal systems take the biggest cost hit. Even still, if you have great soil, you might recapture this extra cost in about two to five years. After that, you are making money while your neighbors send extra money each month to the fuel oil or local utility companies.

Commercial and institutional geothermal installations actually compete with traditional equipment. So if you are building a new church, school, office building, etc. give geothermal heating and cooling a serious look.

Who Does This Work?

The best source of companies that make and install geothermal heating and cooling systems is an organization called:

This organization maintains a current list of high quality manufacturers who make great equipment. They can also supply you with the names and numbers of local companies that are familiar with geothermal installations. You can also find lots of information about installers at their website:

www.geoexchange.org

GeoExchange Annual Operating Costs

It is no wonder why people are excited about geothermal heating and cooling systems. If you live in places that need significant amounts of heating or cooling, you can save some substantial money. You save more money when you heat than when you cool. On average you might expect to see heating cost savings in the neighborhood of 40 to 70 percent. 30 to 60 percent cooling savings are attainable as well. These energy savings can add up over time.

The cost savings you might achieve depend on two things: (1)where you live (the harshness of the climate) and (2) the type of heating and cooling system you currently use. The most expensive traditional heating and cooling system to operate is an electric resistance heating system coupled with standard air conditioning. Look at the table below to see the potential savings. It should open your eyes! The values in the table were provided by the Environmental Protection Agency. (1999)