95c466b3__And_Cooling___Thermal_Systems__Advantages
[Geothermal Loop Type] Slinky Closed-Loop [Disadvantages] Greater pumping energy needed than for straight horizontal-loops; backfilling the trench while ensuring that there are no voids around the pipe coils is difficult with certain types of soil, and even more so with upright coils in narrow trenches than with coils laid flat in wide trenches. [Advantages] 
Slinky loops require less land area and less trenching than other horizontal-loop systems, and installation costs may be significantly less.
Geothermal Home Heating And Cooling - Thermal Systems
Advantages