Category III or IV Installation of Vent/Air Piping
Category III or IV - Multiple Installation - Thru the
Roof
1.
On installations of multiple MODULATING DELTAS,
terminate each vent pipe as described in this manual.
2. The roof penetration of the vent piping should be a
minimum 18 inches from the adjacent vent pipe of
the other appliance for installations in the U.S. as
shown in Fig. 16. For installations in Canada, pro-
vide clearances as required by CSA B149.1 or
149.2.
12" above roof
or projected
snow line
18
" M
in.
Rain Cap
Vent Termination
A
n
y
p
o
rt
io
n
o
f
th
e
b
u
ild
in
g
o
r
ro
o
f.
10
Ft.
M
in.
Category III or IV- Multiple Thru The
Roof Termination
Fig. 16:
Category III or IV - Horizontal
Installation of the vent and combustion air pip-
ing must comply with local codes and require-
ments and with the National Fuel Gas Code
NFPA 54, ANSI Z223.1 for installations in the U.S.
or CSA B149.1 or B149.2 for installations in
Canada.
For direct vent (sidewall) installations in the
Commonwealth of Massachusetts, the installer
must comply with the additional requirement
outlined on pages 33 and 34.
A gas vent extending through a sidewall should
not terminate near an adjacent wall or below any
building extensions such as roof eaves, bal-
conies or decks. Failure to comply with the
required clearances could result in severe per-
sonal injury, death or substantial property dam-
age. The installer can vent horizontally with a
single pipe as shown in Fig. 17 page 26 and
snorkel up outside the building a maximum of
36” as shown in Fig. 17A page 26.
WARNING
NOTICE
NOTICE
25
