Anyone who has retreated to a cold basement on a hot day knows
the concept is as old, quite literally, as the hills. Beneath
the Earth's surface, the temperature is constant. By tapping
that, homeowners with geothermal systems can cool their homes,
or provide heat. A geothermal system circulates a water solution
through pipes that are buried beneath the home, yard or, if
there is a body of water close by, underwater. In the winter,
the fluid carried by the system is warmer than surface air. In
the summer, it is cooler. The home's ventilation system
distributes air, warmed or cooled by the fluid, throughout the
house. A geothermal system costs more to install than a
conventional heating/venting/air conditioning (HVAC) system, but
pumping the warm/cool air through the house uses less
electricity than does a typical heating or cooling system. So it
can yield long-term energy savings which, in turn, can save
money. The system doesn't burn fossil fuels, which makes it the
right choice for many environmentalists. S