By John Ivanko, Urban Farm:
While the sun above may power your urban farm or grace you with a bumper crop of tomatoes on your rooftop, many urban and suburban residents are taking advantage of the ground below to heat and cool their homes. Just 6 feet below the surface is soil that remains between 45 and 75 degrees F year-round, regardless of where you live. That’s why root cellars or underground caves are so efficient for storing food and why water pumped from the ground is refreshingly cool, even on the hottest summer day.
Geothermal heating and cooling systems, also called ground source heat pumps, tap the consistent temperature of the Earth, transferring it through a series of pipes and heat exchangers to be redistributed to heat or cool a building. In the winter, geothermal heat pumps pull heat from the Earth. In the summer, these same pumps use the ground as a heat sink: a place to dump and dissipate heat. Many systems are connected to radiant floor heating, whereby a series of hot-water pipes that run through the floor radiate heat; such systems can provide an additional 40 percent in energy savings over regular forced-air heating systems. Geothermal systems can also be used for heating domestic hot water…. Read more