Wolf COB - Page 17

17
3062547_201802
11 Informationonwatertreatment
Example:
LimitsinrelationtospecicsystemvolumeV
A
(V
A
=systemvolume/max.Ratedheatingoutput
1)
)
conversion,totalhardness:1mol/m³=5.6°dH=10°fH
Total
heating
output
V
A
≤ 20 l/kW V
A
> 20 l/kW and < 50 l/kW V
A
≥ 50 l/kW
Total hardness/
total alkaline earths
Conductivity
2)
at 25°C
Total hardness/
total alkaline earths
Conductivity
2)
at 25°C
Total hardness/
total alkaline earths
Conductivity
2)
at 25°C
[kW] [°dH] [mol/m³] C [µS/cm] [°dH] [mol/m³] C [µS/cm] [°dH] [mol/m³] C [µS/cm]
1 ≤ 50 ≤ 16,8 ≤ 3,0 < 800 ≤ 11,2 ≤ 2 < 800 ≤ 0,11
3)
≤ 0,02 < 800
2 50-200 ≤ 11,2 ≤ 2 < 100 ≤ 8,4 ≤ 1,5 < 100 ≤ 0,11
3)
≤ 0,02 < 100
The total amount of ll and top-up water over the life cycle of the boiler must not exceed three times the nominal volume of the
heating system.
1)
According to VDI 2035, in systems with multiple boilers, use the maximum rated heating output of the smallest heat source
2)
High salinity < 800 µS/cm Low salinity < 100 µS/cm
3)
< 0.11°dH recommended standard; permissible up to limit of < 1°dH
System with a COB-20 system volume = 800 l
Total hardness of untreated potable water = 18°dH
V
A
= 800 l / 20 kW = 40 l / kW
Because the specic System volume V
A
is between 20 and 50 l/kW with a total output
of < 50 kW, the ll 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 lling and top-up water
must be desalinated.
A% desalinated water must be added.
A = 100% - [(C
max
-0.1°dH) / C
Potable water
- 0.1°dH)] x 100%
C
max
: Maximum permissible total hardness in °dH
C
DHW
: Total hardness of untreated potable water in °dH
A = 100% - [(11.2°dH - 0.1°dH) / (18°dH - 0.1°dH)] x 100% = 38%
38% of the lling and top-up water must be desalinated.
V
treatment
= 38% x 800 l = 304 l
At least 304 L of desalinated water must be added when lling the system.
The system can then be topped up with potable water.