Frequently Asked Questions and Glossary of Terms about Geothermal Heating
When you’re shopping for a geothermal heating system (or cooling) you’ll likely hear quite a bit of words and terminology that is new to you. This geothermal glossary guide is designed to give you an understanding of the basic terms and concepts so that you can more effectively dialogue with a geothermal contractor or sales personnel.
Geothermal Glossary of Terms
Closed-loop System: A geothermal heat pump system that uses a horizontal or vertical buried loop made from HDPE plastic.
COP: Coefficient of performance. It states the ratio of the heating provided by the heat pump to the energy it consumes. The higher the COP, the greater the efficiency of the geo thermal heating system.
Coil Loop: This type of geothermal loop is usually made from copper and is often employed in geothermal heating and cooling systems that use a pond as the source/sink.
Compressor: The central component of a geothermal heat pump system is the compressor, which pressurizes refrigerant, causing it to move through the system.
EER: Energy Efficiency Ratio. A measurement of the efficiency of the geothermal cooling system. It compares the cooling provided by the system to the energy consumed. The higher the EER the better. It is the cooling equivalent to COP.
Geothermal Energy: The consistent warmth of the earth below the surface; also used of the heating produced by using the energy found within the earth.
Geothermal Heat Pump: A heat pump that draws heat from the earth for heating and sinks heat into the earth when cooling.
Geothermal Tax Credits: Federal and state tax credits are offered for the installation of geo thermal energy equipment. Current federal geothermal tax credits run through 2016.
Heat Sink: The medium where heat is discarded by a heat pump. It may be the air, the ground or water.
Heat Source: The medium from which the heat pump collects heat – air, the ground or water.
Horizontal Loop: This type of loop requires more ground area than a vertical loop. They are used when bedrock prevents deep excavation and include 100 to 450 feet of pipe in most geo thermal systems.
Hot Water Generator: A device which collects heat taken from the home during cooling, or excess heat during a heating cycle, and uses it to heat water for use within the home. They are used to preheat water and if enough heat can be extracted, to heat the water completely. Hot water generators are often called desuperheaters.
Hydronic System: Also called water to water systems, these geothermal energy systems heat water that is used for domestic potable water or in a radiant floor heat system.
Open-Loop System: A geothermal cooling and heating system that uses groundwater from a well. The well water is the heat source and the heat sink.
Package System: A geothermal energy system that is contained in a single package, accept for the loop. Package systems are usually installed inside.
Payback Period: Geothermal heating and cooling systems come with a higher price tag than conventional heat pumps. However, they lower energy use and cost by up to 50%. The time it will take to recoup the extra cost of the geothermal heat pump via lower energy bills is known as the payback period.
Split System: These geothermal heating and cooling systems feature a condensing unit and a remote air handler. Geothermal manufacturers make condensing unit models for outside installation and models for inside installation. Consult a geothermal contractor for the best choice and the prices for each for your area.
Supplemental Heating: In very cold climates, some geothermal heat pumps lose some of their effectiveness in winter months. Most do not, but those that do may need to be supplemented with another form of heat. This could be electric resistance coils added to the air handler or the inclusion of a gas furnace in the system.
Vertical Loop: These loops are used in geo thermal systems where space requirements prohibit horizontal pipes. Vertical loops may be as shallow as 100 feet and as deep as 450 feet.
Help Us Expand the Geothermal FAQ
This geothermal glossary guide should give you the information you need to research geothermal heating and cooling units online. These terms are ones you should be familiar with as you discuss you specific geothermal energy needs with a geothermal contractor. If you didn’t find the meaning to a term you recently heard, ask us about it! We’re glad to add new definitions to the Geothermal Glossary to suit our visitors.