Heat pumps
...ll environmental cost, and highest "source performance." Closed Lake or Pond Loop Because water transfers heat much better than soil, closed loops can also be sunk in lakes or ponds. The coiled pipe can be placed on the bottom of the pond or lake, where it transfers heat to or from the water. A 1/4 to 1/2-acre, 6-foot-deep pond is acceptable. Pond or lake loops often require less excavation than vertical and horizontal loops. Therefore, they are often less expensive to install. Closed Horizontal Loop If adequate land is available, horizontal loops can be installed. Loops are placed in trenches four to six feet deep. One layer or multiple layers of pipe can be laid in a trench with one foot of soil backfilled between the layers. Closed Vertical Loop If land area is limited, closed loops can be inserted into vertical bore holes (as pictured in animated image on previous page). Holes are drilled to a depth of about 125 to 200 feet per ton of unit capacity. U-shaped loops of pipe are inserted into the holes. The holes are then backfilled with a sealing solution. Open loop-Well system If an abundant supply of good, quality well water is available, an ...