Measuring Vent Length; Terminating The Vent - Navien NFC-175 Installation & Operation Manual

5.3 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 lengths reduce according to
the number of elbows used, as shown in the following table:
Maximum
Vent Size
Length
2 in 60 ft (18 m)
3 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.
The maximum vent lengths at high altitudes are the
●
same as shown in the table above.

5.4 Terminating the Vent

Before installing the boiler, 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 (Sch 40 - UL 1738/ULC S636):
●
2 in Vent Kit
3 in Vent Kit
Maximum
Equivalent Length
# of Elbows
Reduce the
maximum vent
length accordingly
for each elbow used:
Each 90° elbow
●
6
equates to 8 linear
feet of vent
Each 45° elbow
●
equates to 4 linear
feet of vent
Reduce the
maximum vent
length accordingly
for each elbow used:
Each 90° elbow
●
8
equates to 5 linear
feet of vent
Each 45° elbow
●
equates to 3 linear
feet of vent
IPEX Low Profile Termination Kit:
●
2 in Low Profile Vent Kit #196984
3 in Low Profile 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 are approved for
use 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)
The following stainless steel (AL29-4C) vent components are
approved for use as terminations:
Duravent FasNSeal®
FSELB9003 (3" 90° Elbow)
FSELB8803 (3" 88° Elbow)
FSELB4503 (3" 45° Elbow)
FST3 (3" Tee)
FSBS3 (3" Birdscreen)
Heat Fab Saf-T Vent® EZ Seal
9314(LR) or 9314TERM (3 " 90° Elbow)
9311 (3" 45° Elbow)
9390TEE (3" Tee)
9392 (3" Birdscreen)
Only the termination models listed above are
Note
●
approved for use with this appliance.
Only terminations of the same manufacturer as the
●
vent system must be used.
Refer to the vent manufacturer's instructions for
●
detailed installation procedures and guidelines.
Venting the Boiler 57