By Louise Lerner, Science Writer, Argonne National Laboratory
Installed in 2012, the geothermal heat pump system at Argonne’s Visitor Center saves $4,000 in heating costs per year and 53 tons of greenhouse gas emissions. Geothermal heating and cooling uses the constant 55°F temperature of the earth to heat and cool buildings.
Your fridge actually works by removing heat from the air inside, not by cooling it down. Geothermal works the same way, using pipes of liquid refrigerant that loop deep underground. In summer, the liquid absorbs heat from the air in the Visitor Center and then releases it as it goes underground. In winter, the liquid picks up heat from the ground and brings it to the surface, where blowers circulate air past the warm pipes and send the warmed air into the building. The pipes below the Visitor Center go 650 feet underground.