Baxi MULTIFIT Flue Systems - Flue Length Calculations and 80;125 System; Equivalent Length Calculation for Concentric Flues; 80;125 Flue System Adaptor Installation

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© Baxi Heating UK Ltd 2011
Y
X
Y
X
Y
X
C 0.5m
Total Equivalent
Length
Roof
Terminal
Roof
Terminal
A 1m
B 1m
C 0.4m
Roof
Terminal
A 0.7m
B 0.3m
This bend is equivalent to
1 metre
Total Equivalent Length =
A+B+C+1x90°Bend
All vertical and angled runs must be included,
measured from the boiler adaptor (point X) to the
joint with the flue terminal (point Y). One 93° bend
or two 135° bends can be included without
reduction of the flue length.
If further bends are required the flue
length must be reduced by the following
amounts:-
1 metre for each 93° bend
0.5 metre for each 135° bend
The MAXIMUM total
equivalent length is stated in
the Installation & Servicing
Instructions supplied with each
boiler.
X
Y
extensions
135°bend
93°bend
Actual Length
0.5m
1m
3 (A+B+C)
2*
0
1.4m
0
0
CONCENTRIC FLUE
N
o
of
fittings/pipes
Sub total
Equivalent
Length Value
Equivalent Flue Length = 1.4m
*Up to 2 x 135°bends are allowed without
affecting the calculation
extensions
135°bend
93°bend
Actual Length
0.5m
1m
3 (A+B+C)
0
2*
2.5m
0
1m
CONCENTRIC FLUE
N
o
of
fittings/pipes
Sub total
Equivalent
Length Value
Equivalent Flue Length = 3.5m
*1 x 93°bends are allowed without affecting the
calculation
Boiler Adaptor
80/125 Adaptor
Securing Screw
For Use With Flue Group
Ø80/125 Flue Systems
Ø80/125 FLUE SYSTEMS
The adaptor shown is available separately for
vertical flue applications. (It is included with
the 80/125 Horizontal Flue Kit).
Apply lubrication and ensure that the 80/125
adaptor is fully engaged in the boiler adaptor.
Secure with the screws supplied with boiler.
G