Measuring Vent Length; Terminating The Vent - Navien NCB-24LSWE Installation & Operation Manual

5.5 Measuring Vent 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 tyes of terminals (horizontal and vertical),
for both the coaxial removal system and the dual duct 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
Pipe Diameter
Type
(mm)
Ø60/100
Coaxial
Ø80/125
Dual Duct Ø80/80
Equivalent Length of Elbows and Adapters
Pipe Diameter
Type
(mm)
Adapter
Ø60/100 ->
Ø80/125
Coaxial
Ø60/100
Ø80/125
Dual Duct Ø80/80
Maximum
Orientation
Length (m)
Horizontal 20
Vertical 21
Horizontal 68
Vertical 70
Horizontal
110
Vertical
Equivalent
Elbow
Length (m)
- 0.5
45° 1.0
90° 1.3
45° 1.0
90° 2.2
45° 1.4
90° 2.2

5.6 Terminating the Vent

Before installing the boiler, determine what type of vent
termination is appropriate for the installation location and
situation. The subsections that follow describe some typical
venting 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.
Venting the Boiler 35