Metal-Fach SE MAX II, Technical And Operating Manual

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METAL-FACH Heating Technology
26
Chimney selection
In most cases, an approximate method or selection according to the chimney manufacturer's diagrams is
sufficient for chimney selection. In special cases (unfavourable pressure and temperature relationships, large
flue gas volume) chimneys are calculated according to the applicable standard. A low outlet flue gas
temperature at the nominal boiler output can cause damp flue gases, soot deposits, insufficient chimney
draught. This can lead to dampness and corrosion of masonry chimneys. The use of a chimney insert is
recommended:
●
In new buildings, a ceramic flue system resistant to condensation, thermally insulated and with a
condenser is recommended,
●
in existing buildings, it is recommended that the masonry chimney is upgraded with a stainless steel
chimney system (designed for solid fuel boilers) single or double wall.
Flue
The boiler is connected to the chimney by means of a flue and a flue pipe. The flue is made up of pipes and
fittings that are laid indoors. Flue pipes comply with the fire safety requirements for chimneys and are often
made of the same material as the main flue. Smoke ducts should be made of non-combustible products. Smoke
ducts or smoke duct cladding should meet the requirements of the Polish Standard for fire testing of small
chimneys. An enclosure of 12 cm thick solid brick, built with cement-lime mortar, with external plaster or
pointing is permitted. The joints should be as short as possible and laid with an upward slope to the chimney to
avoid heat loss and additional resistance. They must not be routed to other floors. Flue pipes should not be laid
in rooms where fireplaces cannot be installed, nor should they be placed in walls or ceilings. Due to the low
temperature of the flue gases, acid resistant or ceramic chimney liners should be used to protect the chimney
from damp and reduce draught. A distance of at least 6 m should be kept between the chimney and the nearest
edge of a tree crown.