Pond / Lake Loop
Pond or lake loops may indeed be the best system available. Pond loops use coils
of polyethylene piping submerged into a pond or lake. They have the benefit of low
installation costs in addition to the benefits of a closed loop. Also, pond and
lake loops typically have more mild operating temperatures. Pond loops are also
in widespread use in the commercial market due to the compact size and low initial
cost compared to horizontal and vertical loops.