29
6
. Un
i
n
su
l
a
t
e
d
si
n
g
l
e
-
wa
l
l
m
e
t
a
l
ve
n
t
p
i
p
e
sh
a
l
l
n
o
t
b
e
u
se
d
f
o
r
ve
n
t
i
n
g
t
h
i
s a
p
p
l
i
a
n
ce
wi
t
h
o
u
t
i
n
su
l
a
t
i
o
n
.
7
. Th
r
o
u
g
h
-
t
h
e
-
w
a
l
l
ve
n
t
s f
o
r
C
a
t
e
g
o
r
y I
a
n
d
I
I
I
a
p
p
l
i
-
a
n
ce
s sh
a
l
l
n
o
t
t
e
r
m
i
n
a
t
e
o
ve
r
p
u
b
l
i
c wa
l
kwa
ys o
r
o
ve
r
a
n
a
r
e
a
wh
e
r
e
co
n
d
e
n
sa
t
e
o
r
va
p
o
r
co
u
l
d
cr
e
a
t
e
a
n
u
i
sa
n
ce
o
r
h
a
za
r
d
o
r
co
u
l
d
b
e
d
e
t
r
i
m
e
n
-
t
a
l
t
o
t
h
e
o
p
e
r
a
t
i
o
n
o
f
r
e
g
u
l
a
t
o
r
s,
r
e
l
i
e
f
va
l
ve
s,
o
r
o
t
h
e
r
e
q
u
i
p
m
e
n
t
.
8
. L
o
ca
t
e
a
n
d
g
u
a
r
d
ve
n
t
t
e
r
m
i
n
a
t
i
o
n
t
o
p
r
e
ve
n
t
a
cci
-
d
e
n
t
a
l
co
n
t
a
ct
b
y p
e
o
p
l
e
o
r
p
e
t
s.
9
.
DO
NO
T
t
e
r
m
i
n
a
t
e
ve
n
t
i
n
wi
n
d
o
w
we
l
l
,
st
a
i
r
we
l
l
,
a
l
co
ve
,
co
u
r
t
ya
r
d
o
r
o
t
h
e
r
r
e
ce
sse
d
a
r
e
a
.
1
0
.
DO
NO
T
t
e
r
m
i
n
a
t
e
a
b
o
ve
a
n
y
d
o
o
r
,
wi
n
d
o
w
,
o
r
gr
avi
t
y
ai
r
i
nt
ake.
Condensat
e
can
f
r
eeze,
causi
ng
i
ce f
or
m
at
i
ons.
11. Locat
e or
guar
d vent
t
o pr
event
condensat
e f
r
om
dam
agi
ng
ext
er
i
or
f
i
ni
shes.
Use
a
r
ust
-
r
esi
st
ant
sheet
m
et
al
backi
ng pl
at
e agai
nst
br
i
ck or
m
ason-
r
y sur
f
aces.
12. DO
NO
T ext
end exposed vent
pi
pe out
si
de of
bui
l
di
ng
beyond
t
he
m
i
ni
m
um
di
st
ance
r
equi
r
ed
f
or
t
he vent
t
er
m
i
nat
i
on.
Condensat
e coul
d f
r
eeze
and bl
ock vent
pi
pe.
U.
S.
Instal
l
a
ti
ons
Ref
er
t
o t
he l
at
est
edi
t
i
on of
t
he Nat
i
onal
Fuel
G
as
Code.
Vent
t
er
m
i
nat
i
on r
equi
r
em
ent
s ar
e as f
ol
l
ows:
1.
Vent
m
ust
t
er
m
i
nat
e
at
l
east
4
f
t
bel
ow,
4
f
t
hor
i
-
zont
al
l
y f
r
om
or
1 f
t
above any door
,
wi
ndow or
gr
avi
t
y ai
r
i
nl
et
t
o t
he bui
l
di
ng.
2.
The vent must not be less than 7 ft above grade
when located adjacent to public walkways.
3.
Terminate vent at least 3 ft above any forced air
inlet located within 10 ft.
4.
V
ent
must
terminate
at
least
4 ft
horizontally, and
in no
case
above or
below unless 4 ft horizontal
distance is maintained, from electric meters, gas
meters, regulators, and relief equipment.
5.
Terminate vent at least 6 ft away from adjacent
walls.
6. DO NOT terminate vent closer than 5 ft below roof
overhang.
7
. The vent terminal requires a 12 in. vent terminal
clearance from the wall.
8. Terminate vent at least 1 ft above grade, including
normal snow line.
9. Multiple direct vent installations require a 4 ft
clearance between the ends of vent caps located
on the same horizontal plane.
WARNING: The Commonwealth of Massachusetts
requires that sidewall vented heaters, installed in
every dwelling, building or structure used in whole or
in part for residential purposes, be installed using
special provisions as outlined on page 57 of this
manual.
VENT CAPS STACKED VERTICALLY
FLUE GASES MOVING IN PARALLEL
VENT CAPS ALL AT SAME ELEVATION
FLUE GASES MOVING TOWARD EACH OTHER
VENT CAPS AT STAGGERED ELEVATIONS
FLUE GASES MOVING TOWARD EACH OTHER
1
” MINIMUM (TYP)
2” MINIMUM (TYP)
1” MINIMUM (TYP)
DISCHARGE
4’-0” MIN.
(TYP)
4’-0” MIN.
(TYP)
DISCHARGE
Fig. 30: Vent Cap Configurations
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