FLUE
The flue is a crucial element for the fireplace to work
properly. The cross-section of the flue must be as indicated
in the technical specifications for the fireplace. Every
fireplace must have its own flue, without any other
entrances (other fireplaces, boilers, stoves, etc.). The
dimensions of the flue are strictly proportional to its height
(measured from the fireplace to the base of the chimney
pot). To guarantee efficient updraught, the outlet of the
chimney pot must be twice the cross-section of the flue and
must meet the following requirements:
-it must prevent the escape of combustion products, be
impermeable and suitably insulated and lined
-it must be made from materials capable of withstanding
normal mechanical stress, heat, the action of the products
of combustion and any condensation
-it must be mainly vertical with an angle of deviation no
greater then 45°
-it must be kept at a suitable distance from any
combustible or inflammable material by means of an air
gap or suitable insulation
-it must have a circular inside cross-section, where at all
possible: square or rectangular cross-sections must have
rounded corners
-it must have a constant, free and independent inside
cross-section
-it must have rectangular sections with a max ratio of 1.5
between sides
We recommend installing a chimney pot with a shaped
cowl. If the flue is installed on the outside of the building,
this must be lined to prevent the fumes from cooling and the
consequent formation of condensation; the same goes for
the exposed section from the roof to the chimney pot.
We recommend using unlined stainless steel tubes inside
the hood for the connection between the fireplace and the
flue, whenever there are bends or deviations and to make
installation faster, easier and safer.
Elements made from non-combustible materials resistant to
the products of combustion and any condensation should
be used to fix the conduits.
The flue must not pass through areas where the installation
of combustion appliances is prohibited.
Flue sections must be installed to guarantee perfect
tightness during normal working conditions in depression.
Horizontal sections should be avoided wherever possible.
In the case of fireplaces with flue outlets in the wall or
ceiling not perfectly in line with the outlet from the fireplace,
open bends at not more than 45° must be used for any
changes in direction.
In this case the flue must be fitted with a chamber for
collecting solid materials or eventual condensations: it must
be used for flue cleaning, thanks to an inspection air-tight
window easy to be open.
The use of downwards elements is absolutely forbidden.
The flue must allow for recovery of any soot or be easy to
sweep. It is absolutely forbidden to pass other conduits (for
air or plant) inside the flue, even if oversized.