Geothermal heat pumps are increasingly becoming the cooling and heating systems of choice for homeowners who want the ultimate in energy efficiency and home comfort. The first question home owners should ask is whether it will work on their property or not. The success of a geothermal installation relies on the interaction and relationship between several components.
One of the most important factors is the site where it's installed. While geothermal heat pumps can use a variety of configurations, including vertical loops underground and open or closed loops underwater, many installations exclusively employ the most common geothermal strategy, underground horizontal loops.
This type of installation is where horizontal loops of plastic tubing are buried below the ground, and they circulate the heat-exchanging fluid in long trenches up to six feet underground on a property, in all types of soil and rock.
Among the factors a home owner should consider:
Soil conductivity: How much energy and heat can be "rejected" into the ground per foot of drilling? "Reject" in this context means the heat energy that the water/anti-freeze mixture in the loops of piping is able to deposit into the ground, after it has been removed from the home through the refrigeration process. (The heating process works in the opposite manner, extracting heat from the ground and bringing it inside.) In some southern states, the installation technicians will drill between 260 and 500 feet per horizontal geothermal well.
Proper spacing: Most contractors plan for 20-foot centers on the geothermal wells to provide plenty of space for the process of energy rejection. This means the coils are spaced far enough apart that the heat from one does not encroach into the heat from other coils. What can happen is the coils are not able to reject (or gather) enough heat, and the system cannot function properly.
Preserving trees and landscaping: A conscientious contractor will try to protect your landscaping during a geothermal installation. They are accustomed to working areas with large trees, and precautions are made with local help from local arborists to protect the root systems of trees. But if there is a particular tree that needs to be spared, that may affect the geothermal installation plans, and even necessitate a different type of installation. Sometimes the home owner may not have any other choice than to have a tree moved or repositioned in order to accommodate the new installation.
A geothermal installation has several different options for the layout of the coils, their orientation, and even if trees can be moved or worked around. It is important for home owners to explore all of their options before they finally settle on a particular type of installation. That prevents any surprises once the installation is underway.