43
Initial Installation
QUALIFIED INSTALLERS ONLY
Figure 58. Natural Gas Vent Graph
a
LLoWabLe
c
o
-a
xiaL
V
ent
c
onFiGuRations
:
This shows the range of venting options
using either vertical or horizontal
terminations; any layout that remains
within the shaded area is acceptable.
Having the fewest number of elbows
is ideal as they restrict air movement.
The total length of horizontal vent pipe
can not exceed 20 feet (6.1m) and
the total vertical vent length can not
exceed 40ft (12.2m). Any combination
of rise and run can be used as long as
it lays within the shaded area (a total
of three (3) 90
˚
elbows or six (6) 45
˚
elbows can be used. In addition to
what is shown, if a 90
˚
elbow is used
in the horizontal plane, 3 feet (91.4cm)
must be subtracted from the allowable
horizontal run (for each 45
˚
elbow, 1½
feet (45.7cm) must be subtracted).
Restrictor Setting:
Find the point
on the graph where your vent
configuration will terminate. Remember
to consider elbows in the HORIZONTAL
plane account for horizontal distance
as stated above. Use the corresponding
exhaust restrictor setting indicated on
the graph. See the following section in
this manual for restrictor details. Your
climate and altitude may alter what
restrictor is required for your particular
application.
6’
(1.83m)
18”
(0.46m)
6’
(1.83m)
10’
(3.05m)
15’
(4.57m)
15’
(1.52m)
20’
(6.1m)
20’
(6.1m)
25’
(7.62m)
30’
(9.14m)
35’
(10.7m)
40’
(12.2m)
NG Vent
Position
RESTRICTOR 1
RESTRICTOR 1
RESTRICTOR 2
RESTRICTOR 2
RESTRICTOR 3
RESTRICTOR 3
RESTRICTOR 4
RESTRICTOR 4
RESTRICTOR 5
RESTRICTOR 5
12”
(0.30m)
18”’
(1.83m)
High wind guard required for all vertical
vent runs with no horizontal run.
ICC EXCELDirect TM-SVTS
M&G Duravent Pro 46DVA-VWG
**Vertical vent height does not account for elbows
Does your vent configuration fall
outside the limits?
Use our power vent
kit (50-3884) for a much broader venting
range.
