Measuring Vent Length; Terminating The Vent - Navien NHB Series Installation & Operation Manual

5.3 Measuring Vent Length

The maximum vent length when using 3 in exhaust ducts is 60 ft
(18 m). The maximum vent length when using 4 in vent ducts
is 150 ft (45 m). The intake duct length may be identical to the
exhaust duct length. Maximum vent lengths reduces according to
the number of elbows used, as shown in the following table:
Maximum
Vent Size
Length
3 in 60 ft (18 m)
4 in 150 ft (45 m)
The Maximum Length does not include any elbows.
Note
The use of a PVC or polypropylene termination kit
counts as 5 linear feet (1.5 m) of vent.
The use of a tee counts for the same equivalent
length as a 90° elbow for the vent size.

5.4 Terminating the Vent

Before installing the boiler, determine what type of vent
termination is appropriate for the installation location and
situation. Examples in this section describe typical venting
configurations, but they do not include all possible options.
The following PVC vent, terminations are approved for use with
this appliance:
PVC concentric Vent Kit (sch 40 - UL 1738/ULC S636):
3 in Vent Kit
4 in Vent Kit
IPEX Low Profile Termination Kit:
3 in Low Profile Vent Kit #196985
4 in Low Profile Vent Kit #196986
The following polypropylene vent terminations are approved for
use:
Duravent PolyPro Horizontal Concentric Termination Kit
3 in x 5 in Concentric Vent Kit #3PPS-HKL
4 in x 6 in Concentric Vent Kit #4PPS-HKL
Centrotherm Innoflue Low Profile Termination Kit
3 in Vent Kit #ISLPT0303
Hart & Cooley Polyflue Horizontal Termination Kit
3 in Vent Kit #3PF-HCT
4 in Vent Kit #4PF-HCT
58 Venting the Boiler
Maximum
Equivalent Length
# of Elbows
Reduce the
maximum vent
6
length accordingly
for each elbow used:
Each 90° elbow
equates to 5 linear
feet of vent
Each 45° elbow
8
equates to 3 linear
feet of vent
The following polypropylene vent components are approved for
use as terminations:
Duravent PolyPro®
3PPS-E90L or 4PPS-E90L (3" or 4" 90˚ Elbow)
3PPS-E45L or 4PPS-E45L (3" or 4" 45˚ Elbow)
3PPS-TL or 4PPS-TL (3" or 4" Tee)
3PPS-BG or 4PPS-BG (3" or 4" Birdscreen)
Centrotherm Innoflue®
ISEL0387 or ISEL0487 (3" or 4" 87˚ Elbow)
ISEL0345 or ISEL0445 (3" or 4" 45˚ Elbow)
IST03 or IST04 (3" or 4" Tee)
IASPP03 or IASPP04 (3" or 4" Birdscreen)
Hart & Cooley Polyflue™
3PF-90 or 4PF-90 (3" or 4" 90˚ Elbow)
3PF-45 or 4PF-45 (3" or 4" 45˚ Elbow)
3PF-T or 4PF-T (3" or 4" Tee)
3PF-HVST or 4PF-HVST (3" or 4" Birdscreen)
Z-Flex Z-DENS
2ZDE387 or 2ZDE487 (3" or 4" 90° Elbow)
2ZDE345 or 2ZDE445 (3" or 4" 45° Elbow)
2ZDTT3 or 2ZDTT4 (3" or 4" Tee)
2ZDES3 or 2ZDES4 (3" or 4" Birdscreen)
The following stainless steel (AL29-4C) vent components are
approved for use as terminations:
Duravent FasNSeal®
FSELB9003 or FSELB9004 (3" or 4" 90˚ Elbow)
FSELB8803 or FSELB8804 (3" or 4" 88˚ Elbow)
FSELB4503 or FSELB4504 (3" or 4" 45˚ Elbow)
FST3 or FST4 (3" or 4" Tee)
FSBS3 or FSBS4 (3" or 4" Birdscreen)
Heat Fab Saf-T Vent® EZ Seal
9314(LR) or 9314TERM (3" 90˚ Elbow)
9414(LR) or 9414TERM (4" 90˚ Elbow)
9311 or 9411 (3" or 4" 45˚ Elbow)
9390TEE or 9490TEE (3" or 4" Tee)
9392 or 9492 (3" or 4" Birdscreen)