33
Initial Installation
QUALIFIED INSTALLERS ONLY
The following charts show the range
of venting options available for top
vent configurations using either
vertical or horizontal terminations in
conjunction with 0 - 3 90° elbows in
the vertical plane. Having the fewest
number of elbows is ideal as they
restrict air flow. The total length of
horizontal vent pipe can not exceed
20ft (6.1m) and the total vertical
length can not exceed 40ft (12.2m).
Any combination of rise and run can
be used as long as it lays within the
shaded areas of the following charts.
A total of three (3) 90° elbows or
six (6) 45° elbows can be used as
shown in Figure 55 & Figure 56. In
addition to what is shown, if a 90°
elbow is used in the horizontal plane,
3 ft (91.4cm) must be subtracted
from the allowable horizontal run (for
each 45° elbow, 1.5ft (45.7cm) must
be subtracted).
10’
(3.05m)
15’
(4.57m)
20’
(6.10m)
10’
(3.05m)
20’
(6.10m)
30’
(9.14m)
40’
(12.19m)
4’
(1.22m)
2’
(0.61m)
See Minimum Venting Section for Details
NG Top Vent Configurations
t
op
v
ent
c
onfiguRation
- n
atuRaL
g
as
(ng)
Figure 55: Top Vent Configuration Diagram - NG
