Geothermal heating and cooling systems work by moving heat, rather than by converting chemical energy to heat, like a furnace does. Most residential geothermal systems use conventional ductwork to distribute hot or cold air and to provide humidity control. A few systems use water-to-water heat pumps with one or more fan-coil units, baseboard radiators, or under-floor circulating pipes. Properly sized, constructed, and sealed ducts are essential to maintain system efficiency.

Geothermal heat pumps are more efficient than air source heat pumps because earth temperatures are much more uniform through the year than air temperatures. Tens of thousands of homes are being built or retrofitted with geothermal heating and cooling systems every year, because of the advantages these systems offer: economical operation, noise reduction, and product quality. Initially reserved for the most expensive homes, geothermal systems have become affordable options for thousands of low and moderate income housing units because of the system's low life cycle costs compared to all other alternatives in almost every region of the country.

-- Tips courtesy of HomeAdvisor.com