Geothermal FAQs

How does a geothermal system work?
Outdoor temperatures fluctuate as the seasons change. Underground temperatures, however, remain relatively constant year-round. Geothermal heat pumps take advantage of this moderate temperature to achieve very high efficiencies for both heating and cooling.

What makes a geothermal system different from a conventional system?
Geothermal systems use ground heat. Unlike conventional systems that utilize fossil fuels and ambient air temperatures (seasonal), to produce heat, geothermal systems simply transfer heat to and from the earth. Because of their inherent efficiency, they can heat air to a comfortable temperature and eliminate the cold drafty feel of traditional heat pumps.

How is heat transferred between the earth and the home or building?
In closed-loop systems, water is circulated through tubing run underground vertically in boreholes or horizontally in trenches. Inside, the water is circulated through the heat pump which extracts heat in winter or discharges heat in summer to the closed loop and then to the ground. In open loop systems, ground water from an existing water well or dedicated geothermal well is pumped through a heat pump or intermediate heat exchanger and back into the ground.

Can a geothermal heat pump also heat water?
Geothermal heat pumps can use the extracted heat to supply hot water in the summer for free, and preheat water in the winter to reduce hot water costs. There are also heat pumps that heat water directly for in-floor heating systems, domestic hot water, or swimming pools.

Are geothermal systems clean and safe?
Yes. Because the system transfers heat from the ground, there is no burning of fossil fuels. There are no open flames, and carbon monoxide fumes, flammable fuel, or potentially dangerous fuel storage tanks are completely eliminated.

Is my property suited for a geothermal system?
These systems have been installed in existing homes, schools, churches, hotels, office buildings, recreational facilities, multi-use developments, and industrial sites. They are suitable for just about any heating or cooling application, whether in new construction or in an existing structure.

How long will a geothermal system work? Do they require much maintenance?
As geothermal systems contain fewer mechanical components and these are either buried in the ground or located inside, they are protected, durable, and reliable for significantly longer than conventional systems. Properly installed, they can last for decades and have lower maintenance costs than conventional systems.

Are geothermal systems expensive?
Geothermal systems are the most energy efficient and cost-effective heating and cooling systems available. The investment is paid back in lower energy bills and increased property resale value. In a life-cycle cost analysis, geothermal systems are the least expensive heating and cooling system.

Are tax incentives available for geothermal systems?
The initial costs of installation are reduced significantly through Federal and state tax incentives, including the new 30% Federal tax credit enacted as part of the Stimulus legislation. Previously this credit was capped at $2,000, and the removal of the cap significantly reduces the costs. As an example, assume a geothermal system with a cost of $30,000. Previously the maximum credit of $2,000 would reduce the after tax cost to $28,000. With the full 30% credit now available, the after tax cost is reduced to $21,000, a savings of $7,000. In addition, state and local credits may be available depending on where you live. Finally, in some instances, renewable energy grants and low cost loans guaranteed by the Department of Housing and Urban Development may be available.

Do I need to drill in order to have a geothermal system?
More often than not this vertical approach is the case because site conditions that might limit the available space for installation. However, in some applications a horizontal trench may be possible - regardless, the stable temperature of the ground is the heat source and the heat sink for cooling. The advantage of a vertical closed loop system is that less space is needed, satisfying a project with limited land. Horizontal closed loop installations are most cost-effective for small installations where sufficient land area is available for burying pipes in a series of interconnected trenches.