In part three of our Introduction to Geothermal series, we are going to discuss geothermal loop systems and how each type works.
A geothermal loop is the series of underground pipes used to move heat to and from the earth. The pipes are made out of high-density polyethylene to establish a dependable, long-lasting system. They are joined together by the process of thermal fusion that will develop a bond that is far stronger than the original pipe itself. In fact, a properly installed loop can remain up to 200 years.
There are two main types of geothermal loop systems that are almost always used in today’s installs: open loop systems and closed loop systems. Each system has different pros and cons for your heating or cooling solution. We at Haley Mechanical have the training and experience on both types, and we will guide you step by step in the process of determining the right option for your geothermal installation.
Open loop geothermal solutions are designed to maximize the natural groundwater from underneath your home. Using a well, water is pulled from an existing aquifer and delivered to the geothermal heat pump where its heat is extracted, and the water is pushed back into the ground or to a designated runoff. Since the water that you are handling is not being treated in any way, the only thing that is being returned to the earth is water that is slightly warmer or cooler (depending on whether you’re in heating or cooling mode).
One thing to keep an eye on with an open loop system is water quality. Mineral build-up can manifest from the poor quality water. This can be attended to with occasional cleaning. If the water in the earth has higher iron content, you will need to make sure that the discharge water is prevented from coming in contact with air before it is returned to prevent clogs.
The only thing that you need to watch out for when it comes to an open loop system is a mineral build-up if the water’s initial quality is not very good. This can easily be attended to with an occasional cleaning with a mild acid solution. If the water in the earth has a higher iron content, you will need to make sure that the discharge water is prevented from coming in contact with air before it is returned to prevent clogs.
Closed loops are exactly as they sound. Instead of pumping water from a well and depositing it elsewhere, water is circulated in an entirely sealed circuit with a small amount of environmentally-friendly antifreeze.
There are two primary types of closed loop installations: horizontal and vertical. Putting in the system horizontally requires a good chunk of land. 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. This kind of installation can be installed in as little as a 10ft by 10ft area.
In either case, the larger the building, the larger the geothermal heat pump and loop need to be. A good ballpark figure is that for every ton of system capacity, you will need 500 to 600 feet of pipe.
Contact Haley Mechanical today to learn more about what system options are available to you here in Dexter.