Geothermal systems are a way to use the ground near your home to unlock the most powerful renewable energy source…the sun.  Average ground temperatures in the Columbia, SC area are between 60 and 65 degrees all year round.  That is cooler than nighttime temperatures in areas like Blythewood during the summer and much warmer than winter nights in Camden.  Because geothermal systems take advantage of ground temperatures, they don’t need to work nearly as hard as traditional HVAC systems to cool and heat your home.

Now put on your lab coats, and let’s dive into just how geothermal heating and cooling makes the magic happen.

The sun infuses the Earth’s crust with its heat energy. Forty-seven percent of that energy is stored in the ground as heat. Geothermal systems tap this heating potential using an earth loop system; harvesting this free heat for your home. This innovative technology uses the sun’s heat that the earth has readily stored to condition your home or office.

geothermal-diagram

 

Geothermal Heating

During the heating cycle, a geothermal heat pump uses the earth loop to extract heat from the ground. As the system pulls heat from the loop it distributes it through a conventional duct system as warm air. The same heat energy can also be used for a radiant floor system or domestic hot water heating.

Geothermal Cooling

In the cooling mode, the heating process is reversed – creating cool, conditioned air throughout the home. Instead of extracting heat from the ground, heat is extracted from the air in your home and either moved back into the earth loop, or used to preheat the water in your hot water tank.

Ground Loops

At the center of geothermal technology is the ground loop configuration.  To collect or dispose of heat in the surrounding ground, water is used as means to transport the heat. The water is pumped through PVC piping that is buried in the ground. The options for setting up ground loops depend on the resources available near your home. There are four primary designs for group loop installations:

geothermal-horizontal-loop

Horizontal Closed Loop

Putting in the system horizontally requires quite a bit of land space. The piping is embedded in trenches between 4 and 6 feet deep and can be up to 400 feet long.

If you reside on a smaller lot, the loops can be installed vertically by boring straight down using drilling equipment.

geothermal-vertical-loop

Vertical Closed Loop

The vertical loop is realized with multiple trenches of buried PVC pipe or a wide trench where the same length of pipe is laid out like a slinky.

This solution is used where the surrounding geography does not allow for long trenches to hold the PVC pipes. Vertical loops are placed in drilled holes similar to well drilling.

geothermal-pond-loop

Pond Loop

The pond loop uses the thermal properties of a pond to collect or dispose of heat. In this type of installation, the piping is placed at the bottom of a pond.

geothermal-open-loop

Open Loop

The open loop design utilizes ground water directly as transport media for heat. Fresh ground water  is pumped to the geothermal heat pump and disposed of into the ground.

Geothermal vs. Geoexchange: What's in a name?

Geothermal energy has been used to heat and air condition buildings for several decades, and during that time these geothermal systems have been called many different things. Some of the more popular variations include geo-thermal, geo exchange, ground-water, ground-water assisted, ground-water-source, and water-to-water.