Geothermal FAQ

Q: How will I save money with a Geothermal System?

They save money, both in operating costs and maintenance costs.   You can expect to save up to 70% more than with a conventional system.  Investments can be recouped in as little as three years. There is a positive cash flow, since the energy savings exceeds payment on the system.  Additionally, a Geothermal unit can be expected to last twice as long as a conventional system, thereby saving a large amount in the mid-life of the geothermal unit.

Q: How much does a Geothermal System cost? 

The initial investment for a geothermal system is slightly greater than that of a conventional system. However, when you consider the operating costs of a geothermal heating, cooling, and water heating system, energy savings quickly offset the initial difference in purchase price. We provide a free estimate including a comparison to conventional systems for your specific situation which will allow the client to determine how quickly the payback will occur.

Q: Do geothermal systems require much maintenance?

No. Geothermal systems are virtually maintenance free. When installed properly, the buried loop will last for generations.  The other part of the operation—the unit’s fan, compressor and pump—is usually housed indoors, protected from the harsh weather conditions. Usually, periodic checks and filter changes are the only required maintenance.

Q: Are there tax incentives for a Geothermal system? 

YES!  There is presently a 30% tax credit (that’s a 30% total savings, as opposed to a tax deduction) in addition to state credits and rebates.

Q: How efficient is a Geothermal Heat Pump?

According to the U.S. Environmental Protection Agency, geothermal systems are “the most energy efficient, environmentally clean, and cost effective space conditioning available today.” They are roughly 60% to 70% more efficient than conventional systems.  That directly translates into savings for you on your utility bills.

Q: Can one system provide both heating and cooling for my home? And what about heating hot water? 

Yes. It can be a combination heating/cooling and hot water heating system.  Using a desuperheater (heat recovery system), that is located within the geothermal heat pump itself; you can save up to 90% on your water heating bill by preheating your tank water.

Q: How does a Geothermal system heat water for my home? 

Using what is called a desuperheater (heat recovery system), the geothermal heat pump can turn heat removed from your home to the task of heating hot water. When the system is in cooling mode, which is roughly two thirds of the year in East-Tennessee, your hot water is produced free as a byproduct of the thermal process.  In winter, with the heating mode, the desuperheater heats a portion of your hot water. Desuperheaters are standard on some units, optional on others.

Q: What configurations of the pipe systems can be installed?

The typical forms of pipe installation are horizontal, vertical, pond or lake, and pump and dump.  Visual representations of these are found on the front page of this website.  If none of the typical forms of installation are appropriate for a specific site, a properly designed custom installation may be substituted.  We custom design systems for our clients, where necessary, at no additional cost.

Q: What are the environmental and health benefits of Geothermal systems? 

Currently installed systems are making a huge difference in our environment! The systems are annually eliminating more than three million tons of carbon dioxide which equivalent of taking 650,000 automobiles off the road.  A geothermal system reduces your carbon footprint for heating/cooling, which is the second largest contributor to carbon dioxide behind your vehicle, by about two-thirds.  The systems conserve energy and, because they move heat that already exists rather than burning something to create heat, they reduce the amount of toxic emissions in the atmosphere. They use renewable energy from the earth, and because the system doesn’t rely on outside air, it keeps the air inside of buildings cleaner and free from pollens, outdoor pollutants, mold spores, and other allergens.

Q: How noisy is a Geothermal unit? 

They are very quiet providing a pleasant environment inside & outside of the home.  The compressor noise in a geothermal unit is similar to that of a modern day home refrigerator.   In fact, they are considered substantially more quite than a conventional system because they have no noisy fan units to disturb outdoor activities.

Q: How long will my Geothermal system last? 

Geothermal systems are simple, durable and highly reliable. They contain fewer mechanical components than a conventional system, and all components are either buried in the ground or located inside the home, which protects them from outside conditions. The Unit carries a 10 year parts and labor warranty and has a life expectancy of an estimated 30 years; that’s approximately double the life expectancy of a conventional system.

Q: How long will the loop pipe last?

Loop systems should be installed using only high-density polyethylene pipe.  This pipe does not rust, rot or corrode, and is inert to chemicals normally found in soil. Properly installed, these pipes will last for many decades.  Actual life expectancy of the pipe is over 100 years, and comes with a 50 year warranty. PVC pipe should never be used.

Q: What are the advantages and disadvantages of the horizontal and vertical installations, respectively? 

Horizontal installations are simpler, requiring lower cost equipment. However, they require longer lengths of pipe due to seasonal variations in soil temperature and moisture content. Since a horizontal heat exchanger is laid out in trenches, a larger area is usually required than for a vertical system. Where land is limited, vertical installations or a compact Slinky horizontal installation can be ideal. If regional soil conditions include extensive hard rock, a vertical installation may be the only available choice. Vertical installations tend to be more expensive due to the increased cost of drilling versus trenching, but since the heat exchanger is buried deeper than with a horizontal system, vertical systems are usually more efficient and can get by with less total pipe.

Q: Will an earth loop affect my lawn or landscape?

The actual process of installing the loop will disrupt the surface to some degree. With proper restoration, most loop fields become practically, if not completely, un-noticeable. After the initial installation, the loop will have no adverse effect on grass, trees, or shrubs, nor will roots from trees cause a problem with the pipe.

Q: Can these systems be used for commercial, industrial, or apartment requirements?

