Brine Circuit - ECOFOREST AU12 Manuel D'installation

3.2. Brine circuit

The geothermal heat pumps of the ecoGEO Basic and ecoGEO Compact range can operate with outdoor air as the only heat source,
replacing the geothermal collector with one (A) or more AU12 aerothermal units (B). They can also operate as a hybrid system that
uses outdoor air and the earth as heat sources by combining one or more AU12 units with a geothermal collector (C).
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B)
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C)
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Figure 3.1.Options for connecting the brine circuit using AU12 aerothermal units.
Aerothermal brine systems (Diagrams A and B)
The brine system of the heat pump is connected directly to the AU12 unit so the antifreeze mixture flows through a closed circuit,
absorbing energy from the outdoor air when it passes through the AU12 unit and yielding it in the heat pump evaporator.
Aerothermal brine systems with more than one AU12 unit must be connected in parallel, so the flow rate through each one is
similar. The connection should use a reverse return or a collector.
Hybrid brine systems (Diagram C)
In hybrid brine installations, the aerothermal collector and the geothermal collector must be connected in series so the antifreeze
mixture circulates first through the aerothermal collector and then through the geothermal collector. On the other hand, on-off 3-
way valves must be installed between drive and return for each collector to bypass the collector so the antifreeze mixture can
absorb heat from the outdoor air, the earth or both. The heat pump automatically selects the most efficient heat source,
depending on the percentage of energy absorbed from each.
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AU12 Installation Manual and Technical Service
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