30 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 tubes must not exceed the maximum
value defined. If the removal 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 removal 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
6.4 Terminating the Flue
Before installing the boiler, determine what type of flue
termination is appropriate for the installation location and
situation. The subsections that follow describe some typical flue
configurations.
CAUTION
Minimum Clearance to Metering devices and Relief
equipment.
Maintain a minimum horizontal clearance of
1.22 m from electric meters, gas meters, regulators, and
relief equipment. Do not install the boiler above or below
electric meters, gas meters, regulators, or relief equipment
unless a 1.22 m horizontal clearance is maintained.