<?xml version="1.0" encoding="utf-8"?><mads xmlns="http://www.loc.gov/mads/" xmlns:mods="http://www.loc.gov/mods/v3" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.loc.gov/mads/
mads.xsd"><authority><topic authority="http://AATesaurus.cultura.gencat.cat/aat/getty_en">borehole heat exchangers</topic></authority><related type="broader"><topic>heat exchangers</topic></related><variant type="other"><topic>borehole heat exchanger</topic></variant><variant type="other"><topic>downhole heat exchangers</topic></variant><variant type="other"><topic>heat exchanger, borehole</topic></variant> <note xml:lang="en"><![CDATA[ Borehole heat exchangers are used to extract heat stored in the ground by means of a vertical borehole with a “closed loop” 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. ]]></note></mads>