Vertical Loops – Pipes are assembled into hairpin like heat exchangers and installed into bore holes drilled into the ground. Holes are usually drilled between 100′ and 300′ deep on 10′ centres.
The borehold is commonly filled with a bentonite grout surrounding the pipe to provide a thermal connection to the surrounding soil or rock to improve the heat transfer. Thermally enhanced grouts are available to improve this heat transfer. Grout also protects the ground water from contamination, and prevents artesian wells from flooding the property.
Vertical loop fields are typically used when there is a limited area of land available.