. "Borehole heat exchangers are used to extract heat stored in the ground by means of a vertical borehole with a \u201Cclosed loop\u201D collector installation with the help of a geothermal heat pump. A collector hose filled with a carrier fluid is installed in the borehole which is drilled into a geothermal aquifer. This circulating carrier fluid absorbs heat from the surrounding bedrock, which is then extracted by the heat pump for use in space-heating via piping connected to the heat exchanger."@en . . "heat exchanger, borehole"@en . "2013-08-05T15:43:25"^^ . "300387010" . . "borehole heat exchangers"@en . "borehole heat exchanger"@en . "downhole heat exchangers"@en . "2013-11-22T14:48:47"^^ .