8.0 Flue Options
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© Baxi Heating UK Ltd 2014
8.1 Horizontal Flue Systems
Concentric
The maximum equivalent lengths are 4m (horizontal) or
(vertical). Their lengths exclude the standard elbow and
flue/terminal assembly (horizontal) and terminal assembly
(vertical).
Any additional “in line” bends in the flue system must be
taken into consideration. Their equivalent lengths are:
Concentric Pipes: 45° bend 0.5 m
93° bend 1.0 m
NOTE: Flue length is measured from point X to Y as
shown.
IMPORTANT: All flue systems must be securely
supported at least once every metre. Suitable pipe
supports are available as accessories.
X
Y
X
Y
Plume Displacement 70/110 dia Kit
1M Extensions, 45° & 93° bends
are also available - see Section 9.0
NOTE: Horizontal flue pipes should always be installed with a 1.5° fall from the
terminal to allow condensate to run back to the boiler.
Y
X
This bend is equivalent to
0.5 metre
Total equivalent length (up to 4m) =
A+B+2x45°Bends
B
A
This bend is equivalent to
0.5 metre
Horizontal
Flue System Examples