During the summer, neighborhood kids play baseball on the grass field across the street - just as they have for nearly a century. But even more excitement is taking place underground. This playground is home to a state of the art geothermal heating and cooling system.
Below the turf, 70 wells reach down more than 250 feet (80 m) where the temperature is always 56°F (13°C). There, recirculating well water is cooled in the summer and heated in the winter, keeping visitors to the former school comfortable and cutting the park's energy costs by half since its installation in 2002.
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For the efficient transfer of energy, heat exchange systems rely on large areas of land. In this case, the acre of playing fields is a perfect venue.
Miles of pipes with water and antifreeze travel through the playfield, either being warmed or cooled by the surrounding soil. Although expensive to install, a geothermal system can pay for itself in about a decade.
The miles of hose that run beneath the field serve as an efficient heat exchange, the same way your car's radiator cools fluids by dispersing heat to the air.
During the summer, supply lines pump warm fluids into the field to be cooled. The cooler fluid returns to the building to aid in cooling. This process is reversed in the winter.
Wells must extend at least 20 feet (6 m) below the surface to benefit from a constant temperature that is not affected by variations in air temperature. The wells here continue an additional 230 feet (67 m) to compensate for the temperature exchange from the system.