Requirements for a Geothermal Furnace Well

Geothermal furnaces take advantage of the moderate temperatures below ground to provide central heating and cooling to homes and other buildings. Although more expensive to install than other types of furnaces, geothermal units provide consistent heat at no additional energy or financial cost, making them a more efficient long-term heating and cooling system than their gas and oil counterparts. Geothermal heating systems require adequate land, building ductwork and additional hardware to operate.

Land Requirements

• Access to land around the heated structure is necessary for a geothermal well. In small lots, the heat-exchange pipes are installed vertically. In larger lots, horizontal pipes can be used. The pipes are installed below ground, at sufficient depths that the temperature of the ground remains constant throughout the year. At a depth where the temperature is 70 degree Fahrenheit, for example, the heating system heats the home to this temperature in colder months and cools the home in the summer.

Hardware Requirements

• The most prominent component of a geothermal furnace well is the underground piping. This piping contains either water or antifreeze, and absorbs heat from the ground. The system of pipes enters the home in a heat exchanger, where a fan circulates air through the exchanger. As the air flows through the exchanger, it absorbs heat from the pipes. Heat is continually transferred into the exchanger from underground, preventing the dissipation of heat within the exchanger.

Building Requirements

• The ducts required for heated air from a geothermal furnace well are identical to the ducts used to transfer heated air in other systems, such as natural gas or oil-burning furnaces. In older homes, ducts should be inspected for wear, leaks or other compromises to their efficiency. When worn ducts hinder the geothermal unit's transfer of warm air, they should be replaced with new ductwork.