SOLARFOCUS octoplus, Руководство по установке

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Technical requirements
Installation manual octo
plus
7

Calculate at least a further 20 % for wire
mesh in the aeration cross-section.
Boiler output
[in kW]
Minimum area [in cm²] incl. 20%
Austria Germany Switzerland
Supply
air
Ex-
haust
air
Supply air/Ex-
haust air
Supply air
20 kW
>240 >216
>180 >206
25 kW >180 >258
35 kW >180 >361
50 kW >228 >515
70 kW >228 >721
90 kW >276 >927
130 kW >347 >252 >372 >1339
200 kW >533 >336 >540 >2060
400 kW >1067 >576 >1020 >4120
3.6 Room sealed operation (RS)

Room-sealed operation of the octo
plus
is op-
tional.
Basic information
In conventional boiler Installation rooms, the neces-
sary supply air openings from outdoors lead to un-
controlled heat loss. This is prevented by room-
sealed (RS) boilers, as the combustion air is drawn
in from outside in closed supply air lines directly into
the boiler and not in the installation room.
Length of the supply line
The standard intake line has a diameter of Ø80 mm
and is 1 m long (can be extended to a maximum of 3
m). To extend the line further (an additional length of
8 m is possible), the diameter must be increased to
Ø100 mm.
RS line integrated in chimney
The recommended variant: The intake air is taken in
from outside of the chimney pipe down to the boiler.
RS line outside of the chimney
- Fire-rated insulation with rockwool required if the
RS line passes through other rooms.
- Cold insulation of the RS line within building ele-
ments (wall, floor, etc.) required to avoid damage
to the building from condensate.
- Further information: standard EN 15287-2
Establishing the room-sealed connection 
33
3.7 Heating system fill-up water
In regard to the fill-up water quality, two key points
must be observed (in accordance with Guideline
VDI 2035):
- Avoiding scale buildup (limescale)
- Avoiding water-side corrosion (caused by oxygen
in the heating water)
The lowest possible corrosion acceleration rate of
the installed metallic materials is achieved by keep-
ing the circulation water in the correct pH range (8.2
to 9.5) and, at the same time, having the lowest level
of electrical conductivity possible (50 to 100
μS/cm).
3.7.1 Avoiding scale buildup
What is scale buildup?
Scale buildup is the formation of firmly adhering de-
posits on water-contacting walls of hot water heating
systems (e.g. the boiler heat exchanger surfaces).
This can subsequently lead to damage (stress
cracks in metal, leaks).
Causes of scale buildup
The cause of scaling is the presence of limestone in
the water.
The following calculation/table determines the total
permitted hardness of the fill-up water. If the value is
exceeded, the fill-up water must be treated, e.g. sof-
tened.
Calculation of the total permitted hardness of the
fill-up water
To use the table, the specific system volume for the
system must be determined:
System volume divided by total heat output results
in the specific system volume
1166 litres / 25 kW = 46.64 l/kW specific system
volume
Table: Total permitted hardness of the fill-up water
Total heat output
Specific system volume (VDI
2035)
< 20
l/kW
≥ 20 <50
l/kW
≥
50
l/kW
< 50 kW
≤ 16.8°dH ≤ 11.2°dH
< 0.11°dH
50 - 200 kW
≤ 11.2°dH ≤ 8.4°dH
< 0.11°dH
20 - 600 kW
≤ 8.4°dH
< 0.11°dH < 0.11°dH
> 600 kW < 0.11°dH < 0.11°dH < 0.11°dH
In our example: if the total hardness of the fill-up wa-
ter is more than 11.2 dH, then the fill-up water must
be treated.
3.7.2 Avoiding water-side corrosion
Corrosion is usually triggered by the available oxy-
gen in the water. This value can be brought into a
safe range with proper planning, design, installation