40
INSTALLATION
2.10
Neutralization of the condensate
To correctly eliminate the combustion condensate, check if the
condensate needs to be neutralized using a designated acces-
sory.
− For systems with a nominal heat input greater than 200
kW, the condensate always needs to be neutralized
− For systems with a nominal heat input greater than 35
kW but less than 200 kW, the selection and evaluation
criteria is provided in the figure below
0
1
2
3
4
5
6
7
8
9
10
0
10
20
30
40
50
60
70
80
90
100
Number of apartments
Number of occupants
Generator power in kW
0
50
75
35
125 150 175 200
100
Neutralization not
required
Neutralization
required
Example 1
Example 2
Example 1
For a residential building with 4 apartments, a 75 kW condens-
ing boiler needs to be installed. The 4 apartments / 75 kW inter-
section point is within the range "neutralization not required",
therefore the condensate does not need to be neutralized.
Example 2
For an office block with 45 users, a 160 kW condensing boiler
needs to be installed. The 45 users / 160 kW intersection point is
within the range "neutralization required", therefore the con-
densate needs to be neutralized.
In the case of residential applications, reference must be made
to the number of apartments served by the system, while in the
case of non-residential applications, reference must be made to
the number of users.
In the case of mixed applications, the number of apartments
must be converted into equivalent users, or conversely, accord-
ing to the alignment of the two vertical axes, therefore refer only
to one axis (for example, 2 apartments equate to 20 users).
9
The condensate drainage system must be sized and installed
to ensure correct elimination of the effluents produced by
the appliance and/or by the evacuation system of the com-
bustion products in any and all operating conditions.
2.10.1
Water quality requirements
It is ABSOLUTELY NECESSARY to treat the water system in order for
the heat generator to work properly and to guarantee its service
life, as well as that of all its components. This not only applies
to jobs carried out on existing installations but also on new in-
stallations.
Sludge, lime-scale and pollutants contained in the water can
cause permanent damage to the heat generator, also within a
short time and notwithstanding the quality standards of the
materials used.
Contact the Technical Assistance Service for any further informa-
tion on type and use of additives.
The heat transfer fluid (water) for the central heating circuit must
conform to the quality parameters given in the following table:
Parameters
Value
Unit
General
characteristic
Colourless, without
sediment
PH value
Min. 6.5; Max. 8
PH
Dissolved oxygen
< 0,05
mg/l
Total iron (Fe)
< 0,3
mg/l
Total copper (Cu)
< 0,1
mg/l
Na2SO3
< 10
mg/l
N2H4
< 3
mg/l
PO4
< 15
mg/l
CaCO3
Min. 50 ; Max.150
ppm
Trisodium
phosphate
None
ppm
Chlorine
< 100
ppm
Electrical
conductivity
<200
microsiemens/cm
Pressure
Min. 0.6; Max. 6
bar
Glycol
Max. 40% (only
propylene glycol)
%
9
All data in the table refer to water contained in the system
after 8 weeks' operation.
9
Do not use excessively softened water. Excessive water sof-
tening (total hardness < 5° f) results in corrosion due to con-
tact with metal elements (pipes or thermal module com-
ponents)
9
Immediately repair any leaks or drips that could result in air
entering the system
9
Excessive pressure fluctuations can cause stress and fatigue
to the heat exchanger. Keep the operating pressure con-
stant.
9
Water used to fill a system for the first time and water used
to top it up must always be filtered (using synthetic or metal
mesh filters with a filtration rating of no less than 50 mi-
crons) to prevent sludge from forming and triggering de-
posit corrosion.
9
If oxygen enters a circuit continuously or even intermittently
(e.g. in under-floor heating systems whose pipes are not
protected by impermeable synthetic sheaths, in circuits with
open expansion vessels, or in circuits that require frequent
top-ups) always separate the boiler’s water circuit from the
central heating circuit.
To sum up, in order to eliminate contact between air and water
(and to prevent the latter from becoming oxidized), it is neces-
sary:
− that the expansion system be a closed vessel, correctly
sized and with the correct pre-loading pressure (to be
regularly checked);
