Can a heat source from the ground really save you on heating and cooling costs? Find out the pros of geothermal air conditioning, how it works, and what to consider.
Tired of paying high energy bills? Want to switch to a quieter, more energy-efficient and eco-friendly heating and cooling system? Geothermal may be the solution for you.
What is a geothermal heating and cooling system?
A geothermal system consists of two primary components: a ground source (hence geothermal) heat pump situated inside your house and a closed loop of plastic tubing or pipe that is buried in the ground exterior around your home. The pump circulates a fluid mixture — usually water and antifreeze — through the loop. As the fluid circulates, it acts as a heat exchanger, either dispersing or collecting heat from its immediate surroundings.
How does it work?
Geothermal heating and cooling systems do not convert chemical or electrical energy. Instead, they simply move heat. Outside temperatures fluctuate dramatically during the year. However, because of the insulating properties of the earth, temperatures 4 – 6 feet below ground stay fairly consistent year-round. (Depending on where you live, these average underground temperatures can range from between 45 degrees and 75 degrees Fahrenheit.)
If you’ve ever gone spelunking or spent time in a cave — you know how cold subterranean regions can be. In the winter, the ground temperature is typically warmer than the air above it. The geothermal system absorbs heat from the earth and transfers it into your house. In the summer, when the ground temperature is typically cooler than the air above it, the heat pump draws the heat out of your house and back into the ground. In other words, the ground is a heat source in the winter and a heat sink in the summer.
What are the benefits of geothermal heating and air-conditioning systems?
Geothermal systems offer several benefits.
- They are very durable and require little maintenance. Underground earth loops can last for generations (up to 50 years), and because it’s not exposed to the elements like a traditional A/C unit, the heat exchange equipment can have a lifespan of up to 25 years.
- They are one of the most energy-efficient heating and cooling systems available. Geothermal systems use 25 percent to 50 percent less electricity than other residential heating and cooling systems. Moreover, the Environmental Protection Agency (EPA) estimates that geothermal systems are 48 percent more efficient than gas-powered furnaces, 75 percent more efficient than furnaces that burn heating oil, and 43 percent more efficient than conventional HVAC systems at cooling your home.
- They are cost-effective. Although the initial cost of installing a geothermal system can be several times higher than a traditional system of the same capacity, tax incentives and lower monthly energy bills can offset the difference. Nevertheless, it can take between five to 10 years of reduced utility bills to fully recoup those extra costs. Investing in a geothermal system may make the most sense if you’re planning to stay in the same house for some time.
- They are safer for the environment and your family. Geothermal systems aren't just more energy-efficient than conventional HVAC systems. They are also less polluting. When fossil fuels are consumed to supply electricity for conventional heating and cooling systems, those fuels produce potential toxic gasses — such as methane — into the atmosphere. Malfunctioning equipment that relies on fossil fuel technology can also release daily concentrations of carbon monoxide inside your home. This “silent killer,” so-called because it is odorless and colorless and difficult to detect without specialized equipment, takes the lives of over 400 Americans every year.
Where can Geothermal Systems Be Used?
Ground source heating and cooling can be used almost anywhere in the United States. However, your actual ground loop installation options will be determined in part by the composition of the soil, as well as the hydrological conditions in your area.
If you’re building a new home or replacing your old heating and air conditioning system, you may want to consider a geothermal system for its longevity, energy efficiency and eco-friendliness. And a home warranty from a reputable provider like American Home Shield can cover repairs to your geothermal heating and cooling system in the unlikely event they’re required.