Installation manual

76
3.2.6
3.2.6 Standard dimensions of ground heat collectors.
The data in the dimensioning table Table 3.3 on p. 77 is based on
the following assumptions:
 PE pipe (brine circuit): pipe DIN 8074
32 x 2.9 mm – PE 80 (PN 12.5)
 PE feeder pipe between the heat pump and the brine circuit
according to DIN 8074:
 Nominal pressure PN 12.5 (12.5 bar)
 Specific abstraction capacity of the ground 25 W/m
2
 Brine concentration: minimum 25% to maximum 30%
antifreeze (glycol-based)
 Pressure expansion vessel: 0.5 bar admission pressure
NOTE
The dimensioning of the brine circulating pump is only valid for lengths
of up to a maximum of 100 m and the given number of brine circuits!
An increase in the number of brine circuits and a reduction in the
run lengths does not have a critical affect on the pressure drops
if all other parameters remain the unchanged. For varying
framework conditions (e.g. the specific abstraction capacity,
brine concentration), the total permissible pipe length for the flow
and return flow between the heat pump and the brine circuit
manifold must be dimensioned again.
The quantity of antifreeze listed in Table 3.1 on p. 73 is based
upon the given wall thicknesses. The amount of antifreeze
should be increased for smaller wall thicknesses to maintain the
minimum brine concentration of 25%.