When we talk about geothermal energy in HVAC, (Heating, Ventilation, and Air Conditioning) we talk about the energy that can be extracted from the ground to use in ground source or geothermal heat pumps. Since the ground remains at a relatively constant temperature, it can be used as a heat sink during the summer months and as a heat source during the winter months.
A ground source heat pump system is considered a form of renewable energy that takes advantage of the Earth’s relatively moderate temperature of 55 °F, depending on where you are situated geographically. Ground source heat pumps use pipes that are in a loop, and are buried underground, to extract or reject heat from a refrigerant or water running inside that loop. In a typical air conditioning system, the ground would act as the condenser. The video below by DTE Energy shows how geothermal energy works.
Advantages of Geothermal Energy
Geothermal energy works 24 hours a day, 7 days a week, regardless of the weather or temperature above the earth. A ground source heat pump system will increase the value of your property and will get you federal tax credits and possible utility incentives of 30% off the price of the system. A geothermal heat pump system will always save you money in the long run since there is an element of free energy in the design, and the pipes that are buried underground can last more than 50 years without requiring any type of maintenance.
Disadvantages of Geothermal Energy
Geothermal or ground source heat pumps have their disadvantages as well. The work required to dig ground trenches where the pipes are buried can be very expensive and, depending on you city regulations, you might have to get a permit before you can dig. Electricity is still required to drive the heat pump, so they are not completely void of carbon emissions like solar and wind energy.
Geothermal or ground source heat pumps are a great energy-efficient alternative to air condition and heat your home. You just need to be aware that they will cost you more initially than traditional systems, but it’s a cost that can be recovered by the energy savings you will receive over the years.