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COMPACT 24 BOILER
Chapter
4
USE AND MAINTENANCE MANUAL
page
15
Installation
Technical dept. - All rights reserved - Reproduction prohibited
4.3.
Boiler room
Make sure the room complies with the requirements and characteristics set out in the applicable regulations in
force. It is also necessary for the room to provide at least as much air as is required for regular combustion. It is
therefore necessary to make holes in the walls of the room, which comply with the following requirements:
Have a free cross-section of at least 6 cm
2
for every 1 kW (859.64 kcal/h). Nevertheless, the minimum
cross-section of the opening must never be less than 100 cm
2.
The cross-section can also be calculated
using the following ratios:
S = K * Q
≥
100 cm
2
Where “S” is expressed in cm
2
, “Q” in kW, “K” = 6 cm
2
/kW
The opening must be situated at the bottom of an external wall, preferably opposite the one where the
combustion gases are vented.
4.4.
Connection to the flue pipe
For the connection of the flue outlet pipe, local and national regulations must be observed (see Standards
UNI 7129 and UNI 10683).
A flue pipe must comply with the following requirements:
It must be made of waterproof material resistant to the temperature of the smoke and related
condensation.
It must ensure sufficient mechanical resistance and weak heat conductivity.
It must be perfectly sealed, to avoid the cooling of the flue pipe itself.
It must be arranged as vertically as possible.
Chimneys both old and new, built without observing the above specifications, may be conveniently
recovered by "intubating" the chimney itself. This means a metal flue shall be inserted inside the existing
chimney and the space between the metal flue and the chimney shall be filled with suitable insulation.
In order to prevent the wind from creating pressure areas around the chimney that prevail over the rising
force of the combustion gases, the outlet aperture must be positioned at least 0.5 metres above any
structure adjacent to the chimney itself (including the ridge of the roof) at least 8 metres away.
The flue pipe must have a diameter of no less than the boiler union; for flue pipes with a square or
rectangular cross-section, the internal cross-section must be increased by 10% compared to the boiler
union.
The useful cross-section of the flue pipe can be calculated using the following formula:
S = K x P/
√
H
S
ensuing section in cm
2
K
reduction coefficient: 0.045 for wood
P
boiler output in kcal/h
H
height of the chimney in metres, measured from the flame axis to the outlet of the chimney into the
atmosphere. When sizing the flue pipe, please take into account the actual height of the chimney in
metres, measured from the flame axis t the top, decreased by:
0.50 m for every change in direction of the union duct between the boiler and the flue pipe
1.00 m for every metre of horizontal development of the union itself.
