Geothermal Heating and Air Conditioning
Frequently Asked Questions

General System Questions:

What is Geothermal Heating?

Geothermal Brochure coverGeothermal heating is a heating method that uses the thermal energy stored in the earth or ground. Earlier terminology also called it ground source heating. The thermal energy in the earth is transported with heat pumps into the space to be heated, be it a home, an office or any other residential or commercial structure. These systems are multiple times more efficient at space heating than conventional, fossil fuels burning heating systems. These systems save thousands of dollars per year on fuel / heating costs. These systems can operate effectively in almost any climate and soil type for both heating and cooling.

Can these systems cool also?

Yes, the same system can provide heating and cooling. In cooling mode the thermal  energy is transported from the conditioned space to the ground. Forced air rather are preferred for cooling over radiant floor systems.

How efficient is a geothermal heating system?

Geothermal heating systems are the most efficient heating and cooling systems available. Geothermal systems have cost efficiencies in heating mode that are 50 - 80% higher than their competing conventional heating systems. In cooling mode, they are 20-40% more efficient than their conventional air based air conditioner siblings. These efficiencies are the resut of using freely available ground heat for heating. And in cooling mode the thermal capacity of the earth is used to disipate the heat. 

What about comfort?

The heat distribution system has major influence on the achieveable comfort level. Radiant heat systems, especially those realized as floor heating systems, provide even space heating and make rooms very comfortable. Floor radiant heating systems are becoming the system of choice. Geothermal heating can be realized using forced air system to deliver the heat. Warm air (90-105 F) is circulated in higher volumes through the duct system, which warms the building more thoroughly. Forced air systems using geothermal heat provide even heat without hot or cold spots. These systems also prevent the cold rush or cold air blast common to traditional fuel burning furnaces.

How does 40 Fahrenheit water from the ground provide heat?

A heat pump extracts the heat with a refrigeration process. It is the very same process that is used in your refrigerator or air conditioner only back wards. If you understand how air conditioning works then you understand how we can use 40 water to make 120 water.

Geothermal Journal by Water FurnaceWhat is the life expectancy of a geothermal heat pump?

Heat pumps are extremely durable and more reliable than standard conventional heater systems. They contain fewer mechanical components. All components of a geothermal system are either buried in the ground or positioned inside the structure, which protects them from harmful environmental conditions.
Most manufacturers also include a warranty on the major components of the heat pumps, and most piping has up to a 50-year warranty.

How noisy is the heat pump unit?

All heat pumps are very quiet because they have fewer moving parts and especially do not move air like their conventional counterpart. There is no noisy fan outside or near the patio to disturb outdoor activities.

How safe is a Geothermal unit?

The geothermal heat pump systems are very safe and protected. There is nothing burned, so there is no flammable fuel or toxic fumes anywhere. Safety aspects can be compared to household typical refrigerators.

How much maintenance is required?

Very little compared to conventional systems. If the distribution is air then filters would need to be changed. Heat pumps do not burn anything so most of the associated problems and maintenance required of boilers and furnaces is not an issue. Open loop
systems that use ground water directly through the heat exchanger may need descaling every few years. Closed loop systems that circulate an antifreeze solution should be tested to ensure the quality of the antifreeze each season.

Can geothermal systems be used for hot water supply?

Yes it can! Using a desuperheater, you can turn the waste heat from the system into hot water. In the summer when the system is in cooling mode, the excess heat goes straight to heating hot water. In the winter when it is in heating mode, only a portion of
the water is heated. Desuperheaters are standard on some heat pumps, optional on others, and can also be bought as a stand-alone unit.

How much space does a heat pump take up?

A majority of the ground loop system is installed underground, and the heat pump itself is about the same size as a standard heating and cooling unit. 

What max temperature can a heat pump produce?

The typical max temperature is 120 F. It is limited by the pressure and temperature of the refrigerant inside the heat pump.

Costs

How expensive are these systems?