Yes! Many Geothermal systems are being installed using a multitude of systems hooked up to an array of buried vertical or horizontal loops. This simplifies zone control and internal load balancing.

Q: How are the pipe sections of the loop joined?

Pipe sections are joined by thermal fusion which involves heating the pipe and fitting at over 500 degrees, then connecting them to form a joint that’s stronger than the original pipe. This technique creates a secure connection to protect from leakage and contamination.

Q: What fluid is in the loop?

A solution of roughly 80% water and about 20% of either Methanol or Propylene Glycol.  The Methanol and Propylene Glycol act as antifreeze in the event that the system/interior pipes are exposed to subfreezing conditions for an extended period of time.

Q: If the air temperature falls below freezing, will it hurt the system?

No. Due to the nature of radiant heat from the earth, even in the most frigid conditions in East Tennessee, it is very unlikely that the Unit / Interior Pipes would be exposed to temperatures below 10° F.  The antifreeze solution in the loop will keep the Unit / Interior Pipes from freezing down to approximately 10° F.

The exterior pipes are buried deep enough within the ground that it is impossible for them to freeze and the pipes entering the home are insulated to protect them as well.

Q: What are the components of a geothermal heat pump system? 

The three main parts are the heat-pump unit, the liquid heat-exchange medium (open or closed loop), and the air-delivery system (ductwork). The unit’s main components are the compressor, heat exchanger, air coil, blower motor and electrical controls.

Q: Is a geothermal heat pump difficult to install? 

Most units are easy to install, particularly when they replace another forced-air system. They can be installed in areas unsuitable for fossil fuel furnaces because there is no combustion, thus no need to vent exhaust gases. Ductwork must be installed in homes that don’t have an existing air distribution system.

Q: I have existing ductwork, but will it work with this system?

Yes!

Q: Where can a Geothermal Unit be installed within my home?

Anywhere that a conventional system can be located, a Geothermal Unit will fit.  The Geothermal Units are almost identical in size in comparison their conventional counterparts.   Additionally, Geothermal Units come in a horizontal casing as well, at no additional cost, and can be located within crawlspaces, closets, under work benches, etc. which affords additional locations that conventional units may not.

Q: Can a geothermal heat pump be added to my fossil fuel furnace?

A single Geothermal Unit is more than adequate for the East Tennessee climate. However, split systems can easily be added to an existing furnace for those wishing to have a “dual fuel” heating system.  Dual fuel systems use the heat pump as the main heating source and a fossil fuel furnace as a supplement in extremely cold climates if additional heat is needed (which is not the case in East Tennessee).

Q: Do I need a back-up heat supply? 

Geothermal systems are used in climates where temperatures drop below freezing and are generally installed with an auxiliary backup electric resistance heater.  The auxiliary heater is rarely needed in East Tennessee, but a necessity for the rare very deep freeze.   This component is mounted either inside the unit or in the supply duct just outside the unit.  The auxiliary heater serves two purposes: To supply backup heat during extreme deep freezing temperatures, and to provide emergency heat if the compressor fails.

Q: Can I install an earth loop myself? 

Yes, but it’s really not a good idea.  Properly designing and installing an earth loop requires extensive training.  In order to obtain optimum system performance, the earth loop size, design and configuration need to be carefully considered. In addition, special pipe, fittings, and tools for heat fusion and system flushing are required.

Q: Can I reclaim heat from my septic system disposal field?

No. Such use is prohibited by building codes in most all areas.

Q: Can I install a lake loop if I live on a TVA controlled waterway?

Yes.  In fact, TVA encourages geothermal systems and attempts to offer incentives for their installation.  Such an installation will have to be permitted by TVA similar to the installation of a boat-dock and will be inspected by a TVA representative.

Q: Does an open loop system cause environmental damage?

No. They are pollution free. The heat pump merely removes or adds heat to the water. No pollutants are added. The only change in the water returned to the environment is a slight increase or decrease in temperature.

Q: How can I discharge the water when using an open loop system?

There are a number of ways to dispose of water after it has passed through the heat pump. The open discharge method is the easiest and least expensive.  Open discharge simply involves releasing the water into a stream, river, lake, pond, ditch or drainage tile.  Obviously, one of these alternatives must be readily available and have the capacity to accept the amount of water used by the heat pump before open discharge is feasible.  A second means of water discharge is the return well. A return well is a second well that returns the water to the ground aquifer. A return well must have enough capacity to dispose of the water passed through the heat pump. A new return well should be installed by a qualified well driller. Likewise, a professional should test the capacity of an existing well before it is used as a return.

Q: With an open loop system, what problems can be caused by poor water quality?

Poor water quality can cause serious problems in open loop systems. Your water should be tested for hardness, sulfur, acidity and iron content before a heat pump is installed. Your contractor or equipment manufacturer can tell you what quality of water is acceptable.  Mineral deposits can build up inside the heat pump’s heat exchanger. Sometimes a periodic cleaning with a mild acid solution is all that’s needed to remove the build-up. Where well water does not meet the requirements for an open loop geothermal system, a closed loop would be used.

Q: Do soil freezing conditions create any problems? 

Not if a system is properly designed and installed.

Q: Are there any laws that apply to loop installations?

All or part of the installation may be subject to local ordinances, codes, covenants or licensing requirements. Check with local authorities to determine if any restrictions apply in your area, or contact our office.