Dimplex AP SVT, Installation And Operating Instructions Manual

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www.dimplex.de GB-7
English
6
The permissible total pipe lengths and the required cross-sec-
tions of the pipework for flow and return between the heat pump
and the brine manifold/collector must be dimensioned according
to the project planning manual.
The collector, manifold and de-aeration fittings must be installed
at the highest point in the system if possible. Use of a permanent breather directly on the brine manifold and/
or collector is not recommended, as this will stick together within
a very short period of time due to the water/monoethylene glycol
mixture, and correct functioning will no longer be possible. De-
aeration of the brine circuit is ensured using a high-capacity
breather (Spirovent) in the return from the brine manifold to the
heat pump (part of the SZB brine accessory package).
Fig. 5.8: Brine circuit with high-capacity breather and/or micro-bubble
separator (Spirovent)
The system is filled via the filling and drain cocks, which are part
of the AP SVT and AP SVT16 connection packages. These must
be mounted on the brine manifolds and closed off using the end
caps included in the scope of supply after the system is filled with
the water/monoethylene glycol mixture.
All clamping ring fittings on the brine manifolds must be re-tight-
ened after the system has been pressure-tested! If the brine
manifolds are installed in a building, these components must also
be insulated with steam-resistant material.
6 Brine fluid
Antifreeze should be added to the water on the heat source side
to prevent frost damage to the evaporator of the heat pump.
Frost protection between -14 °C and -18 °C is required for pipe
coils buried underground due to the temperatures that may occur
in the refrigerating circuit of the heat pump. A monoethylene gly-
col-based antifreeze is used. The brine concentration for installa-
tion underground must range from 25 % to a maximum of 30 %.
NOTE
The pressure drop of an antifreeze/water mixture (25 %) is 1.5 or 1.7 times
higher than that of pure water (Fig. 6.1 on page 7 / Fig. 6.2 on page 7),
whereas the capacity of many circulating pumps sinks by approximately
10 % (take the pump dimensioning into consideration).
Fig. 6.1: Freezing curve of monoethylene glycol/water mixtures in
relation to the concentration
Fig. 6.2: Relative pressure drop of monoethylene glycol/water mixtures in
comparison to water in relation to the concentration
at 0 °C and - 5 °C
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