An increasingly popular option for homeowners concerned about their energy costs and their environmental impact, a geothermal heat pump circulates a water/anti-freeze solution through buried polyethylene tubing (called a “loop field” or “ground array”) to transfer heat between your home and the ground around it. Although this technology has only been developed in the last half century, the concept traces its roots much further back in time.
Below four feet, the ground stays a consistent 50 to 55 degrees F. Our distant ancestors used this fact when they took to caves to find a stable environment. Today we can use the same principle to provide heating and cooling for our homes.
Here are some of the pros and cons to consider when deciding if a geothermal heat pump is right for you.
Pro: Operating Cost. The low energy required to operate a geothermal heat pump means that energy costs in equipped homes are significantly lower. Better yet, because geothermal doesn’t require combustion to generate heat, the system doesn’t produce any exhaust, making it a environmentally friendly option, like one of these 17 Ways to Honor the UN’s 17 Goals for Sustainable Development
Con: Supplemental Heating. Like a standard heat pump, your geothermal system will have a backup heat source, either a furnace or electric heating elements. These will only kick in on especially cold days, but depending on where you live, it might happen enough to cut into your energy savings.
Pro: No Large Outdoor Unit. With a geothermal heat pump, you don’t need to worry about a large condenser distracting from your home’s curb appeal. Since the loops are buried underground, they’re completely out of sight. The system also runs quiet; the indoor unit makes about as much noise as an average refrigerator.
Con: Limited Service Options. Not all contractors are familiar with geothermal heat pumps, and there may be a limited number of qualified contractors in your area. Proper installation of the loop field is vital, as the savings quickly evaporate if it’s not done correctly.
Pro: Hot Water Tank. During the summer months, when the geothermal heat pump is pulling warmth from the ground, it can also heat your hot water tank much more efficiently than a standard heating element.
Con: Site Dependent. In order to function, a geothermal heat pump needs the loop field to be properly situated. Not all sites lend themselves to this installation. If your property is especially rocky, for example, a horizontal loop might be difficult to install. There are other installation options, such as a vertical well or slinky loops. If you have a sizable pond (about 10 feet deep) then you can run the loops there, using the water rather than soil as the source of stable temperature. The best way to find out if geothermal is right for your lot is to reach out and contact a qualified installer.