1
91.7.1 - GB/IE
InstructIons pErtaInInG to thE InstaLLEr
concentric flue
This type of duct allows to emit exhaust gases and to draw combustion air from outside the building.
The 87° coaxial bend allows to connect the boiler to a flue-air duct in any direction as it can rotate through
360°.
If the flue outlet is placed outside, the flue-air ducting must protrude at least 18mm out of the wall to allow
alluminium weathering tile to be fitted and sealed to avoid water leakages. If the terminal is below 2m then a
terminal gaurd is required.
Ensure a minimum downward slope of 3° towards the boiler.
A 87° bend reduces the total flue length by 1 metre.
A 45° bend reduces the total flue length by 0.5 metre.
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Wh50
Ø80/125
9 m
8 m
7 m
6 m
Wh0
Ø80/125
9 m
8 m
7 m
6 m
Wh70
Ø80/125
9 m
8 m
7 m
6 m
HORIZONTAL CONCENTRIC FLUES
Boiler
Flue size
number of Bends 90°
1
Wh50
Ø80/125
9 m
8 m
7 m
6 m
Wh0
Ø80/125
9 m
8 m
7 m
6 m
Wh70
Ø80/125
9 m
8 m
7 m
6 m
vERTICAL CONCENTRIC FLUES
Boiler
Flue size
number of Bends 90°
1
Wh50
Ø80
59,5 m
59 m
58,5 m
58 m
Wh0
Ø80
59,5 m
59 m
58,5 m
58 m
Wh70
Ø80
59,5 m
59 m
58,5 m
58 m
CONvENTIONAL FLUE
Boiler
Flue size
number of Bends 90°
