© 2007-2008 Broseley Fires Ltd 12
22
FLUE AND CHIMNEY GUIDANCE
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This appliance must be installed into a
‘Class 1 Chimney’.
If there is no existing chimney, then an approved
solid fuel, factory built, prefabricated block type or a twin walled, stainless steel flue can be used. Get advice
from a qualified chimney engineer. Flue sharing is not allowed.
•
The minimum flue diameter for Inserto 80 & 100 must be Ø150mm and Ø125mm for the INSERTO 50.
•
If excessive draw is present, then a suitable ‘flue draught stabilizer’ should be fitted. See data table.
•
If the chimney suffers from down draught, then a special ‘anti-downdraught’ cowl will need to be fitted. In
exposed windy locations, a ‘stabilizing’ cowl may need to be fitted. The minimum cowl requirement that we
recommend, is a rain cowl with a bird guard.
•
To perform satisfactorily, the chimney height must not be less than 5 meters from stove to cowl. If there are any
bends in the flue, this minimum length will need to be increased by 1 meter for each bend.
•
The initial connection to the appliance will need to be 600mm vertical before any bend.
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A maximum of four 45 degree bends is allowed in any complete flue; from stove to cowl.
•
Adequate access for sweeping the flue, such as a soot door, must be provided.
•
Flue pipe should be fitted inside the flue pipe collar (spigot) to prevent creosote and condensates from running
down onto the top of the appliance.
(see specifications for exact collar sizes)
•
All flue pipe must be suitable for solid fuel (complies with latest European regs.) and fitted in accordance with
building regulations, whilst complying with current legislation and manufacturers’ instructions.
•
If a rear flue is able to be fitted, the horizontal length must be no longer than 150mm.
•
Mechanical ventilation in the same room as any solid fuel appliance must be avoided.
Further instruction on the installation of the ‘additional warm air vents’ can be found in chapter 22.
These allow the warm air to be piped into the room in which the appliance is sited. With the installation of the
deluxe ventilator kit; which comprises of a more powerful fan; the warm air can be vented further down the
additional warm air vents.
The natural up-draft on a chimney will depend on a number of factors. The chimney is one of the most important
parts of the installation; great care should be given to its design.
The draw of the chimney should be at least 12 Pa (1.2mm of a column of water). The measurement must always
be done when the stove is hot (producing nominal heat values). When the pressure exceeds 17 Pa (1.7mm of a
column of water) it will be necessary for the installation of a flue draft stabilizer. The flue draft measurement is
critical and MUST be measured. If incorrect, the appliance will NOT operate correctly and damage may occur.
22 A
LINING THE FLUE
An independently certified flexible metal liner can be used to reline a chimney. A chimney liner should be installed
in accordance with Building Regulations Part J, reference should also be made to the manufacturers instructions.
An insulated chimney is the most efficient and safe way to burn wood and coal. Tar deposits condense in a cool
chimney. An insulated chimney helps prevent these deposits. A standard, unlined chimney will gradually get
saturated in tar, this is a fire hazard. Tar stains may appear on the surface of the chimney breast inside the
property.
22 B
FLUE TERMINATION
The height and termination of the flue is an
important part of the installation and consideration
needs to be made to ensure that the flue is high
enough to create sufficient draft to clear the
products of combustion. The termination of the
flue outlet position which can meet the
requirements in common circumstances are
shown in Document J. If there are unusual
circumstances that will affect the efficient and safe
removal of the products of combustion; the height
and/or the separation distances shown in
Document J may need to be increased and a
special cowl may need to be fitted to help correct
the issue.
FIG. 8
Wind induced downdraft
from nearby tall trees
WIND DIRECTION