How Geothermal Works


No matter what climate you live in, the temperature throughout the year varies. For some climates that means blazing summers that cool to frigid winters, and North Carolina is no exception. What many people don't realize is that the temperature below ground (regardless of climate or season) stays fairly consistent all year.

The ground is able to maintain a higher rate of temperature consistency because it absorbs 47% of the suns energy (heat) as it hits the Earth's surface. WaterFurnace geothermal systems are able to tap into this free energy with an earth loop. This technology is then used to provide your home or office with central heating and cooling.

Geothermal Heating

During the heating cycle, a WaterFurnace 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.

How it Works: Closed Loop Systems

The most commons type of geothermal installation is a closed loop system.  The heat exchanger (a loop of piping filled with fluid) is burried underground.
The fluid circulates continuously inside the burried pipe, absorbing heat from the earth during the winter for use inside your home or business.  In warmer months, the fluid takes heat from indoors and trasnfers it back into the earth.

Vertical loops

If the land area available is limited, a vertical loop may be installed for the geothermal piping.
Vertical installations might also be used where the land is too rocky for trenching, for existing buildings, and for large commercial or educational facilities.

To install a vertical loop, a contractor will bore holes into the ground. Long, hairpin-shaped loops of pipe are then inserted. The hole is backfilled, plugged or grouted, and the pipes are connected to headers in a trench leading back to the building. The drilling depth is determined by the lowest total cost based on the conditions at the job site. A typical borehole depth is 150 to 250 feet. The objective of a vertical borehole is to install a specific amount of pipe, not to reach a certain depth. If 1,200 feet of pipe are required, three 200-foot boreholes are acceptable and may be more cost-effective. Drilling boreholes for geothermal loops is much simpler than drilling to find well water. The borehole is generally smaller, which reduces drilling time, and no casing is required because the hairpin-shaped loop is the casing.


Horizontal loops

If adequate land area without hard rock is available, a horizontal loop installation is usually the most economic. Horizontal loops are often used for newly constructed homes and commercial buildings.
A horizontal system uses a number of trenches. The piping can be configured in the trenches in several ways: 
-  A single pipe;
-  Multiple pipes in a narrow trench; or  
-  Multiple pipes in a wider trench.

The trenches are normally four feet deep or more, and vary in length depending on the number of pipes to be buried. One of the advantages of a horizontal loop system is being able to lay the trenches according to the size of the lot. 



How it Works: Open Loop Systems

While the majority of geothermal installations use a closed loop system, another option is an open loop system. Instead of using an antifreeze solution sealed inside the buried piping, an open loop system uses water from a surface or underground source - such as a pond, lake or well.The water is pumped into the heat pump unit where the heat is extracted; the water is then discharged back into the original source. 
Well water designs are the most common and most cost-effective. The well supplies both household water and water for the heat pump. Approximately three gallons per minute of well water are needed per ton of cooling capacity. A 3,000-square-foot, well-insulated home would typically require 10 to 15 gallons per minute.


Water quality is an important issue with open-loop systems. Mineral deposits can build up inside the heat exchanger, iron and other impurities can clog a return well, and organic matter from ponds and lakes can quickly damage a geothermal system. Water should be tested for acidity, mineral content and corrosiveness. 

Pond Loop (Open Loop Systems)

Pond geothermal energy systems are most efficient and economically viable of the three geothermal systems, with the highest potential for producing energy savings. Pond geothermal utilizes a nearby body of water as the energy resource. Similar to the vertical and horizontal earth systems, it has a closed loop of sealed 50 + year plastic pipe, circulating a water – based, food– grade antifreeze solution. The pipe is coiled into a lake / pond – loop “radiator” and submerged where it takes advantage of the ponds consistent temperature to heat in winter and cool in summer.

Lake geothermal energy is the best option if a body of water is available within roughly 300 feet of the home or building. A ½ acre, 8 to 10 foot deep body of water is usually adequate to support the average home. Lake geothermal systems do not require major excavation, so they are usually the most cost effective.

Contact Climate Control Heating & Cooling Co.. Start saving on your energy bills today. 

Call us to set up an appointment!   800-789-3828

About Climate Control Heating & Cooling Co.

Climate Control Heating & Cooling Co. has provided geothermal heating and cooling solutions thourghout North Carolina for many years. We proudly offer  WaterFurnace geothermal systems and stand behind our quality work and products.  Call us at Climate Control Heating & Cooling Co. today.  We are ready to bring you into the WaterFurnace geothermal family.

Geothermal Heat Pumps by WaterFurnace
Copyright 2020 Climate Control Heating & Cooling Co.   |  All Rights Reserved
All content copyrighted by WaterFurnace and Climate Control Heating & Cooling Co.