Which geothermal heat exchanger is a series of loops placed in a body of water?

• A. Pond heat exchanger
• B. Vertical loop
• C. Horizontal loop
• D. Soil heat exchanger

Answer: (A)

A pond heat exchanger places a series of loops in a body of water to transfer heat. The water serves as the heat-transfer medium, and its relatively stable temperature plus good thermal conductivity help the circulating fluid in the loops efficiently absorb or release heat as it moves. This setup is typically simple and cost-effective when a suitable pond exists, since you can lay the loops in the water and run the fluid through a heat pump system connected to the building. In contrast, vertical loops go down into boreholes, horizontal loops are buried in shallow trenches in the ground, and a soil heat exchanger is installed entirely in the earth rather than in water. These options rely on soil or rock rather than a water body.