You may be interested in pursuing various options for making your home more environmentally friendly. You may also want to improve your energy usage while maintaining excellent indoor comfort conditions. In either case, your greenest option for home comfort is a geothermal heat pump. Learning more about how geothermal systems work and the benefits of installing them may prompt you to go green as you consider updating your existing equipment.
Geothermal technology relates to the earth’s internal heat, and a geothermal HVAC system makes use of the more constant earth or water conditions to provide greater energy efficiency in home comfort control. Whereas an air source heat pump uses the surrounding air as heat is absorbed from or released into the environment, a ground source or water source heat pump uses soil or water to facilitate this exchange of energy. Because temperatures are more stable in the ground or in deep water, a geothermal system is able to operate with less energy consumption.
A geothermal heat pump relies on a loop field for outside heat absorption and release. In your air source heat pump, a refrigerant loop is much smaller with outside coils being housed in a condenser unit. The footprint for a geothermal heat exchanger can be extensive. The tubing used to construct these coils is usually plastic, and an antifreeze solution circulates through these coils to exchange heat with the refrigerant in the heat pump. The positioning of the coils in a more stable temperature environment means that the energy transfer between refrigerant and antifreeze remains consistent even in extreme weather conditions.
There are several important elements in a contractor’s design of a geothermal system for your home. Your heating and cooling loads must be calculated to determine the appropriate heat pump sizing. An HVAC contractor will generally size a geothermal system to accommodate between 95 and 98 percent of the heating load in northern climates.
The loop field is the other key component of system design. The four main options include vertical loops, horizontal loops, open loops, and lake or pond loops. Considerations vary based on the landscape and property where the loops must be placed. Common issues include:
The ability to use less energy is an important benefit of this type of system, but those interested primarily in trimming utility bills need to recognize that geothermal projects can be very expensive. According to Energy.gov, the additional costs of a geothermal system can be returned in between five and 10 years through more efficient system operation. Additionally, the life of such a system is estimated at 25 years, exceeding the life of an air source heat pump by more than a decade. The loops are estimated to last for 50 years or more. Energy tax incentives may defray some of the project costs as well.
If the benefits of geothermal energy seem to fit your interests and needs, you can contact W.E. Brown, Inc. in Charlottesville, VA, to schedule a consultation. Our team is available to calculate your heating and cooling loads and to provide you with the most appropriate loop field options based on your property details. Call our office for an appointment.