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reserve the right to make changes
Page 19 of 40
GEO 3 + GEO 6
System construction
Electrical installation/power supply (including safety switch) should be installed by an
authorised electrician.
Connect the unit according to the wiring diagram supplied.
Figure 71: Example of system design
Function of ground source heat system
The Geothermal heat pump GEO is designed for heating homes with low temperature heating sys-
tems with forward-flow temperatures of up to 45 °C, for example floor heating systems.
System components (function)
The ground source heat system obtains heat from the ground through the ground pipe loop (3).
The ground stores heat, which it accumulates from the sun in the summer and releases the heat to
the ground pipe loop (3) in the winter. The temperature in the water/antifreeze mixture (= brine);
from the ground pipes (1).
Brine to be protected against freezing form a freezing point of -20 °C to
-18 °C.
To exploit the heat energy in the brine, the system uses a heat pump to transfer energy
from a low temperature in the brine to a higher temperature in the central heating system. Circula-
tion pumps (8) maintain flow in both the ground pipe loop (3) and the central heating/floor heating
loop (10).
The heat pump consists of an evaporator (4), compressor (5), condenser (6) and an expansion
valve (7). These elements are connected and filled with a refrigerant in a closed cycle in a closed
system. The antifreeze in the ground source loop is heated by the ground and cooled in the evapo-
rator. After the evaporator the refrigerant is compressed in the compressor and the temperature
and pressure of the refrigerant are increased. In the heat exchange process in the condenser, the
refrigerant then releases heat energy to the central heating water, and the temperature of the cen-
tral heating water rises. After the condenser the refrigerant pressure is reduced in the expansion
valve, and the refrigerant continues into the evaporator where it cools the brine before flowing re-
turn into the ground pipe loop (2).
An auxiliary heating element (9) is installed in the central heating loop, which can supplement the
ground source loop in the event of particularly high heating demand.
