Discover why ground-source heat pumps are the best choice for heating and cooling new or existing homes in any climate and how this reliable, silent, n-polluting way of extracting free energy from the earth saves money year after year. Then go a step further and learn the simple science behind this proven techlogy. - Geothermal options: open vs. closed loops, either horizontal or vertical, for water-to-air or water-to-water HVAC systems. - Basic principles of heat pumps and how super-efficiencies are achieved. - Important money questions: costs, tax credits, payback time, increased home values. - Earth Smart Home profiles from around the country. - Performance standards, ratings, and warranties. - Careers: joining the industry. - Extensive appendix. For homeowners, home-building partners, and anyone training for a career in the geothermal industry.