Geothermal Systems In Offices And Commercial Buildings

For applications in the commercial sector, large borehole heat exchanger (BHE) fields or ground- water wells are the preferred groundside alterna- tive. While BHE are feasible virtually everywhere, and promise maintenance-free operation, their individual capacity is limited, resulting in huge BHE fields for systems with high heating/cooling demand (see table below). Groundwater wells, on the other hand, require specific geological site conditions and diligent managing of the wells, but can deliver much higher thermal output per well. So for large installations, ground water use is a favorable option.

What does a geothermal system cost?

A geothermal system for the typical home will cost more than if you bought a conventional central air conditioning system. But you wouldn’t be comparing “apples to apples.” To get an accurate comparison of costs you need to consider the following:

•                        Payback, or how long it takes to recover the difference in costs between the two systems using energy savings. Payback for most geothermal heat pump systems runs three to five years.

•            Federal, state and local tax credits / incentives will significantly reduce the upfront cost of installing a geothermal system.

•            Energy efficiency of the two systems. To get an accurate picture, make sure efficiency claims are substantiated. Your lifestyle and how well your home is insulated affect how economical a system will be, too.

•            Total operating savings from heating, cooling and domestic hot water must be combined to get an accurate picture of total energy savings.

•            Energy costs and availability, both present and future.

•            Maintenance costs and system reliability.