Wolf CGB-75 Installation And Operating Instructions Manual page 44

Example:
System with a 170 kW boiler;
system volume V = 4000 l;
System
V = 4000 l / 170 kW = 23.5 l/kW
A, specific
This is greater than 10 l/kW, therefore stage 3 must be se-
lected instead of stage 2. The fill and top-up water must be
in the range of 2 to 8.4 °dH.
If the total hardness of the untreated drinking water is too high,
some of the fill and top-up water must be desalinated.
A% desalinated water should be added:
A = 100% – [(C – 0.1 °dH) / (C
max
C maximum permissible total hardness in °dH
max
C total hardness of the untreated drinking water
Drinking water
in °dH
We recommend allowing for the expected top-up water during
the first fill. Untreated drinking water can then be added later.
V = A x (V
Treatment
In large systems in stage 4, the top-up water should not be
taken into account during the first fill.
V
Treatment
44
26. Technical information for water treatment
– 0.1 °dH)] x 100%
DHW
+ V )
System Top-up
= A x (V )
System
Example:
System output = 170 kW;
system volume V = 4000 l;
System
Volume of top-up water
V = 1000 l
Top-up
Total hardness of drinking water C
Maximum permissible total hardness C
System output = 170 kW;
system volume V = 4.000 l;
System
Volume of top-up water V
Top-up
VA spec = 4000 l / 170 kW = 23.53 l/kW
Total hardness of drinking water C
Maximum permissible total hardness C
Proportion of filling water to be treated:
A = 100% - [(8.4 - 0.1) / (18.5 – 0.1)] x 100% = 54.9%
54.9 % of the filling and top-up water must be desalinated.
V = 54.9% x (4.000 l + 1.000 l) = 2.746 l
Treatment
When filling the system, 2,745 l of desalinated water must
be added. The system can then be topped up to V max with
drinking water.
When topping up, it is important to check regularly that the
permissible total hardness is not exceeded.
= 18.5 °dH;
DHW
= 8.4 °dH
max
= 1000 l
= 18.5 °dH;
DHW
= 8.4 °dH
max
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