Kostrzewa Twin Bio Luxury Serie Manual De Uso página 58

4. Design guidelines
58
e. Flue system installation guidelines
THE FLUE SYSTEM MUST CONFORM TO THE RELEVANT STANDARDS
AND REGULATIONS.
The flue system removes flue gas from the boiler room to the atmosphere.
The flue system creates draught determined by:
• temperature gradient between the flue gas temperature and the
ambient temperature (difference in density and pressure)
• flue length
• flue shape (bends, inclination, draught breaker etc.)
• flue cross section
• flue diameter (flue diameter must correspond to the boiler's flue
connector diameter)
• flue internal surface roughness
• flue flow capacity
• flue gas tightness (seals, grouts etc.)
• flue thermal insulation
• changes in ambient conditions (temperature, pressure fluctuations due
to the air flow, roof shape, flue location in relation to building envelope
components etc.)
The diameter of a duct connecting the boiler with the flue must correspond to
the diameter of the boiler's flue connector. Do not use any reducing couplings
of the boiler's flue connector or the flue. A transition between the flue and
the duct may include a tee with a correct combination of diameters. The flue
design must guarantee that the flue gas temperature at the entire flue length
to the outlet is higher than the dew point of the flue gas from the boiler
(dry operation). The flue and the smoke ducts must be fitted with drains or
inspection holes with sealed doors and in case of wet flue gas also with a
condensate drain valve..
Guidelines:
• in the lower range of Compact Bio power the flue gas temperature may
fall below 100°C, and for that reason the boilers must be connected to
moisture resistant flues (acid proof liners - steel sheet, vitrified clay
recommended); if the boiler is not connected to the moisture resistant
flue, perform required calculations or use the existing flue data;
• the connection between the boiler's flue connector and the flue must be
insulated and as short as possible, slightly upwards without sharp bends
and a minimum number of bends.
• the smallest diameter or cross section of a natural draught flue and a
smoke duct must be min. 0.14 m, whereas the smallest diameter must
be min. 0.12 m if the steel liners are used;
• horizontal flue duct length must not exceed the effective flue height
or 7 metres
Experts in biomass heating
Tip:
• connect the flue ducts without any loads and stresses
• the flue must be opened upwards and lead horizontally at least
1 metre over the roof surface (with a rain cap)
• flue diameter must be selected in accordance with the flue liner
manufacturer's requirements
• estimate cross sectional area of a circular flue is calculated using
Redtenbacher's equation:
2,6Q
A =
n√h
where:
A =
przekrój komina [m ]
2
Q = boiler thermal power [kcal/h], (1 kcal/h = 1,163 W);
h = flue height, dependent of building height, [m].
The formula is the same for oil-fired boilers, only that it involves a
different factor (0.033)
n =
współczynnik liczbowy (dla drewna n=900,
dla gazu n =1800, dla koksu n =1600 )
CAUTION!
THE INSTALLED FLUE SYSTEM REQUIRES COMMISSIONING
AND INSPECTION OF THE FOLLOWING:
· FLOW CAPACITY
· GAS TIGHTNESS
· DRAUGHT
· CONNECTION AND CONFORMITY WITH THE DESIGN
· STANDARD HEIGHT ABOVE THE ROOF
· ENVIRONMENTAL PROTECTION STANDARD REQUIREMENTS
· INSTALLATION CONFORMITY WITH THE DESIGN
AND AS-BUILT DOCUMENTATION
· VALID CERTIFICATES FOR STRUCTURAL, INSULATION
AND MOUNTING MATERIALS USED FOR INSTALLATION.
THE DEVICE HAS TO BE COMMISSIONED BY AUTHORIZED
PERSONNEL WITH A REPORT.
Twin Bio Luxury User Manual – EN 03.17