References Chiasson, AD, Culver, GG, Favata, D, Keiffer, S. Design, Installation, and Monitoring of a New Downhold Heat Exchanger. Geo-Heat Center, Oregon Institute of Technology, Klamath Falls, OR, USA http://www.houseneeds.com/heating/hydronic-heat-supplies/aic-shell-and-tube-heat-exchanger-300000-btu-b300 westank.com/plate-and-frame-heat-exchangers/ Chenahotsprings.com Culver, Gene, Lund, JW. Downhole Heat Exchangers. Geo-Heat Center, Oregon Institute of Technology, Klamath Falls, OR, USA, September 1999.