Geothermal Heating System: How Does It Work?

In peak summer heat or the iciest days of winter, it's always 55 degrees just a few feet below your sneakers. How is this possible? It’s stored heat from the sunshine. Geothermal works by tapping into the earth's constant warmth to provide home heating—and deposits warm air from your home into the ground in order to cool your home in the summer.

It's a sustainable, age-old technology reimagined for modern life.

What Is Geothermal Energy? 

We promise this science lesson is short.

Geothermal energy refers to the sustainable, renewable energy sourced from the earth's core. The intense pressure at the center of the planet generates thermal energy exceeding 4,000 degrees Celsius, or 7,220 degrees Fahrenheit. The heat rises toward the earth's surface and heats the mantle. The mantle is a semi-liquid mass of molten rock, or magma. This layer is just below the earth's crust, and the thermal energy is strong enough to emanate to the surface.

There’s another source of geothermal heating, though you’ll have to look up to spot it. Solar energy also warms the uppermost layers of the soil, creating a source of stored energy that homeowners can tap into through ground-source heat pumps.

These two energy sources combine to provide substantial amounts of energy and heat. Just a few feet below your yard, the street, or most places on earth, it's always a steady 55 degrees Fahrenheit.

Geothermal energy has been used for heating for tens of thousands of years. Humans have used hot springs for bathing and cooking since the Paleolithic Age or earlier! Humans have also stored food and other goods below ground to capitalize on steady temperatures. Until the refrigerator, many homes relied on cellars for long-term food preservation.

How Does Geothermal Heating & Cooling Work? 

Geothermal vs. Heat Pump: There's a Difference 

Geothermal energy and ground-source heat pumps tend to get lumped together, but they are distinctly different technologies.

Geothermal energy generation is only practical at utility-scale, which means you won't be able to drill a well in your backyard (unless you live in Iceland) to tap into the earth's heat.

Instead, homeowners can invest in a ground-source heat pump.

Ground-source Heat Pump Basics 

Also known as GSHPs, ground-source heat pumps use heat stored relatively close to the earth's surface, usually between 4 and 10 feet deep. GSHPs work by running pipes filled with antifreeze below ground and into the home. Once inside, the fluid passes through a heat exchanger, which then circulates the warm fluid throughout the house to be distributed as warm air.

Related: What Is a Heat Pump?

The utility-scale geothermal power process (that generates electricity) and the ground-source heat pump process (that warms and cools your home) are similar but different and operate at vastly different scales of expense, output, and feasibility.

The Advantages of Geothermal Energy Production

Geothermal power is one of the viable renewable energy sources on the planet. Scientists believe the earth will maintain its thermal energy output for another 4-5 billion years, which means additional plants are a safe long-term investment.

Geothermal energy:

  • Produces 1/6th the carbon dioxide produced by a utility-scale natural gas power plant
  • Is always available, unlike solar and wind energy

The Disadvantages of Geothermal Energy 

Geothermal isn't perfect, but there's little doubt that it will be important in meeting the world's growing appetite for energy.

Geothermal energy:

  • Is only feasible in regions with accessible volcanic energy
  • Is expensive, at $2-7 million per plant
  • Can trigger small localized earthquakes

Geothermal Comes Home 

Much of the United States' thermal energy capacity is focused in western states like Wyoming, Utah, Nevada, and California.

Still, American homeowners anywhere in the country can turn to ground-source heat pumps to utilize the same geothermal advantages offered in their own backyards. Right now, air-source heat pumps are becoming the go-to and sustainable solution for residential HVAC systems, and interest in ground-source heat pumps has never been higher.

Your local One Hour Heating & Air Conditioning can help you decide if a heat pump is right for you, and which kind!

Always Ahead of the Curve 

One Hour Heating & Air Conditioning is always exploring ways to meet the nation's heating and cooling needs sustainably. We take pride in offering innovative, cutting-edge HVAC solutions that keep your family comfortable all year long. From expert installation, repair, and scheduled maintenance, we’re your best choice for residential and commercial heat pumps. Book online or call (800) 893-3523 today to learn more!