Introduction What is a Heat Pump and How Does it Work? Coming to Terms with Heat Pumps Ground Source Heat Pumps (Earth Energy Systems) How Does an Earth-Energy System Work? Parts of the System Energy Efficiency Considerations Sizing Considerations Design Considerations Installation Considerations Major Benefits of Earth-Energy Systems Maintenance Operating Costs Life Expectancy and Warranties Heating Energy Cost Comparison: Heat Pump and Electric Heating Systems Factors Affecting Heating Cost Comparisons Comparison Results Related Equipment Upgrading the Electrical Service Supplementary Heating Systems Conventional Thermostats Electronic Thermostats Heat Distribution Systems Answers to Some Commonly Asked Questions