Navien NCB300-28K, Installation & Operation Manual

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40 Flue System
6.3 Measuring Flue Length
The gas removal and air intake systems may be oriented in any
direction (north, south, east or west). Some special components
such as elbows are used to help reach certain positions. Each
removal terminal kit includes an adapter for connection to the
boiler and a removal terminal.
The total length of the flue must not exceed the maximum value
defined. If the flue installation includes elbows while calculating
the total length you must take into account that each elbow has
a resistance equal to a specific linear Leq equivalent length (see
table).
There are two different types of terminals (horizontal and
vertical), for the coaxial flue system.
Carefully study the diagrams representing the different types of
removal and select the one that best suits the conditions of your
installation. To choose the removal accessories required for each
installation, see the list of accessories on the NAVIEN price list.
Maximum Total Length
Type
Pipe Diameter
(mm)
Orientation
Maximum
Length (m)
Coaxial
Ø60/100
Horizontal 8
Vertical 8
Ø80/125
Horizontal 27
Vertical 28
Equivalent Length of Elbows and Adapters
Type
Pipe Diameter
(mm)
Elbow
Equivalent
Length (m)
Coaxial
Adapter
Ø60/100 ->
Ø80/125
- 0.5
Ø60/100
45° 1.0
90° 1.5
Ø80/125
45° 1.0
90° 2.2
6.2.2 Vertical Coaxial Removal (Type C
33
)
Standard Removal System
Ø80/125 => Max. length: A = 28 m
Ø60/100 => Max. length: A = 8 m
A
A
Extended Removal System
Ø80/125 => Max. length: A+B-(1 x 45°elbow) = 28-1 = 27 m
Ø60/100 => Max. length: A+B-(1 x 45°elbow) = 8-1 = 7 m
A
B
Minimum 350 mm
Pipe Diameter
(mm)
Maximum
Length (m)
Elbow
Equivalent
Length (m)
Ø60/100 8
45° 1.0
Ø80/125 28