Immergas NIKE Mini 28 Manual De Instrucciones página 88

1.4 Room ventilation.
The room where the boiler is installed must have at least as much incoming
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air flow as that required for regular combustion and room ventilation. The
natural air flow must occur directly through:
- permanent apertures made in the walls of the room being ventilated, and
TR opening outwards;
- single or multiple ventilation ducts.
Ventilation air must be drawn directly outside, in a zone away from sources
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of pollution. Natural air flow may also be provided indirectly with ventila-
tion air drawn from adjacent rooms. For further details regarding ventila-
tion of rooms follow the procedures prescribed by the regulations.
Apertures in exterior walls of the room being ventilated. These apertures
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must:
- have a net total section of 6 cm
with a min. of 100 cm
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- be made in such a way that the apertures, both inside and outside the
wall, cannot be obstructed;
- be located near floor level, and if this is not possible, the section of the
apertures must be increased by at least 50%.
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Single ventilation ducts. If the combustion air is to be supplied through
ducts, these must comply with the applicable technical standards.
Collective ventilation ducts. The combustion air may also be supplied
through multiple ducts, provided these comply with current technical
standards.
Indirect natural ventilation. Air flow can also be obtained from an adjoin-
ing room, provided that:
- the adjoining room has direct ventilation, conforming to that previously
specified;
- only appliances connected to exhaust ducts are installed in the room
being ventilated;
- the adjoining room is not a bedroom or does not form a common part
of the building;
- the adjoining room is not a place with fire hazard, such as a depot, garage,
combustible fuel storage room, etc.;
- the pressure in the adjoining room is lower than the room being ventilated
as a result of effect of counter-draught (counter-draught can be caused by
the presence in the room, of another appliance operating on any type of
fuel, or a fireplace, or any kind of suction device, for which an air inlet
has not been provided);
- the airflow from the room adjoining that being ventilated can flow freely
through permanent apertures of overall net section not less than that
specified in the standard.
These apertures can also be obtained by increasing the gap between door
and floor.
Removal of stale air. In rooms where gas appliances are installed, in ad-
dition to the introduction of combustion air, stale air may also have to be
evacuated and replaced by more fresh air. This ventilation must comply
with the provisions of current technical standards.
1.5 Flues.
Gas-fired appliances provided with connection for a flue must have a direct
connection to an efficient chimney or flue.
Only if there is no flue or chimney, may fumes be discharged directly to the
outside, provided this is done in accordance with the applicable standards
Connection to a chimney or flue. The appliance is connected to a chimney
or a flue via a fume duct.
In the case of connection to an existing flue, this must be perfectly clean, because
any eventual deposits detaching from the walls during operation could obstruct
the passage of fumes, thus causing extremely dangerous situations for the user.
The fume duct must be connected to the chimney or the flue in the same
room where the boiler is installed or at the very least in an adjoining room,
and must:
- be sealed and made from material ensuring lasting resistance to normal
mechanical stress, heat and action of fumes and condensation. Regardless
of the external ambient conditions, the temperature of the fumes at any
point in the flue must be above dew point;
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2
for every kW of installed heating power,
2
;
- be tightly sealed at the connections; any materials used for this purpose
must be heat and corrosion resistant;
- be in view, easy to disassemble and installed in such a way as to allow
normal thermal expansion;
- appliances with vertical discharge must have a vertical section of not less
than two diameters in length, as measured from the flue connection;
- after the vertical section, they must run upwards with a minimum incline
of 3% for the entire remaining length. The sub-horizontal part must not
be longer than 1/4 the effective height H of the chimney or the flue and
in any case must not be longer than 2500 mm (see figure), subject to
verification according to the general calculating method as per standards
UNI 9615/90.
- it must have no more than three changes in direction, including the
connection to the chimney/flue, made with internal angles greater than
90°. Changes in direction must only be made using curved elements;
- the axis of the inlet terminal must be perpendicular to the opposite in-
side wall of the chimney/flue. There must a tight seal at the connection
between the flue duct and the chimney/flue, without parts protruding
inside the flue;
- it must have, for its entire a length, a section of not less than that of the
appliance flue connection. If the diameter of chimney or flue is less than
that of the fume duct, a tapered connection must be made at the inlet;
- it must not have cutoff devices (shutters). If these devices are already
fitted, they must be eliminated;
- it must be at least 500 mm away from combustible or flammable materi-
als, if this distance cannot be maintained a special heat protection must
be provided;
- it must receive combustion gases from one appliance only; a maximum
of two appliances can be connected to the same flue, provided that:
- the two appliances have a heating power differing by no more than
30% and are installed in the same room;
- the section of the part of the flue duct shared by both appliances is
at least equal to that of the appliance of greater power multiplied by
the ratio Pc/P1, Pc being the sum of the heating powers of the single
appliances and P1 the higher heat output;
- two appliances with the limitations given in the previous point, can also
be connected directly to the same chimney or flue, in which case the
vertical distance between the axes of the inlet orifices must be at least
250 mm (see figure);
- the same flue must not be used to convey combustion products of gas-
fired appliances and the fumes from hoods over cooking appliances.