Geothermal Systems, LLC.

Geothermal Costs

What does it cost to install a geothermal system?

Every situation is different, but all geothermal systems consist of two parts: the ground loop heat exchanger (or well for pump and dump systems), and the heat pump and the distribution system inside the home. Geothermal loop field size is based on Tons of load. A Ton of heating load is equal to 10,000 Btu (so a home with a 60,000 Btu furnace would need a 6 Ton system).

Types and costs of ground loop heat exchangers

Lake and pond loops

When possible, one of the most cost effective and efficient heat exchangers is a pond or lake loop system. Costs can vary greatly depending on the existing conditions, but expect to pay $900-$1200 per Ton for this type of system. The drawback of this system is that there are significant state and local restrictions and there is potential for damage since the loop system could be exposed to boats, animals, etc.

Open loop

An open loop, or pump and dump system is traditional water well that supplies a constant flow of groundwater to the heat pump. After the heat is absorbed or extracted, the groundwater is dumped into a pond or lake. Expect to pay $4000-$8000 for this type of well, depending on location. The drawback of this system is that state and local governments are starting to disapprove this type of system since the average home can use over a million gallons of water a year.

Horizontal loop

A horizontal loop can consist of "slinky" loops or individual loops buried 5 to 7 feet below ground. Horizontal loops cost between $1300 and $1500 per Ton. The drawback of this type of system is that a large area is required (typically 10'x100' per Ton), the installation is disruptive, and the horizontal systems are more more affected by soil type and moisture content.

Vertical loop

The final type of ground loop heat exchanger is the vertical loop. A vertical loop is set in a 100' to 400' borehole made by a drilling rig (the same type used for drilling water wells). The average vertical loop costs between $2000 and $2400 per Ton, depending on the soil types encountered. The only drawback of this system is that it is the most expensive type of ground source heat exchanger system and can be even more expensive in areas where rock drilling is required. However, it requires the least amount of area to install and therefore can work in almost any situation.

Heat pump and Distribution system

For most retrofits, the existing ductwork can be reused, although there are some situations where the ductwork is too small and would need to be modified. Depending on the size and condition of the existing ductwork and furnace, installation of the heat pump can range between $10,000 and $15,000 dollars.

There are ways to reduce the installation costs such as using an existing furnace for supplemental heating or by installing electric strip heaters in the heat pump. This will reduce the size of the required loop field and heat pump.