Navien NPE Installation & Operation Manual page 40

3.6.3 Measuring Vent Length
The maximum vent length when using 2 in exhaust ducts is 60
ft (18 m). The maximum vent length when using 3 in vent ducts
is 150 ft (45 m). The intake duct length may be identical to the
exhaust duct length. Maximum vent length is reduced according
to the number of elbows used, as shown in the following table:
Vent Max. Max. # of
Size Length Elbows
60 ft
2 in 6
(18 m)
150 ft
3 in 8
(45 m)
The Maximum Length does not include any elbows.
Note
The use of a PVC or polypropylene concentric
termination counts as 5 linear feet (1.5 m) of vent.
The maximum vent lengths at high altitudes are
the same as shown in the above.
40 Installing the Water Heater
Equivalent Lengths
Reduce the maximum vent
length accordingly for each
elbow used:
Each 90° elbow equates to
8 linear ft (2.4 m) of vent
Each 45° elbow equates to
4 linear ft (1.2 m) of vent
Reduce the maximum vent
length accordingly for each
elbow used:
Each 90° elbow equates to
5 linear ft (1.5 m) of vent
Each 45° elbow equates to
3 linear ft (0.9 m) of vent
3.6.4 Terminating the Vent
Before installing the water heater, determine what type of vent
termination is appropriate for the installation location and
materials. The subsections that follow describe some typical
venting configurations, but do not include all possible options.
The following PVC vent terminations are approved for use with
this appliance:
PVC Concentric Vent Kit (ULC S636 required for Canada):
2 in Vent Kit
3 in Vent Kit
IPEX Low Prole Termination Kit:
2 in Low Prole Vent Kit #196984
3 in Low Prole Vent Kit #193985
The following polypropylene vent terminations are approved for
use:
Duravent PolyPro® Horizontal Concentric Termination Kit
2 in x 4 in Concentric Vent Kit #2PPS-HKL
3 in x 5 in Concentric Vent Kit #3PPS-HKL
Centrotherm Innoflue® Low Profile Termination Kit
2 in Vent Kit #ISLPT0202
3 in Vent Kit #ISLPT0303
Hart & Cooley Polyflue™ Horizontal Termination Kit
2 in Vent Kit #2PF-HCT
3 in Vent Kit #3PF-HCT
The following polypropylene vent components can be used as
terminations:
Duravent PolyPro®
2PPS-E90L or 3PPS-E90L ( 2" or 3" 90° Elbow)
2PPS-E45L or 3PPS-E45L ( 2" or 3" 45° Elbow)
2PPS-TL or 3PPS-TL (2" or 3" Tee)
2PPS-BG or 3PPS-BG (2" or 3" Birdscreen)
Centrotherm Innoflue®
ISELL0287 or ISELL0387 (2" or 3" 87° Elbow)
ISELL0245 or ISELL0345 (2" or 3" 45° Elbow)
IST02 or IST03 (2" or 3" Tee)
IASPP02 or IASPP03 (2" or 3" Birdscreen)
Hart & Cooley Polyflue™
2PF-90 or 3PF-90 (2" or 3" 90° Elbow)
2PF-45 or 3PF-45 (2" or 3" 45° Elbow)
2PF-T or 3PF-T (2" or 3" Tee)
2PF-HVST or 3PF-HVST (2" or 3" Birdscreen)
Z-Flex® Z-DEN S
2ZDE_87 or 3ZDE_87 (2" or 3" 87° Elbow)
2ZDE_45 or 3ZDE_45 (2" or 3" 45° Elbow)
2ZDTT or 3ZDTT (2" or 3" Tee)
2ZDES or 3ZDES (2" or 3" Birdscreen)