The purpose of a water furnace is to extract heat from the ground and release it as energy for heating a home. A water furnace can also cool a home by removing and displacing hot air.
Water furnaces are usable year round because the temperature below ground remains relatively consistent despite the season. This is because the ground absorbs 47 percent of the heat energy from the sun, according to WaterFurnace International, Inc.
Benefits of water furnace systems include lower operating costs and environmental friendliness. WaterFurnace International claims that its systems can release five units of energy per one unit of electricity used. The Department of Energy cites water furnace systems as the most environmentally friendly heating and cooling system.