An Overview Geothermal Heating and Cooling Systems are superior to traditional HVAC systems, such as air source heat pumps (ASHP) or gas fired furnaces. Heating/cooling systems using ASHP are much less efficient than Geothermal Heat Pumps (GHPs), because they are dependent upon external air, whose temperatures vary wildly with the seasonal air temperature fluctuations. This is especially noticeable in extreme temperatures. In Illinois, winters are very cold, and summers are very hot. Of course, this makes perfect sense to anyone who has lived in this region for any amount of time. What is also apparent is the huge spike in utility bills during these seasons, as HVAC heating and cooling systems must work much harder in order to maintain a comfortable in-door temperature. Let's look at an example to see why heating bills are so extreme in the winter months. Consider an average 15 degree Fahrenheit day in December, and the savings provided by Geothermal Design will become quite obvious. On a 15 degree day in December, your traditional HVAC heating system (which draws air from outside of the home and heats it) would need to raise the 15 degree air it is conditioning by 55 degrees Fahrenheit, in order to reach a comfortable 70 degree Fahrenheit temperature in the house. This places quite a burden on the HVAC system, and is especially noticeable when it comes time to pay the heating bill. Just think of how much money you spent on heating costs last January! However, with Geothermal Design principles, the "air" is drawn from a series of plastic coils buried in the earth, beneath the frost line, where the temperature, in Illinois' northern latitude, is always around 52 degrees Fahrenheit. In closed loop systems brine at temperature around 40F is cycled through the GHP, and temperature from the heat source needs only to be raised by 30 degrees Fahrenheit in order to reach a comfortable 70 degrees Fahrenheit inside. Imagine the difference this would make in the winter months, when the air temperature is rarely above freezing! It is simple to see that on a 15 degree December day, Geothermal Design shaves 25 degrees of "work" from your heating costs. There is no doubt that these savings add up in a big way, especially when considering the rising costs of electricity and natural gas!

So How Does It Work? The idea is that it is much less expensive to heat and cool with a temperature controlled source. Geothermal means "earth heat." The earth's soil stores heat from the sun, and this heat can not be exhausted. Below the frost line, this heat is not affected by seasonal temperature variations that cause the air to become miserably hot or painfully cold. By placing a Ground Heat Exchanger (GHX) in the earth, below the frost line, Geothermal Design takes advantage of all the solar energy stored in the soil. The gist of it is this: High Density Polyethylene (HDPE) coils filled with eco friendly anti-freeze water solution (heat transfer fluid), are buried in the earth around your building. These coils are made of the same durable polyethylene as the cross-country oil pipelines that channel crude oil. Properly installed, they are nearly impossible to break, and are not susceptible to dry rot, or weakening due to excessive moisture. GHX (ground loops) can either be constructed in a horizontal or vertical manner.

So, the system is flexible and can accommodate the demands of your particular plot of land. Heat transfer fluid in ground loops transfers heat or cold for the geothermal heat pump. Again, the GHP is not dependent on the wildly varying air temperature as it has a place in air source heat pumps. On cold days, the GHP takes advantage of the warmth of the earth. The GHP pulls the temperature controlled liquid from the ground loops and transfers it to conditioned area through either traditional forced air ductwork or hydronic system

. On hot days, the Geothermal Unit takes advantage of the coolness of the earth. The unit pulls the temperature controlled liquid from the buried coils. This liquid produces cool air, which is conditioned to the desired temperature, and released into the building through ducts. Again, separate ducts draw the room temperature air back into the geothermal unit, and the excess hot refrigerant produced is cycled back out into the buried coils, where the earth cools the liquid to 55 degrees. Once again, the 55 degree liquid is drawn back into the building.

Other Benefits Geothermal Design allows for more efficient ductwork and can cut energy costs by 25%-50% per month over traditional gas, oil, or air source heat pump methods. Estimates are mind boggling as to how much fossil fuel this technology could save, not to mention the money spared by avoiding budget breaking HVAC systems. And, even by conservative estimates, a unit prepared for an average building will pay for the extra costs of installation in around 4-6 years. In fact, a typical 2000-sq.-ft. home can be heated and cooled for as little as $1 a day! These systems are also much more durable, and are guaranteed to last. The coils are made from the same high density polyethylene as cross-country oil pipes, guaranteed for 25 years, and expected to last longer than 50. The unit is guaranteed for a minimum of 20 years, with the only expected maintenance being the changing of air filters every 3 months or so. If Geothermal Units are combined with other eco-friendly, sustainable design methods (such as solar heat or radiant heat), budgets and fossil fuels are spared even more! There are other perks as well. The old fashioned HVAC systems, such as heat pumps, must be placed outside of the building they are heating and cooling, either beside the building, or on the roof. This means that HVAC units are highly visible eye-sores! These units are also exposed to weather, vandals, and other pesky interference, because they must be placed outside. If you've ever walked past one of these units, another thing becomes apparent: they are extremely noisy! A whole side of a building, or an entire rooftop, becomes virtually unusable, since no one wants to be near noisy HVAC units. And, Geothermal Units can add value to your structure. Recent studies indicate an increase of $20 in home value for every $1 in annual energy savings. The geothermal system is hidden. The coils are buried beneath the earth. And the system requires a smaller pump, around the size of a small washing machine, which can be hidden in a closet, or some other nook or cranny inside of a building. The unit will never be damaged by weather conditions, vandals, or anything else for that matter. Geothermal units are no louder than a refrigerator. So placing them inside of a building doesn't create annoying noise. In Illinois, there are other perks: Governor Rod Blagojevich is a major proponent of Geothermal Design, and has been for several years. Illinois offers tax breaks, and other perks for people who incorporate Geothermal Design. If you're really curious, and want to know more, follow this link to a governmental organization called GeoExchange, which provides free information, and tons of it, for interested folks. You might be interested to learn that, among other surprising geothermal clients, many of the buildings in "Colonial Williamsburg" are heated and cooled with geothermal technology.

Check out the article entitled "Geoexchange Earns 'A Place In History'" for more details.