Smart Guide to Geothermal

Workers at the end of a line of geothermal coils six feet underground.

If you are a homeowner you probably already own a renewable energy resource that has the potential to heat and cool your home—a silent, non-polluting way of extracting free energy from nature.

Geothermal energy is a heating and cooling resource taken from beneath the earth on your property. It’s a ground-based source of energy that uses the earth’s naturally-emitted heat to provide warmth and drive air-conditioning in your home in a manner similar to how a refrigerator operates – it takes in energy and recycles it.

HVAC from the Earth

Some call it ground-source, and it’s also known as geo-exchange, earth-coupled, or geothermal heat pumping. Whatever its name, geothermal energy is all about energy-efficient, environmentally clean, and cost-effective energy for your home.

First, a warning: installing a geothermal system is not a true do-it-yourself project. It requires a host of professional-grade skills, including metalwork for ducting, electrical work to code, electronic circuitry trouble-shooting, plumbing to code, trench digging, grouting, thermal conductivity, purging, pipe fusion, soil testing, heat pump training, and experience. That’s not to mention getting all the proper permits from your local government.

Even professionals who have gone through geothermal installation training need to be supervised for a while. For example, Canada makes its geothermal installation interns work for a year before giving them certification.

There is a reason for all this caution—every home is unique and presents different problems to solve.

He Wrote the Book

Donal Blaise Lloyd is the author of “The Smart Guide to Geothermal: How to Harvest Earth’s Free Energy for Heating & Cooling.” (PixyJack Press, $19.95). While the book isn’t a do-it-yourself manual, it certainly provides enough information to get the creative juices flowing for anyone contemplating the installation of a system in new construction or retrofitting an existing building.Smart Guide to Geothermal

“Everyone can see solar panels on rooftops, and it is not a stretch to visualize converting sun radiant energy into electrical energy,” Lloyd says. “But (geothermal installations) are invisible and the name has little recognition. Education is the big answer.” Lloyd doesn’t think there are many DIY’ers who have done a geothermal installation. “Some say they have online,” he says. “I personally know of no DIY installation.”

Lloyd adds, however, “I am aware of failed installations near me because the installer just did not know enough.”


Be prepared to spend anywhere from $20,000 to over $40,000 to get a residential geothermal system installed. There may be a Department of Energy Residential Renewable Tax Credit available that can shave roughly 25 to 30 percent of that upfront cost from your taxes, with no cap on how much you will receive and without the necessity of having the installation location as your primary residence. However, your newly installed system must meet federal Energy Star energy-efficiency standards to qualify for the credit and regulations change frequently.

The upshot of a geothermal installation is you can save roughly a couple thousand dollars per year in heating, cooling, and hot water costs once your system is up and running. The actual savings may vary depending on your home’s size, the extremes of weather, and other factors.


If you are determined to go the DIY route, there are geothermal kits available. Most of the necessary tools are found in typical handyman toolboxes. You will probably need to rent a machine to help with digging unless creating fairly deep trenches is your idea of fun.

With some expert help, you can get a decent portion of work done, thereby saving yourself money and enabling you to play a part in giving your home a truly unique renewable energy system. Some contractors offer their services as consultants, allowing you to do the bulk of the work and trouble-shooting for you when you run into a problem.

What You Need to Consider

While not a comprehensive list, here are your major considerations before tackling a geothermal installation project:

Size Matters - How big of a geothermal heating/cooling system do you need? The answer depends on the size of your house and what temperature you wish to maintain. There is software available that will help you calculate geothermal unit size. Many top names in home heating/cooling offer units, including Sears, Carrier, Trane, and others.

Vertical or Horizontal? - The heat pump can be installed either way. What is right for you is determined by how deep the holes you’ll dig will be and how much land you have. Consult an expert to determine your best approach.

Dig We Must - You will need a trench anywhere from five to eight feet deep, running anywhere from 100 to 400 feet from your home to draw the energy from the earth (temps near your home can be affected by the home itself). The specifics on where and how far will be determined by the size of your house, your soil composition, and your land size. A backhoe, boring machine, or well driller needs to be rented. If you can’t run it yourself, you can usually find a contractor.

Piping Up or Down? - Depending on whether yours is a vertical or horizontal install, grouting may be needed to seal the system. You also need to fill the pipes with an anti-freeze. Which direction is the best, would be determined by your specific location.

In Case of Extremes, Back-Up - If you have extreme heat or cold in your area, it’s a good idea to have a source of heat/cooling to supplement your geothermal loop. It’s also a good idea to have an electrical backup in case your heating/cooling system is temporarily offline.

(For other developments in green HVAC, take a look at this.)