Wolf COB Technical Manual And Installation Instructions page 17

Example:
3062547_201802
11 Information on water treatment
Limits in relation to specific system volume V
(V = system volume / max. Rated heating output
A
conversion, total hardness: 1 mol/m³ = 5.6 °dH = 10°fH
V ≤ 20 l/kW
A
Total hardness/
Conductivity
total alkaline earths
[kW] [°dH] [mol/m³] C [µS/cm]
1 ≤ 50 ≤ 16,8 ≤ 3,0
2 50-200 ≤ 11,2 ≤ 2
The total amount of fill and top-up water over the life cycle of the boiler must not exceed three times the nominal volume of the
heating system.
According to VDI 2035, in systems with multiple boilers, use the maximum rated heating output of the smallest heat source
1)
High salinity < 800 µS/cm Low salinity < 100 µS/cm
2)
< 0.11°dH recommended standard; permissible up to limit of < 1°dH
3)
System with a COB-20 system volume = 800 l
Total hardness of untreated potable water = 18°dH
V = 800 l / 20 kW = 40 l / kW
A
Because the specific System volume V
of < 50 kW, the fill and top-up water must be in the range of 2 to 11.2°dH. If the total
hardness of the untreated potable water is too high, some of the filling and top-up water
must be desalinated.
A% desalinated water must be added.
A = 100% - [(C -0.1°dH) / C
max
C : Maximum permissible total hardness in °dH
max
C : Total hardness of untreated potable water in °dH
DHW
A = 100% - [(11.2°dH - 0.1°dH) / (18°dH - 0.1°dH)] x 100% = 38%
38% of the filling and top-up water must be desalinated.
V = 38% x 800 l = 304 l
treatment
At least 304 L of desalinated water must be added when filling the system.
The system can then be topped up with potable water.
V > 20 l/kW and < 50 l/kW
A
Total hardness/
Conductivity
2)
at 25°C total alkaline earths at 25°C
[°dH] [mol/m³] C [µS/cm]
< 800 ≤ 11,2 ≤ 2 < 800
< 100 ≤ 8,4 ≤ 1,5 < 100
is between 20 and 50 l/kW with a total output
A
- 0.1°dH)] x 100%
Potable water
A
)
1)
V ≥ 50 l/kW
A
Total hardness/
Conductivity
2) 2)
total alkaline earths at 25°C
[°dH] [mol/m³] C [µS/cm]
≤ 0,11 ≤ 0,02 < 800
3)
≤ 0,11 ≤ 0,02 < 100
3)
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