Baxi MULTIFIT Flue Systems - Twin Pipe Flue System Examples; Terminal Position - Separate Twin

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© Baxi Heating UK Ltd 2011
Twin Pipe Flue System Examples
FLUE OPTIONS
The MAXIMUM total
equivalent length is stated
in the Installation &
Servicing Instructions
supplied with
each boiler.
1m Min
to
15m Max
The total equivalent
length for this example
is = 6.5 metres.
1m extension
135°bend
91.5°bend
1m
0.25m
0.5m
5
2
2
5.0m
0.5m
1.0m
AIR DUCT
N
o
of
fittings/pipes
Sub total
Equivalent
Length Value
Equivalent Length Air Duct = 6.5m
1m extension
135°bend
91.5°bend
1m
0.25m
0.5m
5
2
2
5.0m
0.5m
1.0m
EXHAUST DUCT
N
o
of
fittings/pipes
Sub total
Equivalent
Length Value
Equivalent Length Exhaust Duct = 6.5m
View
of
Outside
Wall
Fixed Flue
Terminal position
Exhaust
Possible Air Terminal positions
Air
AirAir
Mini Terminal Clearances
Flue
Clearance
Zone
Exhaust
Air
Air Air
Air Exclusion
Zone
Terminal Position - Separate Twin
1. Both terminals must be on the same wall. It is also permissible to situate
the air inlet terminal in a ventilated uninhabited void or compartment (e.g.
loft space)
2.The terminals must not be closer than 120mm when measured between
the centrelines (Fig. A).
3. If this distance is up to 300mm the flue outlet duct must protrude
200mm from the wall face. The air inlet must protrude 60mm (Fig. A).
4. When the distance between centrelines is greater than 300mm the flue
outlet duct must protrude 100mm and the air inlet 60mm (Fig. B).
5. When the air inlet terminal is situated in a ventilated uninhabited void or
compartment there must be at least 300mm from the floor of this space
to the terminal. No obstructions must be placed within a 300mm radius of
the terminal.
60mm
200mm
120mm to
300mm
60mm
100mm
Air Duct
Exhaust Duct
Air Duct
Exhaust Duct
Fig. A
Greater than
300mm
Fig. B