Geothermal Heat Pumps: How We Installed Our Green Alternative to Fuel Oil Heating

Reader Contribution by Allison Ehrman
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Removing an old fuel oil tank from yard.
Photo by Steve Ehrman

During summer 2018, my husband and I began searching for a home out in the country. For 10 years, we had raised our two sons in a kid-friendly townhouse neighborhood in the exurbs of Northern Maryland, and we were ready for a change. We had become known as the weird neighbors who insisted on raising vegetables in a garden that ran all the way around our end-unit home, and we had come to realize what we really wanted was a large yard with a full garden.

After our youngest son graduated from high school, we found our dream house. Built in 1977, this place was beautiful on the outside and had many new updates on the inside. But the best part was that it sat on an almost 2-acre lot with lots of open space, and was surrounded by large trees on all four sides. It was love at first sight.

Finding Greener Options for Fuel Oil Heating

Then came the home inspection. Everything was going smoothly until the very end, when the inspector discovered a fuel oil tank buried in the front yard. We insisted on a pre-sale inspection, which revealed that the tank was leaking, and by law the state EPA was brought in. Fortunately, the sellers were able to take advantage of a Maryland compensation program to help offset much of the expense of having it removed and properly disposing of the contaminated soil.

This meant that at the time of closing in late June, we were without any heat in the house. We had decided we didn’t want the sellers to simply replace the old tank with an aboveground fuel oil tank. Fuel oil is an increasingly expensive way to heat a home, and, of course, it’s not environmentally friendly. At this point, we decided our best option was probably a conventional electric heat pump. Our dream was a geothermal system, but we thought it would be too cost-prohibitive. I’m happy to say we were wrong.

How a Geothermal Heat Pump Works

A geothermal heat pump uses the same general process of heat transfer as a traditional air heat pump, only it’s much more energy-efficient, because the temperature of the earth is consistently warmer than the air during winter and cooler than the air in summer.

When it’s cold outside, a geothermal pump draws heat from the ground, concentrates it, and delivers it into the home. In summer, the opposite happens, as warmth is pulled from the house and sunk into the cooler ground. This is accomplished by running water through a series of “ground loops,” which are basically heavy-duty coiled tubing. This means that about 70 percent of the energy required by a geothermal system comes from the earth itself, which in turn draws its warmth from the sun.

According to the EPA, geothermal heat pumps can reduce energy consumption up to 44 percent compared with air-sourced heat pumps, which are generally considered to be very efficient heating and cooling systems. BGE, our local electricity and gas utility, estimates that many homeowners will see a return on energy cost savings in as little as two years of investing in a geothermal system.

Closed-Loop vs. Open-Loop Heat Pumps

Ground loops can be “closed” or “open.” In a closed ground loop system, the loops are filled with a mixture of water and antifreeze, which never leaves the piping as it circulates through the ground and home.

Our company uses ethanol, which is more environmentally friendly and efficient than propylene glycol, and they test the system regularly to ensure there are no leaks. If there is a well or body of water on a property, an open system can be installed, depending on local regulations. This type of setup uses plain water, exchanging the warmed or cooled water directly back into the well or pond as it runs.

These loops can be installed vertically or horizontally. Vertical loops require less disruption to a yard but are more expensive because of the increased cost of digging to a greater depth. Horizontal loops can be placed just 5 feet below the surface but require tearing up a good deal of the lawn, depending on the square footage of the house and the heating capacity of the water furnace.

Because of the size of our backyard, the fact that we haven’t started any gardens or landscaping projects yet, the lower cost of horizontal loops, and the increased number of regulations and permits in Maryland for vertical ground loops and open loops, we opted for closed horizontal loops.

Different geothermal companies offer different options with installation, including heating for your hot water, smart thermostats, humidifiers, and dehumidifiers. After doing some research into the cost of buying and installing some of these things on our own, we decided that the only other option we wanted was the hot water heating, because it will provide an additional cost and energy savings over time.

Incentives for Geothermal Heat Pumps

Installation and equipment costs vary by location. The total setup for our 1,900-square-foot home, including the hot water option, will cost $24,000. But the reason we can afford to do this is because we’re not paying anywhere near that amount. With incentives and rebates that we’ll receive from the federal government, State of Maryland, our county, and our local energy utility company, the total final cost to us will be closer to $11,200.

And we won’t have to pay anything upfront because we’ve taken out a special one-year, interest-free geothermal installation loan from a reputable company. We’ll have received the tax breaks and grants before the loan is due. Other longer-term payment options are available, but you need to be careful to consider the amount of interest that they’ll charge past any interest-free period.

In the end, we estimate that the geothermal installation and equipment will only cost us about $1,200 more than installing a top-of-the-line air heat pump and furnace. If we’d foregone the water heating option, it would’ve been about the same cost. And since we’ll be using less energy, we’ll end up saving much more over the years. If we’re able to afford solar panels in the future, the house will be more efficient and almost independent of grid energy.

I’ll be writing more articles about our journey into greener living through geothermal in the coming weeks and months, including what the installation process entails and what it’s like living with geothermal. I’ll also be writing about our adventure in rebuilding our lives in the country and all the plants, good food, hard work, and fun that involves.

If you live in Northern Maryland and are looking for a reliable geothermal company, I recommend the services of Ground Loop, Inc.

Allison Ehrmanworks in the corporate world, but her heart and soul reside in her Northern Maryland country home, where she and her husband grow and preserve herbs and vegetables, prepare exotic dishes from locally-sourced foods, and craft natural body care products.

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