Most GHPs use one of three technologies: ground-coupled heat pumps (closed loop), ground water heat pumps (opened loop), or surface water heat pumps (lake/pond loop). The indoor equipment takes up about as much space as a typical furnace, and includes the compressor, blowers, heat exchange coil and control. The only additional equipment needed is the pump that circulates fluid through the loop.

How economical they are depends on where you live and which GHP system you use. For ground-coupled systems, cost varies with the number of available contractors. Where the technology is not well-established, the lack of competition results in higher prices. Open loop systems, because they do not require specialized contractors are less affected by this problem. On average, a properly sized and installed heat pump can save 30-40% on heating and cooling bills. Results will vary based on resident behavior and climate, but geothermal heat pumps are among the most efficient and comfortable heating and cooling technologies currently available.

Consult the excellent resources available from the International Ground Source Heat Pump Association and the Geothermal Heat Pump Consortium for feasibility guidelines, design criteria and installation assistance.