Navien NPE Installation & Operation Manual page 43

Flexible Vent Systems (Polypropylene and Stainless Steel)
Only VERTICAL installations are allowed.
Note
Horizontal terminations are prohibited.
The use of proper adapters and supports are required
to fully complete the installation.
The following table lists the flexible vent models that are approved
for use with this appliance in addition to the maximum allowable
vent lengths for the desired vent system.
Vent
Model Type
Centrotherm
Dia.
Innoflue Flex*
2 in 50 ft
NPE-
150/180/210
3 in 100 ft
2 in n/a
NPE-240
3 in 100 ft
* List of approved materials can be found on page 39.
Only the flexible vent models listed above are approved for use
with this appliance.
All flexible vent pipe must be installed VERTICALLY through the
roof. No horizontal terminations are permitted.
Use a 2 in snap fit coupler or the InnoFlue® Single Wall
Residential vent pipes to connect the InnoFlue® Flex 2 in vent
pipes to the exhaust.
After installation, ensure that the vent system is tightly sealed at
the joints.
All installation using the fl exible vent materials must be in
INDIRECT VENTI NG only.
Refer to the manufacturer's literature for detailed information
and guidelines.
Flexible PP Flexible SS
Duravent Duravent
Polypro Flex* FasNSeal Flex*
n/a 35 ft
n/a n/a
n/a 35 ft
n/a n/a
Outdoor Installation
Outdoor installation should only be considered in mild climates.
Freezing temperatures or contaminated air can damage the
water heater. When installing the water heater outdoors, maintain
clearances from building openings, as described in the "Non-Direct
Venting (Single Pipe)" section on page 37. Outdoor installation
areas should be in an open, unroofed area and should allow for the
following minimum clearances from the water heater:
Top
Intake Air
Back
Side
Bottom 12 in
Back 0.5 in
Sides 3 in
Front 24 in
Top 36 in
When installing a water heater outdoors, follow these guidelines:
The Navien Outdoor Vent Kit must be used to ensure proper
operation of the water heater.
Ensure that there is plenty of clearance around the air intake and
that it is adequately protected to prevent any debris, liquids, or
flammable gases from entering the air intake.
If the water heater is installed under an eave, maintain a
clearance of 3 ft or more from the eave to the top of the water
heater vent terminals.
Exhaust Gas
Side
Front
Bottom
Installing the Water Heater 43