Energy from the sun is absorbed by the Earth’s surface. Depending on what part of the country you are in the earth just a few feet below the surface is a constant 50 to 70 degrees. This is also true for ponds, lakes or wells. A geothermal HVAC system pulls that energy from the earth or water to heat, cool, and even provide hot water for your home.
There are many benefits to geothermal. The systems are quiet and dependable. There are few moving parts so it requires very little maintenance. There is no outdoor equipment which protects the system from the elements and thieves. It maintains a comfortable temperature year round by providing energy for heating, cooling, and hot water. These products are safe because there is no combustion so no chance for carbon monoxide poisoning.
A pump circulates water or an antifreeze type fluid through a series of pipes that travel underwater or underground. The recommended solution is propylene glycol which is non-toxic and in most states the only fluid allowed besides water. During the winter the fluid absorbs heat from the ground or water it is being circulated through. That heat is compressed to a higher temperature and then circulated through the home using a forced air system or radiant system. During the summer the process is reversed. The system pulls heat from the home and lets it be absorbed by the ground or water. The result is a cool dehumidified home.
The two generally used applications for these systems is the open loop system and the closed loop system. Depending on how much property you have or if there is a significant fresh water source will determine which would work best for you. The open loop system would need a fresh water source consisting of a running stream or a well. This application would need approximately one million gallons per year to perform correctly. It is important to have your water tested for sustainability and excess minerals. Excess minerals could damage the equipment nullifying any benefits to installation. A closed loop system typically contains an antifreeze solution which is better at transferring heat. The non-toxic fluid is not exposed to the environment. The piping system is buried underground or placed at the bottom of a pond taking advantage of the energy stored there. The closed loop system in a pond is by far the most cost effective because of the lower installation expenses.
When considering installing a geothermal HVAC system in your home there are many factors to take into consideration. It is paramount that you consult an experienced professional before taking on such a large project.