The initial expense is generally greater than conventional systems but there are some exceptions to that. If the site has easy and sufficient access to ground water then the cost of the ground loop is greatly reduced. Each site is different but in the best-case
scenarios the total system installation would cost the same as a conventional heating system using a furnace or boiler. In all cases the geothermal system will begin paying off its installation costs the moment you start using it. All other conventional systems will consume energy and money for their entire service life.

How much can I save?

Brochure Tax Incentives by Water FurnaceGeothermal heat pumps deliver heat at 400% efficiency. They are operated by electricity. Depending on what we are comparing it to, you can expect savings of up to 70% on what you would pay for conventional heat. Consider the average Montana home that is using propane as it primary means of heat will spend $2000 per year for domestic heat and heat for the domestic water. A geothermal system could provide that same energy for $600. The savings of $1,400 per year will pay for the higher initial investment.

How is the money saved?

Geothermal heating saves you tons of money all year in operating and maintenance costs. You can provide the same heating you are use to for a fraction of the cost. The initial investment can be made up in these savings in as little as three years. Until then
there is usually a positive cash flow, because the savings from the system exceeds the payments on the system. Then after it is paid off, the savings are gigantic.

Are there any state or federal incentives for installing a geothermal system?

Yes, there are many incentives available on both the state and federal levels. The current federal tax credit is 30% of the installed system cost. Check http://www.dsireusa.org for the most up to date incentive information.


Installation / Building

Geo project finishedWhere can these systems be installed?

Virtually anywhere. There are several ways to tap into the earth's energy and a site specific review will determine the most cost effective way

Can geothermal systems be installed in retrofit situations?

Geothermal project picture 2Yes, but some structures and locations are more ideal than others. 

The existing distribution systems like air duct work, need to be able and be compatible with the lower temperatures of geothermal heating systems. Radiant floors are an ideal distribution system. 

High temp radiators are not ideal and some type of supplemental heat would be required.  

Can geothermal systems be used with air distribution?

Yes, but the ductwork should be sized for a larger volume of air than would be used with a furnace. The lower temperature air that will be distributed to the room needs to be delivered in greater quantities than the high temp air a furnace provides. The comfort
level of geothermal systems exceeds that of a furnace because the air is not as dry, there is more air exchange and fewer cold or hot spots in the home.

How far apart are the trenches spaced in a horizontal loop system?

In a horizontal loop system, the trenches are usually spaced 4-6 feet apart, depending on the terrain and soil characteristics.

How far are the boreholes in a vertical loop system spaced?

All the boreholes in a vertical loop system are typically spaced about 10-15 feet apart, which also depends on the terrain and soil composition.

How is the system sized?

The systems are generally sized based off the heating load needed in the house and the climate of the area. But many considerations come into play in determining that size. Soil composition, structure size and layout, area, and land size all play a role in determining the size of an individual system.

Is geothermal heating considered renewable energy?

Absolutely! It uses the heat that is stored in the earth to heat your home. It is considered clean, green and renewable energy. There is no fossil fuels burned, combustion, or dependency on a finite fuel source. It only uses electricity to run the heat pump, and that also can come from many different renewable sources as our electric grid starts to change and develop.

Do Geothermal Systems protect the environment?

Yes they do. The geothermal system runs very efficiently to provide climate control from renewable energy, which lowers emissions. It does not burn fossil fuels and is a completely enclosed system, so no dangerous gases are released into your home or the environment. All the refrigeration systems are factory-sealed, so they seldom or never have to be recharged, which also protects our environment.

Can a geothermal heating system still work in climates with frozen soil?

Absolutely! That is the exact environment where we are thriving in. Winters in the Gallatin Valley are very harsh, and the soil is probably frozen for over half of the year. But because the ground loops are installed below the freeze line (usually 4-8 feet in depth, depending on soil type), the changing temperatures above ground do not affect the heating capabilities.

Can I use the GSHP for snowmelt capabilities?

Yes, the geothermal systems are perfect for snowmelt systems, and we currently have a large one that services our shop.


More questions? Call the Carolina Heating Geo Experts at 800-261-0359 Phone Symbol