Various types of collectors are available for brine-guided heat exchanger systems, but flat collectors are mainly used for pre-temperature control in ventilation systems: The flat collectors are laid in loops with a distance of at least 80 cm at a depth of about 0.80 -1.20 m, similar to underfloor heating. Since the brine is used as a heat exchanger, it is a hygienically perfect separation system in which no gradient is necessary. Depending on the nature of the soil, the yield is approx. 8-40 W/m. Since heat is extracted from the soil over a large area, this can result in the flowering period of plantings in the garden being delayed by up to 2 weeks.
All brine-guided systems work with a heat exchanger inside the device and therefore have separate circuits, which is why they have advantages over ground-air heat exchangers in terms of hygiene and the avoidance of radon accumulation. The disadvantage is that, depending on the size and installation depth of the collector, excavation is sometimes considerably more complex.
Soil surveys are necessary for all types of heat transfer from the ground in order to be able to determine the water content and the location of the groundwater.
Source: bauwion
